Coverage Policy Manual
Policy #: 2010041
Category: Medicine
Initiated: November 2010
Last Review: June 2022
  Hemodynamic Monitoring of Heart Failure, Management in the Outpatient Setting

Description:
Some of the procedures addressed in this policy were previously addressed in policy # 2000027 and #2004052.  These policies have been archived and the procedures have been combined into this single policy.
 
A variety of outpatient cardiac hemodynamic monitoring devices have been proposed to decrease episodes of acute decompensation in patients with heart failure and thus improve quality of life and reduce morbidity. These new outpatient devices include bioimpedance, inert gas rebreathing, and estimating left-ventricular end-diastolic pressure by arterial pressure during Valsalva or use of an implantable pressure sensor.
 
Patients with chronic heart failure are at elevated risk of developing acute decompensated heart failure, often requiring hospital admission. Patients with a history of acute decompensation have additional risk of future episodes of decompensation, and death. Reasons for the transition from a stable, chronic state to an acute, decompensated state include disease progression, as well as acute coronary events and dysrhythmias. While precipitating factors are frequently not identified, the most common preventable cause is noncompliance with medication and dietary regimens (Opasich, 2001). Strategies for reducing decompensation, and thus the need for hospitalization, are aimed at early identification of patients at risk for imminent decompensation. Programs for early identification of heart failure are characterized by frequent contact with patients to review signs and symptoms with a healthcare provider and with education or adjustment of medications as appropriate. These encounters may occur face-to-face in office or at home, or via cellular or computed technology (McAlister, 2004).
 
Precise measurement of cardiac hemodynamics is often employed in the intensive care setting to carefully manage fluid status in acutely decompensated heart failure. Echocardiography, transesophageal echocardiography (TEE), and Doppler ultrasound are noninvasive methods for monitoring cardiac output on an intermittent basis for the more stable patient but are not addressed in this policy. A variety of biomarkers and radiologic techniques may be utilized in the setting of dyspnea when the diagnosis of acute decompensated heart failure is uncertain.
 
The criterion standard for hemodynamic monitoring is pulmonary artery catheters and central venous pressure catheters. However, they are invasive, inaccurate, and inconsistent in predicting fluid responsiveness. Several studies have demonstrated that catheters fail to improve outcomes in critically ill patients and may be associated with harm. To overcome these limitations, multiple techniques and devices have been developed that use complex imaging technology and computer algorithms to estimate fluid responsiveness, volume status, cardiac output and tissue perfusion. Many are intended for use in outpatient settings but can be used in the emergency department, intensive care unit, and operating room. Four methods are reviewed here: implantable pressure monitoring devices, thoracic bioimpedance, inert gas rebreathing, and arterial waveform during Valsalva. Use of the last 3 is not widespread because of several limitations including use of proprietary technology making it difficult to confirm their validity and lack of large randomized controlled trials to evaluate treatment decisions guided by these hemodynamic monitors.
 
Thoracic Bioimpedance
Bioimpedance is defined as the electrical resistance of tissue to the flow of current. For example, when small electrical signals are transmitted through the thorax, the current travels along the blood-filled aorta, which is the most conductive area. Changes in bioimpedance, measured at each beat of the heart, are inversely related to pulsatile changes in volume and velocity of blood in the aorta. Cardiac output is the product of stroke volume by heart rate, and thus can be calculated from bioimpedance. Cardiac output is generally reduced in patients with systolic heart failure. Acute decompensation is characterized by worsening of cardiac output from the patient’s baseline status. The technique is alternatively known as impedance plethysmography and impedance cardiography (ICG).
 
Inert Gas Rebreathing
This technique is based on the observation that the absorption and disappearance of a blood-soluble gas is proportional to cardiac blood flow. The patient is asked to breathe and rebreathe from a rebreathing bag filled with oxygen mixed with a fixed proportion of two inert gases; typically nitrous oxide and sulfur hexafluoride. The nitrous oxide is soluble in blood and is therefore absorbed during the blood’s passage through the lungs at a rate that is proportional to the blood flow. The sulfur hexafluoride is insoluble in blood and therefore stays in the gas phase and is used to determine the lung volume from which the soluble gas is removed. These gases and carbon dioxide are measured continuously and simultaneously at the mouthpiece.
 
Left Ventricular End Diastolic Pressure Estimation Methods
  
Arterial Pressure during Valsalva to Estimate LVEDP
Left-ventricular end-diastolic pressure (LVEDP) is elevated in the setting of acute decompensated heart failure. While direct catheter measurement of LVEDP is possible for patients undergoing cardiac catheterization for diagnostic or therapeutic reasons, its invasive nature precludes outpatient use. Noninvasive measurements of LVEDP have been developed based on the observation that arterial pressure during the strain phase of the Valsalva maneuver may directly reflect the LVEDP. Arterial pressure responses during repeated Valsalva maneuvers can be recorded and analyzed to produce values that correlate to the LVEDP.
 
Pulmonary Artery Pressure Measurement to Estimate LVEDP
LVEDP can also be approximated by direct pressure measurement of an implantable sensor in the pulmonary artery (PA) wall or right ventricular outflow tract. The sensor is implanted via right heart catheterization and transmits pressure readings wirelessly to external monitors. One device, the CardioMEMS Champion Heart Failure Monitoring System (CardioMEMS, now St. Jude Medical, St. Paul, MN), has approval from FDA for the ambulatory management of heart failure patient. The CardioMEMS device is implanted using a heart catheter system fed through the femoral vein and generally requires patients have an overnight hospital admission for observation after implantation.
   
Regulatory Status
 
Noninvasive Left Ventricular End-Diastolic Pressure Measurement Devices
 
In 2004, the VeriCor® (CVP Diagnostics), a noninvasive left ventricular end-diastolic pressure measurement device, was cleared for marketing by U.S. Food and Drug Administration (FDA) through the 510(k) process. The FDA determined that this device was substantially equivalent to existing devices for the following indication:
 
"The VeriCor is indicated for use in estimating non-invasively, left ventricular end-diastolic pressure (LVEDP). This estimate, when used along with clinical signs and symptoms and other patient test results, including weights on a daily basis, can aid the clinician in the selection of further diagnostic tests in the process of reaching a diagnosis and formulating a therapeutic plan when abnormalities of intravascular volume are suspected. The device has been clinically validated in males only. Use of the device in females has not been investigated."
 
FDA product code: DXN.
 
Thoracic Bioimpedance Devices
Multiple thoracic impedance measurement devices that do not require invasive placement have been approved by the FDA through the 510(k) process. The FDA determined that this device was substantially equivalent to existing devices used for peripheral blood flow monitoring. Below is an inexhaustive list of representative devices (FDA product code: DSB).
 
Non-Invasive Thoracic Impedance Plethysmography Devices
BioZ® Thoracic Impedance Plethysmograph, manufactured by SonoSite, received FDA clearance in 2009.
 
Zoe® Fluid Status Monitor, manufactured by Noninvasive Medical Technologies, LLC, received FDA clearance in 2004.
      
Cheeta Starling SV, manufactured by Cheetah Medical, Inc., received FDA clearance in 2008.
     
Physioflow® Signal Morphology- Based Impedance Cardiography (SM-ICG™), manufactured by Vasocom, Inc. now Neumedx, Inc., received FDA clearance in 2008.
 
ReDSTM Wearable System, manufactured by Sensible Medical Innovations, received FDA clearance in 2015.
  
