Level 2: Mid-level evidence
Previous trials investigating cardiac resynchronization therapy (CRT) (biventricular pacing) combined with an implantable cardioverter defibrillator (ICD) in patients with heart failure have shown nonsignificant improvements in mortality compared with ICD monotherapy. A new trial compared the combination of CRT plus ICD vs. ICD alone in 1,798 patients with mild-to-moderate heart failure (New York Heart Association [NYHA] class II or III) and wide QRS complex (≥120 milliseconds) despite optimal medical therapy (N Engl J Med. 2010;363:2385-2395).
At mean follow-up of 40 months, combination therapy was associated with reduced risk of all-cause mortality (20.8% vs. 26.1%, P=0.003, NNT 19) and cardiovascular mortality (14.5% vs. 17.9%, P=0.02, NNT 30). Rates of hospitalization for heart failure were also lower for the combination group (19.5% vs. 26.1%, P <0.001, NNT 15). Combination therapy was associated with a higher rate of implantation-related complications (P <0.001), most commonly lead displacement requiring intervention. There were no significant differences in a subgroup analysis of 360 patients with NYHA class III heart failure. This trial was funded in part by Medtronic of Canada, the manufacturer of both devices.