Discrepancy between visual estimation and computer-assisted measurement of lesion severity before and after coronary angioplasty.
One hundred fourteen coronary stenoses were quantified before and after percutaneous transluminal coronary angioplasty (PTCA) using a semi-automated digital system. The values obtained were considered as standard for comparison with visual estimation by the PTCA operator as well as by independent consensus-reading. The measured percent stenosis was 62.7 +/- 13.7% before and 27.7 +/- 12.4% after angioplasty. Before PTCA, the operator consistently overestimated stenosis severity (87.8 +/- 8.5%, P < 0.0001) and consensus-reading reduced but did not eliminate this overestimation (78.0 +/- 12.3%, P < 0.05). The error in visual estimation was inversely correlated with the measured degree of stenosis: coefficients were -0.79 (P < 0.0001) and -0.51 (P < 0.0001) for operator and consensus-readers, respectively. After PTCA, the operator underestimated the residual stenosis (21.2 +/- 9.9%, P < 0.0001) but there was no systematic bias by consensus-reading (29.4 +/- 12.0%, NS). Again the error in visual estimation was inversely correlated with the measured degree of residual stenosis: coefficients were -0.76 (P < 0.0001) and -0.58 (P < 0.0001) for operator and consensus-reading, respectively. In conclusion, the operator overestimates lesion severity before and underestimates moderate residual stenoses after PTCA, a problem only partially corrected by independent consensus-readers.
Department of Cardiology, University Hospital Gasthuisberg, Leuven, Belgium.
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W
Desmet
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J
Willems
J
J
Van Lierde
J
J
Piessens
D015906:Angioplasty, Balloon, Coronary; D017023:Coronary Angiography / Q000379:methods*; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000628:therapy; D003331:Coronary Vessels / Q000473:pathology*; D003951:Diagnostic Errors; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015588:Observer Variation