Effect of caffeine administered intravenously on intracoronary-administered adenosine-induced coronary hemodynamics in patients with coronary artery disease.

It is believed that caffeine attenuates the coronary hyperemic response to adenosine by blocking the A2a receptors. We studied the effect of caffeine on adenosine-induced myocardial hyperemia measured by fractional flow reserve after intracoronary adenosine administration. Fractional flow reserve was not affected by intravenous caffeine infusion at a dose that was comparable to oral consumption.