Morphological comparison between atherosclerotic plaques of thoracic aorta, carotid and cardiac abnormalities, in patients with stroke

• Grant number: 12/04571-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2012
• End date: May 31, 2013
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: João Carlos Hueb
• Grantee: Bruno Augusto Alvares
• Host Institution: Faculdade de Medicina (FMB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Strokes are the third cause of death in developed countries and the first cause of permanent disabilities. Most strokes (85%) have an ischemic nature. Approximately 20% of ischemic stroke cases have an embolic cause. Numerous studies have shown an association between atherosclerotic plaques in the thoracic aorta and strokes. Their genesis would be related to migration, to the brain circulation, of thrombi and cholesterol crystals that would detach from ulcerated plaques located in the proximal aorta. In general, atherosclerotic plaques in the aorta are more frequently found in older patients, and they are also often associated with diffuse atherosclerosis. Therefore, the association between coronary atherosclerotic, cerebrovascular and peripheral disease is not uncommon. This explains the greater mortality among individuals with atherosclerotic plaques detected in any arterial segment. By using transesophageal echocardiography, Montgomery et al classified atheromatous plaques of the aorta in different grades, according to their thickness, morphology, and presence of adhered thrombi. By such classification, it is possible to define five grades of occurrence related to plaque embolismic potential: Grade I: normal, grade II: intimal thickening, grade III: simple plaque (with less than 5 mm in thickness), grade IV: complex plaque (thickness greater than 5 mm) and grade V: debris (irregular plaque with mobile protrusions). The higher the grade, the greater the embolismic risk. Although transesophageal echocardiography is the method of choice for investigating the cardiac and aortic embolismic source, that test is not performed in all patients with stroke. On the other hand, by means of non-invasive and easily performed exams, such as transthoracic echocardiography and carotid ultrasound, it is possible to obtain data that, when present, are considered to be markers of risk for the cardiovascular event, such as: left ventricular mass, left atrial volume, intimal medial thickening and presence of atherosclerotic plaque in the carotids.OBJECTIVES1- To correlate echocardiographic variables such as left atrial volume and left ventricular mass with atherosclerotic plaques in the proximal aorta and carotids in patients with stroke.2- To correlate intimal medial thickening and atherosclerotic plaques in the carotids with atherosclerotic plaques in the proximal aorta and compare the morphological aspects of aortic plaques with those of carotid plaques. Subjects and methods: this is a prospective study to be conducted in the Botucatu School of Medicine University Hospital by integrating the cardiology and neurology services. The subjects will consist of an approximate number of 100 male and female patients with ischemic stroke and transient ischemic attack (TIA) hospitalized at the emergency hospital and neurology wards. All the ultrasound exams (transthoracic echocardiograms, transesophageal echocardiograms, and carotid ultrasound) will be performed by using the equipment Vivid S6 by General Electric. The echographic examination of the carotids will be performed by a vascular probe, analyzing the common carotids, carotid bulbs, and internal carotids. Intimal medial thickening will be measured according to Mannheim Carotid Intima-Media Thickness Consensus. Atherosclerotic plaques will also be investigated and, whenever present, they will be classified in terms of echogenicity by using the criteria proposed by Gray-Weale. Type I: hypoechoic plaques; Type II: predominantly hypoechoic plaques; Type III: predominantly hyperechoic plaques; Type IV: hyperechoic plaques; Type V: calcified plaque with an acoustic shadow. The more hypoechoic the plaques (type I), the greater their relationship with cardiovascular events. These criteria will also be used for the classification of the plaques present in the proximal thoracic aorta as regards their echogenicity.(AU)