The effectiveness of cardiac contractility modulation: results of two-year follow-up

Abstract

Aim. To evaluate the survival and dynamics of clinical and instrumental data in patients with chronic heart failure (CHF), atrial fibrillation (AF) and cardiac contractility modulation (CCM).Methods. There were included 54 patients (40 men, median age 59.7 [56.6; 63.9] years) with signs of CHF II (n=27, 50%) functional class and III (n=27, 50%) NYHA functional class, significantly decreased left ventricular ejection fraction (LVEF=30 [24,7; 35,5]%), LV dilatation and paroxysmal (n=27, 50%) or permanent (n=27, 50%) AF. In all patients, devices for CCM were implanted. The dynamics of clinical and instrumental parameters were assessed in 2, 6, 12 and 24 months after implantation. The actual survival patients with CCM was compared with the predicted survival calculated using the Seattle model of heart failure and MAGGIC risk score.Results. In 14 (28%) of patients CCM resulted in significantly increased clinical, echocardiographic parameters (increase in LVEF by 15 [11; 20]%, decrease in end-systolic volume by 68,5[37.5;104.5] ml and end-diastolic volume by 44 [30,100] мл), increase in walking distance during 6-minute walking test and decrease of NT-proBNP. The only factor significant for maximal response was non-ischemic etiology of CHF (χ2=4.54, p=0.034). During 2 years 21 (42%) patients died. The all-cause mortality in patients with CCM to the first year of observation was 16%, two-year all-cause mortality - 40%. These figures turned out to be significantly higher than predicted according to the Seattle model (χ2=10.93, p=0.001). The predicted and actual risk of death at 12-month follow-up turned out to be comparable when assessing survival parameters according to the MAGGIC scale. (χ2=2.24, p=0.134).Conclusion. CCM therapy in some patients with CHF of non-ischemic etiology can lead to an improvement of all clinical and instrumental characteristics. At the same time, there is no effect of CCM on the prognosis of patients with CHF. This fact may suggest the need of additional studies with increased number of cases.