Impact of Calci_cation on Diagnostic Accuracy of 64-Slice Spiral Computed Tomography for Detecting Coronary Artery Disease: A Single Center Experience

Background: The main aim of our study was to investigate the in_uence of calci_cation on the accuracy of 64-slice computed tomography for identi_cation of signi_cant coronary artery disease. Methods: A contrast-enhanced 64-slice computed tomography was performed prior to invasive coronary angiography in 168 consecutive patients with suspected coronary artery disease. All coronary segments 1.5 mm or larger in diameter were evaluated for the presence or absence of signi_cant coronary artery stenosis, de_ned as a diameter reduction of >50%. The patients were also ranked by total calcium score which was expressed in Agatston units and the impacts of calci_cation on diagnostic accuracy of 64-slice computed tomography were assessed. Results were compared with quantitative coronary angiography as the standard of reference. Results: The overall sensitivity, speci_city, positive predictive value, and negative predictive value of 64-slice computed tomography for detection of signi_cant stenosis were: by segments, 95%, 98%, 91%, and 99%, respectively; by patient, 98%, 97%, 96%, and 99%, respectively; and by artery, 94%, 93%, 91%, and 95%, respectively. In mild and moderate calcium scores (0 – 418 Agatston units), the sensitivity was 100%, speci_city was 93%, positive predictive value was 97% and negative predictive value was 100%. Severe calci_cation (>419 Agatston units) reduced the sensitivity, speci_city, positive, and negative predictive values of multi-slice computed tomography to 89%, 60%, 89%, and 60%, respectively. Conclusion: Our study revealed that the 64-slice computed tomography is a highly accurate diagnostic modality for detecting hemodynamically signi_cant coronary stenosis; however, severe calci_cation is considered as a shortcoming which limits the routine application of multi-slice computed tomography in daily practice.