Inert Gas Rebreathing Devices
In 2006, the Innocor® (Innovision), an inert gas rebreathing device, was cleared for marketing by the FDA through the 510(k) process. The FDA determined that this device was substantially equivalent to existing inert gas rebreathing devices for use in computing blood flow. FDA product code: BZG.
 
Implantable Pulmonary Artery Pressure Sensor Devices
In 2014, the CardioMEMS™  Heart Failure Monitoring System (CardioMEMS, now Abbott) was approved for marketing by the FDA through the premarket approval process. This device consists of an implantable pulmonary artery (PA) sensor, which is implanted in the distal PA, a transvenous delivery system, and an electronic sensor that processes signals from the implantable PA sensor and transmits PA pressure measurements to a secure database (FDA, 2022). The device originally underwent FDA review in 2011, at which point FDA found no reasonable assurance that the monitoring system would be effective, particularly in certain subpopulations, although the FDA agreed this monitoring system was safe for use in the indicated patient population (Loh, 2013). In February 2022, the CardioMEMS™ HF Monitoring System received expanded approval for the treatment of New York Heart Association (NYHA) Class II-III patients who had been hospitalized at least 1 time in the prior year and/or had elevated natriuretic peptides.
 
Several other devices that monitor cardiac output through measurements of pressure changes in the PA or right ventricular outflow tract have been investigated in the research setting, but have not received FDA approval. These include the Chronicle® implantable continuous hemodynamic monitoring device (Medtronic), which includes a sensor implanted in the right ventricular outflow tract and, and the ImPressure® device (Remon Medical Technologies), which includes a sensor implanted in the PA.
 
 
Note: This policy only addresses use of these techniques in ambulatory care and outpatient settings.
 
There is a specific CPT code for bioimpedance:
93701: Bioimpedance-derived physiologic cardiovascular analysis
 
There are specific CPT category III codes for inert gas rebreathing:
0104T: Inert gas rebreathing for cardiac output measurement; during rest
0105T: during exercise
 
There is no specific code for measuring LVEDP or for implantable direct pressure monitoring of the pulmonary artery. The unlisted code 93799 would be used.

Policy/
Coverage:
EFFECTIVE JUNE 2021
 
Does Not Meet Primary Coverage Criteria Or Is Investigational For Contracts Without Primary Coverage Criteria
 
Cardiac hemodynamic monitoring for the management of heart failure utilizing thoracic bioimpedance, inert gas rebreathing, arterial pressure/Valsalva, and implantable direct pressure monitoring of the pulmonary artery does not meet member benefit certificate primary coverage criteria that there be scientific evidence of effectiveness in the ambulatory care and outpatient settings.
 
For members with contracts without primary coverage criteria, cardiac hemodynamic monitoring for the management of heart failure utilizing thoracic bioimpedance, inert gas rebreathing, arterial pressure/Valsalva, and implantable direct pressure monitoring of the pulmonary artery in the ambulatory care and outpatient settings is considered investigational. Investigational services are specific contract exclusions in most member benefit certificates of coverage.
 
Thoracic electrical bioimpedance is listed as a specific contract exclusion in most member benefit certificates of coverage.
 
EFFECTIVE PRIOR TO JUNE 2021
Cardiac hemodynamic monitoring for the management of heart failure utilizing thoracic bioimpedance, inert gas rebreathing, arterial pressure/Valsalva, and implantable direct pressure monitoring of the pulmonary artery does not meet member benefit certificate primary coverage criteria that there be scientific evidence of effectiveness in improving health outcomes in the ambulatory care and outpatient settings.
 
For contracts without primary coverage criteria, cardiac hemodynamic monitoring for the management of heart failure utilizing thoracic bioimpedance, inert gas rebreathing, arterial pressure/Valsalva, and implantable direct pressure monitoring of the pulmonary artery in the ambulatory care and outpatient settings is investigational.  Investigational services are exclusions in member benefit certificates of coverage.
 
Thoracic electrical bioimpedance is listed as a specific contract exclusion in most member benefit certificates of coverage.
 

Rationale:
Evaluation of a diagnostic technology typically focuses on the following 3 parameters: 1) technical performance; 2) diagnostic parameters (sensitivity, specificity, and positive and negative predictive value) in different populations of patients; and 3) demonstration that the diagnostic information can be used to improve patient outcomes. Additionally, when considering invasive monitoring, any improvements in patient outcomes must be outweighed by surgical and device-related risks associated with implantable devices.
 
 
Thoracic Bioimpedance/Impedance Cardiography (ICG)
A number of small case series have reported variable results regarding the relationship between measurements of cardiac output (CO) determined by thoracic bioelectric impedance and thermodilution techniques. For example, Belardinelli and colleagues compared the use of thoracic bioimpedance, thermodilution, and the Fick method to estimate cardiac output in 25 patients with documented coronary artery disease and a previous myocardial infarction (Belardinelli, 1996). There was a high degree of correlation between cardiac output as measured by thoracic bioimpedance and other invasive measures. Shoemaker and colleagues reported on a multicenter trial of thoracic bioimpedance compared to thermodilution in 68 critically ill patients (Shoemaker, 1994).   Again, the changes in cardiac output as measured by thoracic bioimpedance closely tracked those measured by thermodilution. In contrast, Sageman and Amundson did not recommend the use of bioimpedance as a postoperative monitoring technique for patients who had undergone coronary artery bypass surgery (Sageman, 1993).  In this study of 50 patients, only a poor correlation was found between thermodilution and bioimpedance, due primarily to the postoperative distortion of the patient’s anatomy and the presence of endotracheal, mediastinal, and chest tubes. In a study of 34 patients undergoing cardiac surgery, Doering and colleagues also found that there was poor agreement between thoracic bioimpedance and thermodilution in the immediate postoperative period (Doering, 1995).   The largest case series, the COST study, has been published in abstract form only (Raisinghani, 1998).  In this case series, estimations of cardiac output using thermodilution methods and thoracic bioimpedance were performed in 191 patients who underwent right heart catheterization for a variety of clinical indications. Linear regression analysis revealed an overall correlation of r (Pearson’s correlation coefficient) =0.73. The authors concluded that cardiac output can be reliably measured with either thermodilution or thoracic bioimpedance and that bioimpedance has the additional value of being noninvasive.
 
Packer and colleagues reported on use of ICG to predict risk of decompensation in patients with chronic heart failure (Packer, 2006).   In this study, 212 stable patients with heart failure and a recent episode of decompensation underwent serial evaluation and blinded ICG testing every 2 weeks for 26 weeks and were followed up for the occurrence of death or worsening heart failure requiring hospitalization or emergent care. During the study, 59 patients experienced 104 episodes of decompensated heart failure: 16 deaths, 78 hospitalizations, and 10 emergency visits. A composite score of 3 ICG parameters was a strong predictor of an event during the next 14 days (p=0.0002). Patients noted to have a high-risk composite score at a visit had a 2.5 times greater likelihood of a near-term event, and those with a low-risk score had a 70% lower likelihood when compared to ones at intermediate risk. However, the impact of use of these results on clinical outcomes is not known.
 
While results of more studies of ICG are being published, many studies are limited by small populations and uncertainty about the impact on clinical outcomes. In addition, not all studies have evaluated additional novel markers, such as B-type natriuretic peptide (BNP). In a 2006 review article, Wang and Gottlieb comment that there are limited data concerning improved outcomes using ICG in the clinical setting and that, given the data, ICG use should be limited to the research setting (Wang, 2006).  
 
