Comparison of mid-to-long term outcomes between mitral valve repair and biological valve replacement in patients over 60 with rheumatic mitral valve disease based on a propensity score matching study

Abstract

Objective: To compare and discuss the mid-to-long-term outcomes of mitral valve repair (MVP) versus biological mitral valve replacement (bMVR) in patients over 60 years old with rheumatic mitral valve disease. Methods: This is a retrospective cohort study. A total of 765 patients aged 60 years and older, diagnosed with rheumatic mitral valve disease and who underwent MVP or bMVR at Beijing Anzhen Hospital from January 2010 to January 2023, were retrospectively included. Among them, 186 were male and 579 were female, with an age of (66.1±4.5) years (range: 60 to 82 years). Patients were divided into two groups based on the surgical method: the mitral valve repair group (MVP group, n=256) and the bioprosthetic mitral valve replacement group (bMVR group, n=509). A 1∶1 propensity score matching was performed using a caliper value of 0.2 based on preoperative data. Paired sample t-tests, χ² tests, or Fisher's exact tests were used for intergroup comparisons. Kaplan-Meier method was employed to plot survival curves and valve-related reoperation rate curves for both groups before and after matching, and Log-rank tests were used to compare the mid-to long-term survival rates and valve-related reoperation rates between the two groups. Results: A total of 765 patients who completed follow-up were ultimately included, with a follow-up period (M(IQR)) of 5.1(5.0) years (range: 1.0 to 12.9 years). After matching, each group consisted of 256 patients. The incidence of early postoperative atrial fibrillation (39.1% vs. 49.2%, χ2=4.95, P=0.026) and early mortality rates (2.0% vs. 6.2%, χ2=4.97, P=0.026) were lower in the MVP group. Unadjusted Kaplan-Meier analysis showed significantly higher 5-year and 10-year survival rates for the MVP group (92.54% vs. 83.02%, 86.22% vs. 70.19%, Log-rank P=0.001). After adjustment with propensity scores, the Kaplan-Meier analysis still indicated higher 5-year and 10-year survival rates in the MVP group compared to the bMVR group (92.54% vs. 85.89%, 86.22% vs. 74.83%, Log-rank P=0.024). There were no significant differences in the rates of valve-related reoperation between the two groups before and after matching (5-year and 10-year reoperation rates pre-matching: 1.75% vs. 0.57%, 5.39% vs. 7.54%, Log-rank P=0.207; post-matching: 1.75% vs. 0%, 5.39% vs. 9.27%, Log-rank P=0.157). Conclusion: For patients over 60 with rheumatic mitral valve disease, mitral valve repair offers better mid-to-long-term survival compared to biological valve replacement.