[Impact of cardiac resynchronization therapy on survival in patients with ischemic and nonischemic cardiomyopathy in clinical practice]

Abstract

Aim: To compare the impact of cardiac resynchronization therapy (CRT) on survival in patients with ischemic and non-ischemic cardiomyopathy (CMP) in clinical practice.

Subjects and methods: The study enrolled 206 patients with NYHA Functional Class II-IV chronic heart failure (CHF) and a left ventricular ejection fraction of < or = 35, including 107 patients implanted with CRT devices in combination with continuous drug therapy (DT). Among the 107 patients, 48 were diagnosed as having non-ischemic CMP (NCMP), 59 as coronary heart disease (CHD). The other 99 patients (12 with NCMP and 87 with CHD) were on DT only. Later on the patients from both groups were divided into subgroups according to the treatment policy of CHF: CRT + DT or DT only. The mean follow-up period was 24 +/- 18.1 months.

Results: The Kaplan-Meier survival analysis revealed that overall survival in the patients on CRT + DT was significantly higher than in those on DT (70 and 49%, respectively; p = 0.004). Analysis of the chosen treatment policy in the NCMP subgroup showed no significant differences in survival rates in the patients receiving CRT + DT or DT (74 versus 78%, respectively; p = 0.5). At the same time, the survival rates in the CHD patients on CRT + DT were significantly higher than those in the DT subgroup (68 versus 44%; p = 0.04).

Conclusion: CRT significantly reduces overall mortality in patients with CHF in clinical practice. Our findings indicated that this effect was achieved mainly in patients with CHD, rather than in those with NCMP.