Mitroflow pericardial valve prosthesis in the aortic position: an analysis of long-term outcome and prognostic factors.

ABSTRACT

BACKGROUND AND AIM OF THE STUDY Pericardial valves combine optimal hemodynamic properties with limited durability. To describe the long-term performance of Mitroflow pericardial valves in the aortic position, outcome and risk factors up to 12 years after implantation were analyzed. METHODS: A retrospective study, based on follow up of 1,029 patients who received 1,044 Mitroflow pericardial valves in the aortic position between February 1985 and December 1996, was performed. Follow up was 98.2% complete. Average follow up was 3.79 years. Mean patient age was 75.2+/-6.5 years (range 27.9-90.9 years). At surgery, 86.3% of patients were aged over 70 years. Among patients, 482 (46.8%) had concomitant operations. RESULTS: Results (+/- SE) are given for evident and possible (in parentheses) valve-related events; the latter included all reported postoperative strokes and sudden deaths. Actuarial event-free rates after 5 and 10 years respectively were structural valve deterioration 99.2+/-0.5% and 77.6+/-4.4%; non-structural valve deterioration 99.7+/-0.2% and 99.7+/-1.2%; valve-related complications 95.7+/-0.9% and 73.5+/-4.0% (5 years 90.1+/-1.2%, 10 years 57.0+/-4.3%); endocarditis 96.6+/-0.8% and 92.6+/-1.6%; explantation 98.6+/-0.5% and 80.1+/-3.9%; cerebrovascular accident 95.2+/-0.9% and 82.5+/-3.5%; embolism 99.9+/-0.1% and 99.9+/-0.5%; bleeding 99.8+/-0.2% and 99.8+/-1.3%; overall mortality 69.9+/-1.8% and 35.3+/-3.0%; valve-related death 97.5 +/-1.1% and 95.1+/-4.2% (5 years 91.9+/-1.4%, 10 years 76.1+/-3.2%). The 30-day mortality rate was 4.1%. Patients aged 70 years or more with valve diameters of < or =23 mm showed 10-year freedom rates of 85.8+/-4.6% for structural valve degeneration and 95.1+/-1.2% for evident valve-related death. The detailed risk factor analysis showed results that were in accordance with clinical experience. CONCLUSION: Long-term results with Mitroflow pericardial valves in the aortic position compare well with those for other widely used bioprostheses, especially in patients aged > or =70 years and with small aortic root diameters (< or =23 mm).