On-line independent digital stenosis morphometry avoids self referral bias for interventional coronary therapy

The diameter stenosis (%DS) in 226 coronary lesions of 200 patients undergoing primary (p) PTCA was assessed on-site by both visual "eye balling" (EB) and independent digital quantitative coronary angiography (DQCA). EB overestimated the %DS up to 49% and had a bimodal distribution with a nadir at 55%DS between the two peaks at /spl sim/50% and /spl sim/75%DS and a mean of 69.8/spl plusmn/19.9% whereas DQCA of the identical lesions revealed a near gaussian distribution with a mean of 58.5/spl plusmn/11.3%. EB revealed a %DS/spl ges/60% in 166 stenoses (73.4%), an estimate that led to pPTCA. However, only 119 (52.6%) of these lesions had objectively a %DS/spl ges/60% by DQCA. With regard to the indication for PTCA 47 of 166 performed pPTCA (28.3%) would not meet the indication criteria based on objective DQCA information. EB and DQCA (/spl plusmn/5%DS) led to a concordant indication for pPTCA only in 103 of 226 (60.8%) coronary lesions. The conclusion was reached that independent on-site DQCA supports decision-making and is likely to avoid the bias of "self-referral" and thus improve patient selection for pPTCA.