Abstract 2184: Role of Transesophageal Echocardiography in Patients with Ischemic Stroke of Undetermined Etiology

Abstract

Background: In one-third of patients with ischemic stroke, the etiology remains unknown after diagnostic evaluation. This study examined the diagnostic value and therapeutic impact of routine TEE in patients with stroke of otherwise undetermined etiology. Methods: Between April 2005 and March 2009, 989 stroke patients > 18 years of age with documented brain ischemia on CT and/or MRI received TEE. Without the TEE results, patients were retrospectively classified according to the Trial of Org 10172 in Acute stroke Treatment (TOAST) criteria, based on the results of routine diagnostics, including ECG, Holter-ECG, brain imaging (computed tomography and/or magnetic resonance imaging) and ultrasound or magnetic resonance arteriography of the brain supplying arteries. In 602 patients (63%), stroke etiology could be determined before the TEE results were available. In the remainig 348 patients (37%), the stroke etiology could not be determined after routine diagnostics. We reviewed the TEE examinations of these 348 patients for possible cardiovascular sources of embolism (CSE). Results: All patients (mean age 76 years (range 18 - 95 years) , 53% males) received TEE within a median of 5 days after the stroke event. TEE detected at least one possible source of cardiac embolism in 293 patients (84%). In 8 patients (2%), TEE revealed a high-risk source of embolism with indication for oral anticoagulation or cardiac surgery ( Table ). Seventy-seven patients in the study group were ≤ 55 years of age. In this subgroup, 61% had a positive TEE finding, compared to 91% in the older subgroup. There was no difference in the prevalence of PFO and/or ASA between patients ≤ 55 years and patients > 55 years (36% vs. 32%). In the patients with otherwise normal TEE (cryptogenic stroke patients), the prevalence of PFO and/or ASA was higher, although there was again no difference observed between patients ≤ 55 years > 55 years (45% vs. 42%) ( Table ). However, when an interatrial septum anomaly was detected in a patient ≤ 55 years, it was the only CSE in 89% of cases (versus 16% in the older group, p < 0.001). Conclusion: TEE identified a potential source of cardiac embolism in most patients with stroke of otherwise undetermined etiology. In a limited number of cases, TEE influenced the management of these patients directly. The prevalence of interatrial septum anomalies was high in cryptogenic stroke patients. In stroke patients < 55 years, a PFO was in most cases the only pathologic finding, suggesting its pathogenic character in this subgroup.