Efficacy and survival in patients with cardiac contractility modulation: long-term single center experience in 81 patients

AIMS: To analyze long-term efficacy and survival in patients with chronic heart failure treated with cardiac contractility modulation. METHODS: 81 patients implanted with a CCM device between 2004 and 2012 were included in this retrospective analysis. Changes in NYHA class, ejection fraction (EF), Minnesota Living with Heart Failure Questionnaire, NT-proBNP and peak VO(2) were analyzed during a mean follow up of 34.2 +/- 28 months (6-123 months). Observed mortality rate was compared with that predicted by the MAGGIC Score. RESULTS: Patients were 61 +/- 12 years old with EF 23 +/- 7%. Heart failure was due to ischemic (n=48, 59.3%) or idiopathic dilated (n=33, 40.7%) cardiomyopathy. EF increased from 23.1 +/- 7.9 to 29.4 +/- 8.6% (p<0.05), mean NT-proBNP decreased from 4395 +/- 3818 to 2762 +/- 3490 ng/l (p<0.05) and mean peak VO2 increased from 13.9 +/- 3.3 to 14.6 +/- 3.5 ml/kg/min (p=0.1). The overall clinical responder rate (at least 1 class improvement of NYHA within 6 months or last follow-up) was 74.1%. 21 (25.9%) patients died during follow up, 11 (52.4%) due to cardiac conditions and 10 (47.6%) due to non-cardiac conditions. Mortality rates at 1 and 3 years were 5.2% and 29.5% compared to mortality rates estimated from the MAGGIC risk score of 18.4% (p<0.001) and 40% (p=ns), respectively. Log-Rank analysis of all events through 3 years of follow-up, however, was significantly less than predicted (p=0.022). CONCLUSIONS: CCM therapy improved quality of life, exercise capacity, NYHA class, EF and NT-proBNP levels during long-term follow up. Mortality rates appeared to be lower than estimated from the MAGGIC score.