Long-term results of mitral valve replacement: biological xenograft versus mechanical valves.
We studied 279 patients who underwent mitral valve replacement at the Department of Thoracic and Cardiovascular Surgery, Hyogo College of Medicine, between November 1973 and December 1998. The patients were divided into two groups based on the type of replacement valve (154 patients in the biological xenograft group and 125 patients in the mechanical valve group), and the long-term results were compared. Clinically satisfactory results were obtained in both the biological xenograft group and the mechanical valve group according to the surgical results, long-term survival, and incidence of prosthetic valve endocarditis. At 15 years, fewer patients in the mechanical valve group than in the biological xenograft group were free of bleeding events (92.5 +/- 3.7% vs 100% P < 0.05). At 15 years, the biological xenograft group was lower than the mechanical valve group with respect to freedom from thromboembolism (72.2 +/- 4.6% vs 93.5 +/- 3.6% P < 0.01), freedom from valve failure (22.0 +/- 5.2% vs 87.0 +/- 4.1% P < 0.005) and freedom from cardiac events (16.5 +/- 3.9% vs 47.2 +/- 14.5% P < 0.01). Though it has previously been suggested that biological xenografts used in mitral valve replacement do not need anticoagulation, the current study suggests the need for anticoagulation with the use of biological xenografts. Mechanical valves require close monitoring of anticoagulation, but their use has decreased the incidence of valve failure and thromboembolism, as compared with the use of biological xenografts. Therefore, mechanical valves are currently the preferred choice for mitral valve replacement. We believe that biological xenografts are indicated only for the older patient (> or =65 years).
Yao
Hideki
H
Department of Thoracic and Cardiovascular Surgery, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya 663-8501, Japan. yao@hyo-med.ac.jp
Miyamoto
Takashi
T
Mukai
Sukemasa
S
Yamamura
Mitsuhiro
M
Tanaka
Hiroe
H
Nakagawa
Takashi
T
Ryomoto
Masaaki
M
Inai
Yoshihito
Y
Yoshioka
Yoshiteru
Y
Kaji
Masanori
M
D000328:Adult; D000368:Aged; D001705:Bioprosthesis; D005260:Female; D006349:Heart Valve Diseases / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve; D011183:Postoperative Complications; D011475:Prosthesis Failure; D016019:Survival Analysis; D016896:Treatment Outcome