Manlhiot C, Newburger JW, Low T, et al. - In view of the substantial risk of thrombosis in large coronary artery aneurysms (CAA) (maximum z-score ever recorded ≥ 10) following Kawasaki disease (KD) mandating the necessity for effective thromboprophylaxis, researchers here examined whether anticoagulation (low molecular weight heparin (LMWH) or warfarin) for thromboprophylaxis is effective in large CAA. The International KD Registry yielded data from 383 patients for this work. Differences in treatment duration and follow-up were assessed via time-to-event analysis. From diagnosis onward (96% received acetylsalicylic acid concomitantly), LMWH was administered to 114 patients (median duration: 6.2 (IQR:2.5-12.7) months), warfarin to 80 patients (median duration 2.2 (IQR:0.9-7.1) years) and anticoagulation was not reported in 189. Outcomes suggest seemingly equivalent effectiveness of LMWH and warfarin for preventing thrombosis in large CAAs after KD, although the event rate for secondary thromboprophylaxis and safety outcomes were low. Based on the findings, they suggest providing anticoagulation to all patients with CAA z-score ≥ 10, however, secondary risk factors and patient preferences may aid in making the choice of agent.