CONGRESS ABSTRACT

INTRODUCTION: Coronary arteries have a typical epicardial course and a myocardial bridge (MB) is considered a variant of the coronary anatomy. The diagnosis is traditionally and largely underestimated by invasive coronary angiography and the occurrence of MBs in anginal patients is usually not evaluated despite being reported as a cause of angina in patients without documented coronary atherosclerosis. Computed tomography coronary angiography (CTCA) that allows the simultaneous visualization of the coronary arteries, myocardium and epicardial fat, is an ideal technique for a non-invasive detection of MBs. PURPOSE: The aim of the study was to evaluate complete MB incidence, site and atherosclerotic plaques using CTCA in anginal patients. METHODS: 1316 patients (pts; mean age 63,3 + 12 years, M/F: 882/445) underwent CTCA (light speed, 64 slides-GEHC) for typical anginal pain. A non-ionic contrast medium was always used, the mean volume of the contrast medium was 90 + 10 ml, the rate of injection ranged from 5 to 7 ml/sec. Risk factors, clinical data, indication to perform a CTCA according to international guidelines, presence and severity of coronary atherosclerotic lesions were stored in a database at the time of the examination. RESULTS: out of the 1316 pts, 80 of them (6%) complained of angina (86% on effort and 14% at rest) and showed the presence of a totally tunneled MB. Pts with MB, as compared to the remaining 1236 pts, showed a significantly lower age (60.1 + 12.6 vs 63.5 + 11.8 yrs, p<0.01); other clinical and angiographic characteristics were not statistically different even if MB pts had a lower incidence of significant coronary stenosis (>50%) (25.6 vs 36.1%; p=NS) and showed a greater percentage of patients with absence of atherosclerotic plaques ( 42.3 vs 34.9 %; p= NS). MBs were more frequent in the left anterior descending coronary artery than in the other branches. In these cases, the coronary segments involved in the MB were normal in most cases (94%); an atherosclerotic plaque was found in 6% of them, with a significant stenosis (>50%) in only 1% of these patients. CONCLUSIONS: CTCA is a fundamental technique for the initial evaluation of patients with typical angina, and for the differential diagnosis between MB, coronary atherosclerosis and microvascular disease. The findings of this study agree with the literature data guidelines of stable angina evaluation.