For patients with established left ventricular (LV) thrombus undergoing percutaneous coronary interventions (PCI) following anterior myocardial infarction (MI), the 2018 Canadian Cardiovascular Society (CCS) Focused Update of the Guidelines for the use of Antiplatelet Therapy suggest an initial regimen of triple therapy with ASA 81mg daily plus clopidogrel 75mg daily plus an oral anticoagulant (warfarin or direct oral anticoagulants (DOACs)), although they recognize that the quality of evidence is very low1. The purpose of this study is to assess the effectiveness and safety of DOACs compared to warfarin in the treatment of LV thrombus post-acute MI.
Methods and Results
We present a retrospective cohort study across two sites (Kingston Health Science Center and London Health Sciences Centre) of patients diagnosed with LV thrombus post-anterior ST-elevation MI (STEMI). Treatment and six-month outcomes (embolic events, bleeding, and echocardiographic thrombus resolution) were collected. See Table 1 for baseline demographics. Of a total 1016 Anterior STEMIs, 64 patients had LV thrombus and 49 were included in the study (see Figure 1 for exclusions). In these 49 patients, when comparing warfarin vs DOAC therapy, the cumulative rate of embolic events was 5.4% vs 0% (p=0.411), major bleeding was 0% vs 8.3% (p = 0.549), and minor bleeding was 16.2% vs 16.7% (p=0.971). Thirty patients (warfarin n=21, DOAC n=9) had follow-up echocardiography to assess for thrombus resolution, which showed 69.2% resolution for patients prescribed warfarin vs 88.9% resolution for patients prescribed DOACs (p=0.245).
Our study presents a series of patients treated for LV thrombus with either warfarin or DOAC and showed similar rates of thrombus resolution at three to six months. In the sample size studies, there was no significant difference in embolic events, major or minor bleeding, or rate of clot resolution. Though this study is limited as a retrospective design and low numbers, it provides a very important signal that DOACs may be as safe (with respect to bleeding risk) and effective (stroke prevention and clot resolution) as warfarin for treating LV thrombus. Further multi-center studies are planned with prospective clinical trials.
© 2018 Published by Elsevier Inc.