Assessment of Changes in Non-Calcified Atherosclerotic Plaque Volume in the Left Main and Left Anterior Descending Coronary Arteries over Time by 64-Slice Computed Tomography

Multidetector computed tomography (MDCT) permits the visualization of the coronary arteries and of coronary atherosclerotic plaques. The natural course of noncalcified plaque is not known. This study was conducted to measure the change in noncalcified coronary plaque volume in the left main coronary artery and in the proximal left anterior descending coronary artery over time using 64-slice MDCT. Fifty patients in whom noncalcified lesions had been detected on baseline MDCT received follow-up scans after an interval of 17 ± 6 months. Plaque areas were traced manually in serial multiplanar reconstructions to determine overall volume. The mean plaque volumes were 92 ± 81 mm3 on baseline MDCT and 115 ± 110 mm3 on follow-up MDCT (p <0.001). The mean annualized volume change was 22% (95% confidence interval 14.7% to 29.7%). A weak but significant correlation with low-density lipoprotein cholesterol level was observed for the amount of baseline plaque volume (r = 0.37, p <0.001). In conclusion, the quantification of noncalcified plaque volume is possible on repeated 64-slice MDCT. A significant increase of the amount of noncalcified plaque was observed over a mean interval of 17 months. Contrast-enhanced MDCT may therefore be a tool to study the progression of coronary atherosclerosis.