Medline, Embase, and the Cochrane Library databases were searched, and all randomized controlled trials of CRT alone or combined with ICDs in HF resulting from left ventricular systolic dysfunction were included. Main outcome was all-cause mortality. Summary relative risk (RR) and 95 % confidence interval (CI) were calculated employing random-effects models. Twelve studies were included, with a total of 8,284 randomized patients. For the comparison of CRT alone versus medical therapy, pooled analysis of 5 available trials demonstrated a significant reduction in all-cause mortality with CRT (RR 0.76, 95 % CI: 0.64?.9). Pooled analysis of 6 trials that compared the combination of CRT and ICD therapy to ICD alone also showed a statistically significant reduction in all-cause mortality (RR 0.83, 95 % CI: 0.72?.96). Stratified analysis showed significant mortality reductions in all New York Heart Association class subgroups, with greater effect in classes III¨CIV (RR 0.70; 95 % CI: 0.57?.88). Pooled estimates of implant-related risks were 0.6 % for death and 8 % for implant failure.
Combined CRT and ICD therapy reduces overall mortality in HF patients when compared with ICD alone.