Readmission after coronary artery bypass surgery in women and men

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.

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.

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).

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.