VISUAL ESTIMATION OR QUANTITATIVE ASSESSM ENT OF STENOSIS SEVERITY - IMPACT ON THE OPTION FOR PRIMA VISTA PTCA

In 300 patients with 339 coronary lesions the percent diameter stenosi s (%-DS) was assessed both by visual estimation and by digital quantit ative coronary angiography (DQCA) by use of an on-line computer workst ation. The decision for coronary angioplasty in the same setting (''pr ima vista''-PTCA) was based on history, evidence of ischemia and visua l estimation of %-DS. DQCA measurements of the 339 stenoses revealed a normal distribution of lesion severity with a mean of 58,4 +/- 11,3 % . In contrast to DQCA visual estimation led to a bimodal distribution with a nadir at similar to 55 % between two peaks at similar to 45 % a nd similar to 75 % and a mean of 70,5 +/- 19.6 %. Visual estimation un derestimated lesions in the range of 30-55 % and overestimated the %-D S between 55-99 %. Visual estimation revealed a %-DS greater than or e qual to 60 % in 251 stenoses (74,0 %) of the 339 lesions, an estimate that led to subsequent ''prima vista''-PTCA. Conversely, DQCA revealed only 184 stenoses (54,3 %) with a %-DS greater than or equal to 60 %; thus, 86 stenoses (25,3 %) did not meet the morphologic indication cr iteria for PTCA. The bimodal distribution of stenosis severity accordi ng to visual analysis with an overestimation of borderline stenosis se verity reflects a tendency for ''self-referral'' of patients for PTCA. DQCA serves as an objective tool in the decision-making process for P TCA and may reduce ''cosmetic'' interventions or justify to defer PTCA . Especially in the selection process for ''prima vista''-PTCA DQCA-qu antification of stenosis severity is recommended.