Cardiac resynchronisation for patients with heart failure due to left ventricular systolic dysfunction — a systematic review and meta‐analysis

Abstract

Background: Randomised controlled trials generally suggest that cardiac resynchronisation improves outcomes in patients with heart failure due to left ventricular systolic dysfunction and cardiac dyssynchrony. Our objective was to provide a valid synthesis of the effects of CRT on mortality, major morbidity, quality of life and implantation success rates. Methods: Systematic overview and meta-analysis of randomised trials, both blinded and open, comparing cardiac resynchronisation with control. The primary outcome was all-cause mortality, and secondary outcomes included hospitalisation for worsening heart failure, quality of life and implantation success rates. Results: We identified 8 randomised trials which included 3380 patients and observed a total of 524 deaths. Follow-up ranged from 1 month to a mean of 29.4 months. Most trials were of high quality, with centrally administered randomisation and few patients lost to follow-up. CRT reduced mortality in these trials (odds ratio 0.72, 95% CI 0.59 to 0.88). In addition CRT reduced hospitalisation for worsening heart failure (odds ratio 0.55, 95% CI 0.44 to 0.68) and improved quality of life as measured by the Minnesota Living with Heart Failure Questionnaire (weighted mean difference À7.1, 95% CI À 2.9 to À 11.4). Implantation success rates in the trials were 87% or greater. Conclusion: Cardiac resynchronisation in patients with heart failure characterised by dyssynchrony substantially reduces all-cause mortality, major morbidity and improves quality of life.

Ressincronização ventricular: comparando os marcapassos biventriculares com os marcapassos bifocais de ventrículo direito

“…In this latter study mentioned, mortality reduction occurred in the group of defibrillators associated with resynchronizers. Other large meta-analyses corroborated these findings of reduction in morbidity and mortality, and in mortality alone 16,17 . Some studies have demonstrated that a longer QRS duration is a good predictor of response to resynchronization, like in the subgroups of the CONTAK CD and MIRACLE studies 18 .…”

Can monitoring of intrathoracic impedance reduce morbidity and mortality in patients with chronic heart failure? Rationale and design of the Diagnostic Outcome Trial in Heart Failure (DOT‐HF)☆

“…Moreover, CRT has been demonstrated to improve cardiac function, exercise capacity and quality of life in patients with drug-refractory heart failure and prolonged QRS duration [23,24]. Accordingly, the number of heart failure patients treated with such devices has increased rapidly over recent years and now constitutes a substantial portion of subjects followed at specialized heart failure clinics.…”

Cardiac-Resynchronization Therapy

“…A prolonged QRS has been shown to be a marker for atrioventricular, interventricular, and intraleft ventricular dyssynchronies. 5,6 The net result of these perturbations in the timing of cardiac contraction is decreased pump function.…”