EFFICACY AND SAFETY OF LONG-TERM ANTICOAGULANT THERAPY FOR LARGE CORONARY ARTERY ANEURYSMS IN KAWASAKI DISEASE TAKAHASHI, MASATO; HINOKI, KATHLEEN; BARTON, CHERYL; MASON, WILBERT (Department of Pediatrics, University of Southern California Keck School of Medicine, Los Angeles, California, USA) 【Aim】 To evaluate efficacy and safety of long-term treatment of patients with large coronary artery aneurysms with combination of warfarin and low-dose aspirin. 【Materils and Method】We have retrospectively reviewed 29 cases of Kawasaki disease (KD) with giant coronary artery aneurysms in chronic stage. Historical control group consisting of 11 pts were treated with aspirin only, while 18 more recent pts were treated with combined warfarin and aspirin. Our target INR was 2.0 ~ 2.5. Patient compliance, intercurrent illnesses, dietary changes and concomitant medications were carefully monitored by our anticoagulation nurse. Major and minor complications were recorded. Composite end-points were angiographic evidence of total or subtotal occlusion, or death due to myocardial infarction. Log-rank test was used to test for between-group difference. 【Results】Ten years after start of therapy, warfarin + aspirin group, compared to aspirin only group, showed superior thrombosis-free survival (0.75 v. 0.25; p=0.0525). The benefit of warfarin may reflect unique characteristics of KD coronary artery aneurysm which trigger both arterial- and venous- type thrombosis. Management of anticoagulant regimen in children is made difficult by individual differences in dose-response, frequent minor illnesses, need for concomitant use of antibiotics and other drugs, and erratic dietary habits, all of which significantly alter warfarin metabolism. Examples of common drugs, which potentiate and reduce warfarin action will be discussed. Pharmacogenetic study of warfarin is currently underway. Very few major bleeding complications were encountered. 【Conclusions】(1) For the maximum efficacy and safety, careful monitoring of factors influencing warfarin action is necessary. (2) Elucidation of pharmacogentics of warfarin in children is needed. (3)Finally, there is a need for a new anticoagulant with a greater therapeutic margin, more predictable response and fewer complications.