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

Abstract

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.