Fractional Flow Reserve Versus Instantaneous Wave-Free Ratio in Assessment of Lesion Hemodynamic Significance and Explanation of their Discrepancies. International, Multicenter and Prospective Trial: The FiGARO Study
Abstract
Background:The FiGARO (FFR versus iFR in Assessment of Hemodynamic Lesion Significance, and an Explanation of Their Discrepancies) trial is a prospective registry searching for predictors of fractional flow reserve/instantaneous wave-free ratio (FFR/iFR) discrepancy. Methods and Results:FFR/iFR were analyzed using a Verrata wire, and coronary flow reserve was analyzed using a Combomap machine (both Philips-Volcano).
The risk polymorphisms for endothelial nitric oxide synthase and for heme oxygenase-1 were analyzed. In total, 1884 FFR/iFR measurements from 1564 patients were included.
The FFR/iFR discrepancy occurred in 393 measurements (20.9%): FFRp (positive)/iFRn (negative) type (264 lesions, 14.0%) and FFRn/iFRp (129 lesions, 6.8%) type. Coronary flow reserve was measured in 343 lesions, correlating better with iFR (R=0.56, P<0.0001) than FFR (R=0.36, P<0.0001).
The coronary flow reserve value in FFRp/iFRn lesions (2.24 +/- 0.7) was significantly higher compared with both FFRp/iFRp (1.39 +/- 0.36), and FFRn/iFRn lesions (1.8 +/- 0.64, P<0.0001). Multivariable logistic regression analysis confirmed (1) sex, age, and lesion location in the right coronary artery as predictors for FFRp/iFRn discrepancy; and (2) hemoglobin level, smoking, and renal insufficiency as predictors for FFRn/iFRp discrepancy.
The FFRn/iFRp type of discrepancy was significantly more frequent in patients with both risk types of polymorphisms (endothelial nitric oxide synthase(r)+heme oxygenase-1(r)): 8 patients (24.2%) compared with FFRp/iFRn type of discrepancy: 2 patients (5.9%), P=0.03. Conclusions:Predictors for FFRp/iFRn discrepancy were sex, age, and location in the right coronary artery.
Predictors for FFRn/iFRp were hemoglobin level, smoking, and renal insufficiency. The risk type of polymorphism in endothelial nitric oxide synthase and heme oxygenase-1 genes was more frequently found in patients with FFRn/iFRp type of discrepancy.