Abstract 15620: Diagnostic Performance of Ultra-high-resolution CT Coronary Angiography in Patients With Severe Coronary Artery Disease: Initial Experience

Abstract

Introduction: Conventional resolution coronary CTA (CRCT) is frequently avoided in patients with heavy calcification and prior stents given the diminished diagnostic accuracy. Ultra-high-resolution CT (UHRCT) with detector width of 0.25 mm may overcome partial volume effect limitations. Hypothesis: We hypothesize that UHRCT yields high accuracy for detecting obstructive coronary arterial stenoses in patients with severe coronary artery disease using cardiac catheterization as reference standard. Methods: Nine patients ≥45 years with severe coronary artery disease referred for invasive coronary angiography were prospectively enrolled at a single center. Patients underwent UHRCT within 30 days prior to catheterization and results for significant coronary artery stenoses (≥70%) by visual assessment by blinded expert readers for the two tests were compared. Diagnostic accuracy assessment was performed at a patient-level (N=9) and vessel-level (N=36). Results: Median patient age was 67 (range 53-77). Six patients were obese and 6 had prior stent placement. Estimated radiation dose was 9.3 mSv. Mean Agatston calcium score of patients without stents was 1,688. UHRCT correctly classified all patients as having obstructive or non-obstructive coronary heart disease, respectively, yielding 100% accuracy (95% confidence interval [CI] 64-100%). On a vessel level UHRCT had an accuracy of 93% (95% CI 78-98%). Conclusions: Our initial experience with UHRCT in patients with severe coronary calcification or prior stenting suggests high accuracy for detecting and excluding obstructive stenoses. These results warrant further studies to confirm a role of UHRCT in this challenging population.