Introduction

The addition of implantable cardioverter defibrillators (ICDs) to standard medical therapy has been shown to decrease mortality in patients with ischaemic cardiomyopathy with a low ejection fraction (LVEF).1 In contrast, studies investigating the use of ICDs in dilated non-ischaemic cardiomyopathy showed conflicting results. The Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION) study showed a decrease in mortality rate, while the Cardiomyopathy Trial (CAT) and Amiodarone Versus Implantable Defibrillator (AMIOVIRT) trial did not find any difference between the intervention and control groups.2–4 The results of a 2016 large randomised controlled trial (RCT) (the Danish Study to Assess the Efficacy of ICDs in Patients with Non-ischemic Systolic Heart Failure on Mortality (DANISH)) showed that the use of ICDs in dilated non-ischaemic cardiomyopathy does not decrease all-cause mortality, challenging the recommendations of the American College of Cardiology and the European Society of Cardiology guidelines.3

Several systematic reviews have addressed this topic since the publication of the DANISH trial; however, none of them used the Cochrane methodology nor studied the cost-effectiveness of ICD therapy and its impact on adverse events and quality of life. We therefore conducted a Cochrane systematic review to assess the benefits and harms of using versus not using ICD in addition to medical therapy in patients with dilated non-ischaemic cardiomyopathy.4 A Permission toco-publish an abridged version of a Cochrane Review in Heart was obtained (online supplementary appendix 1). We also studied the effect of ICDs on adverse events and quality of life, and the cost-effectiveness of this intervention. We reported and analysed …