Prevalence and Extent of Obstructive Coronary Artery Disease in Patients with Zero or Low Calcium Score Undergoing 64-slice Cardiac Multidetector Computed Tomography for Evaluation of a Chest Pain Syndrome

We examined the extent of coronary artery disease (CAD) on 64-slice contrast-enhanced multidetector computed tomography in patients who underwent investigation of a chest pain syndrome who had a zero or low coronary calcium score (CS). In 668 consecutive patients with chest pain syndromes (39% with acute presentation, 61% with long-term presentation) who underwent cardiac multidetector computed tomography, we assessed prevalence and severity of coronary stenoses (>or=1 coronary artery stenosis with >or=50% luminal narrowing) in 231 patients (54 +/- 12 years of age, 45% women) with a 0 (n = 125) or low (n = 106) coronary CS. Obstructive (>or=50% lesion) CAD was present in 27 of 231 patients, in 9 of 125 patients (7%) with a 0 CS, in 18 of 106 (17%) with a low CS (1 to 100), and in 14 of 90 patients (16%) with an acute presentation and 13 of 141 patients (9%) with a long-term presentation (p = NS). All patients in the 0 CS group had single-vessel disease, and 9 (50%) with low CS had multivessel disease, with left main involvement in 1. Of the 27 patients with obstructive CAD on multidetector computed tomography, invasive coronary angiography confirmed these findings in 21 of 23 patients (positive predictive value 91%), and 16 (76%) of them (6.9% of the 0 CS and low CS groups) underwent a myocardial revascularization procedure after invasive coronary angiographic concordance. In conclusion, despite the high known negative predictive value of CS for coronary events, a low and even 0 CS does not exclude clinically important obstructive CAD in patients undergoing investigation of an acute or long-term chest pain syndrome. Contrast-enhanced multidetector computed tomography should be the noninvasive computed tomographic test of choice when possible in these patients.