From the Guidelines
Intravenous (IV) beta blockers should be administered to STEMI patients who are hypertensive and do not have any contraindications to their use.
Indications for IV Beta Blockers
- Hypertension
- Ongoing ischemia
- Tachyarrhythmia ### Contraindications for IV Beta Blockers
- Signs of heart failure
- Evidence of a low output state
- Increased risk for cardiogenic shock
- PR interval greater than 0.24 seconds
- Second- or third-degree heart block
- Active asthma or reactive airway disease As noted in the 2007 focused update of the ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction 1, IV beta blockers should not be administered to STEMI patients with certain contraindications. The 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction also supports the use of IV beta blockers in patients with no contraindications who are hypertensive or have ongoing ischemia 2. Additionally, a review of early beta-blocker therapy in myocardial infarction by the European Society of Cardiology suggests that IV beta blockers may be beneficial in patients with tachycardia, relative hypertension, or pain unresponsive to opioids 3.
From the FDA Drug Label
Intravenous administration is usually reserved for life-threatening arrhythmias or those occurring under anesthesia. Intravenous propranolol is indicated for the short-term treatment of supraventricular tachycardia, including Wolff‑Parkinson‑White syndrome and thyrotoxicosis, to decrease ventricular rate Intravenous propranolol is indicated for the treatment of persistent premature ventricular extrasystoles that impair the well‑being of the patient and do not respond to conventional measures. Intravenous propranolol is indicated to control ventricular rate in life-threatening digitalis-induced arrhythmias. Intravenous propranolol is indicated to abolish tachyarrhythmias due to excessive catecholamine action during anesthesia when other measures fail.
Intravenous beta blockers, such as propranolol, are indicated for:
- Life-threatening arrhythmias
- Supraventricular tachycardia
- Wolff-Parkinson-White syndrome
- Thyrotoxicosis
- Premature ventricular extrasystoles
- Digitalis-induced arrhythmias
- Tachyarrhythmias due to excessive catecholamine action during anesthesia 4
From the Research
Intravenous Beta Blockers in Acute Coronary Syndrome
- The use of intravenous (IV) beta blockers in patients with acute coronary syndrome (ACS) has been studied in several trials 5, 6, 7, 8.
- A meta-analysis of 16 randomized trials found that IV beta blockers reduced in-hospital mortality by 8% and the risk of ventricular tachyarrhythmias and myocardial reinfarction 5.
- However, a Swedish nationwide observational study found that IV beta blocker therapy was not associated with a benefit regarding short-term mortality in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) 6.
Effects on Infarct Size and Clinical Outcomes
- A double-blind, placebo-controlled international multicenter study found that early IV beta blockers before PCI did not reduce infarct size, but reduced the incidence of malignant arrhythmias in the acute phase 7.
- A systematic review and meta-analysis of 4 randomized controlled trials (RCTs) found that IV beta blockers may improve left ventricular ejection fraction (LVEF) at 24 weeks post-infarct, and numerically reduce the rates of ventricular arrhythmia, any arrhythmia, and cardiogenic shock during index hospitalization 8.
Usage and Perception
- A study found that cardiologists overestimated the frequency of IV beta blocker administration to patients with acute myocardial infarction (AMI), while emergency physicians usually deferred the decision to cardiologists and reported a frequency of use that was much closer to actual practice 9.
- The perceived versus actual use of IV beta blockers by cardiologists and emergency physicians for patients with AMI highlights the need for accurate assessment of treatment practices 9.