Assessment of coronary artery stenoses: comparison of quantitative coronary angiography with visual interpretation and myocardial scintigraphy

The aim of the study was to compare visual estimates of the severity of coronary stenoses (VE) and quantitative coronary angiography (QCA) and to relate both parameters to myocardial perfusion scintigraphy. The authors studied 80 patients (63 men, 17 women) with angiographically determined single vessel disease (47 LAD, 22 LCX, 11 RCA) and no prior myocardial infarction. 45 of these patients also underwent a Tl-201 perfusion SPECT. VE was performed from coronary angiograms by 3 independent observers. QCA was performed off-line using the QCA-CMS 2.3D. Interobserver variability of VE was highest for intermediate stenoses (40-60% diameter stenosis). VE agreed better with QCA%-area stenosis for severe lesions (>50%-diameter stenosis) and with QCA%-diameter stenosis for mild lesions (<40%-diameter stenosis). Diagnostic accuracies of VE and QCA were high (area under ROC-curve≈0.90). 50% QCA%-diameter stenosis and 63% percent stenosis by VE were the optimal threshold values to differentiate normal and abnormal results of myocardial scintigraphy. Thus, VE yields adequate accuracy in most clinical routine patients. For borderline lesions and for scientific studies QCA should be preferred