Sex Difference in 5-year Relative Survival Following Percutaneous Coronary Intervention

Background: Survival rates following percutaneous coronary intervention (PCI) show variability across studies, particularly regarding sex-specific outcomes. Relative survival analysis, which considers survival patterns in sex-and age-matched general populations, could help explain this variability. Methods: In a 2011 nationwide South Korean PCI cohort study with 48,783 patients, all-cause death was assessed as the primary outcome over 5 years. Observed and relative survival rates at 5 years conditional on surviving 0 days, 30 days, 1 year, and 2 years were assessed. Sex-specific differences in clinical characteristics were adjusted using propensity score-matching. Results: In the unadjusted analyses, 15,710 females had more cardiovascular risk factors than 33,073 males. Both observed survival (HR 1.28; 95% CI [1.22-1.34]) and relative survival (HR 1.21; 95% CI [1.16-1.27]) were lower in females than males (all p<0.001). In the analyses of 14,454 matched pairs, females showed higher observed survival (HR 0.78; 95% CI [0.74-0.82]), but lower relative survival (HR 1.19; 95% CI [1.13-1.26]), compared to males (all p<0.001). This trend was particularly notable in females aged 60 years or older. These findings persisted in analyses conditional on surviving 30 days, 1 year and 2 years. Conclusion: The adjusted 5-year relative survival of older females was lower than that of age-matched males, highlighting the need for the excessive risk reduction in older females undergoing PCI.