Cardiac Imaging Within Emergency CT Angiography for Acute Stroke Can Detect Atrial Clots.

Stoyan Popkirov,Werner Weber,Ilka Kleffner,Uwe Schlegel,Jens Altenbernd

doi:10.3389/fneur.2019.00349

Abstract

Cardiac embolism is presumed to cause a significant portion of cryptogenic strokes. Transesophageal echocardiography may detect intracardiac thrombi, but this remains a rare finding, possibly because remnant clots dissolve spontaneously or following thrombolysis. Cardiac imaging within cerebral CT angiography might offer an alternative method for thrombus detection within hyperacute stroke assessment. In a proof-of-concept study we analyzed records of patients aged ≥ 60 years that presented with suspected stroke and underwent extended cerebral CT angiography as part of their emergency assessment. CT imaging of patients with ischemic stroke or transient ischemic attack (TIA) and atrial fibrillation and of those with embolic strokes of undetermined source (ESUS) was reviewed for intracardiac clots and other cardiac or aortic pathology. Over a period of 3 months 59 patients underwent extended CT angiography for suspected stroke, 44 of whom received a final diagnosis of ischemic stroke or TIA. Of those, 17 had atrial fibrillation, and four fulfilled ESUS criteria. Thrombi were detected within atrial structures on CT angiography in three cases. In two ESUS patients complex atheromatosis of the proximal ascending aorta with irregular and ulcerating plaques was detected. Cardiac imaging within emergency cerebral CT angiography is feasible and can provide valuable diagnostic information in a patient group that might not routinely undergo transesophageal echocardiography. A small change to emergency assessment could potentially uncover cardioembolic pathology in cases that would have remained cryptogenic otherwise.

Highlights

A significant proportion of embolic strokes of undetermined source (ESUS) are probably cardiogenic, but cardioembolic pathologies can elude standard assessments [1]
At our center emergency cerebral CT angiography (CCTA) is routinely performed when large artery occlusion or stenosis is suspected as a cause of acute stroke or transient ischemic attack (TIA) according to standard protocol as described elsewhere [7]
Our results demonstrate that co-imaging of cardiac structures within emergency CCTA in elderly patients with ischemic stroke or TIA and atrial fibrillation or ESUS can visualize intracardiac clots before thrombolytic treatment, as well as other emboligenic pathologies such as ulcerating plaques of the ascending aorta

Summary

Introduction

A significant proportion of embolic strokes of undetermined source (ESUS) are probably cardiogenic, but cardioembolic pathologies can elude standard assessments [1]. Transesophageal echocardiography (TEE) is the gold standard for detection of emboligenic abnormalities, but it is not routinely performed in all patients for various reasons. The utility of routine TEE in cryptogenic stroke has been questioned, not least because of a low rate of atrial clot detection [2]. An alternative method for detecting left atrial thrombi (and other cardiac pathology) is computed tomography (CT) [4], but ECG-triggered contrast-enhanced cardiac CT would unjustifiably delay thrombolysis and/or thrombectomy. Relevant cardiac abnormalities, including left atrial clots, can be detected on non-cardiac CT [5, 6]. When cerebral CT angiography (CCTA) is performed to detect large artery occlusion or stenosis within emergency stroke assessment, extending the scan range of the angiogram by several inches to include the heart seems feasible

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Conclusion