[Association between fractional flow reserve and quantitative coronary angiography parameters in intermediate coronary artery stenosis].

Objective: To explore the relationship between quantitative coronary angiography (QCA) parameters and fractional flow reserve (FFR) for identifying ideal angiographic parameters predictive of myocardial ischemia.
Methods: The study included 121 lesions with QCA and FFR data from 106 patients [mean age: (63 ± 10) years]. The lesions were grouped into FFR > 0.75 group and FFR ≤ 0.75 group. Assessed parameters by QCA included percentage diameter stenosis, minimum luminal diameter (MLD), percentage area stenosis, minimum luminal area (MLA), reference vessel diameter (RVD) and lesion length (LL). Correlation analysis was used to identify the relationship between QCA parameters and FFR value, and receiver operating characteristic (ROC) curve was used to determine parameters predictive of FFR ≤ 0.75.
Results: LL was significantly higher [(14.8 ± 7.9) mm vs. (10.7 ± 5.4) mm, P = 0.024] while MLD [(1.47 ± 0.31) mm vs. (1.82 ± 0.51) mm, P = 0.028], RVD [(2.30 ± 0.50) mm vs. (2.81 ± 0.64) mm, P = 0.036], and MLA [(2.30 ± 1.50) mm(2) vs. (3.60 ± 2.30) mm(2), P = 0.038] were significantly lower in FFR ≤ 0.75 group than in FFR > 0.75 group. LL (r = -0.209, P = 0.040) was negatively correlated with FFR, and MLD (r = 0.414, P = 0.040), RVD (r = 0.303, P = 0.000) and MLA (r = 0.315, P = 0.002) were positively correlated with FFR. ROC analysis showed that MLD ≥ 1.6 mm was the best cut-off value to predict FFR > 0.75 with sensitivity 63%, specificity 82%, and positive predictive value 96%.
Conclusions: QCA derived anatomic parameters of intermediate coronary lesions correlate to FFR value in some extent. MLD ≥ 1.6 mm is the best cut-off value to predict FFR > 0.75 in patients with intermediate coronary lesions.