A North American, prospective, multicenter assessment of the Mitroflow aortic pericardial prosthesis

Abstract

Background: The aim of the Mitroflow aortic pericardial valve study was to prospectively assess performance of the Mitroflow prosthesis among North American patients.

Methods: The study was conducted between November 2003 and December 2007 on patients requiring aortic valve replacement. The study cohort consisted of 689 patients (391 male, 298 female), with a mean age of 74.3 +/- 8.4 years, and 46.6% of whom were New York Heart Association (NYHA) class I/II preoperatively. Patients were followed at 3 to 6 months and yearly until study closure. Mean follow-up was 25.7 +/- 12 months, and total follow-up was 1,474.4 patient-years, with a maximum of 48.7 months.

Results: Postoperatively, more than 97% of evaluated patients were NYHA class I/II. At 3 years, 131 patients had died, for an actuarial survival of 79.1%; and the 3-year actuarial freedom from valve-related death, valve explant, all valve reoperation, and structural valve dysfunction was 97.0%, 98.1%, 97.9%, and 99.2%, respectively. Other valve-related complications included prosthetic valve endocarditis (1.4% per patient-year), thromboembolic episodes (1.3% per patient-year), major embolism (0.5% per patient-year), perivalvular leak (0.6% per patient-year), and major anticoagulation-related bleeding (0.6% per patient-year). Echocardiograms at 1 year showed mean pressure gradients averaged from 7.3 +/- 1.8 mm Hg to 13.4 +/- 5.1 mm Hg, and peak gradients averaged from 14.3 +/- 4.7 mm Hg to 26.0 +/- 9.2 mm Hg for valve sizes 27 to 19. Aortic regurgitation in patients was absent/trace (90.2%) or mild (8.7%); none was severe.

Conclusions: The early results of this study show a low incidence of valve-related adverse events and excellent hemodynamic performance. Continued follow-up is needed to determine if long-term durability in North American patients is comparable to that in previous reports on the durability of the Mitroflow valve.