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

Abstract

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 CTA, 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 CTA (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 CTA 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 CTA 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 CTA, increasing procedural convenience and reducing radiation exposure vs placebo.

Keywords: Computed tomography; Coronary CT angiography; Heart rate control; Ivabradine.