Abstract 15233: The Lesion Length Gives a Better Effect on the Fractional Flow Reserve Than the Minimal Luminal Area in the Intermediate Coronary Artery Lesion

Abstract

Introduction: The pressure gradient of the circulation fluid in a stenosis area depends on minimal luminal area (MLA) of the stenosis, lesion length (LL), and the fluid velocity. However, the correlation of the LL and the MLA; the cutoff values are uncertain. Hypothesis: LL and MLA differently influences the FFR. Methods: We studied 117 patients with intermediate coronary artery disease who underwent FFR and IVUS measurement out of 302 patients in FAVOR study. This study was a prospective, 1:1 randomized, open label multicenter trial to demonstrate the clinical outcomes between FFR and IVUS-guided PCI. Inclusion criteria were as follows: 1)Angina or documented silent ischemia 2) De novo intermediate coronary artery disease (30-70% diameter stenosis) by visual estimation, 3) Reference vessel diameter ≥ 3.0mm by visual estimation. We excluded left main disease, MI, EF< 40%, and graft vessel. There were no significant differences in baseline clinical characteristics. The mean values are the QCA (54.3±14.0 %), MLA (3.6±1.4 mm2) and LL (20.6±1.4mm), respectively. We were performed the path analysis using AMOS 18, and estimated the ROC curve in SPSS 18. Results: Standardized estimates were the LL -0.47,QCA -0.28 and MLA -0.21 (R2=0.594, p<0.000) in path analysis. The model is recursive and statistically significant. The FFR was ≤0.80 in 47 lesions (31%). The optimal LL for an FFR of ≤0.80 was 15.8mm (90% sensitivity, 50% specificity, 44% positive predictive value, 87% negative predictive value, area under the curve: 0.75, 95% CI: 0.66 to 0.85; p < 0.001) and MLA 3.9mm (sensitivity 86%, specificity 59%, 35% positive predictive value , 94% negative predictive value, area under the curve: 0.78, 95% CI: 0.67 to 0.85; p < 0.001) Conclusions: The lesion length influenced more the FFR than MLA. The lesion length ≥ 15.8mm and MLA ≤ 3.9mm are risk zones, which need to be confirm the functional status with FFR because of the low positive predictive value