Dual-source CT imaging to plan transcatheter aortic valve replacement: accuracy for diagnosis of obstructive coronary artery disease.

ABSTRACT

PURPOSE: To assess the accuracy of computed tomographic (CT) examinations performed for the purpose of transcatheter aortic valve replacement (TAVR) planning to diagnose obstructive coronary artery disease (CAD). MATERIALS AND METHODS: With institutional review board approval, waivers of informed consent, and in compliance with HIPAA, 100 consecutive TAVR candidates (61 men, mean age 79.6 years ± 9.9) who underwent both TAVR planning CT (with a dual-source CT system) and coronary catheter (CC) angiographic imaging were retrospectively analyzed. At both modalities, the presence of stenosis in the native coronary arteries was assessed. Additionally, all coronary bypass grafts were rated as patent or occluded. With CC angiographic imaging as the reference standard, the accuracy of CT for lesion detection on a per-vessel and per-patient basis was calculated. The accuracy of CT for the assessment of graft patency was also analyzed. RESULTS: For per-vessel and per-patient analysis for the detection of stenosis that was 50% or more in the native coronary arteries, CT imaging had, respectively, 94.4% and 98.6% sensitivity, 68.4% and 55.6% specificity, 94.7% and 93.8% negative predictive value (NPV), and 67.0% and 85.7% positive predictive value. Per-patient sensitivity of stenosis 50% or greater with CT for greater than 70% stenosis at CC angiographic imaging was 100%. All 12 vessels in which percutaneous coronary intervention was performed were correctly identified as demonstrating stenosis 50% or greater with CT. There was agreement between CT and CC angiographic imaging regarding graft patency in 114 of 115 grafts identified with CC angiographic imaging. CONCLUSION: TAVR planning CT has high sensitivity and NPV in excluding obstructive CAD. An additional preprocedural CC angiographic examination may not be required in TAVR candidates with a CT examination that does not show obstructive CAD.