Noninvasive assessment of plaque morphology and composition in culprit and stable lesions in acute coronary syndrome and stable lesions in stable angina by multidetector computed tomography.

OBJECTIVES The purpose of this study was to assess morphology and composition of culprit and stable coronary lesions by multidetector computed tomography (MDCT). BACKGROUND Noninvasive identification of culprit lesions has the potential to improve noninvasive risk stratification in patients with acute chest pain. METHODS Thirty-seven patients with acute coronary syndrome (ACS) or stable angina underwent coronary 16-slice MDCT and invasive selective angiography. In all significant coronary lesions two observers measured the degree of stenosis, plaque area at stenosis, and remodeling index and assessed plaque composition. Differences between culprit lesions in patients with ACS and stable lesions in patients with ACS or stable angina were determined. RESULTS We analyzed 40 lesions with excellent image quality in 14 patients with ACS and 9 patients with stable angina. Culprit lesions in patients with ACS (n = 14) had significantly greater plaque area and a higher remodeling index than both stable lesions in patients with ACS (n = 13) and in patients with stable angina (n = 13) (17.5 +/- 5.9 mm2 vs. 9.1 +/- 4.8 mm2 vs. 13.5 +/- 10.7 mm2, p = 0.02; and 1.4 +/- 0.3 vs. 1.0 +/- 0.4 vs. 1.2 +/- 0.3, p = 0.04, respectively). The prevalence of non-calcified plaque was 100%, 62%, and 77%, respectively, and the prevalence of calcified plaque was 71%, 92%, and 85%, respectively, in culprit lesions in patients with ACS and in stable lesions in patients with ACS or stable angina. CONCLUSIONS We introduce the concept of noninvasive detection and characterization of coronary atherosclerotic lesions in patients with ACS by MDCT. We identified differences in lesion morphology and plaque composition between culprit lesions in ACS and stable lesions in ACS or stable angina, consistent with previous intravascular ultrasound studies.