One-Year Outcome of Cardiac Contractility Modulation in Patients With Reduced Ejection Fraction, Atrial Fibrillation, and Previous Resynchronization: A Pilot Study

After 6 months of therapy, cardiac contractility modulation (CCM) has been shown to improve symptoms, exercise tolerance, and quality of life as well as reduce the rate of hospitalizations in patients with heart failure with reduced left ventricular ejection fraction (HFrEF), but long-term effects data are lacking, with no randomized trial to date.What is the long-term benefit of the CCM device implantation in symptomatic patients with severe, optimally treated HFrEF?We conducted a prospective trial involving patients with symptomatic HFrEF [New York Heart Association (NYHA) Class III or IV, left ventricular ejection fraction (LVEF) ≤35%] who were supported by a CCM device.Twenty patients (19 men), aged 66.5 ± 6.9 years, were provided with CCM therapy and followed up for an average duration of 321.7 ± 113.5 days. The etiology of heart failure was ischemic in 16 patients (80%), 9 patients (45%) had atrial fibrillation, 6 patients (30%) had diabetes mellitus, and mean creatinine clearance value was 54.8 ± 13.0 mL/min. Eleven patients (60%) had LVEF ≤25%. Although all the patients had an implanted cardioverter-defibrillator, 6 of them (30%) also had resynchronization therapy. The pharmacological treatment has been optimized in all patients. One year after implantation, the LVEF increased from 24.68% ± 4.5 to 34.6 ± 5 ( P < 0.0001), NYHA class improved from 3.2 ± 0.5 to 1.4 ± 0.5 ( P < 0.0001), and exercise tolerance evaluated with a 6-Minute Walk Test increased (from 307.9 ± 74.1 m to 567 ± 99.5 m; P < 0.00001). These improvements were largely seen in the first 6 months.Over the course of a year, CCM therapy was associated with improved LVEF and NYHA class, as well as significantly better exercise tolerance, even in patients with atrial fibrillation and cardiac resynchronization therapy and did not seem to be associated with additional significant device-related problems.