Safety and Clinical Outcome of Subcutaneous Implantable Cardioverter‐Defibrillators in an Asian Population: A Prospective Study

Background There is limited data on long‐term safety and efficacy of subcutaneous implantable cardioverter defibrillator (S‐ICD) in Asian patients with a lower body mass index (BMI) due to smaller body build. Methods We performed a 2 year prospective study in 5 Asian cities from May 2017 to May 2018 to investigate the safety and feasibility of S‐ICD for primary or secondary prevention of sudden cardiac death in an Asian population. Results We enrolled 75 S‐ICD recipients (77% males; age 49.6 ± 16.8 years) with a mean BMI of 24.6 ± 5.0 (range 15.9–40.9) with 67% (50/75) with BMI ≤ 23. The indications of S‐ICD were primary and secondary prevention in 26 (35%) and 49 (65%) patients, respectively. Among them, 51 patients suffer from ischemic (30, 59%) or nonischemic (21, 41%) cardiomyopathy, and 25 patients have channelopathies. Their mean left ventricular ejection fraction was 44.4 ± 15.1%. All patients had successful S‐ICD implantation with a mean procedural duration of 75.5 ± 28.1 min using conscious sedation in majority of patients (65/75, 87%); and defibrillation testing was performed in 62 patients (83%). After 2 years of follow‐up, 8 patients developed serious adverse events, including 4 deaths (2 asystole, 1 sepsis, 1 myocardial infarction), 2 ventricular tachycardia storm, 1 pocket infection, and 1 lead failure requiring replacement. Both patients with ventricular tachycardia storm received appropriate shocks, and no patient developed inappropriate shocks. Conclusions S‐ICD implantation for both primary and secondary prevention of sudden cardiac death was found to be safe in an Asian population, including those with a low BMI, and was associated with a low rate of device‐related complications.