Knowledge on Anticoagulation Use in Atrial Fibrillation With Left Atrial Appendage Thrombus Among Medicine Residents

Introduction: Left atrial appendage (LAA) thrombus increases thromboembolic risk in patients with atrial fibrillation (AF). Importantly, 40% of LAA thrombus patients will have an inadequate response to anticoagulation during follow-up. Of note, these patients are frequently followed by medicine residents in the clinic. Therefore, we aimed to explore residents' knowledge on anticoagulation use for the treatment of LAA thrombus. Hypothesis: Insufficient knowledge on anticoagulation for the treatment of LAA thrombus could contribute to inadequate treatment response during patients' follow-up. Methods: All medicine residents (n=96) at Rutgers University New Jersey Medical School were emailed a 26-question survey on the indication, dosing, pharmacokinetics and clinical experience using direct oral anticoagulants (DOACs) and vitamin-K-antagonists (VKA) in AF patients with LAA thrombus. Results: Of 62 responders, 42 (68%) have been prescribing DOACs in the clinic with apixaban being most commonly prescribed. Thirty-seven (61%) indicated DOACs as the first-line agents for LAA thrombus whereas 24 (39%) chose VKA. Nineteen (33%) responders indicated apixaban dosing correctly, and 51 (84%) indicated appropriately relation of apixaban with meals. If follow-up imaging reconfirmed LAA thrombus, 54 (89%) would switch to VKA whereas 7 (11%) would use other DOACs. Nineteen (32%) responders indicated rivaroxaban dosing correctly and only 10 (16%) indicated appropriately how to administer rivaroxaban with meals. If follow-up imaging reconfirmed LAA thrombus, 43 (71%) would switch to VKA whereas 18 (29%) would use other DOACs. Forty-one (72%) responders indicated dabigatran dosing correctly and 36 (58%) indicated no relation to food intake. If follow-up imaging reconfirmed LAA thrombus, 40 (65%) responders would switch to VKA whereas 22 (35%) would use other DOACs. For VKA, 51 (88%) indicated therapeutic INR range of 2-3 and 7 (12%) chose 2.5-3.5. If follow-up imaging reconfirmed LAA thrombus, 38 (61%) would increase INR goal whereas 24 (39%) would switch to DOACs. Conclusions: This survey identified knowledge gaps in dosing and pharmacokinetics of DOACs among medicine residents despite being more likely to prescribe DOACs over VKA to treat LAA thrombus.