Long-term outcomes of mechanical versus biological aortic valve prosthesis: Systematic review and meta-analysis

Background: In recent years, the use of surgically implanted biological aortic valves has been favored over mechanical prosthesis in patients between 50 and 70 years of age. However, outcomes on long-term survival are contradictory. The objective of this study was to determine if patients with mechanical valves have worse long-term survival than patients with biological prostheses. Methods: We systematically searched published studies that: (1) were propensity score-matched or randomized controlled trials; (2) provided survival data with a minimum follow-up of 5 years; and (3) included patients older than 50 and younger than 70 years of age. Review articles, case reports, and editorials were excluded. We conducted a meta-analysis on the basis of 2 types of analysis. A reconstruction of the database of each study to simulate a patient-level meta-analysis was performed. Log rank test of Kaplan-Meier curves was recalculated. Hazard ratio (HR) was calculated using a univariate Cox regression. In addition, we calculated a pooled HR using the fixed-effect inverse variance method. Results: Four propensity score-matched studies and 1 randomized controlled trial met the inclusion criteria. Data of 4686 patients were analyzed. Survival rates for mechanical versus biological valves at 10 and 15 years of follow-up were: 76.78% (95% confidence interval [CI], 74.72%-78.69%) versus 74.09% (95% CI, 71.96%-76.08%), and 61.58% (95% CI, 58.29%-64.69%) versus 58.04% (95% CI, 54.57%-61.35%). Log rank test was statistically significant (P = .012) and the pooled HR was 0.86 (95% CI, 0.76-0.97; P = .01). Conclusions: Compared with biological aortic valves, mechanical valves are associated with a long-term survival benefit for patients between 50 and 70 years.