Randomized Control of Sympathetic Drive With Continuous Intravenous Esmolol in Patients With Acute ST-Segment Elevation Myocardial Infarction: The BEtA-Blocker Therapy in Acute Myocardial Infarction (BEAT-AMI) Trial

Abstract

Objectives: This study sought to evaluate the role of esmolol-induced tight sympathetic control in patients with ST-segment elevation myocardial infarction (STEMI).

Background: Elevated sympathetic drive has a detrimental effect on patients with acute STEMI. The effect of beta-blocker-induced heart rate mediated sympathetic control on myocardial damage is unknown.

Methods: The authors conducted a prospective, randomized, single-blind trial involving patients with STEMI and successful percutaneous intervention (Killip class I and II). Patients were randomly allocated to heart rate control with intravenous esmolol for 24 h or placebo. The primary outcome was the maximum change in troponin T release as a prognostic surrogate marker for myocardial damage. A total of 101 patients were enrolled in the study.

Results: There was a significant difference between patients allocated to placebo and those who received sympathetic control with esmolol in terms of maximum change in troponin T release: the median serum troponin T concentration increased from 0.2 ng/ml (interquartile range [IQR] 0.1 to 0.7 ng/ml) to 1.3 ng/ml (IQR: 0.6 to 4.7 ng/ml) in the esmolol group and from 0.3 ng/ml (IQR: 0.1 to 1.2 ng/ml) to 3.2 ng/ml (IQR: 1.5 to 5.3 ng/ml) in the placebo group (p = 0.010). The levels of peak creatine kinase (CK), CK subunit MB (CK-MB), and n-terminal brain natriuretic peptide (NT-proBNP) were lower in the esmolol group compared with placebo (CK 619 U/l [IQR: 250-1,701 U/l] vs. 1,308 U/l [IQR: 610 to 2,324 U/l]; p = 0.013; CKMB: 73.5 U/l [IQR: 30 to 192 U/l] vs. 158.5 U/l [IQR: 74 to 281 U/l]; p = 0.005; NT-proBNP: 1,048 pg/ml (IQR: 623 to 2,062 pg/ml] vs. 1,497 pg/ml [IQR: 739 to 3,318 pg/ml]; p = 0.059). Cardiogenic shock occurred in three patients in the placebo group and in none in the esmolol group.

Conclusions: Esmolol treatment statistically significantly decreased troponin T, CK, CK-MB and NT-proBNP release as surrogate markers for myocardial injury in patients with STEMI. (Heart Rate Control After Acute Myocardial Infarction; DRKS00000766).

Keywords: STEMI; beta-blocker; clinical trial; heart rate; sympathetic nervous system.