Readmission after coronary artery bypass surgery in women and men.

OBJECTIVES: Readmissions after coronary artery bypass grafting (CABG) are common and contribute substantially to long-term morbidity, yet extended follow-up data remain limited. Women experience higher perioperative morbidity, mortality, and short-term readmission rates than men, but long-term sex-specific patterns of readmission after CABG are poorly defined. METHODS: Nationwide data for patients undergoing CABG between 2015 and 2021 from the Austrian Cardiac Surgery Registry were linked to the federal social insurance claims database to assess long-term cardiovascular (CV) and all-cause readmission. Cumulative incidence functions accounting for the competing risk of death and cause-specific Cox proportional hazards models were used. RESULTS: A total of 12,169 patients (2,192 [18%] women) were included. Cumulative incidences of CV readmission were higher in women than in men at 1 year (19.1% vs. 17.3%), 4 years (37.8% vs. 34.9%), and 6 years (46.9% vs 43.4%) (p = 0.003). All-cause readmission showed a similar pattern at 1 year (42.2% vs. 37.6%), 4 years (69.6% vs. 66.7%), and 6 years (79.1% vs 75.9%) (p = 0.0004). Female sex was not independently associated with CV (HR 1.01, 95% CI 0.94-1.10, p = 0.73) or all-cause readmission (HR 0.99, 95% CI 0.94-1.05, p = 0.74). Earlier readmission correlated with earlier CV (ρ = 0.36, 95% CI 0.28-0.44) and all-cause death (ρ = 0.39, 95% CI 0.34-0.43). CONCLUSIONS: Women experienced higher unadjusted cumulative incidences of readmission. Long-term readmission after CABG is driven primarily by clinical risk rather than biological sex, underscoring the need for targeted management of high-risk comorbidities.