Abstract O.70: Safey and Efficacy of Warfarin Therapy in Kawasaki Disease

Abstract

Purpose: Giant aneurysms are managed with combined anticoagulation and anti-platelet therapy, heightening risk of bleeding complications. We sought to describe the safety and efficacy of warfarin for Kawasaki disease (KD) patients (pts) with giant coronary artery aneurysms (CAA, ≥8 mm). Methods: We reviewed the % time in therapeutic range (%TTR); % of INR’s in range; bleeding events, categorized as major bleeding, clinically-relevant non-major bleeding, and minor bleeding; clotting events; INRs ≥5; and INRs <1.5. Results: Our anticoagulation service managed 9 KD pts (5 male), median age 13.2 y (range 7-22 y). INR testing was prescribed weekly to monthly and was done by home monitor (n=6) or lab (n=3). Median length of warfarin therapy was 6.5 y (1.6-12.5). Goal INR was 2.0-3.0 (n=6) or 2.5-3.5 (n=3), based on CAA size and history of CAA thrombosis. All pts were treated with aspirin; 1 was on triple therapy with warfarin, aspirin, and clopidogrel. From 6/2011-6/2014, the median %INRs in range was 62% (34-93%), and median %TTR was 68%(53-92%). INRs >6 occurred in 2 pts (2 events); INRs 5 <6 in 5 pts (9 events); and INRs <1.5 in 5 pts (21 events) . During warfarin therapy, 3 major bleeding events occurred in 3 pts: 1 hemorrhage in calf muscle with compartment syndrome requiring surgical clot evacuation (INR 2.5); 1 hemorrhagic ovarian cyst needing hospitalization and Vit K (INR 5.2); and 1 hemopericardium (INR 2.8) 9 days post CABG requiring readmission to the hospital, pericardiocentesis and blood transfusion. There were 2 clinically-relevant non-major bleeding events in 2 pts: 1 hospitalized for bleeding 1 wk after wisdom teeth extraction (INR 6.1) and 1 requiring cauterization for nose bleeds. Minor bleeding events included: a) severe recurrent nosebleeds in 3 pts, causing 4 ER visits (2 pts) and Hgb fall to 7 mg/dL (1 pt, Fe treatment); and b) heavy menses in the 2 post-pubertal females, both treated with oral contraceptives. Four of 9 pts had no bleeding events, and no pt had new CAA thrombosis. Conclusions: Bleeding complications are common in pts on warfarin and aspirin. Despite management by a hospital anticoagulation service, INRs were in range only 2/3 of the time. Studies on oral Factor Xa inhibitors as an alternative to warfarin are needed in this at-risk population.