Intensive recreational athletes in the prospective multinational ICD Sports Safety Registry: Results from the European cohort

In the ICD Sports Safety Registry, death, arrhythmia- or shock-related physical injury did not occur in athletes who continue competitive sports after implantable cardioverter-defibrillator (ICD) implantation. However, data from non-competitive ICD recipients is lacking. This report describes arrhythmic events and lead performance in intensive recreational athletes with ICDs enrolled in the European recreational arm of the Registry, and compares their outcome with those of the competitive athletes in the Registry. The Registry recruited 317 competitive athletes？≥？18 years old, receiving an ICD for primary or secondary prevention (234 US; 83 non-US). In Europe, Israel and Australia only, an additional cohort of 80 ‘auto-competitive’ recreational athletes was also included, engaged in intense physical activity on a regular basis (≥2×/week and/or？≥？2？h/week) with the explicit aim to improve their physical performance limits. Athletes were followed for a median of 44 and 49 months, respectively. ICD shock data and clinical outcomes were adjudicated by three electrophysiologists. Compared with competitive athletes, recreational athletes were older (median 44 vs. 37 years; p？=？0.0004), more frequently men (79% vs. 68%; p？=？0.06), with less idiopathic ventricular fibrillation or catecholaminergic polymorphic ventricular tachycardia (1.3% vs. 15.4%), less congenital heart disease (1.3% vs. 6.9%) and more arrhythmogenic right ventricular cardiomyopathy (23.8% vs. 13.6%) (p？<？0.001). They more often had a prophylactic ICD implant (51.4% vs. 26.9%; p？<？0.0001) or were given a beta-blocker (95% vs. 65%; p？<？0.0001). Left ventricular ejection fraction, ICD rate cut-off and time from implant were similar. Recreational athletes performed fewer hours of sports per week (median 4.5 vs. 6？h; p？=？0.0004) and fewer participated in sports with burst-performances (vs. endurance) as their main sports: 4% vs. 65% (p？<？0.0001). None of the athletes in either group died, required external resuscitation or was injured due to arrhythmia or shock. Freedom from definite or probable lead malfunction was similar (5-year 97% vs. 96%; 10-year 93% vs. 91%). Recreational athletes received fewer total shocks (13.8% vs. 26.5%, p？=？0.01) due to fewer inappropriate shocks (2.5% vs. 12%; p？=？0.01). The proportion receiving appropriate shocks was similar (12.5% vs. 15.5%, p？=？0.51). Recreational athletes received fewer total (6.3% vs. 20.2%; p？=？0.003), appropriate (3.8% vs. 11.4%; p？=？0.06) and inappropriate (2.5% vs. 9.5%; p？=？0.04) shocks during physical activity. Ventricular