Retrospective Observational Analysis of Outcomes After Surgical Valve Replacement: A 15 Years' Experience in a Tertiary Care Hospital

Background: None of the currently available prosthetic valves are comparable to native valves in hemodynamic functions. One has to choose between durability, thrombogenicity, or risk of major bleeds. These questions can be answered effectively with the help of long-term follow-up data. Aims and Objectives: We aimed to assess primary and secondary outcomes in patients who had undergone valve replacement (bioprosthetic or mechanical) over the last 15 years at our institution. Materials and Methods: Retrospective data on clinical outcomes of all patients of valve replacement surgery over the last 15 years was taken. Standardized definitions were used to report primary and secondary outcomes, and appropriate statistical methods were applied to evaluate the data. Results: There were a total of 681 patients (66.7% mechanical and 33.3% bioprosthetic valves) with a median follow-up of 7.5 years. Overall survival rates for bioprosthetic valves for 1,5, and 10 years were 99% and for mechanical valves were 98% and 96% at 5 years and 10 years respectively. Late mortality predictors in the mechanical valve group were pre-operative New York Heart Association (NYHA) class, left ventricular (LV) systolic function, atrial fibrillation, post-operative sub-therapeutic international normalized ratio (INR) values and valve replacement at mitral position. Conclusion: The study showed that mechanical valves had a 96 % survival rate at 10 to 15 years which was dependent upon preoperative NYHA class, preoperative LV functions AF, and postoperative INR values. In contrast, bioprosthetic valves had 99% survival but with a higher incidence of secondary outcomes, mainly in the form of structural valve degeneration.