Abstract 8796: Comparison of Coronary Flow Velocity Reserve Measurement by Transthoracic Doppler Echocardiography with 320-Row Multidetector Computed Tomography Coronary Angiography for Predicting Coronary Artery Stenosis in Calcified Lesions in the Three Major Coronary Arteries

Abstract

Objectives: This study examined the diagnostic accuracy of coronary flow velocity reserve (CFR) measurement using transthoracic Doppler echocardiography (TTDE) by comparing 320-row multidetector computed tomography coronary angiography (CTCA) for predicting coronary artery stenosis in calcified lesions in the 3 major coronary arteries. Methods and Results: Invasive coronary angiography (ICA), CTCA, and CFR measurement were performed in 101 patients. The presence of stenosis ≥50% was considered significant stenosis by ICA. By CTCA, the degree of coronary artery calcification was assessed using the Agatston calcium score (CS) method. Prospectively electrocardiographically-gated CTCA was performed with the use of test-injection method for the assessment of coronary artery stenosis. Coronary flow velocity was recorded in each target coronary artery by TTDE at rest and during hyperemia induced by intravenous infusion of adenosine triphosphate. CFR <2, calculated as the ratio of hyperemic to basal peak and mean diastolic velocity, was considered ≥50% stenosis. Results: A significant coronary stenosis by ICA was found in 60 vessels. Coronary artery legions were successfully assessed in 91% and 95% of all vessels by CTCA and TTDE, respectively. CTCA had a sensitivity of 92%, a specificity of 93%, a positive predictive value (PPV) of 73%, and a negative predictive value (NPV) of 98% in patients with 0-299 CS, and had a sensitivity of 89%, a specificity of 67%, a PPV of 47%, and an NPV of 95% in patients with 300-599 CS for predicting coronary artery stenosis. In patients with ≥ 600 CS, 73% of vessels were unassessable. CFR<2.0 had a sensitivity of 90%, a specificity of 90%, a PPV of 71%, and an NPV of 97% in patients with 0-299 CS, had a sensitivity of 92%, a specificity of 89%, a PPV of 79%, and an NPV of 96% in patients with 300-599 CS, and had a sensitivity of 100%, a specificity of 85%, a PPV of 77%, and an NPV of 100 % in patients with ≥ 600 CS for predicting coronary artery stenosis. Conclusions: CFR measurement accurately predicts significant coronary artery stenosis irrespectively of the degree of coronary artery calcification whereas progression of coronary calcification negatively influences diagnostic accuracy of CTCA-based assessment of coronary artery stenosis.