Thoracic bioimpedance may have an important role in the outpatient management of heart failure, but "earlier studies have not sought to evaluate the clinical importance of the data generated by impedance cardiography. They have not determined whether evaluation of the status of the central circulation by impedance cardiography can predict clinical events and, thus, be used to alter the treatment of patients. Obtaining such information is critical if the use of impedance cardiography is to expand from its present application where it has excelled, in short-term management of acutely ill hospitalized patients, to the long-term outpatient management of recently ill or hospitalized patients with severe chronic disorders."  (Strobeck, 2000)
 
Inert Gas Rebreathing
In contrast to thoracic bioimpedance, relatively little literature has been published on inert gas rebreathing, although a literature search suggests that this technique has been used as a research tool for many years (Christensen, 2000) (Durkin, 1994) (Stok, 1993) (Lang, 2007).  A literature search did not identify any clinical articles exploring how inert gas rebreathing may be used to improve patient management in the outpatient setting.
 
Arterial pressure/ Valsalva LVEDP
Studies have shown high correlation between invasive and non-invasive measurement of LVEDP. For example, McIntyre and colleagues reported a comparison of pulmonary capillary wedge pressure (PCWP) measured by right heart catheter and an arterial pressure amplitude ration during Valsalva. The two techniques were highly correlated in both stable and unstable patients (R2 [coefficient of determination] =0.80–0.85) (McIntyre, 1992).   More recently, Sharma et al. performed simultaneous measurements of the LVEDP based on 3 techniques: direct measurement of LVEDP, considered the gold standard; indirect measurement using pulmonary capillary wedge pressure (PCWP); and non-invasively using the VeriCor® device in 49 patients scheduled for elective cardiac catheterization (Shama, 2002).  The VeriCor® measurement correlated well with the direct measures of LVEDP (r=0.86) and outperformed the PCWP measurement, which had a correlation coefficient of 0.81 compared to the gold standard.
 
A literature search did not identify any published articles that evaluated the role of non-invasive measurement of the LVEDP on the management of the patient. Therefore, evidence is inadequate to permit scientific conclusions regarding the clinical utility of this technology.
 
Implantable Direct Pulmonary Artery Pressure - LVEDP
An abstract of the CHAMPION clinical trial was presented at the European Society of Cardiology Heart Failure Congress in June 2010 (Abraham, 2010).  The trial evaluated the safety and efficacy of an implanted pulmonary artery pressure monitor on New York Heart Association Class III (NYHA III) patients. The investigators report a statistically significant reduction in readmissions for heart failure at 6 months. Results have not been formally published. There is a lack of data regarding impact on health outcomes.
 
Summary
The quality of the evidence to date remains limited. Randomized controlled trials, as well as studies , that specifically address use of ambulatory cardiac hemodynamic monitoring compared with current care are lacking. Some form of intensive outpatient monitoring and follow-up for patients with heart failure may be warranted, but convincing evidence of the use of the above mentioned technologies cannot be supported at the present time.
 
Additional clinical trials registered at ClinicalTrials.gov have the potential to add to our understanding for these devices in the management of chronic heart failure.
 
Technology Assessments, Guidelines, and Position Statements
In 2002, the Agency for Healthcare Research and Quality (AHRQ) published a technology assessment on thoracic bioimpedance, which concluded that limitations in available studies did not allow the agency to draw meaningful conclusions to determine the accuracy of thoracic bioimpedance compared to other hemodynamic parameters (Jordan, 2010).  The agency also found a lack of studies focusing on clinical outcomes and little evidence to draw conclusions on patient outcomes for the following clinical areas:
 
  • Monitoring in patients with suspected or known cardiovascular disease;
  • Acute dyspnea;
  • Pacemakers;
  • Inotropic therapy;
  • Post-heart transplant evaluation;
  • Cardiac patients with need for fluid management; and
  • Hypertension.
 
The 2009 American College of Cardiology Foundation/American Heart Association (ACCF/AHA) Guidelines for the Diagnosis and Management of Heart Failure in Adults (Jessup, 2009) conclude that no role for periodic invasive or noninvasive hemodynamic measurements has been established in the management of heart failure. “Most drugs used for the treatment of HF [heart failure] are prescribed on the basis of their ability to improve symptoms or survival rather than their effect on hemodynamic variables. Moreover, the initial and target doses of these drugs are selected on the basis of experience in controlled trials and are not based on the changes they may produce in cardiac output or pulmonary wedge pressure.”
 
2011 Update
The CHAMPION (Cardiomems Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in New York Heart Association [NYHA] Class III Patients) Trial Study was a prospective, single-blind, randomized, controlled, trial (RCT) conducted at 64 centers in the United States (Adamson, 2011).  This trial was designed to evaluate the safety and efficacy of an implanted, passive, wireless, pulmonary artery pressure monitor developed by CardioMEMS for the ambulatory management of heart failure patients. The CardioMEMS pulmonary artery pressure monitoring device has not yet received FDA approval and is currently under FDA review. The CardioMEMS device is implanted using a heart catheter system fed through the femoral vein and requires patients have an overnight hospital admission for observation after implantation. The CHAMPION study enrolled 550 patients who had at least one previous hospitalization for heart failure in the past 12 months and were classified as having NYHA Class III heart failure for at least 3 months. Left ventricular ejection fraction (LVEF) was not a criterion for participation, but patients were required to be on medication and stabilized for 1 month before participating in the study if LVEF was reduced. All enrolled patients received implantation of the CardioMEMS pulmonary artery radiofrequency pressure sensor monitor and standard of care heart failure disease management. Heart failure disease management followed American College of Cardiology and American Heart Association guidelines along with local disease management programs. Patients were randomized by computer in a 1:1 ratio to the treatment group (n=270), which used data from the pulmonary artery pressure sensor in patient management or the control group (n=280), which did not incorporate pulmonary artery pressure sensor data into patient management. All patients took daily pulmonary artery pressure readings but were masked to their treatment groups for the first 6 months.
 
The primary efficacy outcome of this trial was the rate of heart failure-related hospitalizations in the 6 months after implantation. The primary safety outcomes were device-related or system-related complications (DSRC) and pressure-sensor failures (Abraham, 2011). The investigators reported a statistically significant reduction in readmissions for heart failure at 6 months by 30% in the treatment group (n=83) over the control group (n=120) (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.60-0.84, p<0.0001). This benefit was maintained over the entire randomized follow-up (mean 15 months) (153 vs. 253 hospitalizations, respectively) (HR 0.64, 95% CI 0.55-0.75, p<0.0001). For the primary safety outcomes, freedom from device-related complications was 98.6% with no occurrences of pressure-sensor failure. However, 15 adverse events occurred including 8 which were device-related and 7 which were procedure-related. Additionally, length of stay for these hospitalizations was significantly shorter in the treatment group when compared to the control group (2.2 days vs. 3.8 days, respectively, p=0.02). There was also benefit reported for other secondary outcomes. There were also improvements in the secondary outcomes of mean pulmonary pressure and quality of life (QOL) at 6 months. There was no difference in overall mortality, although the trial was not designed with sufficient power to evaluate mortality benefit. There were 15 deaths in the treatment group and 26 deaths in the control group at 6 months (HR 0.77, 95% CI 0.40-1.51, p=0.45).
 
