Cardiac Thrombus in Early Cardiac CT Scan in Etiological Workup of Ischemic Stroke: Prospective Study

Overview

Stroke can be linked to atherosclerosis of the large vessels, occlusion of the small intracerebral vessels (gaps), cardioembolic pathology or other rarer etiologies. The cardioembolic etiology of stroke in elderly patients may be difficult to prove. Paroxysmal atrial fibrillation (AF) is a common cause of cerebral infarction (25%). Detecting AF is not easy. A 24-hour long-term holter and an implantable cardiac monitor (Reveal®) may be required. This etiology is all the more important as it requires anticoagulation treatment reducing the risk of recurrence in the short and long term. The left atrium thrombus is an indisputable marker of atrial fibrillation but it is rarely seen. Other cardiac etiologies such as a thrombus in the left ventricle, a large plaque or a thrombus of the aortic arch are possible. Finally, the permeable oval foramen and the aneurysm of the intra-auricular septum constitute a cause apart in young subjects (\<60 years). Typically, the search for thrombus of the left atrium goes through a trans-thoracic cardiac ultrasound and a transesophageal cardiac ultrasound. These examinations, often negative, are performed several days after the onset of the cerebral infarction. The transesophageal cardiac ultrasound, considered as the "gold standard" examination to look for an intracardiac thrombus and an embologenic plaque in the aortic arch, is poorly tolerated. It is rarely performed in patients over 75 years of age. In addition, the length of stay for these patients may increase due to the wait for these exams. Several studies have validated the non-inferiority of the cardiac scanner compared to the transesophageal cardiac ultrasound for the detection of intracardiac thrombus (left atrium or left ventricle). In the study by Hur et al. performed in 55 consecutive patients with a probable cardioembolic infarction, 14 thrombi of the left atrium were detected and confirmed by the cardiac scanner, but the patients were young, with a median age of 61 years. In the Berlin prospective HEBRAS study, 475 patients underwent cardiovascular MRI. The results are being analyzed but the cardiac scanner is more sensitive for the detection of thrombus in the left atrium. A prospective study confirmed that the cardiac scanner is more precise in differentiating the left atrial thrombus from circulatory stasis in patients with stroke In this study, there is no information on the time between the stroke and the completion of the cardiac scanner. Almost all patients with stroke benefit from an angio-scan of the CT scan of supra-aortic trunks as part of the urgent assessment on Day 1 or Day 2. The investigators propose to perform at the same time a cardiac scanner in order to allow a rapid morphological cardiological assessment, at the level of the left atrium, the left ventricle and the arch of the aorta.