In survivors of SCA because of a reversible and correctable cause, ICD therapy is associated with lower all-cause mortality except if the SCA was because of myocardial infarction. These data deserve further investigation in a prospective multicenter randomized controlled trial, as they may have important and immediate clinical implications.

In this large, outpatient cohort, we have shown that sex differences in ICD therapy continue to exist, but the difference in ICD prevalence by race was attenuated. Dedicated studies are required to fully understand the causes of persistent sex differences in ICD therapy.

Background: Implantable cardioverter-defibrillators (ICDs) are indicated in patients with left ventricular ejection fraction ≤35%, but many eligible patients do not receive this therapy. In this cluster randomized trial, we investigated the impact of a best practice alert (BPA) through the electronic health records on the rates of electrophysiology referrals, ICD implantations, and all-cause mortality in severe cardiomyopathy patients. Methods and Results: Providers in the Heart and Vascular Institute (n=106) and in General Internal Medicine (n=89) were randomized to receive or not receive a BPA recommending consideration for ICD implantation. Patients belonging to the BPA and no BPA groups of providers were followed to the end points of electrophysiology referrals, ICD implantations, and all-cause mortality. Between 2013 and 2015, patients with reduced left ventricular ejection fraction were managed by 93 providers in the BPA (n=997 patients) and 102 providers in the no BPA (n=909 patients) groups. Patients in the 2 groups had comparable baseline characteristics. After a median follow-up of 36 months, 638 (33%) patients were referred to electrophysiology, 536 (27%) received an ICD, and 445 (23%) died. Patients in the BPA group were more likely to be referred to electrophysiology (hazard ratio=1.23; P =0.026), to receive ICD therapy (hazard ratio=1.35; P =0.006), and exhibited a trend towards slightly lower mortality (hazard ratio=0.85; P =0.091). Conclusions: Delivering a BPA through the electronic health record recommending to providers consideration of ICD implantation when the left ventricular ejection fraction is ≤35% improves the rates of electrophysiology referrals and ICD therapy in patients with severe left ventricular dysfunction.