A Closer Look at Remote Pulmonary Artery Monitoring

For high-risk patients with heart failure, emerging literature suggests that remote pulmonary artery (PA) monitoring enhances quality of life and enables physicians to effectively assess PA pressures to inform treatment. By Barbara Zeiger

The number of patients with heart failure (HF) is expected to continue to increase, impacting patient quality of life and life expectancy and exerting a burden on health care institutions and resources. People with heart failure need frequent and consistent monitoring for, among other concerns, clinical signs of congestion that can impact the volume of blood flow. This need can be ameliorated using remote monitoring techniques rather than in-person examinations.

In its early utilization, remote monitoring comprised manual patient provision of data including weight, blood pressure, and heart rate. The development and use of implanted cardiac devices allowed for the transmission of physiological data associated with intrathoracic impedance. This evolved into the ability to measure functions related to intracardiac filling pressures, which enables physicians to be proactive rather than reactive to clinical signs of decompensation.

Ambulatory hemodynamic monitoring gained footing in the early 2000s, and through the years numerous devices were developed and tested for use, including right ventricular, left atrial, and pulmonary artery (PA) monitoring. These devices feature various sensor types and locations that facilitate direct measurement of PA pressures.

The safety and efficacy of invasive (implanted) sensors have been studied and compared. In a recently published review of modalities utilized for remote monitor- ing of patients with heart failure, Radhoe et al noted that the Cardio-microelectromechanical HF system (CardioMEMS, Abbott) has proven safety and efficacy in preventing heart failure-related hospital admissions. Results from the 2011 single-blind, randomized CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Heart Failure Patients (CHAM- PION) trial demonstrated the device’s clinical efficacy in lack of device failure as well as its ability to enhance clinician decision making regarding patients with advanced HF—for example, the need to provide diuretics to reduce fluid volume and subsequent pressure on the heart.

These outcomes led to the United States Food and Drug Administration (FDA) 2014 approval of the CardioMEMSTM HF System for use in patients with chronic HF (ie, patients with New York Health Association (NYHA) HF classification of III and a prior history of heart failure hospitalization within 12 months). Additional cohort, Medicare claims-based, observational, and post-marketing surveillance studies confirmed the CHAMPION study findings. Continued research in the U.S. and Europe enabled the expansion of patients eligible for CardioMEMS(tm) PA Sensor implantation to people with NYHA II HF and elevated natriuretic peptides or BNP.

CardioMEMS is the only PA pressure sensor with an FDA label and European Conformity (CE) mark in current use. A similar device, Cordella Pulmonary Artery Pressure Sensor System (Endotronix), additionally measures blood pressure, weight, and oxygen saturations. This device does not currently have FDA approval or a CE mark, but investigation is ongoing.

How PA Monitoring With CardioMEMS Works

The CardioMEMS HF System utilizes a small sensor (about the size of a dime) that is implanted under fluoroscopy and calibrated during a simple outpatient or inpatient procedure though the femoral or internal jugular vein. The sensor components, housed in a silicone case, measure pressure waveforms and heart rate as well as diastolic, systolic, and mean PA pressure. The sensor is compatible with implantable cardioverter defibrillators and cardiac resychronization therapy devices (CRT-D) and is measured remotely by an electronic unit. It does not require a power supply.

To obtain measurements, the patient lays on a specially designed pad once a day for a few seconds. Data are transmit- ted to a 24/7 secure website from which clinicians can readily access PA pressure readings that, along with other clinical ramifications of HF, are utilized to pro- vide and adjust medical therapy as appropriate. For example, PA pressures are thought to increase before clinical signs and symptoms of cardiac decompensation are noted. PA monitoring facilitates expedited clinician intervention that can help prevent clinical decompensation and associated hospital admissions.

The CardioMEMS HF System is compatible with other medical care and diagnostic devices, such as magnetic resonance imaging. The sensor has lifelong durability and because it is thought that anticoagulants cause endothelialization, sensor explantation should be avoided. Anticoagulant use (eg, warfarin, if it is currently part of the care regimen, clopidogrel, and/ or low-dose aspirin) is recommended.

Pulmonary Artery Monitoring and Left Ventricular Assist Devices

Pulmonary artery monitoring is frequently utilized before a patient needs a left ventricular assist device (LVAD).
It is not a therapy but can guide care. Implantation and use are associated with a less than 1 percent chance of significant complications. Patients can receive PA monitoring and LVAD concurrently.

A Guide to Contraindications

Pulmonary artery monitoring has fewer contraindications than LVAD use, and they include avoiding implantation in people with recurrent pulmonary embolism, people with less than one year to live, and/or persons who are morbidly obese.

Specifically, the CardioMEMS HF System may not be appropriate for implantation in patients with congenital heart disease or a mechanical right heart valve, known coagulation disorders, or an active infection; people who have under- gone implantation of CRT-D within the past three months; a history of recurrent deep vein thrombosis or pulmonary embolism; an estimated glomerular filtration rate of less than 25 mL/minute in people who are unresponsive to diuretic therapy or on chronic renal dialysis unable to tolerate a right heart catheterization; or hypersensitivity to aspirin or clopidogrel.

Assessing the Benefits of Remote Monitoring

Patrick J. McCann, MD, the director of Heart Failure and Mechanical Circulatory Support at Prisma Health Heart Hospital, Columbia, SC, says providing the ability to remotely assess heart function and adjust treatment appropriately has several benefits.

“Most importantly, remote monitoring helps keep the patient out of the hospital, which is of particular importance when health care is currently being strained by the effects of the pandemic,” notes Dr. McCann, a clinical assistant professor at the University of South Carolina School of Medicine.

“In addition, remote monitoring increases access to care, a special consideration when the patient is a distance from a medical facility. Lastly, the ability to recognize and address a problem before it escalates improves patient quality of life, not only in terms of alleviating symptoms like shortness of breath, but also in giving patients the knowledge and reassurance they need to enjoy life.”

Final Notes

Pulmonary artery monitoring allows surveillance of blood flow in patients with HF, keeping them out of the hospital, increasing access to care, and, in turn, improving quality of life. The hemodynamic data transmitted are used by physicians for the proactive and continuing management of HF. Although a number of products are available, research has demonstrated the safety and efficacy of the CardioMEMS HF System, which is currently the only monitoring system to have achieved FDA and CE mark approval. As the number of patients with HF continues to grow and regulatory approval is sought, additional research is most likely forthcoming