Negative calcium score and the presence of obstructive coronary lesions in patients with intermediate CAD probability.

We intended to estimate how the zero coronary artery calcium (CAC) score in symptomatic patients with intermediate probability of coronary artery disease predicts the absence of obstructive non-calcified coronary plaques (NCAPs). CAC scoring and coronary arteries were evaluated by means of 64-multislice CT coronary angiography (CCTA). In 166 subject with CAC=0, Non-obstructive NCAPs (less than 50%) were found in 17 patients (10.2%), while significant stenosis were diagnosed in 3 (2%). In the female insignificant stenoses were more frequent (12%) than in men (6%), however, all 3 cases with significant stenosis were male. In our study, where CCTA has been used as diagnostic method for CAD diagnosing, the prevalence of non-calcified plaques in CAC=0 subjects is relatively high. Our study confirms a relatively low incidence of significant coronary stenosis in this subset of CAD-suspected subjects.