Mechanical versus bioprosthetic valve for aortic valve replacement in dialysis patients: Systematic review and individual patient data meta-analysis.

Objective: There is little evidence regarding the most beneficial choice between a mechanical and a bioprosthetic valve in the aortic position in dialysis patients. This meta-analysis compares the survival and freedom from reintervention rates between mechanical and bioprosthetic valves in patients on dialysis undergoing aortic valve replacement surgery.

Methods: Two databases were searched, and the systematic review was performed in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. We conducted one-stage and two-stage meta-analysis with Kaplan-Meier-derived individual patient data and meta-analysis with random-effects model.

Results: Eight studies were included, providing data about 1215 dialysis patients receiving mechanical valves and 1851 patients receiving bioprosthetic valves. During a mean follow-up of 43.1 months, overall survival rates were significantly improved in the mechanical valve group in comparison to the bioprosthetic one (hazard ratio [HR]: 0.76, 95% confidence interval [CI]: 0.69-0.84, p < 0.001). This was confirmed by the two-stage meta-analysis (HR: 0.72, 95% CI: 0.62-0.83, p = 0.00, I² = 17.79%). Regarding freedom from reintervention, no arm offered a statistically significant advantage, according to the two-stage generated analysis (HR: 1.025, 95% CI: 0.65-1.61, p = 0.914). Similarly, there was no evident superiority of a valve type for perioperative outcomes.

Conclusions: Mechanical valves are likely to be associated with a better survival outcome compared to bioprosthetic valves for patients on dialysis undergoing aortic valve replacement. However, freedom from reoperation rates and perioperative outcomes were comparable between the two valve types, with no arm exhibiting a statistically significant advantage.