Aortic valve replacement with mechanical vs. biological prostheses in patients aged 50-69 years

Aims The objective was to investigate the long-term all-cause mortality in patients aged 50-69 years after aortic valve replacement (AVR) with bioprosthetic or mechanical valves. Methods and results All patients aged 50-69 years who had undergone AVR in Sweden 1997-2013 were identified from the Swedish Websystem for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies register. Subsequent patient-level record linkage with national health-data registers provided patient characteristics, vital status, and clinical outcomes. Of the 4545 patients, 60% (2713/4545) had received mechanical valves and 40% (1832/4545) bioprostheses. In 1099 propensity score-matched patient pairs, 16% (180/1099) had died in the mechanical valve group and 20% (217/1099) in the bioprosthetic group; mean follow-up 6.6 (maximum 17.2) years. Survival was higher in the mechanical than in the bioprosthetic group: 5-, 10-, and 15-year survival 92, 79, and 59% vs. 89, 75, and 50%; hazard ratio 1.34; 95% confidence interval (CI) 1.09-1.66; P = 0.006. There was no difference in stroke [subdistribution hazard ratio (sHR) 1.04; 95% CI 0.72-1.50, P = 0.848]; however, the risk for aortic valve reoperation was higher (sHR 2.36; 95% CI 1.42-3.94, P = 0.001), and for major bleeding lower (sHR 0.49; 95% CI 0.34-0.70, P, 0.001), in patients who had received bioprostheses than in those with mechanical valves. Conclusion Patients aged 50-69 years who received mechanical valves had better long-term survival after AVR than those with bioprostheses. The risk of stroke was similar; however, patients with bioprostheses had a higher risk of aortic valve reoperation and a lower risk of major bleeding.