Detection of major cardioembolic sources in real-world patients with ischemic stroke or transient ischemic attack of undetermined cause

Background/Aim: Current guidelines recommend transthoracic echocardiography (TTE) and ambulatory rhythm monitoring following ischemic stroke or transient ischemic attack (TIA) of undetermined cause for identifying cardioembolic sources (CES). Due to ongoing controversies about this routine strategy, we evaluated its yield in a real-world setting. Methods: In a tertiary medical center, we retrospectively evaluated consecutive patients with ischemic stroke or TIA of undetermined cause, who (after standard work-up) underwent TTE, ambulatory rhythm monitoring, or both. CES were classified as major if probably related to ischemic events and warranting a change of therapy. Results: Between January 2014 and December 2017, 674 patients had ischemic stroke or TIA of undetermined cause. Of all 484 patients (71.8%) who underwent TTE, 9 (1.9%) had a major CES. However, 7 of them had already been identified for cardiac evaluation due to new major electrocardiographic abnormalities or cardiac symptoms. Thus, only 2 patients (0.4%) truly benefitted from unselected TTE screening. Ambulatory rhythm monitoring was performed in 411 patients (61.0%) and revealed AF in 10 patients (2.4%). Conclusion: Detecting a major CES is essential because appropriate treatment lowers the risk of recurrent stroke. Nonetheless, in this real-world study that aimed at routine use of TTE and ambulatory rhythm monitoring in patients with ischemic stroke or TIA of undetermined cause, the prevalence of major CES was low. Most patients with major CES on TTE already had an indication for referral to a cardiologist, suggesting that major CES might also have been identified with a much more selective use of TTE.