LA Thrombus on DOAC — EECC MCQ

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HardCardiac PharmacologyLA Thrombus on DOACEECC

A 55-year-old man with dilated cardiomyopathy and LVEF 25% is found to have a left atrial thrombus on TOE despite being on apixaban 5 mg bd for AF. What should be done?

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Correct answer: C — Switch to warfarin (which has a longer track record for intracardiac thrombus resolution) with target INR 2.0-3.0, and repeat imaging in 3-6 weeks; DOACs have limited evidence for LA thrombus resolution

LA/LAA thrombus on anticoagulation represents treatment failure. While DOACs are effective for stroke prevention in AF, evidence for thrombus RESOLUTION is predominantly from warfarin-era studies. When LA thrombus is detected on a DOAC: (1) switch to warfarin (INR 2.0-3.0) — longer track record, dose-adjustable, reliable intracardiac thrombus resolution; (2) repeat TOE in 3-6 weeks to assess resolution; (3) if cardioversion was planned, defer until thrombus resolves. Some case series show DOAC-mediated thrombus resolution (particularly with rivaroxaban and apixaban), but evidence is observational and incomplete. Ensuring adherence (missed doses are more consequential with short-half-life DOACs than warfarin) is crucial. Alternative causes of anticoagulation failure (malabsorption, drug interactions, non-adherence) should be excluded.

Reference: ESC (2024): AF Guidelines