Impact of Age on Subcutaneous Implantable Cardioverter-Defibrillator in a Large Patient Cohort

BACKGROUND The subcutaneous implantable cardioverter-defibrillator (S-ICD) is an accepted alternative to trans -venous (TV) ICD to provide defibrillation therapy to treat life-threatening ventricular tachyarrhythmias in high-risk patients. S-ICD outcomes by age group have not been reported.OBJECTIVES In this study, the authors sought to report S-ICD outcomes in different age groups in a multicenter S-ICD post-approval study (PAS) involving the largest cohort of patients ever reported.METHODS Patients were prospectively enrolled in the S-ICD PAS and stratified based on age: young, aged 15-34 years; adult, aged 35-69 years; and elderly, aged $70 years. Patient characteristics and clinical outcomes through 3 years of follow up after implantation were compared.RESULTS The S-ICD PAS enrolled 1,637 patients. Elderly patients were more likely to receive an S-ICD as a replacement of a TV-ICD (15.1% elderly vs 12.3% adult vs 7.4% young). Secondary prevention indication decreased with age (32.7% young vs 22.2% adult vs 20.5% elderly). Mortality rate was significantly higher in the elderly group (24.0% elderly vs 13.0% adult vs 7.4% young; P < 0.0001), whereas the complication rate did not differ significantly (12.3% young vs 11.3% adult vs 8.1% elderly). Rates of appropriate shock (12.7% young vs 13.0% adult vs 13.8% elderly) and inappropriate shock (7.8% young vs 9.1% adult vs 8.8% elderly) rates did not differ between groups (P = 0.96 and P = 0.98, respectively).CONCLUSIONS Implant complications and appropriate and inappropriate shock rates were similar among age groups. S-ICD for secondary prevention was more common in the young group. Replacing a TV-ICD for an S-ICD increases with age. (S-ICD System Post-Approval Study; NCT01736618)(c) 2023 by the American College of Cardiology Foundation.

Automated summary

This study analyzed S-ICD outcomes in different age groups and found no significant differences in implant complications and rates of appropriate and inappropriate shocks among the groups. Older patients were more likely to receive S-ICD as a replacement for TV-ICD.