Cardiac contractility modulation for heart failure: a meta-analysis of randomized controlled trials

Cardiac contractility modulation (CCM) emerges as a promising device treatment for heart failure (HF). This meta-analysis aimed to systematically review the latest available randomized evidence on the effectiveness and safety of CCM in HF.

The Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE were searched in November 2011 to identify eligible randomized controlled trials comparing CCM with sham treatment or usual care. Primary outcomes of interest were all-cause mortality, all-cause hospitalizations, and adverse effects. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated for dichotomous data using a random-effects model.

Three studies enrolling 641 participants were included. Pooled analysis showed that, compared to control, CCM did not significantly improve all-cause mortality (n = 629, RR 1.19, 95% CI 0.50-2.86, P = 0.69), nor was there a favorable effect in all-cause hospitalizations. No increase in adverse effects with CCM was observed.

Meta-analysis of data from small randomized trials suggests that CCM, although with no clear benefits in improving clinical outcomes, is not associated with worsening prognosis. Large, well-designed trials are needed to confirm its role in HF patients for whom cardiac resynchronization therapy is contraindicated or unsuccessful.