Stevenson and colleagues reported on the COMPASS-HF (Chronicle Offers Management to Patients with Advanced Signs and Symptoms of Heart Failure Study) randomized trial in 2010 (Stevenson, 2010). The COMPASS trial evaluated outcomes on 274 patients implanted with a Medtronic hemodynamic monitoring system. Patients enrolled in the study were stabilized NYHA Class III or IV heart failure patients and had at least one heart failure-related event within the 6 months prior to enrollment. LVEF was not a criterion. Similar to the CHAMPION trial, all patients were implanted with the monitoring device and received standard heart failure disease treatment during the first 6 months post-implantation. One half of the patients were randomized to incorporate pressure monitoring data into heart failure management, while information from the other half of patients was not used in treatment decisions. The authors of this article reported 100 of 261 patients (38%) from both treatment groups had heart failure-related events during the 6 months follow-up despite weight-guided management. Separate reports on heart failure events by treatment group were not provided. Heart failure event risk increased with higher readings of chronic 24-hour estimated pulmonary artery pressure and at 18 mm Hg diastolic pressure, event risk was 20% and increased to 34% at 25 mm Hg and to 56% at 33 mm Hg. While pressure readings correlated with event risk, the authors noted optimal filling pressures and needed surveillance for event avoidance have not been established.
 
Ongoing Clinical Trials
The Left Atrial Pressure Monitoring to Optimize Heart Failure Therapy (LAPTOP-HF) is a randomized trial to evaluate the safety and clinical effectiveness of an implantable device, the HeartPOD™ System or Promote® LAP System, for left atrial pressure measurements to manage heart failure. (NCT01121107) This trial began in April 2010 and is expected to enroll 730 patients for completion in 2013.
 
Summary
Evidence from randomized controlled trials is emerging for invasive pulmonary artery pressure monitoring. One report from the CHAMPION RCT reports that pressure readings may be used to reduce heart failure-related hospitalizations. However, this trial was single-blinded, and the decision to hospitalize patients may have been influenced by knowledge of group assignment. Also, the surgical risks of pressure monitoring devices must be balanced with improvements in net health outcomes and compared longer-term with outcomes of traditional management. Finally, FDA-approval is lacking for these devices at the present time. While this preliminary evidence suggests that intensive outpatient monitoring and follow-up for patients with heart failure may benefit patients with heart failure, convincing evidence that the use of these technologies improves outcomes cannot be supported at the present time.
 
2012 Update
A search of the MEDLINE database through July 2012 did not reveal any new literature that would prompt a change in the coverage statement. The following is a summary of the relevant literature:
 
Thoracic Bioimpedance
A large case series, the COST study, has been published in abstract form only (Hoskin, 2012). In this case series, estimations of cardiac output using thermodilution methods and thoracic bioimpedance were performed in 191 patients who underwent right heart catheterization for a variety of clinical indications. Linear regression analysis revealed an overall correlation of r (Pearson’s correlation coefficient) =0.73. The authors concluded that cardiac output can be reliably measured with either thermodilution or thoracic bioimpedance and that bioimpedance has the additional value of being noninvasive.
 
Arterial pressure/Valsalva LVEDP
In 2012, Silber and colleagues reported on finger photoplethysmography during Valsalva performed in 33 patients prior to cardiac catheterization (Silber, 2012). LVEDP greater than 15 mm Hg was identified by finger photoplethysmography during Valsalva with 85% sensitivity (95% confidence interval [CI]: 54-97%) and 80% specificity (95% CI: 56-93%). However, literature searches did not identify any published articles that evaluated the role of non-invasive measurement of the LVEDP on the management of the patient. Therefore, evidence is inadequate to permit scientific conclusions regarding the clinical utility of this technology.
 
Implantable Direct Pulmonary Artery Pressure – LVEDP
In 2011, Adamson et al. reported on the Reducing Decompensation Events Utilizing Intracardiac Pressures in Patients With Chronic Heart Failure (REDUCEhf ) study that evaluated an implantable cardioverter-defibrillator (ICD) coupled with an implantable hemodynamic monitoring (IHM) system (Adamson, 2011). The REDUCEhf study was a prospective, randomized, multicenter, single-blinded trial of 400 patients with NYHA class II or III symptoms who were hospitalized for heart failure within the past 12 months and qualified for an ICD. The study had expected to enroll 1,300 patients, but after ICD lead failures had been reported in other studies, enrollment was limited to 400 patients. After the ICD was placed, an IHM sensor was implanted in the right ventricle. Similar to the COMPASS-HF and CHAMPION trials above, the treatment group of 202 patients received heart failure management that incorporated pressure monitoring information from the IHM compared to the control group of 198 patients that did not use pressure monitoring information in treatment planning. After 12 months of follow-up, rates of heart failure hospitalizations, emergency department visits, and urgent clinic visits did not differ between groups (HR: 0.99, 95% CI: 0.61-1.61, p=0.98). While the study was underpowered to detect differences in these events because of limited enrollment, there were no trends favorable to the monitoring group to suggest that the lack of difference was due to inadequate power.
 
Ongoing Clinical Trials
Additional clinical trials registered at online site ClinicalTrials.gov have the potential to add to our understanding of these devices in the management of chronic heart failure. The Left Atrial Pressure Monitoring to Optimize Heart Failure Therapy (LAPTOP-HF) is a randomized trial to evaluate the safety and clinical effectiveness of an implantable device, the HeartPOD™ System or Promote® LAP System, for left atrial pressure measurements to manage heart failure. (NCT01121107) This trial began in April 2010 and is expected to enroll 730 patients for completion in 2013. The Prevention of Heart Failure Events with Impedance Cardiography Testing (PREVENT-HF)) trial will evaluate the impact of incorporating impedance cardiography readings into treatment planning using the BioZ Dx device in 500 patients. (NCT00409916) The PREVENT-HF trial will follow patients for 24-52 weeks and is expected to be completed in December 2012.
 
Practice Guidelines
The 2011 update of the National Institute for Health and Clinical Excellence clinical guideline on chronic heart failure management does not include outpatient hemodynamic monitoring as a recommendation (Mant, 2011).
 
2013 Update
A literature search conducted using the MEDLINE database did not identify any new information that would prompt a change in the coverage statement. The ACCF/AHA published guidelines for the management of heart failure (Yancy, 2013; Yancy, 2013) which did not offer recommendations for the use of ambulatory monitoring devices.
  
2014 Update
A literature search conducted through July 2014 did not reveal any new information that would prompt a change in the coverage statement. The key identified literature is summarized below.
 
In a sub-analysis of 170 subjects from the ESCAPE study, a multicenter randomized trial to assess pulmonary artery catheter-guided therapy in patients with advanced heart failure, Kamath et al compared cardiac output estimated by the BioZ device to subsequent heart failure death or hospitalization and to directly-measured hemodynamics from right heart catheterization in a subset of patients (n=82) (Kamath, 2009). There was modest correlation between ICG and invasively measured cardiac output (r=0.4 to 0.6), but no significant association between ICG measurements and subsequent heart failure death or hospitalization.
 
