Comparison of intravenous adenosine to intracoronary papaverine for calculation of pressure-derived fractional flow reserve

For calculation of fractional flow reserve (FFR), simultaneous registration of both aortic pressure (P(a)) and transstenotic distal coronary pressure (P(d)) is necessary at steady-state maximum coronary hyperemia. The aim of the present study was to compare the maximum transstenotic gradient (ΔPmax) and pressure-derived myocardial fractional flow reserve (FFR(myo)), observed during intravenous adenosine infusion, to ΔPmax and FFR(myo) induced by intracoronary papaverine, which is considered to be the gold standard for induction of coronary hyperemia, but acts too short for steady- state hyperemic pressure recordings and is associated with QT-prolongation. In 24 patients with coronary stenoses of various degrees, P(a) and P(d) were measured simultaneously by the diagnostic catheter and a high fidelity 0.018'' fiberoptic pressure monitoring guide wire, respectively. Excellent steady-state phasic intracoronary pressure recordings were obtained in all patients within 1 min after start of intravenous adenosine infusion at a rate of 140 μg/kg/min, and compared to ΔPmax obtained 30 sec after intracoronary administration of papaverine (12 mg LCA, 10 mg RCA). ΔPmax was 24 ± 15 mmHg during adenosine infusion and 24 ± 15 mmHg after papaverine administration. Myocardial fractional flow reserve, calculated from these pressure recordings, was 0.75 ± 0.16 and 0.75 ± 0.15, respectively, with an individual difference of 0.02 ± 0.01 between both values (r = 0.99). No important side effects by intravenous infusion of adenosine were observed. Thus intravenous adenosine infusion at a rate of 140 μg/kg/min is an excellent and safe alternative for induction of steady-state maximum coronary hyperemia and therefore is an ideal vasodilator for determination of fractional flow reserve based upon pressure recordings.