219 ISOLATED CORONARY OSTIAL STENOSIS DUE TO RECURRENT AORTIC WALL THROMBOSIS
Authors: De Gaspari Monica , Rizzo Stefania , Cassaro Mauro , Facchin Michela , Verlato Roberto , Basso Cristina , Buja Paolo 
Published: December 2022

Abstract

Background
Coronary ostial lesions are a rare entity and isolated coronary ostial stenosis is even less frequent. Diffuse coronary artery atherosclerosis is the main cause for the non-isolated stenosis, based on old post-mortem series and histological analysis of tissue removed during atherectomies.

Case presentation
A 49-year-old woman suffering from mild non-familial hypercholesterolemia reported to her family physician repeated episodes of chest pain related to exercise. During a cardiological outpatient evaluation, 12 lead electrocardiogram (ECG) and echocardiography turned out normal. During a stress test she had recurrent chest pain coupled with ECG ischemic changes (diffuse ST segment elevation). She was immediately referred to the emergency department where the ECG was back to normal and the troponin dosage within normal range. Coronary angiography was performed: non-selective cannulation revealed some irregularities of the aortic wall profile at the level of the right coronary ostium, with inability to visualize the right coronary artery. The selective cannulation of the left main coronary artery (LMCA), left anterior descending (LAD) and left circumflex branches showed a critical ostial stenosis at the origin of the LMCA without any other relevant lumen restriction, in a left-dominant pattern of coronary circulation. A suspicion of LAD dissection was raised when a laminar flux was observed at its origin. At the end of the procedure, the patient suddenly collapsed. The recorded rhythm was initially bradycardia, evolving to episodes of ventricular tachycardia for which multiple shocks were applied. Despite the resuscitation efforts, the patient never recovered. Autopsy was performed at the local hospital. At gross analysis, a non-uniform pale-tan thickening at the level of the sino-tubular junction was evident with involvement of both the right and left coronary ostia. Histological examination allowed to ascribe the thickening to recurrent thrombosis, without any underlying inflammatory process at the level of the aortic wall and with only minimal atherosclerotic plaques. No coronary artery dissection nor significant stenosis was present in all the coronary tree. Regarding the ventricular myocardium, one focus of replacement-type fibrosis was identified at subendocardial level in the infero-septal wall coupled with a small spot of loose connective tissue rich in hemosiderin-laden macrophages in the same region, consistent with an area of subacute ischemic damage.

Conclusion
Several series reported a higher frequency of isolated coronary ostial stenosis in women versus men. In fact, female sex along with hypertriglyceridemia have been recognized as independent risk factors for ostial lesions. The case herein reported highlights the diagnostic relevance of the autopsy investigation together with clinicopathological correlation, particularly in cases where the definite diagnosis can't be achieved in vivo.