In 2012, Anand et al reported results of the Multi-Sensor Monitoring in Congestive Heart Failure (MUSIC) Study, a nonrandomized prospective study designed to develop and validate an algorithm for the prediction of acute heart failure decompensation using a clinical prototype of the MUSE system, multisensory system that includes intrathoracic impedance measurements, along with electrocardiographic and accelerometry data (Anand, 2011; Anand, 2012). The study enrolled 543 patients (206 in the development phase and 337 in the validation phase) with heart failure with ejection fraction less than 40% and a recent heart failure admission, all of whom underwent monitoring for 90 days with the MUSE. There was a high rate of study dropout: 229 patients (42% of the total; 92 development, 137 validation) were excluded from the analysis, primarily due to withdrawal of consent or failure of the prototype device to function. Subjects were assessed for the development of an acute heart failure decomposition event (ADHF), which was defined as any of the following: 1. Any heart failure-related hospitalization, emergency room or urgent care visit that required administration of IV diuretics, inotropes, or ultrafiltration for fluid removal; 2. A change in diuretic directed by the health care provider that included one or more of the following: a change in the prescribed diuretic type; an increase in dose of an existing diuretic; or the addition of another diuretic; 3. An ADHF event for which death was the outcome. Data from the 206 subjects in the development phase were used to generate a multiparameter algorithm to predict outcomes that incorporated fluid index, a breath index, and personalization parameters (age, sex, height, weight). When the algorithm was applied to the validation cohort, it had a sensitivity of 63%, specificity of 92%, and a false positive rate of 0.9 events per patient-year. The algorithm had an mean advance detection time of 11.5 days, but there was wide variation in this measure, from 2 to greater than 30 days, and it did not differ significantly from less specific algorithms (eg, based on fluid index alone). The high rate of study dropout makes it difficult to generalize these results. Further research is needed to determine whether prediction of heart failure decomposition is associated with differences in patient outcomes.
 
A number of studies have evaluated the impact of thoracic bioimpedance devices that are integrated into implantable cardioverter defibrillator (ICD), cardiac resynchronization therapy (CRT), or cardiac pacing devices. These include the Fluid Accumulation Status Trial (FAST), a prospective trial to evaluate the use of intrathoracic impedance monitoring with ICD or CRT devices in patients with heart failure (Abraham, 2011), and the Sensitivity of the InSync Sentry for Prediction of Heart Failure (SENSE-HF) study, which evaluated the sensitivity of the OptiVol fluid trends feature in predicting heart failure hospitalizations (Conraads, 2011). Thoracic bioimpedance devices that are integrated into implantable cardiac devices are addressed in policy 2.02.10 (Biventricular Pacemakers [Cardiac Resynchronization Therapy] for the Treatment of Heart Failure).
 
Section Summary. The evidence on thoracic bioimpedance devices consists of non-randomized studies that correlate measurements with other measures of cardiac function, and studies that use bioimpedance measurement as part of an algorithm for predicting future heart failure events. These monitors have also been part of clinical trials in combination with ICD and/or CRT devices. The evidence does not demonstrate that these devices improve clinical outcomes.
 
In the Summary of Safety and Effectiveness Data for the CardioMEMS 2014 application, the FDA noted that “trial conduct included subject-specific treatment recommendations sent by nurses employed by the CardioMEMS to the treating physicians. These subject-specific recommendations were limited to subjects in the treatment arm of the study. The possible impact of nurse communications was determined to severely limit the interpretability of the data in terms of effectiveness”(FDA, 2014). In response, the manufacturer continued to follow all patients implanted with the device during an open access period, in which all patients were managed with pulmonary artery pressure monitoring, and no nurse communication occurred. Follow up data were available for 347 patients. For these patients, the following comparisons in heart failure-related hospitalization rates were reported to attempt to ensure that outcomes with the CardioMEMS device during the open access period (“Part 2”) were similar to those in the randomized period (“Part 1”):
  • Former Control vs Control -- To determine whether the heart failure hospitalization rate was lower in the Former Control group than the Control group, when physicians of Former Control patients received access to PA pressures (neither had nurse communications).
  • Former Treatment to Treatment – To evaluate whether heart failure hospitalization rates remain the same in subjects whose physician’s access to PA pressures remained unchanged, but no longer received nurse communications.
  • Former Control to Former Treatment -- To demonstrate that the rates of heart failure hospitalizations were similar during Part 2 when both groups were managed in an identical fashion (access to PA pressure and no nurse communications).
  • Change in heart failure hospitalization rates in the control group (Part 2 vs. Part 1) compared to the change in heart failure hospitalization rates in the treatment group (Part 2 vs. Part 1) -- To demonstrate that the magnitude of change in HFR hospitalization rates after the transition from Control to Former Control (Part 1 vs. Part 2, initiation of physician access to PA pressures in Part 2) was greater than the magnitude of change in HFR hospitalization rates after the transition from Treatment to Former Treatment (Part 1 vs. Part 2, no change in physician access to PA pressure).
 
The FDA concluded that these longitudinal analyses indicated that heart failure hospitalization rates in Former Control patients in Part 2 of the study decreased to levels comparable to the heart failure hospitalization rates in Treatment group patients whose PA pressures were available throughout the study.
 
There are several randomized, controlled trials of implantable hemodynamic monitoring systems. One of these trials (CHAMPION trial) used an FDA-approved monitor and was powered to report on clinical outcomes. This trial reported a decrease in hospitalizations for patients using the monitor as part of heart failure management compared to usual care. However, this trial had some methodologic limitations, one of which was the lack of double-blinding. While the patients were blinded and efforts to maintain patient masking were undertaken, the clinicians were not blinded to treatment assignment. The unblinded clinicians were presumably also making decisions on whether to hospitalize patients, and these decisions may have been influenced by knowledge of treatment assignment. A second limitation was the unequal intensity of treatment between groups, with the implantable monitor group having greater frequency of contact with study nurses. Because of these limitations, further high-quality trials are needed to determine whether health outcomes are improved.
 
The largest body of evidence is for direct pulmonary pressure monitors, such as the CardioMEMS device that has FDA-approval. Evidence from randomized controlled trials (RCTs) for various pulmonary artery pressure monitors has demonstrated a correlation between increased pressure readings and increased heart failure event risk. One RCT (the CHAMPION trial) reported that noted that the use of pulmonary artery pressure readings may reduce heart failure-related hospitalizations, but this study was subject to a number of potential biases. Therefore, the evidence is insufficient to form conclusions that the CardioMEMS device is associated with improvements in health outcomes. Studies of other implantable direct pulmonary artery pressure measurement devices have not demonstrated significantly improved outcomes.
 
2015 Update
A literature search conducted through July 2015 did not reveal any new information that would prompt a change in the coverage statement.  The key identified literature is summarized below.
 
Noninvasive Thoracic Bioimpedance/Impedance Cardiography Accuracy of Thoracic Bioimpedance Measurements
A number of early studies evaluated the accuracy of thoracic bioimpedance compared with other methods of cardiac output measurements, in both the inpatient and outpatient settings. In 2002, the Agency for Healthcare Research and Quality published a technology assessment on thoracic bioimpedance, which concluded that limitations in available studies did not allow meaningful conclusions concerning the accuracy of thoracic bioimpedance compared with other hemodynamic parameters.2
 
The DEFEAT-PE study used an algorithm to estimate thoracic bioimpedance from several different impedance vector measurements from various ICD or CRT device leads (Heist, 2014). This study reported low sensitivity for bioimpedance monitoring in predicting heart failure events.
 
 
No studies were identified that determined how thoracic bioimpedance measurements are associated with changes in patient management or in patient outcomes. Prospective studies that evaluate whether prediction of heart failure decomposition through thoracic bioimpedance allows earlier intervention or other management changes are needed to demonstrate that outcomes are improved.
 
