Seventeen-year clinical results of 1,037 Mitroflow pericardial heart valve prostheses in the aortic position.

BACKGROUND AND AIM OF THE STUDY: It is generally believed that the pericardial tissue valve is associated with a greater propensity to early structural failure and subsequent valve-related complications. However, a modified valve design during recent years has considerably improved the clinical durability of this bioprosthesis.

METHODS: Between April 1986 and December 2003, single Mitroflow pericardial valve prostheses were inserted in the aortic position in 1,037 patients (mean age 72.4 +/- 8.4 years). Coronary artery bypass grafting (CABG) was performed in 373 patients (36%). Preoperative echocardiographic findings of structural valve deterioration (SVD) were confirmed at reoperation. Total follow up was 5,022 patient-years (pt-yr) (mean 4.85 +/- 4.7 years) and was 99.7% complete (three patients lost).

RESULTS: Early (30-day) mortality was 2.9% for elective surgery; 434 patients (41.9%) died during the follow up period. Actuarial survival at 17 years was 23.2 +/- 2%. Actuarial freedom from valve-related mortality at 17 years was 92.0 +/- 2.2%, whereas the linearized mortality rate was 0.4%/pt-yr. Linearized valve-related complications occurred at a rate of 3.6%/pt-yr (n = 122). SVD of Mitroflow bioprostheses occurred at a rate of 1.0%/pt-yr, and caused stenosis (36.7%), insufficiency (20.4%) and combined stenosis and insufficiency (42.9%). Actual freedom from SVD at 17 years was 95.3 +/- 0.7% for all patients, 96.2 +/- 0.6% for those aged > 60 years, and 99.0 +/- 0.4% for those aged > 70 years.

CONCLUSION: The Mitroflow pericardial bioprosthesis, in the aortic position, provides an excellent clinical performance and a low rate of valve-related morbidity, mortality and reoperation for up to 17 years. The prosthesis also demonstrates satisfactory hemodynamic performance, and is therefore recommended for patients aged > or = 70 years and for those aged 60-69 years with comorbidities.