The Mitroflow bioprosthesis. Results after 6 years

: From March 1982 through December 1986, 139 Mitroflow pericardial heart valves were utilized in 129 patients. There were 69 males and 60 females, with an average age of 55.2 years (range 26 to 74 years). Eighty-nine patients underwent isolated aortic valve replacement, 27 isolated mitral valve replacement, three isolated tricuspid valve replacement and ten mitral-aortic valve replacement. In 20.9% additional cardiac surgery was performed. Maximum follow-up was 6 years with a mean of 43.9 months. The cumulative follow-up was 491 patients/year. Overall hospital mortality was 1.6% (2 cases). There were 3 late deaths in this series (2.4%). The linearized incidence of late mortality was 0.49% per patient/year. The survival actuarial curve was 96% +/- 1.8. The incidence of thromboembolism was 1.22% per patient/year, and the actuarial thromboembolism-free rate was 93% +/- 2.7. Three patients developed primary tissue failure of the Mitroflow valve in the mitral position. The linearized incidence of primary tissue failure was 0.73% per patient-year and the actuarial freedom from primary tissue failure was 95% +/- 3.2%. A total of 4 patients underwent reoperation (0.49% per patient/year). In conclusion, the clinical performance of the Mitroflow pericardial heart valve at medium-term follow-up is satisfactory; however a significant number of early primary tissue failures have already occurred in the mitral position.