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Objectives: We sought to determine the diagnostic accuracy of noninvasive visual (computed tomography coronary angiography [CTCA]) and quantitative computed tomography coronary angiography (QCT) to predict the hemodynamic significance of a coronary stenosis, using intracoronary fractional flow reserve (FFR) as the reference standard., Background: It has been demonstrated that CTCA provides excellent diagnostic sensitivity for identifying coronary stenoses, but may lack accurate delineation of the hemodynamic significance., Methods: We investigated 79 patients with stable angina pectoris who underwent both 64-slice or dual-source CTCA and FFR measurement of discrete coronary stenoses. CTCA and conventional coronary angiography (CCA), and QCT and quantitative coronary angiography (QCA), were performed to determine the severity of a stenosis that was compared with FFR measurements. A significant anatomical or functional stenosis was defined as >/=50% diameter stenosis or an FFR <0.75. Stented segments and bypass grafts were not included in the analysis., Results: A total of 89 stenoses were evaluated of which 18% (16 of 89) had an FFR <0.75. The diagnostic accuracy of CTCA, QCT, CCA, and QCA to detect a hemodynamically significant coronary lesion was 49%, 71%, 61%, and 67%, respectively. Correlation between QCT and QCA with FFR measurement was weak (R values of -0.32 and -0.30, respectively). Correlation between QCT and QCA was significant, but only moderate (R = 0.53; p < 0.0001)., Conclusions: The anatomical assessment of the hemodynamic significance of coronary stenoses determined by visual CTCA, CCA, or QCT or QCA does not correlate well with the functional assessment of FFR. Determining the hemodynamic significance of an angiographically intermediate stenosis remains relevant before referral for revascularization treatment.

Objectives: We assessed the usefulness of 64-slice computed tomography coronary angiography (CTCA) to detect or rule out coronary artery disease (CAD) in patients with various estimated pretest probabilities of CAD., Background: The pretest probability of the presence of CAD may impact the diagnostic performance of CTCA., Methods: Sixty-four-slice CTCA (Sensation 64, Siemens, Forchheim, Germany) was performed in 254 symptomatic patients. Patients with heart rates > or =65 beats/min received beta-blockers before CTCA. The pretest probability for significant CAD was estimated by type of chest discomfort, age, gender, and traditional risk factors and defined as high (> or =71%), intermediate (31% to 70%), and low (< or =30%). Significant CAD was defined as the presence of at least 1 > or =50% coronary stenosis on quantitative coronary angiography, which was the standard of reference. No coronary segments were excluded from analysis., Results: The estimated pretest probability of CAD in the high (n = 105), intermediate (n = 83), and low (n = 66) groups was 87%, 53%, and 13%, respectively. The diagnostic performance of the computed tomography (CT) scan was different in the 3 subgroups. The estimated post-test probability of the presence of significant CAD after a negative CT scan was 17%, 0%, and 0% and after a positive CT scan was 96%, 88%, and 68%, respectively., Conclusions: Computed tomography coronary angiography is useful in symptomatic patients with a low or intermediate estimated pretest probability of having significant CAD, and a negative CT scan reliably rules out the presence of significant CAD. Computed tomography coronary angiography does not provide additional relevant diagnostic information in symptomatic patients with a high estimated pretest probability of CAD.

Objectives: Our objective was to prospectively evaluate the diagnostic performance of the high-speed dual-source computed tomography scanner (DSCT), with an increased temporal resolution (83 ms), for the detection of significant coronary lesions (> or =50% lumen diameter reduction) in a clinically wide range of patients., Background: Cardiac motion artifacts may decrease coronary image quality with use of earlier computed tomography scanners that have a limited temporal resolution., Methods: We prospectively studied 100 symptomatic patients (79 men, 21 women, mean age 61 +/- 11 years) with atypical (18%) or typical (55%) angina pectoris, or unstable coronary artery disease (27%) scheduled for conventional coronary angiography. Mean scan time was 8.58 +/- 1.52 s. Mean heart rate was 68 +/- 11 beats/min. Quantitative coronary angiography was used as the standard of reference. Irrespective of image quality or vessel size, all segments were included for analysis., Results: Invasive coronary angiography demonstrated no significant disease in 23%, single-vessel disease in 31%, and multivessel disease in 46% of patients; 1,489 coronary segments, containing 220 significant (14.8%) stenoses, were available for analysis. Sensitivity, specificity, and positive and negative predictive values of DSCT coronary angiography for the detection of significant lesions on a segment-by-segment analysis were 95% (95% confidence interval [CI] 90 to 97), 95% (95% CI 93 to 96), 75% (95% CI 69 to 80), 99% (95% CI 98 to 99), respectively, and on a patient-based analysis 99% (95% CI 92 to 100), 87% (95% CI 65 to 97), 96% (95% CI 89 to 99), and 95% (95% CI 74 to 100), respectively., Conclusions: Noninvasive DSCT coronary angiography is highly sensitive to detect and to reliably rule out the presence of a significant coronary stenosis in patients presenting with atypical or typical angina pectoris, or unstable coronary artery disease.