Intravenous ivabradine for control of heart rate during coronary CT angiography: A randomized, double-blind, placebo-controlled trial

Background: Low heart rates (HRs) are preferable for coronary CT angiography (CTA). We evaluated the use of an intravenous bolus of ivabradine, a selective sinus node inhibitor, to lower HR before coronary CTA in a prospective, randomized, double-blind, placebo-controlled multicenter trial. Methods: A total of 370 patients scheduled for CIA, with sinus rhythm >= 70 beats/min but ineligible for intravenous beta-blockers, were randomized to an intravenous bolus of 10 mg (HR, 70-79 beats/min) or 15 mg (HR >= 80 beats/min) ivabradine or placebo. Primary end point was the proportion of patients achieving HR <= 65 beats/min at the initiation of coronary CIA (Ta). Results: Baseline HR was 79 +/- 8.5 beats/min. At Ta, HR <= 65 beats/min was achieved in 55% of the ivabradine group vs 23% for placebo (P < .0001) and in 68% vs 16% 1-hour after bolus administration (P < .0001). Contrast-enhanced coronary CIA was performed in 87% of the ivabradine group vs 65% for placebo (P < .0001). Mean HR at Ta was 67 +/- 10 beats/min for ivabradine vs 75 10 beats/min for placebo (P <.0001). Procedural convenience was scored better with ivabradine ("good" or "very good" in 79% vs 63% for placebo; P = .0005). The effective radiation dose of contrast-enhanced CIA was 13 +/- 7 mSv for ivabradine vs 16 +/- 7 mSv for placebo (P < .05). Ivabradine was well tolerated. Conclusions: An intravenous bolus of ivabradine achieves rapid, safe, and sustained HR lowering during coronary CIA, increasing procedural convenience and reducing radiation exposure vs placebo. (C) 2015 Society of Cardiovascular Computed Tomography. All rights reserved.