Krahnke and colleagues published a subgroup analysis of the CHAMPION trial evaluating outcomes for heart failure patients with chronic obstructive pulmonary disease (COPD) (Krahnke, 2015). Of the total study population, 187 were classified as having COPD; these patients were more likely to have coronary artery disease and a history of myocardial infarction, diabetes, and atrial fibrillation. COPD-classified patients in the intervention group had lower rates of heart failure hospitalization than those in the control group (0.55 vs 0.96; HR=0.59; 95% CI, 0.44 to 0.81; p<0.001). Rates of respiratory hospitalizations were lower in COPD classified patients in the intervention group (0.12 vs 0.31; HR=0.38; 95% CI, 0.21 to 0.71; p=0.002). Rates of respiratory hospitalizations did not differ significantly between intervention and control group patients for non-COPD patients.
 
Ongoing and Unpublished Clinical Trials
Some currently unpublished trials that might influence this policy are listed below:
 
Ongoing
(NCT01121107) Left Atrial Pressure Monitoring to Optimized Heart Failure Therapy Study; planned enrollment 730; projected completion date June 2017
 
Unpublished
(NCT004099016) an industry sponsored or cosponsored trial.  Prevention of Heart Failure Events with Impedance Cardiography Testing (PREVENT-HF); planned enrollment 500; projected completion date December 2012.
 
2016 Update
A literature search conducted through July 2016 did not reveal any new information that would prompt a change in the coverage statement. The key identified literature is summarized below.
 
A follow-up report of the CHAMPION trial was published in 2016 (Abraham, 2016). It included data on 13 months of open-label follow-up for 347 (63%) of the original 550 randomized patients. For patients originally randomized to the control group, information from the monitoring device was available during this phase. The rate of hospitalizations was significantly lower in this group (HR=0.52; 95% CI, 0.40 to 0.69; p<0.001) compared to the period when no monitoring information was available.
 
2017 Update
A literature search conducted through July 2017 did not reveal any new information that would prompt a change in the coverage statement. The key identified literature is summarized below.
 
Amir and colleagues reported comparison of the a noninvasive thoracic base wave impedance monitor that provides measurement of patient lung fluid content (ReDS) with chest computed tomography (CCT) for measurement of total lung fluid in 16 patients with acute decompensated heart failure and 15 controls without heart failure (Amir, 2013). The fluid content measurements were highly correlated (intraclass correlation, 0.90; 95% CI, 0.80 to 0.95). The absolute mean difference between the measurement of fluid content with the 2 methods was 3.8% (SD=2.2%).
 
Clinical Utility
Amir and colleagues reported results of a single-arm study of the ReDS technology in 50 patients recently hospitalized for heart failure (Amir, 2016) Patients were enrolled after admission for heart failure and were managed according to the American College of Cardiology Foundation/American Heart Association and Heart Failure Society of America guidelines. Patients were also equipped with the ReDS wearable vest that was worn once a day at home for measurement of lung fluid content. For 90 days, measurements were sent to the treating physician via a secured website but were not visible to patients. Readings that crossed lower or upper thresholds for absolute values or rates of change resulted in an alert message sent to investigators. Physicians could adjust medication doses, recommend dietary changes and/or encourage compliance with prescribed therapies based on ReDS readings. After the 90 day ReDS-guided management period of follow-up, patients were followed for an additional 90 days without ReDS measurements. Mean follow-up during the ReDS-guided period was 83 days; it is unclear how many patients completed the post-ReDS period. The authors reported that compliance with taking daily measurements was 95%. The rate of heart failure hospitalizations was lower during the ReDS-guided follow-up compared to post-ReDS period (HR=0.11; 95% CI, 0.01 to 0.88; p=0.04). Interpretation of results is limited due to the lack of concurrent control and randomization, short-term follow-up, large confidence intervals, and uncertainty about lost-to-follow-up during the post-ReDS period. An RCT comparing ReDS standard of care is ongoing and expected to finish in September 2017.
 
Hassan and colleagues compared 4 methods of measuring cardiac output, including IGR, in 97 patients with heart failure and reduced ejection fraction. The intraobserver variability of IGR was measured using intraclass correlation coefficient (ICC) calculated on repeated measurements in 30 patients; the selection criteria were not described. The ICC was 0.94. Cardiac output indexed to body surface area was significantly but modestly correlated between IGR and cardiac magnetic resonance imaging (r=0.7; p<0.001) as well as IGR and cardiac catheterization (r=0.6; p<0.001) and significantly correlated between IGR and echocardiography (r=0.4; p<0.001) (Hassan, 2017).
 
Clinical Utility
No studies were identified that determined how use of inert gas rebreathing measurements is associated with changes in patient management or evaluated effects on patient outcomes.
 
No studies were identified that determined how noninvasive measurements of the LVEDP are associated with changes in patient management or evaluated effects on patient outcomes.
 
NICE issued interventional procedure guidance (IPG463) on insertion and use of implantable pulmonary artery pressure monitors in chronic heart failure (NICE, 2013).  The recommendations concluded that “Current evidence on the safety and efficacy of the insertion and use of implantable pulmonary artery pressure monitors in chronic heart failure is limited in both quality and quantity”.
 
ONGOING AND UNPUBLISHED CLINICAL TRIALS
Some currently unpublished trials that might influence this review are listed below:
 
Ongoing:
(NCT02448342) Sensible Medical Innovations (Noninvasive) Lung Fluid Status Monitor Allows Reducing Readmission Rate of Heart Failure Patients- a Randomized Controlled Study (SMILE); planned enrollment 380; projected  completion date September 2017
 
2018 Update
Annual policy review completed with a literature search using the MEDLINE database through May 2018. No new literature was identified that would prompt a change in the coverage statement. The key identified literature is summarized below.
 
CardioMEMS Device
Abraham et al have reported on the results of the CHAMPION single-blind RCT in which all enrolled patients were implanted with the CardioMEMS device (Abraham, 2011; Abraham, 2016). Patients were randomized to the CardioMEMS group, in which daily uploaded pulmonary artery pressures were used to guide medical therapy, or to the control group, in which daily uploaded pressures were not made available to investigators and patients continued to receive standard of care management, which included drug adjustments in response to patients’ clinical signs and symptoms. An independent clinical end points committee, blinded to the treatment groups, reviewed abstracted clinical data and determined if hospitalization was related to heart failure hospitalization. The randomized phase ended when the last patient enrolled completed at least 6 months of study follow-up (average, 18 months) and was followed in an open-access phase during which investigators had access to pulmonary artery pressure for all patients (former control and treatment group). The open-access phase lasted for an average of 13 months. In the randomized phase of the trial, if the investigator did not document a medication change in response to an abnormal pulmonary artery pressure elevation, a remote CardioMEMS nurse could send communications to the investigator related to clinical management. No such activity occurred in the nonrandomized phase. The trial met its primary efficacy end point, with a statistically significant 28% relative reduction in the rate of heart failure‒related hospitalizations at 6 months. However, members of the U.S. Food and Drug Administration (FDA) advisory committee in 2011 were unable to distinguish the effect of the device from the effect of nurse communications, and so FDA denied approval of CardioMEMS and requested additional clarification from the manufacturer (Loh, 2013). Subsequently, FDA held a second advisory committee meeting in 2013 to review additional data (including open-access phase) and address previous concerns related to impact of nurse communication on the CHAMPION trial (FDA, 2013).
 
The 2 major limitations in the early data were related to the potential impact of nurse communication and lack of treatment effect in women.
 
