Performance of Mechanical and Biological Mitral Prostheses in Young Rheumatics Aged Below 45 Years

Abstract

Background and Aim: We compared 22-year composites of valve-related reoperation, morbidity, and mortality following mitral mechanical and bioprostheses in young rheumatics aged <45years. Methods: Retrospective comparative analysis of valve-related reoperations and survival data were performed from 466 consecutive propensity matched patients undergoing either bioprosthetic MVR (Group I, n=233) or mechanical MVR (Group II, n=233) between 1998 and 2019. Results: The median age was 33 (IQR: 27-40) and 34 (IQR: 28-39) years for Group I and II respectively. The mean follow-up was 3278.9 patient-years in the biological arm and 3384.4 patient-years in mechanical arm. Bioprosthetic arm exhibited lesser cumulative mortality (4.5% vs 9.9%, SMD= -0.04, p=0.65). Hazard regression for mortality included (HR, 95% CI) preoperative congestive heart failure (CHF) 11.44 (8.44, 624.9), p<0.0001; renal failure 19.51 (8.04, 47.35), p<0.0001; previous operation 6.84 (2.48, 18.84), p<0.0001; atrial fibrillation (AF) 7.64 (1.02, 57.13), p=0.006; LA clot 61.94 (8.28, 463.08), p<0.0001; giant LA >65 mm 7.87 (2.62, 23.56), p<0.0001; poor left ventricular (LV) function 0.94 (0.92, 0.97), p<0.0001; and prolonged aortic clamp time 1.07 (1.04, 1.11), p<0.0001). Propensity matching did not exhibit any difference in reoperations between bioprostheses and mechanical prostheses (18.8% vs 13.3%, SMD= -0.152, p=0.1). At a median follow-up of 136 (IQR: 76-197) months, actuarial survival was 90.32%±0.02% (p=0.09) and there was no difference between the groups (p=0.09). Conclusions: Bioprostheses are an acceptable alternative to mechanical prostheses in young rheumatics aged <45 years unwilling for mechanical valve, redo surgeries, life-long anticoagulation, and those desirous of pregnancy.