Abstract Body (Do not enter title and authors here): Introduction: Previous research has found that women have higher mortality after cardiac surgery compared to men. However, research on the impact of sex on clinical outcomes after aortic valve replacement is sparse. In addition, loss of life expectancy or net-survival measures should be used to adjust for the difference in general population life expectancy when examining sex differences. The aim of this study was to analyze clinical long-term outcomes in men versus women after surgical aortic valve replacement.

Material and Methods: This observational, nationwide cohort study included all adult patients who underwent surgical aortic valve replacement between 1997 and 2022 in Sweden. Regression standardization was used to account for baseline differences. Flexible parametric survival models were used to estimate loss of life expectancy and net mortality, net mortality being a metric which can be interpreted as if the population under study could only die of the cause of interest. The primary outcome was all-cause mortality and loss of life expectancy, and secondary outcomes were aortic valve reintervention and heart failure hospitalization.

Results: In total, 38,342 patients (men: 25,253, women: 13,109) were included. The mean age was 68 years and 34% of the patients were women. After adjusting for baseline characteristics, male patients had a higher mortality than female patients (cumulative incidence difference at 15 years: 7.1%, 95% CI 6.1%–8.1%). The loss of life expectancy was higher in women, where the largest loss-in-life-expectancy was observed in 50-year old women operated year 2002 (12.1 years, 95% CI 10.1–14.1 years). There was a higher regression standardized cumulative incidence of net-mortality in men at 15 years compared to women (difference 2.3%, 95% CI: 0.4% to 4.1%). At 15 years, there was no difference in the cumulative incidence of reintervention (0.6%, 95% CI -0.2–1.4%) or heart failure hospitalization (-1.1%, 95% CI -2.2–0.1%) between men and women.

Conclusions: Men had a higher long-term all-cause mortality after aortic valve replacement than women. However, women had a higher loss of life expectancy compared to men. The difference in loss of life expectancy between the sexes decreased during the study period. After multivariable adjustment, men had a higher net-mortality compared to women. No differences were found in reintervention or heart failure hospitalization between the sexes.