Implanted pulse generator ups exercise tolerance in HF

BOSTON – Cardiac contractility modulation (CCM), an electrical device–based modality, may improve exercise tolerance and quality of life in heart failure patients with ejection fraction between 25% and 45%, results of a randomized, controlled trial suggested.

Notably, clinical effectiveness appeared to be even greater in the subset of patient with ejection fractions between 35% and 45%, according to results presented at the annual scientific sessions of the Heart Rhythm Society.

Dr. William T. Abraham

The CCM approach was designed to treat chronic heart failure patients with reduced and midrange ejection fractions. It involves the delivery of electrical signals during the cardiac absolute refractory period to enhance contraction strength. Key components include an atrial lead used for sensing and two ventricular leads used for sensing local electrical activity and delivery of CCM signals.

The device was previously evaluated in FIX-HF-5, a 428-patient randomized trial of CCM in patients with New York Heart Association functional class III/IV and reduced ejection fraction. That study failed to meet its primary efficacy end point, but a subgroup analysis showed significant treatment effects in patients with ejection fractions between 25% and 45%.

Consequently, Dr. Abraham initiated the FIX-HF-5 confirmatory study (FIX-HF-5C) to prospectively evaluate CCM in patients with ejection fractions in that range.

The study included 160 with NYHA class III/IV heart failure, QRS duration less than 130 ms, and ejection fractions of 25%-45% who were randomized either to CCM or to continued optimal medical therapy. The control arm included 86 patients, and the CCM arm included 74 patients, of whom 68 received device implantation.