Aortic valve replacement with the Mitroflow pericardial bioprosthesis: Durability results up to 21 years

Objective: The study aim was to analyze the performance profile of a large series of Mitroflow pericardial valves (Sorin Group Canada Inc. Mitroflow Division) in the very long term. Methods: Data from 1513 patients with isolated aortic valve replacement who received pericardial bioprostheses between 1986 and 2007 were analyzed. Cumulative duration of follow-up was 6164 patient-years with a maximum duration of 21 years. Actuarial rates of valve-related events were calculated by the Kaplan-Meier method and the Cox multivariate analysis to identify independent determinants of outcome. Results: Hospital mortality for elective surgery was 2.5%. Late death was 40.6%. Reoperation was required in 86 (5.7%) patients and was valve related in 83: structural valve deterioration in 64 (4.2%) patients, prosthetic valve endocarditis in 17 patients (1.1%), valve thrombosis in 1, and periprosthetic leak in 1. Rates of 20-year actuarial freedom from valve-related morbidity were as follows: structural valve deterioration 84.8% (actual 96.6%) in patients 70 years of age or older; thromboembolism 94.1%; and prosthetic valve endocarditis 96.8%. Twenty-year actual risk of reoperation for structural valve deterioration was 11.4% in all patients and 3.4%, in patients 70 years or age or older. Advanced age, renal insufficiency, pulmonary disease, and low body mass index were independent risk factors for late outcome (P < .001). Conclusions: After 2 decades of follow-up, the Mitroflow pericardial aortic valve continues to be a valve of choice with a predictable low rate of valve-related events, particularly for patients over the age of 65 to 70 years and others with comorbidities.