AT THE AHA SCIENTIFIC SESSIONS 2016
NEW ORLEANS (FRONTLINE MEDICAL NEWS) – An interatrial septal shunt device continued to provide “sustained and meaningful clinical benefit” at 1-year follow-up for 64 patients who had heart failure with preserved ejection fraction (HFpEF), David M. Kaye, MD, PhD, reported at the American Heart Association scientific sessions.
The device is implanted via cardiac catheterization and is intended to reduce elevated left atrial pressure, particularly that associated with exertion, by allowing a small amount but not excessive left-to-right shunting. Patients showed improvements in 6-minute walk distance, New York Heart Association class, and HF-related quality of life scores at 6 months, and those effects persisted at the most recent (12-month) follow-up, he said in a presentation that was simultaneously published online in Circulation (2016 Nov 16).
REDUCE LAP-HF (Reduced Elevated Left Atrial Pressure in Patients With Heart Failure), a manufacturer-sponsored, nonrandomized, open-label study established the device’s safety and performance in a relatively small group of patients. A larger, double-blind, randomized trial with sham controls is now underway “to validate the utility of this novel therapy,” said Dr. Kaye of Alfred Hospital, Melbourne.
Overall survival at 1 year was 95%. Three patients died (one from combined pneumonia and renal failure, one from a fatal stroke, and one from an undetermined cause) and one was lost to follow-up. Thirteen patients required 17 hospitalizations for heart failure.
Six-minute walk distance improved from 331 meters at baseline to 363 meters. NYHA classification improved dramatically, as did quality of life scores as assessed by the Minnesota Living with HF questionnaire.
All 48 devices that were evaluable on echocardiographic imaging remained patent, showing continued left-to-right shunting. Left ventricular ejection fraction remained unchanged while right ventricular ejection fraction was significantly elevated over baseline levels. “In conjunction, there were modest but stable reductions in LV end-diastolic volume index with a concomitant rise in RV end-diastolic index,” he said.
A subset of 18 study participants underwent heart catheterization during both rest and exercise so that hemodynamics could be assessed. Exercise time increased significantly, from 8.2 minutes at baseline to 9.7 minutes at 6 months and to 10.4 minutes at 1 year. Similarly, peak work capacity during supine cycling increased from 48 watts at baseline to 60 watts at 6 months and 55 watts at 1 year. These benefits occurred without any increase in pulmonary capillary wedge pressure.
Systemic blood pressure did not change over time, either at rest or during exercise. Left and right atrial volumes also remained unchanged.
Perhaps most importantly, Dr. Kaye said, right-sided cardiac output increased significantly, while left-sided cardiac output remained unchanged. There was no evidence of increased pulmonary pressure or pulmonary vascular resistance. This meant that patients could do more physical activity for a given level of left atrial pressure, he said.
To discussant Nancy K. Sweitzer, MD, PhD , the most important aspect of the 1-year results of REDUCE LAP-HF was the strong showing for device safety. Sustained, chronic elevation in right-sided output has never been studied, so the effects are unknown. But the results are encouraging because device flow remained left-to-right in all evaluated patients.
Furthermore, 1-year mortality was lower in this trial, at 4.6%, than in the placebo groups of the I-PRESERVE trial in irbesartan (5.2%) and the U.S. group of the TOPCAT trial in spironolactone (7.7%), said Dr. Kaye, professor and chief of cardiology at the University of Arizona, Tuscon.
Device therapy could have an enormous impact in carefully selected patients with HFpEF, for whom there are no medical treatments, despite the nonrandomized nature of the trial.
REDUCE LAP-HF was funded by Corvia Medical, maker of the shunt device. Dr. Kaye is an unpaid member of Corvia’s scientific advisory group. Dr. Sweitzer is an investigator in the ongoing randomized trial of the interatrial shunt.
