Sex-Based Differences in Early Outcomes Following Mitral Valve Surgery for Degenerative Disease

OBJECTIVES: To determine whether sex-based differences exist following surgery for degenerative mitral valve disease. METHODS: Using a national database, we analysed data on mitral valve surgery for degenerative disease (n = 22,658) between January 2000 and March 2019 in the UK. We split the cohort into men (n = 14,681) and women (n = 7977) and compared background characteristics, intraoperative variables and early postoperative outcomes. Our primary outcome was hospital mortality; secondary outcomes included re-exploration for bleeding, prolonged admission (>10 days) and mitral replacement. We used binary logistic regression models for all outcomes, with multiplicative interaction terms to determine the nature of any differences. RESULTS: Women presented older (70 ± 11 years vs. 67 ± 11 years, p < 0.001) with worse symptom profiles (New York Heart Association Class III-IV 57% vs. 44%, p < 0.001). They had higher rates of preoperative atrial fibrillation (39% vs. 35%, p < 0.001) and tricuspid disease requiring surgery (21% vs. 15%, p < 0.001). They had lower repair rates (66% vs. 76%, p < 0.001), higher mortality (3% vs. 2%, p < 0.001) and were more likely to have a prolonged admission (48% vs. 40%, p < 0.001). Female sex was an independent predictor of mortality (odds ratio (OR): 1.52, 95% CI: 1.21-1.90, p < 0.001). Age and Canadian Cardiovascular Society (CCS) score showed significant interactions with sex. The relationship between advancing age and mortality was found to be more pronounced in women. CONCLUSIONS: (1) Female sex is an independent predictor of hospital mortality, prolonged hospital admission and mitral valve replacement. (2) The relationship between female sex and mortality is exacerbated by worsening CCS score and advancing age. (3) Women have significantly lower repair rates.