Mitroflow heart valve: 5.5 years clinical experience

Mitroflow Pericardial Bioprosthesis: Experience to Seven Years

Between 1983 and 1987, the Mitroflow pericardial prosthesis was implanted in 99 patients, ranging in age from 28 to 94 years (mean 62.8 years). Early mortality was 6.1% (6 patients), and late mortality was 4.8% per patient-year (22 patients). Total cumulative follow-up was 458 patient-years (mean 4.6 years). At 7 years, patient survival was 62% for aortic valve replacement and 63% for mitral valve replacement. The overall rate of valve-related complications was 7.4% per patient-year (34 events): thromboembolism, 2.8%; antithromboembolic-relatedhemorrhage, 1.1%; prosthetic valve endocarditis, 0.7%; non-structural dysfunction, 0.7%; and structural valve deterioration, 2.8%. At 7 years, freedom from thromboembolism was 80.3%, and freedom from prosthetic valve endocarditis was 95.5%. At 5 and 7 years, freedom from structural valve deterioration was 93.4% and 69.7%, respectively. At 5 years, freedom from structural valve deterioration was 97.3% for aortic valve replacement (AVR), 86.6% for mitral valve replacement (MVR), and 100% for multiple valve replacement (MR). At 7 years, freedom from structural valve replacement was 84.6% and 61.3% for AVR and MVR, respectively. At 7 years, overall freedom from reoperation was 68.2%; from valve-related mortality, 81.4%; from valve-related residual morbidity, 97.4%; and from treatment failure (valve-related mortality and residual morbidity), 79.0%. At 7 years, the Mitroflow pericardial bioprosthesis has provided satisfactory clinical performance, especially in the aortic position, with an acceptable freedom from structural valve deterioration.

Mitroflow pericardial valve: long-term durability

Isolated aortic (n = 107), mitral (n = 63), and tricuspid (n = 1) valve replacement and 28 double-valve replacements were performed with a second generation of pericardial valves, the Mitroflow valve, in 199 patients from March 1983 to December 1986. Follow-up (total, 1,058 patient-years) was extended to 106 months and 91.5% complete. Mean age was 58 +/- 13 years. The operative mortality included 22 deaths, non-cardiac-related in 7. The actuarial probability of survival for all patients was 66% +/- 4% at 8.5 years. There were no significant differences between patients with aortic valve replacement, mitral valve replacement, or double-valve replacement. The rate of thromboembolic events, antithromboembolic therapy-related hemorrhage, periprosthetic leak, and endocarditis is extremely minimal. Structural valve dysfunction occurred at a rate of 3.2% +/- 0.5%/patient-year. Actuarial freedom from the event was 94.6% +/- 1.7% at 5 years and 63.7% +/- 6.5% at 8.5 years for all valves. There were no difference in structural valve dysfunction rate between patients having aortic, mitral, or double-valve replacement. Thirty-five patients were reoperated on (3.4 +/- 0.6%/patient-year for all). The rate of all valve-related morbidity and mortality was 5.6% +/- 0.7%/patient-year for all patients, actuarial freedom from the event being 44% +/- 7% at 8.5 years. These data suggest that the excellent hemodynamic characteristics of the valve are balanced by a risk of valve failure that is slightly increased when compared with porcine valves.

Early structural deterioration with the mitroflow pericardial xenograft in the mitral position

Early structural deterioration with the mitral Mitroflow pericardial valve requiring reoperation occurred in 6 patients. Clinical diagnosis of prosthetic failure was made 5 to 58 months after valve implantation (mean, 38 months). Re-replacement was carried out 22 to 80 months (mean, 55 months) after the initial operation. Mode of failures were cuspal tear without calcification in three valves and massive calcifications in the remaining bioprostheses. High incidence of early structural deterioration of the Mitroflow pericardial valve makes this new prosthesis an unsatisfactory alternative as a substitute in the mitral position.