In vitro assessment of physiological impact of recipient artery intervention on the contralateral donor artery

Abstract

Background: Donor artery fractional flow reserve (FFR) often improves after treatment of recipient artery stenosis, but the physiological mechanism underlying this phenomenon has not been elucidated. This study aimed to assess two novel equations that explain the donor-recipient artery interaction.

Method: Eq. (A) predicts the donor artery FFR after complete release of recipient artery stenosis, while Eq. (B) predicts the donor artery FFR after partial release of recipient artery stenosis. Eq. (B) is a general form of Eq. (A). FFR'1−pred = ((FFR1−CFI1)(FFR2−CFI2)−CFI1CFI2(1−FFR1)(1−FFR2)+CFI1(1−FFR1)(1−CFI2))/((1−C FI1)(FFR2−CFI2)) (A) FFR''1−pred = ((FFR1−CFI1)(FFR2−CFI2)−CFI1CFI2(1−FFR1)(1−FFR2)+CFI1(1−FFR1)(1−CFI2))FFR'2/((1−C FI1)(FFR2−CFI2)) (B) Eqs. (A) and (B) were assessed using an in vitro model of coronary circulation with a collateral channel connecting the donor and recipient arteries.

Results: The donor artery FFR always improved after releasing the recipient artery stenosis. A good linear correlation was found between the predicted FFR of Eq. (A) and the actual FFR (n=40, r=0.95, p<0.0001) and between the predicted FFR of Eq. (B) and the actual FFR (n=40, r=0.94, p<0.0001).

Conclusions: Eqs. (A) and (B) accurately predicted the true FFR value of the donor artery in a coronary circulation model and explain the donor-recipient artery interaction observed in clinical practice.

Keywords: Chronic total occlusion; Collateral circulation; Coronary physiology; Fractional flow reserve.