Prognostic Impact of Definite and Marginal Discordance Between Fractional Flow Reserve and Nonhyperemic Pressure Ratio.

BACKGROUND

Fractional flow reserve (FFR) and nonhyperemic pressure ratios (NHPR) can show either marginal or definite discordance.

OBJECTIVES

This study sought to investigate the clinical significance and factors associated with the magnitude of discordance between FFR and NHPR.

METHODS

From the J-PRIDE registry, 4,304 lesions from 3,200 patients were categorized into 6 groups: (G1) definite FFR-/NHPR- (FFR ≥0.82 and NHPR ≥0.91), (G2) definite FFR+/NHPR+ (FFR ≤0.78 and NHPR ≤0.87), (G3) marginal discordant FFR+/NHPR- (FFR ≤0.80 and NHPR = 0.88-0.90, or FFR = 0.79-0.81 and NHPR >0.89), (G4) definite discordant FFR+/NHPR- (FFR ≤0.78 and NHPR ≥0.91), (G5) marginal discordant FFR-/NHPR+ (FFR = 0.79-0.81 and NHPR ≤0.89, or FFR >0.80 and NHPR = 0.88-0.90), and (G6) definite discordant FFR-/NHPR+ (FFR ≥0.82 and NHPR ≤0.87). The study endpoint was the cumulative 1-year incidence of major adverse cardiac events (defined as all-cause mortality, myocardial infarction, and clinically driven revascularization).

RESULTS

Compared with G1, groups with definite discordance exhibited higher risks of major adverse cardiac events (G4, adjusted hazard ratio [aHR]: 1.98; 95% CI: 1.07-3.68; P = 0.029; and G6, aHR: 2.18; 95% CI: 1.18-4.04; P = 0.013), whereas those with marginal discordance (G3 and G5) did not. Additionally, G6 had an increased risk of all-cause mortality (aHR: 2.57; 95% CI: 1.19-5.56; P = 0.017). In FFR+/NHPR- lesions, G3 and G4 showed divergent associations with left anterior descending or left main coronary artery lesions and diameter stenosis. In FFR-/NHPR+ lesions, lower body mass index, diabetes mellitus, anemia, aortic stenosis, left ventricular hypertrophy, and in-stent restenosis were associated with G6, but not with G5.

CONCLUSIONS

Definite discordance between FFR and NHPR differs from marginal discordance in terms of clinical prognosis and associated factors.