Heart rate control with oral ivabradine in computed tomography coronary angiography: a randomized comparison of 7.5 mg vs 5 mg regimen.

Abstract

Background: Heart rate (HR) reduction is essential to achieve optimal image quality and diagnostic accuracy with computed tomography coronary angiography (CTCA). Administration of oral ivabradine seems to be more effective than beta-blockade in reducing HR in patients referred for CTCA. Methods: Two-hundred-fifty-nine consecutive patients referred for CTCA were prospectively enrolled. Patients not receiving beta-blocker at baseline (group 1) and those with beta-blocker therapy (group 2) were enrolled in the study. Each group was randomized into 3 parallel arms with 1:1:1 allocation. Patients who did not receive beta-blocker at baseline: underwent CTCA without beta blocker (n=49), and received ivabradine 5 mg (n=48), or 7.5 mg ivabradine (n=48). Patients with beta-blocker therapy: continued with the prior beta-blocker without any dose modification (n=38), and received ivabradine 5 mg (n=38), or ivabradine 7.5 mg (n=38). Results: HR and blood pressure were assessed at admission (T0), immediately before CTCA (T1) and during CTCA (T2). Administration of ivabradine 7.5 mg significantly reduced mean relative HR at T1 and T2 (p<0.01), the rate of patients not achieving target HR at T1 (p<0.001) and T2 (p<0.01), and the percentage of patients needing additional IV beta-blockade prior to CTCA (p<0.01). Results remained statistically significant even after correction for age, gender, ejection fraction, risk factors and HR at T0, in a multivariable analysis. Conclusions: Ivabradine 7.5 mg is more effective than ivabradine 5 mg in increasing the rate of patients at target HR in patients referred for CTCA.