Subcutaneous Implantable Cardioverter-Defibrillator Therapy in Women

BACKGROUND The subcutaneous implantable cardioverter-defibrillator (S-ICD) is an established therapy for sudden cardiac death prevention, but sex-specific outcomes remain incompletely characterized. OBJECTIVES This study evaluated sex-related differences in baseline characteristics, appropriate shocks, complications, reinterventions, and mortality among S-ICD recipients. METHODS The nationwide HONEST (S-ICD French Cohort Study) cohort enrolled all patients who received an S-ICD in France between 2012 and 2019. Clinical endpoints were centrally adjudicated. Sex-specific associations with outcomes were assessed by using propensity score-based inverse probability weighting. RESULTS Among 4,924 S-ICD recipients, 1,148 were women (23.3%). Compared with men, women were younger (47.3 ± 15.6 years vs 50.6 ± 14.7 years; P < 0.001), less frequently received an implant for primary prevention (57.6% vs 65.1%; P < 0.001), less often had coronary artery disease (38.9% vs 56.5%; P < 0.001), and more often had electrical heart disease (26.3% vs 20.4%; P < 0.001). After adjustment, women had a lower 5-year risk of appropriate shocks (HR: 0.85; 95% CI: 0.74-0.98; P = 0.023) and similar overall complication and reintervention rates but a distinct complication profile, with higher risks of chronic pain (HR: 2.63; 95% CI: 1.61-4.29; P < 0.001) and lead dislodgment (HR: 1.79; 95% CI: 1.09-2.95; P = 0.022) and a lower risk of inappropriate shocks (HR: 0.64; 95% CI: 0.50-0.82; P < 0.001). All-cause mortality was lower in women, whereas S-ICD-unresponsive sudden death and device-related mortality were similar. CONCLUSIONS Women receiving an S-ICD experienced fewer appropriate shocks, with similar overall complication and reintervention rates, but a distinct complication profile. These findings support sex-informed S-ICD selection and follow-up. (S-ICD French Cohort Study [HONEST]; NCT05302115).