Medium-term survival of patients with mechanical and biological aortic prosthesis at the 6th decade of life.

Objective: The best aortic prosthesis type in 60-70 year old patients is not established. Our aim was to evaluate the survival in a National cohort of patients between 60-70 years old who required surgical aortic valve replacement for aortic stenosis (SAVR) with either a mechanical (MP) or bioprosthesis (BP) valve.

Methods: This is a retrospective study using national data from the Ministry of Health. We included all patients between 60 to 70 years old who underwent SAVR for aortic stenosis in Uruguay from 2011 to 2021. The primary outcome was overall survival according to type of prosthesis used stratified by effect modifiers. The independent effects of gender and use of statins were evaluated.

Results: We included 1196 patients (66±3.0 years old; 39.1% female). Mortality was higher for BP (296, 29.9%%) than MP (36, 17.1%; p<0.001). Median follow-up time was 4.5 years (Interquartile range [IQR] 3.4-6.5). The unadjusted incidence rate ratio was higher for BP (Incidence rate ratio [IRR] = 1.43;95%CI: 0.99, 2.14, p = 0.045). The effect of BP on mortality rate was greater in males (IRR = 1.82;95%CI:1.14,2.92. p interaction = 0.08) and patients who were not taking statins (IRR = 1.97;95%CI:1.14,3.41. p interaction = 0.06). The use of BP was an independent predictor of overall survival in male patients (Hazard ratio [HR] = 1.32;95%CI: 1.68, 1.04. p = 0.021) and in patients who were not taking statins (HR = 2.07;95%CI: 1.17, 3.67. p = 0.013).

Conclusion: The use of BP was associated with worse survival in male patients and patients not taking statins. Gender and statins use should contribute to type of prosthesis decision in the 60-69 age group.