Sex-Based Differences in Long-Term Outcomes Following Intravascular Brachytherapy for In-Stent Restenosis

Background In-stent restenosis (ISR) remains a challenging complication following percutaneous coronary intervention, and intravascular brachytherapy (IVBT) has proved to be an important treatment strategy. However, limited data exist on sex-specific outcomes following IVBT. Methods This retrospective, single-center cohort study included 223 patients (61 women, 162 men) treated with IVBT for ISR between 2014 and 2023. The primary end points were all-cause mortality, target lesion revascularization, and major adverse cardiovascular events. Secondary outcomes included technical success, myocardial infarction, cardiac death, and heart failure hospitalization. Multivariable Cox regression was used to adjust for clinical and procedural covariates. Results Baseline characteristics were largely similar between sexes, except for higher body surface area and diabetes prevalence in men. Procedural success rates did not differ between groups. However, female sex was independently associated with a higher risk of target lesion revascularization (adjusted HR, 1.80; 95% CI, 1.07-3.01; P = .026) and major adverse cardiovascular events (adjusted HR, 1.63; 95% CI, 1.09-2.45; P = .017). Women also had a higher risk of myocardial infarction (adjusted HR, 2.58; 95% CI, 1.29-5.19; P = .008), whereas no significant sex-based differences were observed for all-cause mortality or heart failure hospitalization. Conclusions Despite comparable procedural outcomes, women undergoing IVBT for ISR experienced higher rates of adverse cardiovascular events. These findings underscore the need for sex-stratified risk assessment and further prospective research to understand and address sex-based differences in outcomes after IVBT.