Cardiac resynchronisation may reduce all-cause mortality: meta-analysis of preliminary COMPANION data with CONTAK-CD, InSync ICD, MIRACLE and MUSTIC.

Landmark trials have demonstrated that biventricular pacing (also called cardiac resynchronisation therapy or CRT) in chronic heart failure due to left ventricular dysfunction improves symptomatic status, exercise capacity and quality of life. Yet critically, all-cause mortality has not been demonstrated to be reduced in any of the four randomised controlled trials with mortality data (CONTAK-CD, InSync implantable-cardioverter defibrillator (ICD), MIRACLE and MUSTIC). With the much larger COMPANION study now terminated, however, the currently available pooled data from all five trials shows a significant reduction in all-cause mortality, odds ratio (OR), 0.74: 95% confidence interval (CI) 0.56-0.97. This may now establish biventricular pacing as a standard therapy for a specific subset of patients with chronic heart failure and LBBB.