CT Scans Deemed To Be Effective for Detecting Coronary Artery Disease

Computed tomography (CT) angiography is as accurate as an invasive angiogram in detecting coronary artery disease (CAD), according to the findings of the first two prospective multicenter 64-slice scanner trials.

The trials were presented in November 2007 at the annual meeting of the Radiological Society of North America (RSNA), held in Chicago, IL, USA. The Coronary Artery Evaluation Using 64-Row Multidetector Computed Tomography Angiography (CORE-64) Trial, conducted by researchers at nine international centers, including Beth Israel Deaconess Medical Center (BIDMC; Boston, MA, USA), evaluated 291 patients who were scheduled to undergo invasive coronary angiography for suspected or unknown coronary artery disease. The study found that 64-slice multidetector CT angiography was highly accurate in detecting blockages of greater than 50%, with a sensitivity of 85% and a specificity of 90%. The noninvasive exam was equal in accuracy to invasive angiography in its ability to identify patients to be referred for angioplasty or bypass surgery.

"This study shows that patients with low to intermediate risk of coronary blockages are likely to benefit from a non-invasive scan,” said Melvin Clouse, M.D., a radiologist from BIDMC and one of two lead trial investigators. "The study suggests that that CT angiography may eventually replace other non-invasive tests that rely on reduction of blood flow to the heart to diagnose arterial blockage.”

"CT angiography may indeed replace cardiac catheterization and guide further interventions including risk factor modification/medical therapy, catheter-based, or surgical revascularization,” said Roger Laham, M.D., a BIDMC cardiologist and co-principal investigator. "This heralds a new and promising era in diagnostic cardiac imaging with cardiologists and radiologists working together to provide best care to our patients.”

A second trial, called the Assessment by Coronary Computed Tomographic Angiography of Individuals UndeRgoing InvAsive Coronary AngiographY (ACCURACY) Trial, compared 64-row coronary computed tomographic angiography (CCTA) to quantitative coronary angiography (QCA). The trial's findings demonstrated that CCTA is very accurate in detecting coronary blockages in chest pain patients referred for invasive coronary angiography and an effective noninvasive method to exclude obstructive coronary blockages. Sixteen institutions performed CCTA on 232 patients with typical or atypical chest pain prior to invasive coronary angiography. Results were then compared to those of QCA, the reference standard used to quantify the results of the invasive coronary angiography.

A total of 82 blockages greater than 50% in 49 patients, and 31 blockages greater than 70% were detected in 28 patients by QCA. Per-patient sensitivity and specificity of CCTA were 93% and 82%, respectively, for blockages greater than 50%, and 91% and 84% for blockages greater than 70%. In addition, its negative predictive value was 97-99%.


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