In vivo assessment of ergonovine-induced coronary artery spasm by 64-slice multislice computed tomography.

BACKGROUND The potential of multislice CT (MSCT) to predict coronary spasm has not been elucidated. The aim of this study was to investigate whether the morphological features observed on MSCT at the site of ergonovine-induced epicardial spasm could be used as diagnostic criteria for coronary spasm. METHODS AND RESULTS A total of 296 plaques in 199 patients with clinically suspected coronary spastic angina without coronary stenosis (<75%) who underwent invasive angiography with intravenous ergonovine provocative testing were analyzed by MSCT. Calcification, CT attenuation, and patterns of vascular remodeling were evaluated in each plaque by MSCT. Plaques were divided into spasm group or nonspasm group based on the results of the ergonovine provocative test. On a per-plaque basis, noncalcified plaques were more frequently observed in the spasm group (96% versus 20%, P<0.01). Intermediate attenuation plaques (CT density ≥53.8 Hounsfield units identified by receiver operating characteristic analysis) were more common in the spasm group (93% versus 28%, P<0.01), as was negative remodeling (67% versus 11%, P<0.01). Multivariable analysis revealed noncalcified (odds ratio [OR], 48.7; 95% CI, 8.81-269; P<0.01), intermediate attenuation (OR, 19.3; 95% CI, 4.96-75.4; P<0.01); negative remodeling (OR, 8.83; 95% CI, 2.87-27.2; P<0.01); and male sex (OR, 4.55; 95% CI, 1.24-16.6; P=0.02) as predictors of the plaque associated with coronary spasm. CONCLUSIONS MSCT can detect differences in individual plaque composition and morphology among atherosclerotic plaques without significant luminal narrowing in areas of inducible vasospasm compared to areas without vasospasm.