Abstract
The myocardial fractional flow reserve （FFR） is a useful measure of physiological stenosis in the coronary artery. Previous reports have identified peripheral FFR （pFFR） as another useful measure in peripheral artery disease （PAD）; however, the vasodilators used to obtain maximal hyperemia varied among studies. The present study was conducted to identify the ideal vasodilator and vasodilator dose for pFFR assessment. We enrolled 24 patients with 26 lesions, comprising 14 lesions of the iliac artery and 12 lesions of the superficial femoral artery （SFA）. After measuring the mean aortic pressure （Pa）, the guidewire was advanced across the lesion and the mean distal pressure （Pd） was measured at the baseline Pd/Pa. A 100-µg dose of adenosine 5’-triphosphate （ATP） was then administered to obtain a pFFR with a washout interval of 5 to 10 minutes. Next, 200µg of ATP, 10mg of papaverine hydrochloride, or 1.5mg of isosorbide dinitrate was administered before the final pFFR measurement. The baseline Pd/Pa （0.88±0.08） was significantly decreased after each vasodilator （P＜0.0001）, but there was no significant difference in pFFR among vasodilators （P＝0.7569）. The study was discontinued in two patients with SFA lesions due to decreased systemic blood pressure after vasodilator administration. The hyperemic efficacy of 100µg of ATP administered intra-arterially was similar to the efficacies of 200µg of ATP, 10mg of papaverine hydrochloride, and 1.5mg of isosorbide dinitrate. Given the milder side effects of ATP versus other vasodilators, an intra-arterial dose of ATP 100µg may be optimal as a first-line agent for pFFR measurement.
