Use of regadenoson for measurement of fractional flow reserve.

OBJECTIVE: To compare the use of regadenoson to adenosine for measurement of fractional flow reserve (FFR). BACKGROUND: FFR is an accepted method to assess the functional significance of intermediate coronary artery stenoses and uses adenosine to induce maximal hyperemia. The use of the selective A2a receptor agonist regadenoson for FFR is not established. METHODS: Fifty-seven patients undergoing clinically indicated FFR assessment of intermediate coronary stenoses were included. For the initial assessment of FFR, hyperemia was achieved by a standard intravenous adenosine infusion (140 mcg/kg/min). After a washout period of 10 min, FFR was reassessed using regadenoson as a single 0.4 mg intravenous bolus. FFR measurements were recorded at baseline and following maximal hyperemia with both agents. RESULTS: Mean age was 57 ± 8 years and 47 were male. Sixty coronary lesions were evaluated and were located in the left anterior descending in 34, the left circumflex in 9, right coronary in 15, and left main coronary artery in 2. Mean ( ± SD) FFR following adenosine and regadenoson was 0.79 ( ± 0.09) and 0.79 (±0.09), respectively, P = NS. Time to FFR nadir was shorter with regadenoson compared to adenosine, 36.6 ± 24 versus 66 ± 0.19 sec, P < 0.0001, respectively. No patients experienced any significant side effects related to regadenoson. CONCLUSIONS: Regadenoson is a viable alternative to intravenous adenosine for achieving maximal hyperemia during FFR assessment. Compared to adenosine, regadenoson has a similar hemodynamic response, achieves more rapid hyperemia, is easier to use, and has an excellent side-effect profile.