Determination of culprit coronary artery branches using hemodynamic indices from angiographic images

A recently reported angiographic technique for hemodynamic indices based on first-pass distribution analysis (FPA) could potentially be helpful for determining the culprit artery responsible for myocardial ischemia. The purpose of this study was to determinate the culprit coronary arterial branches based on coronary flow reserve (CFR) and fractional flow reserve (FFR) using only angiographic images. The study was performed in 14 anesthetized swine. Microspheres were injected into coronary arterial branches to create microvascular disruption. Stenosis was also created by inserting plastic tubings in LAD and LC_X arterial branches. Adenosine was used to produce maximum hyperemia. Angiographic CFR (CFR_a), relative angiographic CFR (rCFR_a), and angiographic FFR (FFR_a) were calculated by FPA. The diagnostic abilities of CFR_a, rCFR_a, and FFR_a were compared in three models: (1) epicardial stenosis model (S), (2) microcirculation disruption model (M), and (3) combined(S + M) model by using the area under the ROC curve (AUC). The mean differences between FFR_a and the pressure-derived FFR (FFR_p) measurements were −0.01 ± 0.21 in S model (N = 37) and 0.01 ± 0.18 in M model (N = 53). From 225 measurements in S model, the AUCs for CFR_a and FFR_a were 0.720 and 0.918, respectively. From 262 measurements in M model and 238 measurements in (S + M) model, the AUCs for CFR_a, rCFR_a, FFR_a were 0.744, 0.715, 0.959 and 0.806, 0.738, 0.995, respectively. The hemodynamic indices of the small branches (down to ~0.7 mm) could be measured using only angiographic image data. The application of FFR_a could potentially provide a useful method to assess the severity of disease in coronary arterial branches.