Abstract 1909: Effect of Coronary Artery Calcium Score on Complete Coronary Tree Visualization by 64-Slice Computed Tomographic Coronary Angiography
Background: Coronary artery calcium (CAC) is known to significantly limit visualization of the coronary arterial tree by 4- and 16-slice computed tomographic coronary angiography (CTCA). We aimed to determine the effect of CAC on coronary arterial visualization by 64-slice CTCA.
Methods: We reviewed imaging findings of 1009 consecutive outpatients who underwent CAC scoring followed by 64-slice CTCA. Based on the AHA 17-segment coronary tree model, CTCA data was evaluated for the visualization quality of each coronary artery segment (adequate or inadequate). A study is considered of incomplete quality when any segment of the coronary tree was inadequately imaged.
Results: Proportion of CTCA studies with complete visualization quality was high when CAC scores were less than 300 (98.6% for CAC of 0, 97.1% for CAC 1–50, 91.4% for CAC 51–100, 93.5% for CAC 101–200, 89.5% for CAC 201–300). This rate was markedly decreased when CAC scores were greater than 1000 (47.2% for CAC 1001–5000, 33.3% for CAC > 5000). Intermediate rates were found for CAC scores 301–1000 (80.8% for CAC 301–500, 73.4% 501–1000).
Conclusions: The likelihood of achieving a 64-slice CTCA study that adequately visualizes the entire coronary tree is excellent in patients with CAC scores less than 300. In contrast, CAC scores greater than 1000 is associated with a drastic drop-off in complete coronary tree visualization, suggesting that alternative methods to assess coronary arterial anatomy should be pursued in such patients.