Abstract 3530: Low yield of Transthoracic and Transesophageal Echocardiography in the Management of Patients with Acute Ischemic Strokes
Background Echocardiography has become ubiquitous in the diagnostic armamentarium of ischemic strokes. There is however insufficient evidence to recommend transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) in every patient with ischemic stroke. We sought to determine diagnostic yield of TTE and TEE in determining cardiac etiology for ischemic strokes.
Methods This is a retrospective chart review of patients with diagnosis of ischemic stroke admitted to the Foothills Medical Center, Calgary from Jan 2009 to June 2010. These patients had TTE and/or a TEE as part of inpatient diagnostic evaluation. Patients with previous history of atrial fibrillation and anticoagulation were excluded. Clinical findings,baseline cardiac exam and ECG were noted. High yield findings on TTE and TEE were defined using American Heart association guidelines( mitral stenosis,LV/LA thrombus/aneurysym,apical akinesia/septal aneurysym,severe LV dysfunction,ASD,vegetation).Topographical distribution of infarcts on follow-up brain imaging and vascular imaging findings within 7 days after the event were documented. These imaging findings were categorized in following groups: normal, infarcts with presumed cardioembolic source (single cortical, multiple cortical, bilateral infarcts with normal vascular imaging), lacune (single subcortical) and infarcts due to large artery atherosclerosis (single or multiple infarcts in the territory of an abnormal large artery).
Results 397 patients with TTE and 67 with TTE/TEE as a workup for ischemic stroke were included in the study. High yield TTE findings were seen in 34/397(8.6%) patients. High yield TEE findings were found in 5/65 (7.7%) patients. Thirteen of 34 (38%) patients with high yield TTE findings had abnormal ECG or baseline cardiac exam at presentation in comparison to 10/423(2%) patients with no high yield findings (p=0.02). There was a suggestion that imaging patterns with presumed cardioembolic source showed association with high yield TTE findings [19/39 (50%) patients in comparison to 144/423(19%)] patients with no high yield findings.(p=0.07 OR 1.84 95% CI 0.95-3.84). Among the various topographical patterns, single cortical infarct with normal vascular imaging was significantly associated with high yield TTE findings. (p<0.03, OR 2.20 95% CI 1.04 - 4.64).
Conclusion The diagnostic yield of TTE and TEE in determining cardio-embolic sources is relatively low. Baseline abnormal ECG and clinical exam along with specific patterns of imaging may help to determine cardioembolic etiology. A more rational approach to use of cardiac imaging is required in settings with limited resources.
- © 2012 by American Heart Association, Inc.