Noninvasive detection of coronary artery stenosis with 16-slice spiral computed tomography in a population at low to moderate risk for coronary artery disease.

OBJECTIVE

To evaluate the feasibility and accuracy of 16-slice spiral computed tomography (MSCT) in detecting coronary artery lesions in a low to moderate risk population.

METHODS

MSCT was performed in 33/78 patients at low to moderate risk for coronary artery disease affected by mitral and/or aortic valve disease and scheduled for conventional coronary angiography for pre-surgery evaluation. The sensitivity (SE), specificity (SP), positive (PPV) and negative predictive values (NPV) to identify >or=50% obstructed lesions were evaluated. Moreover, a discriminant predictive statistical analysis was performed.

RESULTS

MSCT visualised 428/479 (89%) segments identified at coronary angiography and the percentage of evaluable segments was 87%. By including all coronary branches, SE, SP, PPV and NPV were 69%, 96%, 58% and 97%, respectively. By excluding the segments with a diameter of <or=2 mm, SE and SP were 74% and 96%, respectively (MSCT correctly identified 17/23 lesions). In the evaluable coronary arteries, SE and SP were 86% and 88% for the left anterior descending coronary artery, 100% and 85% for the left circumflex coronary artery, and 86% and 89% for the right coronary artery, respectively. SP was 100% for the left main artery. When restricting the analysis to the patients, 22/23 patients were adequately evaluable, and SE, SP, PPV and NPV were 100%, 80%, 85% and 100%, respectively. Using the discriminant predictive statistical analysis of quantitative (age, heart rate and calcium score) and qualitative variables (presence or absence of critical lesions at MSCT), an overall accuracy of 85% was obtained.

CONCLUSIONS

The percentage of adequately evaluable patients was low because of limitations due to calcifications. In selected populations at low to moderate risk for coronary artery disease, MSCT has a high NPV in the evaluation of coronary artery stenosis.