Twenty-year single-center experience with the medtronic open pivot mechanical heart valve

Since May 1992 the Medtronic Open Pivot mechanical heart valve has been implanted routinely at the authors' institution. The study aim was to analyze, retrospectively, the 20-year clinical results of the valve.

Between May 1992 and December 2011 a total of 1,520 valves was inserted into 1,382 consecutive patients (1,012 aortic, 473 mitral, 26 tricuspid, 9 pulmonary). The mean age of the patients was 61±13.2 years. Preoperatively, 65% of the patients were in New York Heart Association (NYHA) class III or greater. Frequent comorbidities included atrial fibrillation (n=419), coronary disease (n=357), and diabetes (n=255). The 99% complete follow-up totaled 10,527 patient-years (range 12 to 244 months).

Ninety-day mortality was 5.2% (n=73, 8 valve related). Of the 550 total deaths, 240 were cardiac and 56 valve related. Multivariate analysis selected age, NYHA III or greater, concomitant coronary revascularization, and respiratory insufficiency as risk factors for death. Renal failure was considered a risk factor in the aortic and atrial fibrillation in the mitral subgroup. Erratic international normalized ratio (INR), NYHA class III or greater, and non-sinus rhythm were risk factors for thromboembolism; likewise redo operations in the aortic subgroup. Erratic INR and age were risk factors for bleeding as were over-coagulation and coronary revascularization in the aortic subgroup and redo operations and renal failure in mitral patients.

This 20-year experience demonstrated excellent clinical outcomes with no structural valve failure. Odds ratio defined aortic patients as the lowest risk for adverse events. By contrast atrial fibrillation and elderly age, in combination with instable anticoagulation, yielded the worst long-term results.