OBJECTIVE: To evaluate the diagnostic accuracy of a dual-source computed tomography (DSCT) coronary angiography, with a particular focus on the effect of heart rate and calcifications. MATERIALS AND METHODS:One hundred and nine patients with suspected coronary disease were divided into 2 groups according to a mean heart rate (< 70 bpm and > or = 70 bpm) and into 3 groups according to the mean Agatston calcium scores (< or = 100, 101-400, and > 400). Next, the effect of heart rate and calcification on the accuracy of coronary artery stenosis detection was analyzed by using an invasive coronary angiography as a reference standard. Coronary segments of less than 1.5 mm in diameter in an American Heart Association (AHA) 15-segment model were independently assessed. RESULTS: The mean heart rate during the scan was 71.8 bpm, whereas the mean Agatston score was 226.5. Of the 1,588 segments examined, 1,533 (97%) were assessable. A total of 17 patients had calcium scores above 400 Agatston U, whereas 50 had heart rates > or = 70 bpm. Overall the sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) for significant stenoses were: 95%, 91%, 65%, and 99% (by segment), respectively and 97%, 90%, 81%, and 91% (by artery), respectively (n = 475). Heart rate showed no significant impact on lesion detection; however, vessel calcification did show a significant impact on accuracy of assessment for coronary segments. The specificity, PPV and accuracy were 96%, 80%, and 96% (by segment), respectively for an Agatston score less than 100% and 99%, 96% and 98% (by artery). For an Agatston score of greater to or equal to 400 the specificity, PPV and accuracy were reduced to 79%, 55%, and 83% (by segment), respectively and to 79%, 69%, and 85% (by artery), respectively. CONCLUSION: The DSCT provides a high rate of accuracy for the detection of significant coronary artery disease, even in patients with high heart rates and evidence of coronary calcification. However, patients with severe coronary calcification (> 400 U) remain a challenge to diagnose.
Calcinosis/*radiography ; Coronary Angiography/methods/*standards ; Coronary Disease/*radiography ; Coronary Vessels/*pathology ; Female ; *Heart Rate ; Humans ; Male ; Middle Aged ; Predictive Value of Tests ; Sensitivity and Specificity ; Tomography, X-Ray Computed/methods/*standards

To evaluate the feasibility and usefulness of transthoracic Doppler echocardiography (TTDE) as a non-invasive method in recording distal anterior descending (LAD) coronary flow velocity, we compared coronary flow reserve (CFR) measured by TTDE with measurements by intracoronary Doppler wire (ICDW). Twenty-one patients without LAD stenosis were studied. ICDW performed at baseline and after intracoronary injection of 18 microg adenosine. TTDE was performed at baseline and after intravenous adenosine (140 microg/kgmin for 2 min). Adequate Doppler recordings of coronary flow velocities during systole were obtained in 14 of 21 study patients (67%) and during diastole in 17 (81%) patients. Baseline and hyperemic peak diastolic flow velocities measured by TTDE were significantly smaller than those obtained by ICDW (p<0.05). However, diminishing trends of diastolic and systolic velocity ratio after hyperemia were similarly observed in both methods. CFR obtained by TTDE (3.0+/-0.5), was higher than the value calculated by ICDW (2.5+/-0.4). There were significant correlations between the values obtained by the two methods (r=0.72, p<0.01). It is concluded that TTDE is a feasible method in measuring coronary flow velocity and appears to be a promising non-invasive method in evaluating CFR.
Adult ; Aged ; Blood Flow Velocity ; Comparative Study ; Coronary Angiography ; Coronary Circulation* ; Coronary Disease/ultrasonography* ; Echocardiography, Doppler/standards ; Echocardiography, Doppler/methods* ; Female ; Heart Rate ; Human ; Hyperemia/ultrasonography ; Linear Models ; Male ; Middle Age ; Prospective Studies ; Reproducibility of Results