The effect of cardiac resynchronization without a defibrillator on morbidity and mortality: insights from an individual patient data meta‐analysis of COMPANION and CARE‐HF

Abstract

This article refers to 'The effect of cardiac resynchronization without a defibrillator on morbidity and mortality: an individual patient data meta-analysis of COMPANION and CARE-HF' by J.G.F. Cleland et al., published in this issue on pages 1080-1090.In this issue of the Journal, in the individual patient data meta-analysis of COMPANION (Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure) 1 and CARE-HF (Cardiac Resynchronization-Heart Failure), 2 Cleland et al. 3 explore the effects of cardiac resynchronization therapy pacemaker (CRT-P) versus medical therapy alone in 1026 CRT-P recipients and 712 controls receiving optimal medical therapy (OMT). They found that CRT-P led to a lower risk for all-cause mortality and the composite endpoint of all-cause mortality or heart failure (HF) hospitalization. Whilst a smaller body surface area and treatment with beta-blockers predicted a benefit from CRT, other baseline characteristics, namely sex, aetiology, QRS duration or morphology, PR interval and medical therapy other than beta-blockers did not. This is a welcome meta-analysis of the only randomized controlled trials (RCTs) to compare the effects of CRT-P versus OMT, undertaken nearly 20 years ago. Since then, numerous, relevant meta-analyses have been published, 4-7 but a unique aspect of this study is the comparison of CRT-P with 'no device' rather than an implantable cardioverter defibrillator (ICD). First, it confirms the prognostic benefit of CRT, both in terms of prolonging survival and reducing HF hospitalizations. Second, according to our interpretation, the confidence for a benefit of CRT is greater in QRS durations >150 ms than QRS durations <150 ms. Third, the

Effect of Spironolactone on QRS Duration in Patients at Risk for Heart Failure (from the HOMAGE Trial)

“…Dyssynchrony causes impairment of global cardiac function and adversely affects prognosis in patients with heart failure (HF) and a dilated left ventricle, which might be improved by cardiac resynchronisation therapy. [2][3][4][5][6][7][8] For patients with heart failure and a preserved ejection fraction (HFpEF), there is a linear relation between increasing QRS and worsening prognosis. 3 However, little is known about the impact of pharmacologic therapies on QRS duration, particularly for patients with pre-symptomatic HF with a preserved LV ejection fraction (i.e., stage B HFpEF).…”