BACKGROUND: Achievement of maximal hyperemia is mandatory for an accurate calculation of fractional flow reserve (FFR) and it is obtained with adenosine given either as an intravenous infusion or as an intracoronary bolus. AIMS: The purpose of this study was to compare the infusion of adenosine with intracoronary adenosine bolus dose escalation in the optimal assessment of peak FFR. METHODS: We enrolled consecutive patients with borderline coronary lesions that were assessed by FFR with the use of adenosine intracoronary boluses (100, 200, 400 and 600 µg) and intravenous infusion of 140 µg/kg/min and 280 µg/kg/min. FFR values were assessed and compared. RESULTS: Fifty patients with 125 borderline coronary artery stenoses were enrolled. Physiological severity assessed with: intravenous adenosine infusion at 140 µg/kg/min was mean 0.82 ± 0.09; infusion at 280 µg/kg/min - 0.81 ± 0.09; intracoronary bolus of 100 µg, 200 µg, 400 µg and 600 µg - 0.83 ± 0.09; 0.83 ± 0.09, 0.83 ± 0.09; and 0.83 ± 0.09, respectively. There was a strong linear correlation between FFR values obtained from 140 µg/kg/min infusion and adenosine intracoronary 100, 200, 400 and 600 µg bolus injection (r = 0.989, r = 0.99, r = 0.993, r = 0.994, respectively, p < 0.001 for all). CONCLUSIONS: FFR values achieved with intracoronary boluses of adenosine are very similar, but not identical to those obtained using intravenous adenosine administration. The values of FFR may vary between escalating doses of intracoronary boluses and intravenous infusion.
BACKGROUND: Achievement of maximal hyperemia is mandatory for an accurate calculation of fractional flow reserve (FFR) and it is obtained with adenosine given either as an intravenous infusion or as an intracoronary bolus. AIMS: The purpose of this study was to compare the infusion of adenosine with intracoronary adenosine bolus dose escalation in the optimal assessment of peak FFR. METHODS: We enrolled consecutive patients with borderline coronary lesions that were assessed by FFR with the use of adenosine intracoronary boluses (100, 200, 400 and 600 µg) and intravenous infusion of 140 µg/kg/min and 280 µg/kg/min. FFR values were assessed and compared. RESULTS: Fifty patients with 125 borderline coronary artery stenoses were enrolled. Physiological severity assessed with: intravenous adenosine infusion at 140 µg/kg/min was mean 0.82 ± 0.09; infusion at 280 µg/kg/min - 0.81 ± 0.09; intracoronary bolus of 100 µg, 200 µg, 400 µg and 600 µg - 0.83 ± 0.09; 0.83 ± 0.09, 0.83 ± 0.09; and 0.83 ± 0.09, respectively. There was a strong linear correlation between FFR values obtained from 140 µg/kg/min infusion and adenosine intracoronary 100, 200, 400 and 600 µg bolus injection (r = 0.989, r = 0.99, r = 0.993, r = 0.994, respectively, p < 0.001 for all). CONCLUSIONS: FFR values achieved with intracoronary boluses of adenosine are very similar, but not identical to those obtained using intravenous adenosine administration. The values of FFR may vary between escalating doses of intracoronary boluses and intravenous infusion.