Multidetector computed tomography angiography (MDCTA) may offer a noninvasive alternative for evaluating coronary artery anatomy in patients with suspected coronary artery disease (CAD). This imaging modality has good diagnostic accuracy for determining the presence of significant coronary artery stenosis in symptomatic patients and also identified those who were likely to be referred for a revascularization procedure (angioplasty or coronary bypass surgery).

“Our interpretation of this analysis is that multidetector CT will become an integral part of the diagnostic algorithm in patients with coronary artery disease,” said Julie Miller, MD, Johns Hopkins University, Baltimore, MD, who reported on the study.

The international, multicenter, trial (CORE-64) was the first prospective study to compare 64-row 0.5 mm MDCTA with – quantitative coronary angiography (QCA). The final analysis was done on data for 291 patients (868 vessels; 3,782 segments) who were a median of 59 years old and had an Agatston calcium score ≤600 (a score of >400 indicates a high likelihood of at least one stenosis). The patients had ECG-gated contrast-enhanced 64-slice MDCT (0.5 mm slice thickness) within 30 days before scheduled QCA and were followed up for clinical events at 30 days and 6 months.

The study differed from other studies in that the entire coronary tree was analyzed, said Dr. Miller; all nonstented segments of at least 1.5 mm were evaluated by both methods. Significant stenosis by QCA was defined as more than 50% stenosis. The diagnostic accuracy (sensitivity and specificity) of MDCTA for identifying significant stenosis (compared with QCA) was the primary endpoint.

The diagnostic performance of MDCTA was better on a per patient basis than on a per vessel basis. On a per patient basis, MDCTA had a sensitivity of 85% and a specificity of 90% (Table 1). In contrast, the sensitivity and specificity were 76% and 93%, respectively, on a per vessel basis. Dr. Miller noted that MDCTA was highly diagnostic based on receiver operating characteristics (ROC) analysis of the data – the ROC area was 93% on a per patient basis, and 91% on a per vessel basis. The ability of MDCTA to predict the need for revascularization was similar to that of QCA; the ROC area for MDCTA was 0.84 compared with 0.82 for QCA (p=0.36) on a per patient basis and 0.84 and 0.89, respectively, on a per vessel basis.

Previous studies have shown highly variable results for the diagnostic accuracy of MDCTA, but Dr. Miller pointed out that those studies were single-center studies and did not compare MDCTA with QCA in predicting revascularization.