Extravascular implantable cardioverter-defibrillators (ICDs) can be safely implanted, according to a study published in the New England Journal of Medicine. Paul Friedman, MD, and colleagues conducted a prospective, single-group, nonrandomized premarket global clinical study involving patients (N=356) with a class I or IIa indication for an ICD who received an extravascular ICD. Successful defibrillation at implantation was the primary efficacy endpoint, and the primary safety endpoint was freedom from major system- or procedure-related complications at 6 months. Among those for whom ventricular arrhythmia could be induced and the defibrillation testing protocol was completed, 98.7% had successful defibrillation. Overall, 94.6% of 316 patients were discharged with a working ICD system. At 6 months, 92.6% of patients were free from major system- or procedure-related complications. There were no reports of major intraprocedural complications, although 25 major complications were observed in 23 of 316 patients at 6 months. The success rate of anti-tachycardia pacing was 50.8%.