Hemolysis after mitral valve replacement with mechanical valve prostheses.
OBJECTIVE
We evaluated effects of type, size, and orientation of mechanical mitral valve prostheses on hemolysis.


METHODS
Subjects were 84 patients who had undergone mitral valve replacement. Lactate dehydrogenase was mainly used as a marker of hemolysis and was measured before surgery, 1 month after surgery, and in the late postoperative period.


RESULTS
Valves used included 16 Medtronic-Hall, 32 St. Jude Medical, and 36 CarboMedics valves. Medtronic-Hall valves caused less hemolysis than St. Jude Medical or CarboMedics valves in the late postoperative period. This resulted because hemolysis due to Medtronic-Hall valves was more severe 1 month after surgery than in the late postoperative period and because hemolysis due to St. Jude Medical or CarboMedics valves was more severe in the late postoperative period than 1 month after surgery. One reason for this finding is that cardiac output was greater in the late postoperative period than 1 month after surgery, making regurgitation through the pivots of bileaflet valves more severe. The orifice area and the orientation of prostheses did not affect hemolysis.


CONCLUSIONS
St. Jude Medical or CarboMedics valves caused more severe hemolysis than Medtronic-Hall valves in the late postoperative period.
Ninomiya
M
M
Department of Cardiothoracic Surgery, Faculty of Medicine, University of Tokyo, Tokyo, Japan.
Yagyu
K
K
Kaneko
Y
Y
Kotsuka
Y
Y
Takamoto
S
S
D000368:Aged; D002302:Cardiac Output; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects*; D006461:Hemolysis; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000097:blood / Q000503:physiopathology / Q000601:surgery; D008946:Mitral Valve Stenosis / Q000097:blood / Q000503:physiopathology / Q000601:surgery; D011474:Prosthesis Design
D007770:L-Lactate Dehydrogenase