The Diagnostic Performance of 64-Slice Multislice Computed Tomography in Assessment of Coronary Artery Disease

The diagnostic performance of 64 slice multislice computed tomography in assessment of coronary artery disease. Aim of the Work: To assess the diagnostic performance of 64-slice computed tomography coronary angiography (CTCA) to detect or rule out coronary artery disease (CAD). Secondary Objective: To assess the usefulness of CTCA in patients with various estimated pretest probabilities of CAD. Background: The pretest probability of the presence of CAD may impact the diagnostic performance of CTCA. Design: Analytic comparative study. Sampling: Comprehensive universal sample. Site of the Study: Farwania Hospital, Kuwait. Methods: 42 patients, mean age 54 (±18) years with known and suspected coronary artery disease underwent 64- slice MSCT. Patients with heart rates 65 beats/min. received beta-blockers before CTCA. The pretest probability for significant CAD was estimated by type of chest discomfort, age, gender, and traditional risk factors and defined as high ( 71%), intermediate (31% to 70%), and low ( 30%). Significant CAD was defined as the presence of at least 1³50% coronary stenosis on quantitative coronary angiography, which was the standard of reference. Main Outcome Measures: Diagnostic accuracy of 64- slice MSCT to detect obstructive ( 50% luminal narrowing) stenosis in patients. Results: On segmental level, 608 coronary segments were of sufficient quality (85.2%). In the 42 patients included; the sensitivity (88.4%) and specificity (94.3%) on a segmental level. On a patient level, the sensitivity (87%), specificity (78.9%) whereas on the vessel level, the sensitivity and specificity were 91.2% and 87.4% respectively. The estimated pretest probability of CAD in the high (n = 18), intermediate (n = 13), and low (n = 11) groups was 88%, 54%, and 12%, respectively. The diagnostic performance of CT was different in the 3 subgroups. The estimated post-test probability of the presence of significant CAD after a negative CT scan was 16%, 0% and 0% and after a positive CT was 95%, 86%, and 66%, respectively. Conclusion: The findings confirm the high diagnostic accuracy of 64-slice MSCT coronary angiography. CTCA is useful in symptomatic patients with a low or intermediate estimated pretest probability of having significant CAD, and a negative CT accurately rules out the presence of significant CAD. CTCA does not provide additional relevant diagnostic information in symptomatic patients with a high estimated pretest probability of CAD.