Competing stroke mechanisms despite adequate oral anticoagulant therapy: the role of transesophageal echocardiography

Abstract

Aims: Ischemic strokes in patients on oral anticoagulant therapy (OAT) despite optimal adherence pose a therapeutic challenge. We assessed the utility of transesophageal echocardiography (TEE) in identifying potential competing cardiac causes for stroke that occurred despite adequate OAT.

Methods: This retrospective observational study included patients admitted for acute ischemic stroke between January 2022 and June 2023 who were on OAT for an established long-term indication. Transthoracic and transesophageal echocardiography, along with assessment of OAT adherence, were conducted. Demographic data, OAT details, and stroke characteristics were analysed to determine the influence of TEE findings on therapeutic decisions.

Results: We included 26 patients. TEE identified potential cardiac competing stroke mechanisms in 88% of cases, with valvular thrombi and left atrial or appendage thrombus being predominant. Infective endocarditis, often asymptomatic, was unexpectedly prevalent. TEE significantly influenced therapeutic decisions, especially in cases where transthoracic echocardiography was inconclusive.

Conclusions: TEE may be crucial for unravelling the mechanisms of ischemic stroke in patients on adequate OAT, guiding precise therapeutic strategies and potentially reducing the risk of recurrent embolic events. Our findings underscore the limitations of standard echocardiography in detecting cardiac embolic sources and emphasize the importance of tailored decision-making in secondary stroke prevention.