Impact of Lesion Length on Functional Significance in Intermediate Coronary Lesions

Abstract

Myocardial fractional flow reserve (FFR) is useful in the evaluation of coronary lesion ischemia. However, the impact of lesion length on FFR has not been adequately assessed. We hypothesized that lesion length would influence functional significance in intermediate coronary lesions. FFR measurements were assessed in 136 patients (163 lesions) with stable angina who had >40% stenotic coronary lesion by quantitative coronary angiography (QCA). One hundred sixty-three lesions were classified as intermediate (40%-70% stenosis; n=107; group I) or significant (≥70%; n=56; group S) by QCA. We assessed the relationships between lesion length, coronary stenosis, and FFR in these 163 lesions. Regression analysis revealed an inverse correlation between the percentage of diameter stenosis (%DS) and FFR in group S (r = -0.83, P < 0.0001). In group I, no significant correlation was found between %DS and FFR (r = -0.06, P = 0.55), whereas lesion length was significantly inversely correlated with FFR (r = -0.79, P < 0.0001). Receiver operating characteristic curve analysis demonstrated that the best cutoff value for predicting an FFR value <0.80 was a lesion length >16.1 mm in group I (sensitivity, 86%; specificity, 94%). These study findings suggest that lesion length has a physiologically significant impact on intermediate-grade coronary lesions.