Thromboembolic and bleeding complications in patients treated with oral anticoagulant therapy after mechanical heart valve prostheses implantation
Kanaoka, Y.; Tanemoto, K.; Murakami, T.; Kuroki, K.
Kyobu Geka. Japanese Journal of Thoracic Surgery 53(9): 754-758
2000
ISSN/ISBN: 0021-5252 PMID: 10935402 Document Number: 520975
Thromboembolic and bleeding events are major cause of morbidity and mortality in patients with mechanical heart valves. Ninety-three patients had been received anticoagulant (warfarin with bucolome 300 mg) for mechanical prosthetic valves, and the regulation of anticoagulation was performed within a prothrombin time international normalized ratio (PT-INR) about 2.0 of normal. The mean duration of follow-up was 64.1 months, and the total duration of follow-up was 496.8 patient-years (py). The valve related complications occurred in 10 cases (2.0 per 100 py). Anticoagulant related hemorrhagic events occurred in 7 cases, and valve thrombosis in 3 cases. All three cases of valve thrombosis were in cases with Björk-Shiley valve at the mitral position. An artificial valve in mitral position increased the valve related risk compared with the aortic position (3.1%/py vs 0.0%/py). Bileaflet valve showed a lower incidence of thromboembolism than tilting disc valve (2.3%/py vs 0.0%/py). The risk of valve related complication varied with the type and the position of the prosthesis, it is desirable that the intensity of anticoagulation would be changed according to the prosthetic valve type and its position. These results suggest that the intensity of anticoagulation is optimal when the PT-INR is 1.8-2.0 for patients with bileaflet valve in the mitral position, and is 1.6-1.8 in the aortic position. Tilting disc valve needs more intensity of anticoagulation, and needs additional antiplatelet agent in the mitral position.