The sponsor conducted multiple analyses to address the impact of nurse intervention on heart failure-related hospitalizations. These analyses included: (1) independent auditing of all nurse communication to estimate quantitatively the number of hospitalization that could have been influenced by nurse communication, (2) using a propensity-based score to match patients in the CardioMEMS group who did not receive nurse communications with those in the control base, (3) comparing whether the new knowledge of pulmonary arterial pressure in the former control during the open-access phase led to reductions in heart failure-related hospitalizations, (4) comparing whether the ongoing access to pulmonary artery pressures in the treatment group during the open-access phase was accompanied by continued reduced rates of heart failure hospitalizations, and (5) comparing whether if similar access to pulmonary artery pressures in the former control group and treatment group during the open-access phase was associated with similar rates of heart failure-related hospitalizations (FDA, 2013). FDA concluded that all such analyses had methodologic limitations. Propensity matching cannot balance unmeasured characteristics and confounders, and therefore conclusions drawn from propensity analysis were not definitive (FDA, 2013). While FDA concluded that the third-party audit of nurse communication was valid, it was difficult to estimate accurately how many heart failure-related hospitalizations were avoided by the nurse communications. FDA stated that the longitudinal analyses were the most useful regarding supporting device effectiveness. It is important to acknowledge that all such analyses were post hoc and were conducted with the intent to test the robustness of potentially biased RCT results and therefore results from these analyses should be evaluated to assess consistency and ­­­­­not as an independent source of evidence to support efficacy. The longitudinal analyses of individual patient data showed that the device appears to be associated with reducing heart failure-related hospitalization rate. However, there are important trial limitations, notably, subject dropouts were not random, and patient risk profiles could have changed from the randomized phase to the open-access phase. In the open-access phase, 93 (34%) of 270 subjects in the treatment group and 110 (39%) of 280 subjects in control group remained in the analysis.
 
According to the FDA documents, the apparent lack of reduction in heart failure-related hospitalization in women resulted from a greater number of deaths among women in the control group early in the trial and this early mortality resulted in a competing risk for future heart failure hospitalizations. While both the FDA and sponsor conducted multiple analyses to understand device effectiveness in women, FDA statisticians concluded that such analyses did clearly delineate the limited treatment effect in women (FDA, 2013). The effectiveness of CardioMEMS in women may be clarified when results of a postmarketing study, currently ongoing and proposed to enroll at least 35% (n=420) women of the enrollment (n=1200), are published.
 
Nonrandomized Studies
Desai et al published a retrospective cohort study of Medicare administrative claims data for individuals who received the CardioMEMS device following FDA approval (Desai, 2017). Of 1935 Medicare enrollees who underwent implantation of the device, 1114 were continuously enrolled and had evaluable data for at least 6 months before, and following, implantation. A subset of 480 enrollees had complete data for 12 months before and after implantation. The cumulative incidence of heart failure-related hospitalizations were significantly lower in the postimplantation period than in the preimplantation period at both 6- and 12-month follow-ups. Limitations of this pre-post retrospective study include lack of data on medical history, ejection fraction, indication for implantation and possible confounding due to amplified touchpoints with the health care system necessitated by the device’s implantation.
 
Vaduganathan analyzed mandatory and voluntary reports of device-related malfunctions reported to FDA to identify CardioMEMS HF System-related adverse events within the first 3 years of FDA approval (Vaduganathan, 2017). From among the more than 5500 CardioMEMS implants in the first 3 years, there were 155 adverse event reports covering 177 distinct adverse events for a rate of 2.8%. There were 28 reports of pulmonary artery injury/hemoptysis (0.5%) that included 14 intensive care unit stays, 7 intubations, and 6 deaths. Sensor failure, malfunction, or migration occurred in 46 cases, of which 35 required recalibrations. Compared with a reported 2.8% event rate, the serious adverse event rate in CHAMPION trial was 2.6% with 575 implant attempts, including 1 case of pulmonary artery injury and 2 deaths. Limitation of the current analysis primarily included lack of adjudication and limited clinical data.
 
Case Series
Heywood et al reported pulmonary artery pressure data for the first 2000 consecutive patients with at least 6 months of follow-up who were implanted with CardioMEMS. No clinical data were reported except for pulmonary artery measurement (Heywood, 2017). The mean age of the cohort enrolled was 70 years and the mean follow-up period was 333 days. There was a median of 1.2 days between remote pressure transmissions and greater than 98% weekly use of the system, demonstrating a high level of adherence.
 
Section Summary: Implantable Pulmonary Artery Pressure Monitoring
The pivotal CHAMPION RCT reported a statistically significant decrease in heart failure-related hospitalizations in patients implanted with CardioMEMS device compared with usual care. However, trial results were potentially biased in favor of the treatment group due to use of additional nurse communication to enhance protocol compliance with the device. The trial intended to assess the physician’s ability to use pulmonary artery pressure information and not the capabilities of the sponsor’s nursing staff to monitor and correct physician-directed therapy. The manufacturer conducted multiple analyses to address the potential bias from the nurse interventions. These analyses were reviewed favorably by FDA. While these analyses demonstrated the consistency of benefit from the CardioMEMS device, all such analyses have methodologic limitations. With greater adoption of this technology, it is likely to be used by a broader group of clinicians with variable training in the actual procedure and used in patients at a higher risk compared with those in the CHAMPION trial. Early safety data have been suggestive of a higher rate of procedural complications, particularly related to pulmonary artery injury. Given that the intervention is invasive and intended to be used for a highly prevalent condition, in the light of limited safety data, lack of demonstrable mortality benefit, and pending questions related to its benefit for reduction in hospitalization, the net benefit remains uncertain. Many concerns may be clarified by an ongoing postmarketing study that proposes to enroll 1200 patients (at least 35% women) is reported.
 
Practice Guidelines and Position Statements
 
American College of Cardiology et al
The 2017 joint guidelines from the American College of Cardiology, American Heart Association, and Heart Failure Society of America on the management of heart failure offered no recommendations for the use of ambulatory monitoring devices (Yancy, 2017).
 
European Society of Cardiology
The European Society of Cardiology guidelines on the diagnosis and treatment of acute and chronic heart failure stated the following: “Monitoring of pulmonary artery pressures using a wireless implantable hemodynamic monitoring system (CardioMEMS) may be considered in symptomatic patients with heart failure with previous heart failure hospitalization in order to reduce the risk of recurrent heart failure hospitalization (Class IIb Level B recommendation) (Kirchhof, 2016).”
 
2019 Update
A literature search was conducted through May 2019.  There was no new information identified that would prompt a change in the coverage statement.
 
2020 Update
A literature search was conducted through May 2020.  There was no new information identified that would prompt a change in the coverage statement.  
 
2021 Update
Annual policy review completed with a literature search using the MEDLINE database through May 2021. No new literature was identified that would prompt a change in the coverage statement. The key identified literature is summarized below.
 
