Initial clinical and hemodynamic experience with Edwards MIRA mechanical bileaflet valve.
OBJECTIVE
An enhanced bileaflet valve, the Edwards MIRA feminine Mechanical Valve became available in 1998. Favorable hydrodynamic features and a redesigned sewing ring encouraged us to implant this device in indicated patients. Hemodynamics and clinical performance parameters were evaluated.


METHODS
Between February 1998 and October 1999, 338 patients (171 males, 167 females) underwent native valve replacement with a MIRA prosthesis. Mean age 56.6+/-13.6 years, 320 patients were in NYHA class III/IV. Sixty-seven patients had echocardiographic examinations. Standard cardiopulmonary bypass was employed utilizing institutionally accepted implantation techniques. Aortic valve replacement was performed in 163 patients, mitral valve replacement in 134 patients, 35* double valve replacements and 1 triple valve replacement.


RESULTS
Follow-up is 98% complete. Mean follow-up is 6.9+/-3.3 months (178.2 patient years). There were no operative deaths. Four early deaths were seen (1.18%). Late deaths reported in 12 patients. Linearized rate of late mortality was 6.7% per patient year (ppy). Overall actuarial survival at 13 months is 92.2%. Mean gradients and Effective Orifice Areas (EOA's) are comparable to other bileaflet valves. Linearized rates for valve-related complications was 4.49% ppy. Only 5 transient thromboembolic events (TE = 2.81% ppy) and 3 non-structural valve dysfunction events (NSVD = 1.68%) were seen. No reports of bleeding events, prosthetic endocarditis, valve thrombosis or structural valve deterioration. One patient required mitral valve reoperation for perivalvular leak.


CONCLUSIONS
Short-term hemodynamic and clinical results are comparable to other bileaflet valves. The sewing ring is non-obstructive, compliant with smoother needle penetration. Early clinical results are encouraging, follow-up should be continued.
De Feo
M
M
Department of Cardio-Thoracic Sciences, 2nd University of Naples, Naples, Italy.
Renzulli
A
A
Onorati
F
F
Della Corte
A
A
Dialetto
G
G
Covino
F E
FE
Cotrufo
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D001672:Biocompatible Materials; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006305:Health Status Indicators; D006349:Heart Valve Diseases / Q000503:physiopathology / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications; D011474:Prosthesis Design; D015996:Survival Rate; D016896:Treatment Outcome; D014859:Warfarin / Q000627:therapeutic use
D000925:Anticoagulants; D001672:Biocompatible Materials; D014859:Warfarin