Visual-functional mismatch between coronary angiography and fractional flow reserve

Abstract

Objectives: The goal of this study was to identify clinical and lesion-specific local factors affecting visual-functional mismatch.

Background: Although lesion severity determined by coronary angiography has not been well correlated with physiological significance, the mechanism of the discordance remains poorly understood.

Methods: The authors assessed quantitative coronary angiography, intravascular ultrasound (IVUS), and fractional flow reserve (FFR) in a prospective cohort of 1,000 patients with 1,129 coronary lesions. Three-dimensional computational simulation studies were performed.

Results: Lesions with angiographic diameter stenosis (DS) ≥50% and FFR >0.80 ("mismatches") were seen in 57% of non-left main lesions and in 35% of the left main lesions, respectively (p = 0.032). Conversely, among the lesions with DS <50% and FFR <0.80 ("reverse mismatches") 16% were found in the non-left main lesions and 40% in the left main lesions (p < 0.001). The independent predictors for mismatch were advanced age, non-left anterior descending artery location, absence of plaque rupture, short lesion length, large minimal lumen area, smaller plaque burden, and greater minimal lumen diameter. Conversely, reverse mismatch was independently associated with younger age, left anterior descending artery location, the presence of plaque rupture, a smaller minimal lumen area, and larger plaque burden. In a computational simulation study, FFR was influenced by DS, lesion length, different lesion shape, plaque eccentricity, surface roughness, and various shapes of plaque rupture.

Conclusions: There were high frequencies of visual-functional mismatch between angiography and FFR. The discrepancy was related to the clinical and lesion-specific factors frequently unrecognizable by angiography, thus suggesting that coronary angiography cannot accurately predict FFR. (Natural History of FFR-Guided Deferred Coronary Lesions [IRIS FFR-DEFER]; NCT01366404).