Insufficient adenosine-induced hyperemia is a major determinant of discordance between non-hyperemic pressure ratio and fractional flow reserve

Abstract

Adenosine occasionally overestimates fractional flow reserve (FFR) values (i.e., insufficient adenosine-induced hyperemia), leading to low non-hyperemic pressure ratios (NHPR)-high FFR discordance. We investigated the impact of insufficient adenosine-induced hyperemia on NHPR-FFR discordance and the reclassification of functional significance. We measured resting distal-to-aortic pressure ratio (Pd/Pa) and FFR by using adenosine (FFR_ADN) and papaverine (FFR_PAP) in 326 patients (326 vessels). FFR_ADN overestimation was calculated as FFR_ADN - FFR_PAP. We explored determinants of low Pd/Pa - high FFR_ADN discordance (Pd/Pa ≤ 0.92 and FFR_ADN > 0.80) versus high Pd/Pa - low FFR_ADN discordance (Pd/Pa > 0.92 and FFR_ADN ≤ 0.80). Reclassification of functional significance was defined as FFR_ADN > 0.80 and FFR_PAP ≤ 0.80. Multivariable analysis identified FFR_ADN overestimation (p = 0.002) and heart rate at baseline (p = 0.048) as independent determinants of the low Pd/Pa-high FFR_ADN discordance. In the low Pd/Pa-high FFR_ADN group (n = 26), papaverine produced a further decline in the FFR value in 21 vessels (81%) compared with FFR_ADN, and the reclassification was observed in 17 vessels (65%). Insufficient adenosine-induced hyperemia is a major determinant of the low resting Pd/Pa-high FFR discordance. Physicians should bear in mind that the presence of low NHPR-high FFR discordance may indicate a false-negative FFR result.