Safety and Efficacy of Subcutaneous Cardioverter Defibrillator in Patients at High Risk of Sudden Cardiac Death　― Primary Japanese Experience

• Published in: Circulation Journal Vol. 82; no. 6; pp. 1546 - 1551
• Main Authors: Sasaki, Shingo, Tomita, Hirofumi, Tsurugi, Takuo, Ishida, Yuji, Shoji, Yoshihiro, Nishizaki, Kimitaka, Kinjo, Takahiko, Endo, Tomohide, Nishizaki, Fumie, Hanada, Kenji, Sasaki, Kenichi, Horiuchi, Daisuke, Kimura, Masaomi, Higuma, Takumi, Okamatsu, Hideharu, Tanaka, Yasuaki, Koyama, Junjiroh, Okumura, Ken
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Circulation Society 25.05.2018
• Subjects: Subcutaneous cardioverter defibrillator; Sudden cardiac death; Transvenous implantable cardioverter defibrillator; Sudden cardiac death; Subcutaneous cardioverter defibrillator; Transvenous implantable cardioverter defibrillator
• ISSN: 1346-9843; 1347-4820
• DOI: 10.1253/circj.CJ-17-1001

Background:The entirely subcutaneous implantable cardioverter defibrillator (S-ICD) was introduced as a new alternative to conventional transvenous ICD (TV-ICD) in Japan in February 2016, but its safety and efficacy are unclear.Methods and Results:A total of 60 patients (48 men, median age, 60 years; IQR, 44–67 years; primary prevention, n=24) underwent S-ICD implantation between February 2016 and August 2017. The device pocket was formed in the intermuscular space between the serratus anterior muscle and the latissimus dorsi muscle, and the parasternal S-ICD lead was placed according to pre-implant screening. Defibrillation test was performed in 56 patients (93%). Ventricular fibrillation (VF) was induced in 55 patients and terminated by a single 65-J shock in all patients. The median time to shock therapy was 13.4 s (IQR, 12.1–14.9 s) and the median post-shock impedance of the S-ICD lead was 64 Ω (IQR, 58–77 Ω). There were no operation-related complications or subsequent infectious complications. During follow-up (median, 275 days; IQR, 107–421 days), 1 patient (1.7%) had appropriate shock for VF with successful termination, whereas 5 patients (8.3%) had inappropriate shock due to oversensing of myopotential (n=3) or T-wave (n=1), and detection of supraventricular tachycardia (n=1).Conclusions:S-ICD is a safe and effective alternative to conventional TV-ICD. The long-term safety and efficacy of the S-ICD need further investigation.