Author + information
- Shunsuke Aoi,
- Neil Patel,
- Bora Toklu,
- Wonkyoung Lee,
- John Fox and
- Yumiko Kanei
Instantaneous wave-free ratio (iFR) is a newly developed coronary artery pressure index measured in the wave-free period of diastole in absence of hyperemia. An iFR-guided revascularization strategy was shown to be noninferior to fractional flow reserve (FFR)-guided revascularization strategy in multiple recent randomized controlled trials. The effect of gender differences on iFR and FFR remains to be elucidated. The purpose of this study is to compare the effect of gender on iFR and FFR in the intermediate coronary lesions.
We retrospectively reviewed 1024 intermediate coronary lesions requiring functional evaluation using iFR in 837 patients referred for coronary angiography between January 2015 and June 2016. The standard protocol was the hybrid approach, where the intermediate iFR range lesions between 0.86 and 0.93 underwent additional FFR assessment and a cutoff value of 0.80 or less was used to indicate the presence of hemodynamically important stenosis. In our analysis, the threshold cutoff value of 0.89 or less for iFR was applied retrospectively for positive iFR.
Among 1024 intermediate coronary lesions, 616 lesions (60.2%) were men compared to women with 408 lesions (39.8%). The hybrid protocol of measuring FFR was done in 451 coronary lesions. Women had significantly higher rate of positive iFR compared to men (23.8% vs. 18.3%, p=0.035). On the contrary, men had significantly higher rate of positive FFR compared to women (28.4% vs. 15.5%, p=0.001). Women had more diabetes mellitus and left anterior ascending artery. Men had more acute coronary syndrome presentation, concomitant chronic total occlusion, and left circumflex artery compared to women. Multivariate analysis showed diabetes mellitus and left anterior descending artery to be independent predictors of positive iFR (OR 1.64 and 6.95, p=0.002 and <0.001); however, female gender was not an independent predictor for positive iFR (OR 1.22, p=0.24). Multivariate analysis for FFR showed male gender, acute coronary syndrome, and concomitant chronic total occlusion to be independent positive predictors (OR 1.84, 2.02, and 2.29, p=0.02, 0.003, 0.03) while left circumflex artery was a negative predictor for positive FFR (OR 0.19, p=0.01).
In this single-center, real-world retrospective study, women had higher rate of positive iFR while men had higher rate of positive FFR. Multivariate analysis showed female gender was not an independent predictor for positive iFR while male gender was an independent predictor for positive FFR.