Sex-related differences in patient characteristics, practice patterns and outcomes after bioprosthetic and mechanical aortic valve replacement

OBJECTIVES: This study examines sex-based differences in baseline characteristics, practice patterns and mid-term survival following aortic valve replacement (AVR). METHODS: The study design included all consecutive patients from the AVR Registry with a 3-year follow-up. Patients were initially categorized by sex and prosthesis type. The primary end-point was 3-year all-cause mortality. Subgroup observations included the age-recommended threshold for mechanical prosthesis (<65 years) and the patient-prosthesis mismatch (PPM). RESULTS: The present study revealed that females (n = 517) compared to males (n = 732) were significantly older (67.2 ± 9.3 years vs 64.4 ± 12.2 years, P < 0.001), had higher body mass index (2.23 ± 7.2 cm2 vs 2.01 ± 0.2 cm2, P < 0.005) and lower left ventricular ejection fractions (51.8 ± 13.5% vs 57.7 ± 10.8%, P < 0.001) at the time of the index procedure. Additionally, females received significantly more bioprosthetic AVR than males (38.1% vs 32.6%, P = 0.040). There were no significant differences in 3-year mortality risk between males and females (14.6% vs 14.1%, P = 0.87). In subgroup analyses of patients with mechanical prostheses, females experienced a higher incidence of PPM than males (9.6% vs 2.2%, P < 0.001), whereas no significant difference was observed among those who received bioprosthetic valves. The male cohort observed reduced mortality associated with mechanical versus bioprostheses (hazard ratio [HR] 0.54, 95% confidence interval [CI] 0.36-0.81, P = 0.003). This effect was particularly significant in males under 65 (HR 0.27, 95% CI 0.11-0.68, P = 0.005). However, there was no difference in mortality related to prosthesis type in females, regardless of age group. CONCLUSIONS: At the time of referral for AVR, female patients were significantly older and had worse clinical profiles than male patients. Despite the higher rates of bioprosthetic valve implantation and PPM in females, mid-term survival rates were not significantly different. In contrast, males, especially those under 65, showed higher mortality following bioprosthetic AVR. These findings underscore the need for further research focusing on the sex-based treatment determinates in AVR.