An ICD implant to detect and alleviate life-threatening arrhythmias in patients with ischaemic and non-ischaemic cardiomyopathologies [25, 26] and cardiac resynchronization therapy [27] both play a fundamental role in the treatment of heart failure—and thus represent a pivotal recommendation in current heart failure guidelines. Remarkably, publication of the DANISH (Danish Study to Assess the Efficacy of ICDs in Patients with Non-ischaemic Systolic Heart Failure on Mortality) trial subsequent to the last European Society of Cardiology guideline recommendation on the treatment of heart failure raised uncertainty about prophylactic ICD implants: device treatment in patients with symptomatic systolic heart failure not caused by coronary heart disease was not associated with a significantly lower long-term rate of death from any cause than was usual clinical care [28]. Basically, the latest guideline recommendations are based mainly on the MADIT-II (Multicentre Automatic Defibrillator Implantation Trial II) [29] and the SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial) [30] trial, which were published more than a decade ago. But pharmacological treatment and coronary revascularization in coronary heart disease have changed fundamentally since these early trials with an impact on mortality and a significant reduction in sudden cardiac deaths [31]. Hence, current recommendations should be critically reappraised and supported by further randomized controlled trials.