Sex Differences in In-Hospital Mortality After Open Cardiac Valve Surgery

BACKGROUND: Cardiac valvular disease affects millions of people worldwide and is a major cause of morbidity and mortality. Female patients have been shown to experience inferior clinical outcomes after nonvalvular cardiac surgery, but recent data are limited regarding open valve surgical cohorts. The primary objective of our study was to assess whether female sex is associated with increased in-hospital mortality after open cardiac valve operations.

METHODS: Utilizing the Healthcare Cost and Utilization Project (HCUP) State Inpatient Databases (SID), we conducted a retrospective cohort study of patients who underwent open cardiac valve surgery from 2007 to 2018 in Washington, Maryland, Kentucky, and Florida; from 2007 to 2011 in California; and from 2007 to 2016 in New York. The primary objective of this study was to estimate the confounder-adjusted association between sex and in-hospital mortality (as recorded and coded by SID HCUP) after open cardiac valve surgery. We used multilevel multivariable models to account for potential confounders, including intrahospital practice patterns.

RESULTS: A total of 272,954 patients (108,443 women; 39.73% of sample population with mean age of 67.6 ± 14.3 years) were included in our analysis. The overall mortality rates were 3.8% for male patients and 5.1% for female patients. The confounder-adjusted odds ratio (OR) for in-hospital mortality for female patients compared to male patients was 1.41 (95% confidence interval [CI], 1.35-1.47; P < .001). When stratifying by surgical type, female patients were also at increased odds of in-hospital mortality ( P < .001) in populations undergoing aortic valve replacement (adjusted OR [aOR], 1.38; 95% CI, 1.25-1.52); multiple valve surgery (aOR, 1.38; 95% CI, 1.22-1.57); mitral valve replacement (aOR, 1.22; 95% CI, 1.12 - 1.34); and valve surgery with coronary artery bypass grafting (aOR, 1.64; 95% CI, 1.54 - 1.74; all P < .001). Female patients did not have increased odds of in-hospital mortality in populations undergoing mitral valve repair (aOR, 1.26; 95% CI, 0.98 - 1.64; P = .075); aortic valve repair (aOR, 0.87; 95% CI, 0.67 - 1.14; P = .32); or any other single valve repair (aOR, 1.10; 95% CI, 0.82 - 1.46; P = .53).

CONCLUSIONS: We found an association between female patients and increased confounder-adjusted odds of in-hospital mortality after open cardiac valve surgery. More research is needed to better understand and categorize these important outcome differences. Future research should include observational analysis containing granular and complete patient- and surgery-specific data.