Age and the cascade impact on coronary flow reserve (CFR) and discordance of fractional flow reserve and non‐hyperemic pressure ratios (NHPR)

Aging changes human physiology through tissue degradation. As the heart is no exception, one expects that the normal microcirculatory responses as measured by coronary flow reserve (CFR) would be diminished over time. However, the magnitude and impact of this change are highly variable as physiologic age and chronological age are not always matched. As one physiologically young nonagenarian said to me, age is just a number (quote from Beatrice Kern Julian, age 95, deceased. From a conversation at age 90 after receiving a transcatheter aortic valve replacement). To gauge the impact of age on the pressure and flow measurements used for lesion assessment and percuteaneous coronary intervention (PCI) decisions, Faria et al. report their retrospective analysis of the large prospective International Collaboration of Comprehensive Physiologic Assessment registry. They examined 1134 patients who had pressure and flow measured to provide CFR