Aims: Cardiac contractility modulation (CCM) is a new form of electrical therapy in patients with congestive heart failure. Recently published clinical studies provide evidence of safety and improvements of exercise tolerance and quality of life. In this study, we investigated the impact of CCM on cardiac and all-cause mortality.
Methods and results: Fifty-four consecutive patients (age 63 ± 10 years, 91% male, left ventricular ejection fraction 23 ± 6%, baseline peak oxygen consumption 10.0 ± 4.8 mL/min/kg, N-terminal pro-B-type natriuretic peptide 5194 pg/mL, New York Heart Association III/IV) who underwent implantation of an Optimizer system (IMPULSE Dynamics, Orangeburg, NY, USA) at our centre between June 2003 and June 2010 were analysed retrospectively. Patients were followed every 3 months at our outpatient clinic. This study determined long-term outcomes of patients receiving CCM therapy. Twenty-four (44%) patients died during the follow-up period, which included 19 cardiac deaths (3 sudden cardiac deaths and 16 terminal cardiac pump failure deaths). The Kaplan-Meier analysis calculated a median survival time of 992 days (33.1 months) and a mean death rate of 18.4% per year. All-cause mortality for these patients was precisely predicted by the Seattle Heart Failure Model.
Conclusion: Cardiac contractility modulation appears to be a safe therapeutic option for advanced heart failure patients who have no other therapeutic options. Symptomatic improvement by CCM has been shown in earlier studies but our observational study suggests, for the first time, that there is no adverse effect of CCM on long-term survival.