Nutrition Status May be Related to Discordance of the Resting Full-Cycle Ratio and Fractional Flow Reserve

Clinical guidelines recommend using both hyperemic (fractional flow reserve [FFR]) and non-hyperemic (instantaneous wave-free ratio or resting full-cycle ratio [RFR]) methods to evaluate coronary artery stenoses in patients with coronary artery disease (CAD). However, discordant results have been reported between RFR and FFR. Previous studies have demonstrated that malnutrition is associated with adverse cardiovascular events in patients with CAD. This study aimed to assess the relationship between nutritional status and discordance between RFR and FFR measurements.

A total of 168 coronary arteries in 168 patients with CAD were analyzed. Ischemia was defined as FFR ≤ 0.80 and RFR ≤ 0.89. The vessels (n = 168) were categorized into four groups based on FFR and RFR results, including high FFR/high RFR, high FFR/low RFR, low FFR/high RFR, and low FFR/low RFR groups.

Univariate analysis revealed that low levels of hemoglobin, albumin, and estimated glomerular filtration rate, as well as low prognostic nutritional index (PNI) and Geriatric Nutritional Risk Index scores, were associated with discordance in the high FFR/low RFR group. Multivariate analysis identified albumin and PNI as independent predictors of high FFR/low RFR discordance among vessels with discordant FFR and RFR results.

Nutritional status may influence the pattern of discordance between FFR and RFR measurements, particularly distinguishing high FFR/low RFR from low FFR/high RFR cases.