Shavelle et al reported 1 year outcomes from the open-label, observational, single-arm, post-approval study of CardioMEMS in 1200 patients (37.7% female) across 104 centers in the U.S. with NYHA Class III heart failure and a heart failure-related hospitalization in the prior year (Shavelle, 2020). Study visits were planned at 1, 6, 12, 18, and 24 months. The primary efficacy outcome was the difference between rates of adjudicated heart failure-related hospitalization 1 year after compared to 1 year prior to device implantation. The 12-month visit was completed in 875 patients (72.9%). Prior to 1 year, 76 patients (6.3%) withdrew from the study and 186 patients (15.5%) died. The heart failure-related hospitalization rate was significantly lower at 1 year post-implantation (0.54 versus 1.25 events/patient-year; hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.39 to 0.47; P<0.0001). The rate decreases remained significant regardless of the number of pre-enrollment heart failure-related hospitalizations, with a trend towards a more significant benefit in a small subgroup of patients (n=21) with 5 pre-enrollment heart failure-related hospitalizations. The rate of all-cause hospitalization (ACH) was also significantly lower (1.67 versus 2.28 events/patient-year; HR, 0.73; 95% CI, 0.68 to 0.78; P<0.0001). These results were consistent across subgroups defined by ejection fraction, sex, race, cardiomyopathy cause, and presence or absence of implantable cardiac defibrillator or cardiac resynchronization therapy. The mean rate of daily pressure transmission was 76 ± 24%. Pressure changes differed according to baseline mean pulmonary artery pressure, with the largest decreases observed in patients with baseline pulmonary artery pressure 35 mmHg (n=550). Pulmonary artery pressure also decreased in the subgroup of patients that died in the year postimplantation. During the study, 94.1% of patients had a medication change, with an average of 1.6 medication changes per month. Medication changes related to an increase or decrease in pulmonary artery pressure were implemented in 81.8% and 55.8% of patients, respectively. The primary safety outcome was defined as freedom from device- or system-related complications and pressure sensor failure at 2 years. Two year safety follow-up has not yet been concluded. At 1 year, freedom from device- or system-related complications was 99.6% (5 events) and freedom from pressure sensor failure was 99.9% (1 event). The nature of these events and the frequency of procedure-related adverse events was not reported. Study interpretation is limited by the lack of a randomized control group and the potential influence of both information and survivor bias. Assessing heart failure-related hospitalizations as a study entry requirement and an endpoint may also reflect a bias of prior hospitalization in favor of any intervention. Notably, 82.8% of patients had a medication change that was unrelated to changes in pulmonary artery pressure (eg, uptitration of neurohormonal modulation in stable patients). Therefore, it is unclear to what degree heart failure-related hospitalization reduction can be explained by a more intensive follow-up and drug uptitration plan in the year following implantation. Details regarding the frequency of nursing and/or provider communications were not reported.
 
Angermann et al published results from the CardioMEMS European Monitoring Study for Heart Failure (MEMS-HF) (Angermann, 2020). This was an industry-sponsored, prospective, observational, non-randomized study designed to assess the safety and feasibility of the CardioMEMS HF system over 12-month follow up in 31 centers across Germany, the Netherlands, and Ireland. A total of 239 patients (22% female) with NYHA class III heart failure and 1 heart failure-related hospitalization in the prior year were enrolled for remote pulmonary artery pressure-guided heart failure management. Patients were also contacted by nursing staff on a weekly basis during the first month, and biweekly or monthly based on current NYHA class. NYHA class improved in 83 patients (35.5%) and worsened in 4 patients (1.7%) at 12 months. Mean daily adherence to pulmonary artery pressure transmission was 78.1 ± 23.5% (median, 87.6% [interquartile range, 69.4% to 94.9%]). Co-primary outcome measures, 1-year rates of freedom from device- or system-related complications and sensor failure, were 98.3% (95% CI, 95.8 to 100.0) and 99.6% (95% CI, 97.6 to 100), respectively. Twenty-one serious adverse events (8.9%) were reported during 236 implant attempts, of which 4 were categorized as device- or system-related and 21 as procedure-related. Three procedure-related cardiac deaths were reported. The overall 12-month mortality rate was 13.8%, with no device- or system-related deaths. The secondary outcome measures included heart failure-related hospitalization rate at 12 months compared to the prior year before implantation and health-related quality of life. Heart failure-related hospitalizations decreased 62% (0.60 versus 1.55 events/patient year; HR, 0.38; 95% CI, 0.31 to 0.48; P<0.0001). These reductions were consistent across subgroups defined by sex, age, heart failure etiology, device use, ejection fraction, baseline pulmonary artery pressure, and various comorbidities. Patient-reported health-related quality of life outcomes were assessed with the Kansas City Cardiomyopathy Questionnaire (KCCQ), 9-Item Patient Health Questionnaire (PHQ-9), and the EQ-5D-5L. All measures significantly improved at 6 months and were sustained through 12 months. Cumulative medication changes and the average rate of monthly per-patient medication changes were highest in months 0 to 3 postimplant, with diuretics adjusted most often. While the observed heart failure-related hospitalization rate reduction in MEMS-HF is consistent with U.S. experience with the CardioMEMS device, the authors note that study results may have been impacted by information bias, regression to the mean, asymmetrical data handling, and confounding or selection of patients thought to be adherent to remote patient management requirements. Although helpful for evaluating safety and feasibility, prospective registries using historical events for within-patient comparisons cannot provide definitive effectiveness data. The Hemodynamic-GUIDEd Management of Heart Failure (GUIDE-HF) randomized controlled trial of the CardioMEMS device is currently ongoing in the U.S., with a planned enrollment of 3600 patients across 139 centers.
 
Abraham et al published a retrospective matched cohort study of Medicare beneficiaries who received the CardioMEMS device between 2014 and 2016 (Abraham, 2019). Patients were matched to 1087 controls by demographics, history and timing of heart failure-related hospitalizations, and number of ACH. Propensity scoring based on arrhythmia, hypertension, diabetes, pulmonary disease, and renal disease was used for additional matching. Follow-up was censored at death, ventricular assist device implant, or heart transplant. At 12 months post implantation, 616 and 784 heart failure-related hospitalizations occurred in the treatment and control cohorts, respectively. The rate of heart failure-related hospitalizations was lower in the treatment cohort at 12 months (HR, 0.76; 95% CI, 0.65 to 0.89; P<0.001). Percentage of days lost to heart failure-related hospitalizations (HR, 0.73; 95% CI, 0.64 to 0.84; P<0.001) and ACH or death (HR, 0.77; 95% CI, 0.68 to 0.88; P<0.001) were both significantly lower in the treatment group. The treatment cohort had 241 deaths and 20 ventricular assist device implants or heart transplants; over the same period, the control cohort had 325 deaths and 13 ventricular assist device implants or heart transplants. Mean (standard deviation [SD]) length of hospital stay was 6.6 (6.5) and 6.5 (5.8) days in the control and treatment cohorts, respectively (P=0.70). Mean (SD) total days spent in hospital for heart failure was 3.7 (9.5) and 4.4 (10.3), respectively. The percentage of days lost owing to heart failure-related hospitalization or death was reduced in the treatment cohort (relative risk [RR], 0.73; 95% CI, 0.63 to 0.83). Limitations of this study include lack of medical history data, including ejection fraction, natriuretic peptide levels, renal function, and medication use. Residual confounding by unmeasured covariates remains possible, including the role of heightened health care team involvement in implanted patients.
 
2022 Update
Annual policy review completed with a literature search using the MEDLINE database through May 2022. No new literature was identified that would prompt a change in the coverage statement.

CPT/HCPCS:
33289Transcatheter implantation of wireless pulmonary artery pressure sensor for long term hemodynamic monitoring, including deployment and calibration of the sensor, right heart catheterization, selective pulmonary catheterization, radiological supervision and interpretation, and pulmonary artery angiography, when performed
93264Remote monitoring of a wireless pulmonary artery pressure sensor for up to 30 days, including at least weekly downloads of pulmonary artery pressure recordings, interpretation(s), trend analysis, and report(s) by a physician or other qualified health care professional
93701Bioimpedance derived physiologic cardiovascular analysis
93799Unlisted cardiovascular service or procedure

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