Sex-Based Differences in Long-Term Outcomes Following Percutaneous Coronary Intervention for Chronic Total Occlusions

<b>Background/Objectives</b>: Sex-based differences in clinical profiles and outcomes following percutaneous coronary intervention (PCI) for chronic total occlusions (CTO) remain poorly understood. We sought to examine the association between sex and long-term clinical outcomes following CTO-PCI in a contemporary real-world cohort. <b>Methods</b>: We conducted a retrospective study of 928 consecutive patients (788 men, 140 women) undergoing CTO-PCI at a high-volume centre between 2011 and 2024. The primary endpoint was a composite of major adverse cardiac events (MACE: all-cause death, myocardial infarction [MI], or stroke) at a 6-year follow-up. To account for baseline differences, an Inverse Probability of Treatment Weighting (IPTW)-adjusted Cox regression analysis was performed. <b>Results</b>: Women were significantly older (69.7 ± 10 vs. 64.1 ± 10 years; <i>p</i> < 0.001) and had a higher prevalence of diabetes and hypertension. However, women exhibited lower angiographic complexity, with lower J-CTO scores (2 [1-2] vs. 2 [1-3]; <i>p</i> < 0.001) and less frequent severe calcification or tortuosity. Technical and procedural success rates were comparable between sexes (85.4% vs. 86.7%; <i>p</i> = 0.695). Unadjusted MACE rates were higher in women (29.3% vs. 22.1%; hazard ratio (HR) 1.51, 95% CI: 1.08-2.13; <i>p</i> = 0.017). After adjustment, the female sex was no longer associated with the primary endpoint (aHR 1.15, 95% CI: 0.76-1.74; <i>p</i> = 0.517), but the risk of MI remained significantly higher in this group (aHR 2.85, 95% CI: 1.23-6.63; <i>p</i> = 0.015). <b>Conclusions</b>: CTO-PCI appeared to be equally safe and effective in women and men. Over long-term follow-up, although the overall adjusted MACE risk was similar between sexes, the female sex was associated with a higher risk for MI.