SAN DIEGO – Patients with stage C heart failure who received HeartNet, an investigational implantable device made of nitinol that is designed to wrap around the walls of the heart for support, experienced no statistically significant improvements in peak oxygen consumption, compared with a control group who received standard medical care alone, results from a prospective randomized trial showed.
However, the trial – known as PEERLESS-HF (Prospective Evaluation of Elastic Restraint to Lessen the Effects of Heart Failure) – showed evidence of reverse remodeling as well as a significant reduction in serious heart failure events at 6 months in the treatment group, Dr. William T. Abraham reported at the annual meeting of the Heart Failure Society of America.
Dr. William T. Abraham
When 50% of the patients reached 6 months’ follow-up, an independent data safety-monitoring board reviewed the data and recommended that the trial be stopped “for futility, particularly because there was no demonstrable difference between the treatment and control group for change in peak VO2,” explained Dr. Abraham, who directs the division of cardiovascular medicine at Ohio State University in Columbus. “This was due in large part to a much-better-than-expected improvement of peak VO2 in the control group. There was a 0.7 mL/kg per minute average improvement in peak VO2 in the control patients, something that we haven’t seen in other trials that have used peak VO2 as a primary end point.”
Manufactured by Sunnyvale, Calif.–based Paracor Medical Inc., HeartNet is delivered using a minimally invasive approach through a minithoracotomy. The device is self-anchoring and self-tensioning, and is presized based on echo measurements.
“Based on preclinical or animal data, we believe that it exerts just the right amount of cardiac support that is below the level at which myocardial constriction might occur,” Dr. Abraham said of the device. “The goal is to provide some external support without creating constriction.”
Courtesy of Paracor Medical, Inc.
HeartNet is an investigational implantable device that wraps around the heart for support and is self-anchoring and self-tensioning. It is presized based on echo measurements.
The purpose of PEERLESS-HF was to evaluate the safety and efficacy of the HeartNet ventricular elastic support system plus optimal HF therapy (treatment group) compared with optimal therapy alone (control group) in 244 patients. “We purposely enriched enrollment of patients with cardiac resynchronization therapy [because] there is preclinical animal mechanistic data [that suggest] possible synergy between cardiac support and CRT,” he said. “Our own preliminary data from the feasibility trial of this device also suggested the potential for a better response in a CRT population.”
To be eligible for the trial, patients had to be aged 18-75 years with stage C symptomatic ischemic or nonischemic heart failure for 6 months; be on stable, evidence-based heart failure therapy for at least 3 months; have a left ventricular ejection fraction of 35% or less; and have a 6-minute walk distance of 150-450 meters. Patients on current cardiac resynchronization therapy were accepted into the trial, but the relevant device must have been placed at least 3 months prior to randomization.
The study’s three coprimary end points, assessed at 6 months, were peak VO2, with the responder threshold set at 1 mL/kg per minute; 6-minute walk test, with the responder threshold set at 45 meters; and quality of life as measured by the Minnesota Living With Heart Failure Questionnaire (MLHFQ), with the responder threshold set at 7 units.
The primary safety end point, assessed at 1 year, was all-cause mortality by noninferiority analysis.
In all, 217 patients were enrolled in the study, with 114 in the control group and 103 in the treatment group. Ultimately, 92 patients were actually treated because of premature termination of the trial.
The mean age of patients was 55 years, 70% were male, 48% had NYHA class III heart failure, 47% had systemic hypertension, and 34% had diabetes mellitus.
“At baseline, this was a moderately sick group of patients,” Dr. Abraham said.
The average peak VO2 was 15.5 mL/kg per minute, the average 6-minute walk distance was about 350 meters, and the mean MLHFQ score was 52.
At 6 months, there were no statistically significant differences between the treatment and control groups on any of the coprimary end points. There were no safety concerns in the trial, and the rate of survival at 12 months was similar between groups (93% in the control group and 92% in the treatment group).
“The HeartNet is safe, demonstrating no increase in all-cause mortality,” Dr. Abraham said. “Even though terminated early, this trial did hit its prespecified safety end point of all-cause mortality at 12 months.”