Multi-slice computed tomography: Can it adequately rule out left main coronary disease in patients with an intermediate probability of coronary artery disease?

BACKGROUND Multi-slice computed tomography (MSCT) is a fast-growing technology that permits a non-invasive, yet reliable, assessment of coronary atherosclerosis. We sought to explore the diagnostic accuracy of MSCT angiography in the detection of significant stenosis of the left main coronary artery (LMCA) in a series of patients with an intermediate pre-test likelihood of coronary artery disease (CAD). METHODS We prospectively enrolled 30 consecutive patients with an intermediate pre-test likelihood of CAD. Patients underwent 64-slice MSCT angiography to detect significant stenosis of the LMCA (defined as ≥ 50% luminal obstruction). They subsequently underwent invasive coronary angiography according to the standard technique. RESULTS The mean age was 52.7 ± 6.3 years, 24 (80%) being males. Three (10%) patients had significant stenosis of the LMCA by invasive coronary angiography, while four (13.3%) patients were categorized as having significant LMCA stenosis by MSCT coronary angiography. MSCT coronary angiography was able to detect significant LMCA stenosis with a sensitivity of 100%, specificity of 96.3%, positive and negative predictive values of 75% and 100% respectively, and a diagnostic accuracy of 96.7%, with reference to invasive coronary angiography. CONCLUSIONS In patients with an intermediate pre-test likelihood of CAD, MSCT coronary angiography provides a highly accurate diagnostic modality for ruling out significant LMCA stenosis, with reference to invasive coronary angiography.