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 afte r percutaneous transluminal coronary angioplasty (PTCA) using a semi-a utomated digital system. The values obtained were considered as standa rd 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 PT CA, the operator consistently overestimated stenosis severity (87.8 +/ - 8.5%, P < 0.0001) and consensus-reading reduced but did not eliminat e this overestimation (78.0 +/-12.3%, P < 0.05). The error in visual e stimation was inversely correlated with the measured degree of stenosi s: coefficients were -0.79 (P < 0.0001) and -0.51 (P < 0.0001) for ope rator and consensus-readers, respectively. After PTCA, the operator un derestimated the residual stenosis (21.2 +/- 9.9%, P < 0.0001) but the re was no systematic bias by consensus-reading (29.4 +/- 12.0%, NS). A gain 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, respe ctively. In conclusion, the operator overestimates lesion severity bef ore and underestimates moderate residual stenoses after PTCA, a proble m only partially corrected by independent consensus-readers. (C) 1994 Wiley-Liss, Inc.