Caffeine Consumption and Heart Rate and Blood Pressure Response to Regadenoson

Background Current guidelines recommend that caffeinated products should be avoided for at least 12 hours prior to regadenoson administration. We intended to examine the effect of caffeine consumption and of timing of last dose on hemodynamic effects after regadenoson administration for cardiac stress testing. Methods 332 subjects undergoing regadenoson stress testing were enrolled. Baseline characteristics, habits of coffee/caffeine exposure, baseline vital signs and change in heart rate, blood pressure, percent of maximal predicted heart rate, and percent change in heart rate were prospectively collected. Results Non-coffee drinkers (group 1) (73 subjects) and subjects who last drank coffee >24 hours (group 3) (139 subjects) prior to regadenoson did not demonstrate any difference in systolic blood pressure, heart rate change, maximal predicted heart rate and percent change in heart rate. Systolic blood pressure change (15.2 +/- 17.1 vs. 7.2 +/- 10.2 mmHg, p = 0.001), heart rate change (32.2 +/- 14 vs. 27.3 +/- 9.6 bpm, p = 0.038) and maximal predicted heart rate (65.5 +/- 15.6 vs. 60.7 +/- 8.6%, p = 0.038) were significantly higher in non-coffee drinkers (group 1) compared to those who drank coffee 12-24 hours prior (group 2) (108 subjects). Subjects who drank coffee >24 hours prior (group 3) exhibited higher systolic blood pressure change (13 +/- 15.8 vs. 7 +/- 10.2, p = 0.007), and heart rate change (32.1 +/- 15.3 vs. 27.3 +/- 9.6, p = 0.017) as compared to those who drank coffee 12-24 hours prior to testing (group 2). Conclusions Caffeine exposure 12-24 hours prior to regadenoson administration attenuates the vasoactive effects of regadenoson, as evidenced by a blunted rise in heart rate and systolic blood pressure. These results suggest that caffeine exposure within 24 hours may reduce the effects of regadenoson administered for vasodilatory cardiac stress testing.