15 years outcomes following bioprosthetic versus mechanical aortic valve replacement in patients aged 50–65 years with isolated aortic stenosis

Objectives: To investigate long term survival (15 years) and major morbidity in patients aged 50–65 years undergoing primary isolated aortic valve replacement with bioprosthetic or mechanical valves. Methods: A single center retrospective analytical study of all patients aged 50–65 years with severe aortic stenosis who underwent surgery between 2000 and 2015 was performed (n = 200). Two groups, mechanical (n = 117) and biological (n = 83) were obtained. Propensity score matching was performed for analysis. Primary outcome was survival, secondary outcome was major adverse cardiovascular complications (30-day mortality, stroke, any prosthesis-related reoperation and major bleeding). Results: Mean age was 60 ± 4 years, 33% female, mean follow up was 8.2 ± 3 years (range 0–17 years). Matched overall survival was similar between groups, 65% at 15 years [Log Rank p = 0.71, hazard ratio 0.87 (95% CI, 0.41–1.82)]. After matching, mechanical prosthesis presented a trend toward of more major adverse cardiovascular complications (30% versus 15%, p = 0.07) with more major bleedings (15% versus 6.3%, p = 0.06), stroke 11% versus 7.6% (p = 0.44), and cardiac-related rehospitalization (33.7% versus 21.5%, p = 0.06). Reoperation was nonsignificant between groups (2.5% mechanical versus 6.3% bioprosthesis, with only 2 cases of structural valve degeneration). Follow up mean transprosthetic gradients were higher in the mechanical group (18 ± 6 versus 15 ± 7 mmHg, p = 0.01). Conclusions: Among propensity matched patients there were no differences in survival between groups at 15 years. The mechanical prosthesis presented a trend toward twofold more major adverse cardiovascular complications specially due to major bleeding. Studies with larger sample sizes are needed to confirm these results.