Is there a relation between non-calcifying coronary plaques and acute coronary syndromes? A retrospective study using multislice computed tomography.

OBJECTIVES: The purpose of this study was to assess whether different coronary plaque types as classified by multislice computed tomography (CT) are retrospectively correlated with acute coronary syndromes (ACS) in an unselected study population. METHODS: Sixty-three consecutive patients were examined with 16-slice CT coronary angiography. Coronary plaque types were classified as calcifying type 1, mixed (calcifying > non-calcifying) type 2, mixed (non-calcifying > calcifying) type 3, and non-calcifying type 4. Patients who had an ACS within 17 days were included. All patients underwent invasive coronary angiography. RESULTS: Fifty-eight patients (92%) had coronary plaques evaluated by CT: 18 type 1 (31%), 10 type 2 (17%), 16 type 3 (28%) and 14 type 4 (24%). The presence of a non-calcifying plaque component (types 2-4; 40 of 63 patients, 63%) was correlated with ACS (n = 15; 24%) (p < 0.001). Only type 3 was significantly correlated with ACS (p = 0.01), but plaque types 2 and 4 were not. The diagnostic accuracy of CT for detection of stenosis >50% in proximal segments was: sensitivity 98%, specificity 90%, negative predictive value 97%, positive predictive value 97% per patient. CONCLUSIONS: Mixed calcifying/non-calcifying plaques with a predominantly non-calcifying component (type 3) as classified by multislice CT are retrospectively correlated with ACS.

Role of 16-multidetector computed tomography in the assessment of coronary artery stenoses: A prospective study of consecutive patients.

BACKGROUND: Recent studies have demonstrated a high sensitivity (S) of 16-multidetector computed tomography (16-MDCT) for the detection of significant coronary artery stenoses. Whether these results are applicable to clinical practice is unclear. Therefore, the aim of the present study was to compare 16-MDCT angiography with conventional coronary angiography (CCA) for the detection of significant coronary artery stenoses in a consecutive series of patients. METHOD: A total of 93 consecutive patients (mean [+/- SD] age 59+/-9 years), in whom CCA was performed for stable angina pectoris, underwent 16-MDCT angiography (16x0.75 mm, table feed 6.5 mm/s, rotation time 0.42 s; Sensation 16, Siemens Medical Solutions, Germany) the day before performing CCA. Patients with diabetes mellitus, serum creatinine level higher than 132.6 mumol/L and/or acute coronary syndromes were excluded. Two observers blinded to CCA results evaluated MDCT angiograms according to standard criteria. Segment-based (13 segments per patient) and patient-based (at least one stenosis greater than 50% lumen diameter reduction) analyses were performed. RESULTS: A total of 1209 segments were analyzed. Of these segments, 173 (14%) were excluded due to poor image quality or massive calcification. In 86 segments, CCA revealed significant coronary artery stenosis (greater than 50% diameter reduction). However, 16-MDCT detected only 47 of these, resulting in a S of 55% and a specificity (SP) of 97% (positive predictive value 64%; negative predictive value 96%). On a patient-based analysis, the S increased to 89%, whereas the SP still remained high (87%). CONCLUSION: In this relatively large consecutive cohort, S for the detection of significant coronary artery stenoses was moderate on a segment-based analysis but increased on a patient-based analysis using 16-MDCT. In contrast, SP was high in both analyses, supporting the use of 16-MDCT for the exclusion of significant coronary artery stenoses. Further improvement of spatial and temporal resolution in MDCT technology may lead to a lower exclusion rate and higher S.