Impact of Aortic Stiffness Evaluated by Aortic Pulsatility on Fractional Flow Reserve.

Background: Fractional flow reserve (FFR) is a highly reproducible, accurate and lesion-specific index to indicate inducible ischemia for a particular coronary artery lesion. Invasively measured aortic pulsatility (AP) is an indicator of aortic stiffness. In this study we aimed to evaluate the possible impact of AP in terms of aortic stiffness on FFR measurement.

Methods: In this study, we reviewed the FFR evaluation of 90 patients who had intermediate lesions (40-70% stenosis measured with quantitative coronary analysis) at the left anterior descending artery (LAD). AP was calculated as the ratio of aortic pulse pressure (systolic-diastolic pressure) to mean pressure.

Results: Aortic systolic pressure, aortic diastolic pressure, aortic pulse pressure and also aortic pulsatility did not differ significantly between patients with FFR ≤ 0.80 and FFR > 0.80 (p = 0.44, p = 0.28, p = 0.93 and p = 0.41, respectively). In subgroups arranged according to the degree of luminal narrowing (40-50%, 51-60%, and 61-70%), we did not observe significant correlation between AP and FFR value in subgroups with 40-50% and 51-60% lesions (r = 0.03, p = 0.95 and r = 0.07, p = 0.69, respectively). However, a statistically significant negative correlation between FFR value and AP in the subgroup of patients with 61-70% lesions was detected (r = -0.54, p = 0.04).

Conclusions: These findings suggested that aortic stiffness might have a possible impact on FFR measurement in coronary lesions of 61-70% stenosis evaluated quantitatively.

Key Words: Aortic pulsatility; Fractional flow reserve; Stiffness.