Comparison of intravenous adenosine and intravenous regadenoson for the measurement of pressure-derived coronary fractional flow reserve

AIMS: Defining the clinical and physiologic significance of an intermediate coronary artery stenosis is aided by measurement of fractional flow reserve (FFR). Adenosine is the most common agent used in the cardiac catheterisation laboratory for the measurement of FFR. Regadenoson, a selective adenosine receptor agonist, with fewer side effects than adenosine has been used extensively in stress testing to induce hyperaemia. We postulated that FFR measurements would be equivalent following administration of regadenoson and adenosine. METHODS AND RESULTS: Twenty patients with an angiographic intermediate coronary artery stenosis (50% to 80%) were included in the study. FFR was measured during three minutes of intravenous (IV) adenosine infusion and for five minutes after an injection of regadenoson. The mean difference between the FFR measured by IV adenosine and IV regadenoson was 0.0040 (min -0.04, max +0.04, standard deviation [SD] 0.025). There was a strong linear correlation between the FFR measured by IV adenosine and IV regadenoson (R2 linear=0.933). The FFR at maximum hyperaemia was achieved earlier using regadenoson than adenosine (59±24.5 sec vs. 93±44.5 sec, p=0.01). CONCLUSIONS: Regadenoson produces similar pressure-derived FFR compared to IV adenosine infusion.