Context

The implantable cardioverter defibrillator (ICD) is a life-saving therapy in patients with systolic heart failure. This benefit was first demonstrated by randomised clinical trials that enrolled outpatients who had well-controlled heart failure. Therefore, when those trials were published, it was not clear whether the results would apply to patients seen in clinical practice who might be older and sicker. Consequently, several studies reported on the outcomes of the ICD in clinical practice with one study showing no significant difference in survival between clinical trial ICD patients and a similar group of clinical practice ICD patients.1 The analysis by Chen …