The Edwards MIRA™ Heart Valve Prosthesis:

 Background:The Edwards MIRA™ mechanical heart valve is designed to optimize hemodynamics, reduce thrombogenicity, and avoid mechanical failure with a special hinge mechanism. The purpose of the study was to investigate the clinical performance and postoperative hemodynamic results of the first European patients receiving Edwards MIRA™ mechanical heart valves. Methods: From March 1998 to March 1999 a total of 54 Edwards MIRA™ valves model numbers 3600 (aortic, n = 44) and 9600 (mitral, n = 10) were implanted in 52 (36 male, 16 female; mean age 61 ± 10.1 years) consecutive patients undergoing mechanical valve replacement in a prospective study. Follow‐up of the patients including physical examination, ECG, blood tests, and Doppler were performed prior to discharge, at 6 months, at 1 year, and at least 2 years postoperatively. Results: Through October 2001 a total of 172 follow‐up examinations were completed (51 patients at discharge, 46 patients at 6 months, 43 patients at 12 months, 32 patients at 2 years or beyond). All patients were in NYHA class I and II at the 6‐month and 2+‐year follow‐up. All the patients stated an improved quality of life. Hospital mortality was 1.9%. There were no complications related to anticoagulation. Mean international normalized ratio at 6 months was 3.2 (range 1.9 to 4.3); lactate dehydrogenase was slightly increased with 264 ± 103 U/L on average (normal value 80 to 240 U/L). No signs of valvular dysfunction or paravalvular leakage were observed. Mean pressure gradients were related to valve diameter: after mitral valve replacement (size 27, 29, 31 mm: 4.8, 3.2, 2.1 mmHg); after aortic valve replacement (size 19, 21, 23, 25 mm: 12.1, 13.1, 9.3, 8.2 mmHg). Conclusions: These preliminary data suggest good hemodynamic function and a low rate of valve‐related complications of the Edwards‐MIRA™ mechanical prosthesis. (J Card Surg 2004;19:226‐231)