Esmolol is noninferior to metoprolol in achieving a target heart rate of 65 beats/min in patients referred to coronary CT angiography: a randomized controlled clinical trial

Abstract

Background: Coronary CT angiography (CTA) is an established tool to rule out coronary artery disease. Performance of coronary CTA is highly dependent on patients' heart rates (HRs). Despite widespread use of β-blockers for coronary CTA, few studies have compared various agents used to achieve adequate HR control.

Objective: We sought to assess if the ultrashort-acting β-blocker intravenous esmolol is at least as efficacious as the standard of care intravenous metoprolol for HR control during coronary CTA.

Methods: Patients referred to coronary CTA with a HR >65 beats/min despite oral metoprolol premedication were enrolled in the study. We studied 412 patients (211 male; mean age, 57 ± 12 years). Two hundred four patients received intravenous esmolol, and 208 received intravenous metoprolol with a stepwise bolus administration protocol. HR and blood pressure were recorded at arrival, before, during, immediately after, and 30 minutes after the coronary CTA scan.

Results: Mean HRs of the esmolol and metoprolol groups were similar at arrival (78 ± 13 beats/min vs 77 ± 12 beats/min; P = .65) and before scan (68 ± 7 beats/min vs 69 ± 7 beats/min; P = .60). However, HR during scan was lower in the esmolol group vs the metoprolol group (58 ± 6 beats/min vs 61 ± 7 beats/min; P < .0001), whereas HRs immediately and 30 minutes after the scan were higher in the esmolol group vs the metoprolol group (68 ± 7 beats/min vs 66 ± 7 beats/min; P = .01 and 65 ± 8 beats/min vs 63 ± 8 beats/min; P < .0001; respectively). HR ≤ 65 beats/min was reached in 182 of 204 patients (89%) who received intravenous esmolol vs 162 of 208 of the patients (78%) who received intravenous metoprolol (P < .05). Of note, hypotension (systolic BP <100 mm Hg) was observed right after the scan in 19 patients (9.3%) in the esmolol group and in 8 patients (3.8%) in the metoprolol group (P < .05), whereas only 5 patients (2.5%) had hypotension 30 minutes after the scan in the esmolol group compared to 8 patients (3.8%) in the metoprolol group (P = .418).

Conclusion: Intravenous esmolol with a stepwise bolus administration protocol is at least as efficacious as the standard of care intravenous metoprolol for HR control in patients who undergo coronary CTA.

Keywords: Beta-receptor blocker; Coronary CT angiography; Esmolol; Heart rate control; Metoprolol.