Mechanical Versus Biological Aortic Valve Replacement in Patients Aged 50-70 Years: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis evaluated outcomes after aortic valve replacement in patients aged 50 to 70 years, including 30 studies and more than 120,000 patients.  The findings indicated that mechanical valves were associated with improved long-term survival (approximately 12 percent relative reduction in mortality) compared with bioprosthetic valves. Stroke rates were similar between the groups. However, mechanical valves had a significantly higher risk of major bleeding, reflecting the need for lifelong anticoagulation, while bioprosthetic valves were associated with substantially higher reoperation rates due to structural valve degeneration.  The evidence base was predominantly observational, with only one randomized trial, limiting causal inference. Despite this, international practice is shifting toward increased use of bioprosthetic valves in this age group, likely driven by patient preference and evolving transcatheter options, but without robust long-term randomized evidence to support this trend.