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CardioMEMS: Pulmonary artery sensor decreases hospitalizations in HF
NEW ORLEANS — Patients with HF who were treated with pulmonary artery pressure-guided therapy through ambulatory hemodynamic monitoring with an implantable sensor had decreases in HF hospitalizations, pulmonary artery pressures and all-cause hospitalizations, according to data presented at the American College of Cardiology Scientific Session.
There were few complications related to the system used in this study (CardioMEMS, Abbott), which uses both a sensor and a home electronics unit.
David M. Shavelle, MD, associate professor of clinical medicine at University of Southern California Keck School of Medicine, and colleagues analyzed data from 1,200 patients (mean age, 69 years; 38% women) with NYHA class III HF who had at least one HF hospitalization within the prior year. Patients attended both a screening visit and a baseline visit to undergo a right heart catheterization, sensor implantation and to collect information on baseline hemodynamics. Patients were followed up at 1 month, 6 months, 1 year and 2 years.
Pulmonary artery sensor technology
“The system includes a small miniaturized sensor. Nanometer deflections in the body of the sensor result in a change in frequency and allow the ability to construct a pulmonary pressure wave form,” Shavelle said during the presentation.
The home electronic unit sends pulmonary artery pressures to a secure website that health care providers can access. Pulmonary artery pressure trends and established normal pressure ranges helped health care providers decide how to adjust medical therapies for the patient.
Patients in this postmarket study, which was conducted as a condition of FDA approval, were advised to submit pulmonary artery pressures daily.
The primary efficacy endpoint was a reduction in the rate of HF hospitalizations at 1 year after implantation compared with the year before enrollment into the study. Primary safety endpoints were rates of freedom from device- and system-related complications of at least 80% at 2 years and freedom from sensor failure of at least 90% at 2 years.
At baseline, 637 patients had an ejection fraction less than 40% (mean age, 67 years; 29% women), 198 had an ejection fraction between 41% and 50% (mean age, 70 years; 38% women) and 363 patients had an ejection fraction greater than 50% (mean age, 72 years; 53%). Of the entire patient population, more patients with an ejection fraction less than 40% were on medical therapy including beta-blockers, angiotensin-converting enzyme inhibitors, aldosterone agonists and loop diuretics compared with the other groups.
There was a significant reduction in pulmonary artery pressures over time. In addition, pressure transmission compliance was high on a daily level (mean, 76%) and on a weekly level (92%).
“We’d like patients to transmit data daily knowing that they are probably going to transmit several times a week,” Shavelle said during the discussion portion of the presentation. “I personally think weekly is not enough. For a stable patient, weekly is enough. For an unstable patient, weekly is not enough. If we can get our patients to go every 2 to 3 days, we think we are helping.”
Rates of hospitalizations
The rate of hospitalization for HF decreased from 1.24 events per patient-year before implantation to 0.52 events per patient-year 1 year after implantation, contributing to a 58% reduction (HR = 0.42; 95% CI, 0.38-0.47). This was also seen before and after implantation for HF hospitalizations or death (1.24 to 0.69 events per patient-year; HR = 0.56; 95% CI, 0.51-0.62) and all-cause hospitalizations (2.25 to 1.61 events per patient-year; HR = 0.72; 95% CI, 0.67-0.77).
When patients were stratified by ejection fraction, patients with an ejection fraction less than 40% had a 54% reduction in HF hospitalizations after implantation (HR = 0.46; 95% CI, 0.4-0.52). This reduction was 63% in those with an ejection fraction between 41% and 50% (HR = 0.37; 95% CI, 0.29-0.48) and 61% in patients with an ejection fraction greater than 50% (HR = 0.39; 95% CI, 0.32-0.49).
When stratified by planned subgroups, benefit with the system was seen regardless of sex, cardiomyopathy etiology, implantable cardioverter defibrillator use or race.
At 1 year, freedom from device- or system-related complications occurred in 99.7%, and 99.9% of patients had freedom from sensor failure.
“PA pressure-guided therapy was safe with few device- and system-related complications and a low rate of pressure sensor failure,” Shavelle said during the presentation. – by Darlene Dobkowski
Reference:
Shavelle DM, et al. Joint American College of Cardiology/Journal of the American Medical Association Late-Breaking Clinical Trials. Presented at: American College of Cardiology Scientific Session; March 16-18, 2019; New Orleans.
Disclosures: The trial was sponsored by Abbott Medical Devices. Shavelle reports he received consultant fees/honoraria from Abbott Vascular; served on the data safety monitoring board for the NHLBI; received research support from Abbott Vascular, Abiomed, Biocardia and V-Wave Medical, and served on the speaker’s bureau for Abbott Vascular.