Effects of high doses of intracoronary adenosine on the assessment of fractional flow reserve

Maximal hyperemia is the critical prerequisite for FFR assessment. Despite IV adenosine currently representing the recommended approach, IC administration of adenosine constitutes a valuable alternative in everyday practice. However, it is surprisingly unclear which IC strategy allows the achievement of FFR values comparable to IV adenosine. Objectives: This study sought to compare increasing doses of intracoronary (IC) adenosine versus intravenous (IV) adenosine for fractional flow reserve (FFR) assessment. Background: Maximal hyperemia is the critical prerequisite for FFR assessment. Despite IV adenosine currently representing the recommended approach, IC administration of adenosine constitutes a valuable alternative in everyday practice. However, it is surprisingly unclear which IC strategy allows the achievement of FFR values comparable to IV adenosine. Methods: Thirty intermediate coronary stenoses undergoing FFR measurement were prospectively and consecutively enrolled. Hyperemia was sequentially induced by bolus of IC adenosine (AND 150 μg) and by IV adenosine infusion (IVADN) (140 μg/kg/min). FFR values, symptoms, and development of atrioventricular block were recorded. Results: 150 μg dose of IC adenosine were well tolerated and associated with fewer symptoms than IV adenosine. Intracoronary adenosine doses induced a significant decrease of FFR compared with baseline levels (p 0.00).Among the 6 patients with FFR values >0.80 with IVADN, 4 were correctly identified also by 150 μg bolus IC adenosine. Conclusions: Intracoronary adenosine, at doses higher than currently suggested, lows obtaining FFR values similar to IV adenosine. Intravenous adenosine, which remains the gold standard, might thus be reserved for those lesions with equivocal FFR values