Related Experiment Video

Updated: Jul 17, 2026

A Modified Simple Method for Induction of Myocardial Infarction in Mice
04:29

A Modified Simple Method for Induction of Myocardial Infarction in Mice

Published on: December 3, 2021

A population-based analysis of the class effect of beta-blockers after myocardial infarction

Stéphane Rinfret1, Michal Abrahamowicz, Jack Tu

  • 1Division of Cardiology, Department of Medicine, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada.

American Heart Journal
|January 24, 2007
PubMed

Insights

Beta-blockers reduce mortality after acute myocardial infarction (AMI). However, this study found higher mortality with metoprolol compared to acebutolol or atenolol, challenging the idea of a universal class effect for AMI secondary prevention.

Area of Science:

  • Cardiology
  • Pharmacology
  • Public Health

Background:

  • Long-term beta-blocker use is associated with reduced mortality following acute myocardial infarction (AMI).
  • The existence of a class effect for beta-blockers in secondary AMI prevention remains uncertain.

Purpose of the Study:

  • To investigate whether beta-blockers exhibit a class effect in reducing mortality among elderly patients post-AMI.
  • To compare the mortality rates associated with metoprolol, atenolol, and acebutolol in secondary AMI prevention.

Main Methods:

  • Analysis of administrative healthcare data for Canadian patients aged 65+ discharged with AMI (1996-2000).
  • Comparison of mortality rates between patients prescribed metoprolol, acebutolol, or atenolol within 90 days of discharge.
  • Statistical control for clinical characteristics, comorbidities, and medication dosage and duration.

Main Results:

  • Among 31,576 patients, metoprolol was most common (67%), followed by atenolol (24%) and acebutolol (9%).
  • Acebutolol (HR 0.71) and atenolol (HR 0.79) were associated with significantly lower mortality compared to metoprolol, after adjusting for multiple factors.
  • No significant differences in clinical characteristics or beta-blocker coverage duration were observed between the groups.

Conclusions:

  • The observed differential mortality rates challenge the notion of a uniform class effect for beta-blockers in the secondary prevention of AMI.
  • Metoprolol use was associated with higher mortality compared to atenolol and acebutolol in this elderly cohort.
  • Further research is warranted to understand the specific mechanisms underlying these observed differences.
Abstract

More Related Videos

Post-Myocardial Infarction Heart Failure in Closed-chest Coronary Occlusion/Reperfusion Model in Göttingen Minipigs and Landrace Pigs14:35

Post-Myocardial Infarction Heart Failure in Closed-chest Coronary Occlusion/Reperfusion Model in Göttingen Minipigs and Landrace Pigs

Published on: April 17, 2021

Related Concept Videos

Heart Failure Drugs: β-Blockers01:22

Heart Failure Drugs: β-Blockers

β-adrenergic antagonists, commonly known as β-blockers, block the effects of sympathetic neurotransmitters such as noradrenaline (NA) and adrenaline (ADR). They have several beneficial effects in heart failure treatment. They reduce heart rate, the force of contraction, and cardiac muscle relaxation. They also slow the atrial-ventricular conduction rate and raise the threshold for arrhythmias. The concentration of β-blockers determines their effects on bronchodilation, vasodilation, and...
Antihypertensive Drugs: Types of β-Blockers01:28

Antihypertensive Drugs: Types of β-Blockers

β receptors are classified into three subclasses: β1, β2, and β3. β1 receptors are primarily located in the heart and kidneys. When they get activated, they increase heart rate, contractility, and renin release. This process enhances blood pressure and aids in stress management. In contrast, β2 receptors are situated mainly in the lungs, blood vessels, and skeletal muscles. Upon activation, they trigger smooth muscle relaxation, causing bronchodilation and vasodilation. This widens airways and...
Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers01:24

Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers

Adrenergic stimulation generally impacts cardiac rate and rhythm. Specifically, stimulation of the β-adrenoceptors triggers an increase in intracellular calcium ion influx and pacemaker currents, which may cause arrhythmias. Catecholamines like adrenaline also demonstrate β2-adrenoceptor-mediated hypokalemia, impacting cardiac action potential and disrupting the normal cardiac rhythm. Class II antiarrhythmic drugs are β-adrenoceptor antagonists or β-blockers, which indirectly block calcium...
Adrenergic Antagonists: Pharmacological Actions of β-Receptor Blockers01:27

Adrenergic Antagonists: Pharmacological Actions of β-Receptor Blockers

β-receptor blockers significantly impact the cardiovascular system by counteracting catecholamine-induced sympathetic responses. These medications decrease heart rate, contractility, and cardiac output, potentially leading to cardiac depression, life-threatening bradycardia, and death. Therapeutically, β-blockers function as mild antihypertensives and are utilized in treating angina pectoris and cardiac arrhythmias. However, nonselective β-blockers inhibit β2-receptors in bronchial smooth...
Adrenergic Antagonists: Chemistry and Classification of β-Receptor Blockers01:25

Adrenergic Antagonists: Chemistry and Classification of β-Receptor Blockers

β-adrenergic antagonists, or β-blockers, modulate the sympathetic nervous system by targeting β-adrenoceptors and inhibiting catecholamine-mediated sympathetic responses. β-blockers differ in their adrenoceptor subtype affinity, lipophilicity, and α-blocking capabilities. The history of β-blocker development began with the prototype, dichloroisoprenaline, which exhibited partial agonist activity. As a result, propranolol was developed as a pure antagonist but nonselective agent, paving the way...
Adrenergic Antagonists: ɑ and β-Receptor Blockers01:31

Adrenergic Antagonists: ɑ and β-Receptor Blockers

Third-generation β-blockers, such as labetalol and carvedilol, represent a significant advancement in managing cardiovascular conditions. Unlike conventional β-blockers, which can induce peripheral vasoconstriction, third-generation drugs block α1 adrenoceptors. This promotes vasodilation through several mechanisms, such as increased nitric oxide production, inhibition of calcium ion entry, opening of potassium ion channels, and antioxidant action. Labetalol, for instance, is clinically...