Disturbed Coronary Hemodynamics in Vessels With Intermediate Stenoses Evaluated With Fractional Flow Reserve

BACKGROUND: In chronic ischemic heart disease, focal stenosis, diffuse atherosclerotic narrowings, and microcirculatory dysfunction (MCD) contribute to limit myocardial flow. The prevalence of these ischemic heart disease levels in fractional flow reserve (FFR) interrogated vessels remains largely unknown. METHODS AND RESULTS: Using intracoronary measurements, 91 coronaries (78 patients) with intermediate stenoses were classified in 4 FFR and coronary flow reserve (CFR) agreement groups, using FFR>0.80 and CFR0.80, most (63%) presented disturbed hemodynamics: abnormal CFR in 28 (52%) and MCD in 18 (33%). Vessels with FFR>0.80 presented higher IMR adjusted mean 27.6 (95% confidence interval, 23.4-31.8) than those with FFR≤0.80 17.3 (95% confidence interval, 13.0-21.7), p=0.001. Atherosclerotic burden was inversely correlated with CFR (r=-0.207, P=0.055), and in vessels with FFR>0.80 and CFR0.80 present disturbed hemodynamics. Integration of FFR, CFR, and IMR supports the existence of differentiated patterns of ischemic heart disease that combine focal and diffuse coronary narrowings with variable degrees of MCD.