IntErnationaL eLeCTRicAl storm registry (ELECTRA): Background, rationale, study design, and expected results

Electrical storm (ES) is defined as three or more episodes of ventricular fibrillation (VF) or ventricular tachycardia (VT) within 24 h and is associated with an increased cardiac and all-cause mortality. ES is a full arrhythmic emergency, its prevalence steadily increasing along with the number of implantable cardioverter-defibrillator implanted every year in developed countries. Nowadays, little evidence exists regarding clinical predictors of ES and their potential association on mortality and heart failure (HF), nor optimal pharmacological and non-pharmacological treatment has ever been codified. The intErnationaL eLeCTRicAl storm registry (ELECTRA) is a multicentre, observational, prospective clinical study with two major aims. First, to create an international database on ES encompassing clinical features, pharmacological management, and interventional treatment strategies. Second, to describe mortality and rehospitalization rates in patients with ES over a long follow-up. The primary endpoint is all-cause mortality 3 years after the ES index event. The main secondary endpoint is hospitalization for all causes 3 years after the ES index event. Other secondary endpoints includes ES recurrences, unclustered VTs/VFs recurrences, and hospitalizations for HF worsening. A minimum of 500 patients will be included in the registry, and all patients will be followed-up for a minimum of three years. The present paper describes the background and current rationale of the ELECTRA study and details the study design, from enrolment strategy to data collection methods to planned data analysis. A brief overview of the expected results and their potential clinical and research implications will also be presented (NCT02882139).