Effect of cardiac resynchronization therapy on quality of life: the best gets the least

This editorial refers to ‘Effect of cardiac resynchronization therapy and implantable cardioverter defibrillator on quality of life in patients with heart failure: a meta-analysis’ by S. Chen et al ., on page 1602 Heart failure (HF) is a syndrome that poses a substantial clinical and economic burden.1 Frequently, life-threatening ventricular arrhythmias may also accompany this condition.1 In the past, two large randomized clinical trials (RCTs), MADIT II (Multicenter Automatic Defibrillator Implantation Trial), and SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial),2,3 have demonstrated that implantable cardioverter-defibrillator (ICD) therapy produces a significant reduction in total mortality when used for primary prevention in patients at risk for sudden cardiac death. Although ICDs reduce the risk of life-threatening ventricular arrhythmias, they have no effect on ventricular structure and function, and underlying cardiomyopathy hence remains unchanged. Biventricular pacing, introduced into clinical practice in the early 1990s, has become an accepted therapeutic modality for patients with HF in addition to optimum medical therapy (OMT). This novel pacing strategy, more generally defined cardiac resynchronization therapy (CRT), restores synchronized ventricular contraction, which consequently results in an improved pumping efficiency, enhanced left ventricular filling, and a reduction in the severity of mitral regurgitation. Cardiac resynchronization therapy has substantially modified the natural history of HF, exerting its physiological impact through favourable ventricular remodelling, with a reduction in left ventricular volumes and improvement in left ventricular ejection fraction (LVEF). This in turn translates into long-term clinical benefits such as improved symptoms, and functional capacity, with a concomitant reduction in hospitalization for HF and overall mortality.4 However, whether the combination of CRT and ICD (CRT-D) would bring any additional benefit over CRT or ICD alone has been a matter of debate for a long while. In a systematic review of 4420 patients in 14 trials, McAlister …