Cardiology Department, University of Foggia, Ospedali Riuniti Hospital, Foggia, Italy.
Int J Cardiol. 2013 Sep 20;168(1):362-8. doi: 10.1016/j.ijcard.2012.09.041. Epub 2012 Oct 9.
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.
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 5mg (n=48), or 7.5mg ivabradine (n=48). Patients with beta-blocker therapy: continued with the prior beta-blocker without any dose modification (n=38), and received ivabradine 5mg (n=38), or ivabradine 7.5mg (n=38).
HR and blood pressure were assessed at admission (T0), immediately before CTCA (T1) and during CTCA (T2). Administration of ivabradine 7.5mg 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.
Ivabradine 7.5mg is more effective than ivabradine 5mg in increasing the rate of patients at target HR in patients referred for CTCA.
心率（HR）降低对于实现计算机断层冠状动脉成像（CTCA）的最佳图像质量和诊断准确性至关重要。与β受体阻滞剂相比，口服伊伐布雷定在降低 CTCA 患者的 HR 方面似乎更有效。
前瞻性纳入 259 例连续接受 CTCA 的患者。未在基线时接受β受体阻滞剂的患者（组 1）和接受β受体阻滞剂治疗的患者（组 2）被纳入研究。每组随机分为 3 个平行组，1:1:1 分配。未在基线时接受β受体阻滞剂的患者：不接受β受体阻滞剂进行 CTCA（n=49），接受伊伐布雷定 5mg（n=48）或伊伐布雷定 7.5mg（n=48）。接受β受体阻滞剂治疗的患者：继续使用先前的β受体阻滞剂且不改变剂量（n=38），同时接受伊伐布雷定 5mg（n=38）或伊伐布雷定 7.5mg（n=38）。
在入院时（T0）、CTCA 前即刻（T1）和 CTCA 期间（T2）评估 HR 和血压。伊伐布雷定 7.5mg 的给药显著降低了 T1 和 T2 时的平均相对 HR（p<0.01）、T1 和 T2 时未达到目标 HR 的患者比例（p<0.001 和 p<0.01）以及 CTCA 前需要额外静脉注射β受体阻滞剂的患者比例（p<0.01）。即使在多变量分析中校正年龄、性别、射血分数、危险因素和 T0 时的 HR 后，结果仍具有统计学意义。
与伊伐布雷定 5mg 相比，伊伐布雷定 7.5mg 能更有效地提高 CTCA 患者的目标 HR 率。
