Myocardial Infarction May Not Be Helped By Beta-blockers

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myocardial infarction

Myocardial infarction (heart attack) is often treated with beta-blockers in the long-term, but the effectiveness of this medication is not well studied in patients without heart failure. Dondo and colleagues recently showed that there is no benefit to using beta-blockers in patients without heart failure.

Myocardial infarction, or heart attack, happens when the heart stops receiving oxygen and heart tissue dies. Each year heart attacks are responsible for over 10% of deaths worldwide. Quick action in treating a myocardial infarction is vital to saving lives. Beta-blockers are medications that reduce blood pressure, and are typically used as a first line of treatment for patients suffering myocardial infarctions. However, their long-term effectiveness in patients without heart failure has not been tested, and recommendations about their use differ.

Dondo and colleagues recently published a study in Journal of the American College of Cardiology that addressed the effectiveness of beta-blockers as treatment for patients suffering from myocardial infarctions but without heart failure. The researchers analyzed data from MINAP, a registry of cardiac-related hospitalizations in the United Kingdom. They included a total of 179,810 patients who were first admitted to hospital between 2007 and 2013 with a final diagnosis of myocardial infarction, who had not previously experienced heart failure, and who had not previously received beta-blockers as treatment for any condition. The researchers then looked at survival over one year.

Between 93% and 95% of patients were prescribed beta-blockers as treatment after their diagnosis with different kinds of myocardial infarction. Those who did not receive beta-blockers were typically older, more female, and typically had conditions other than myocardial infarction as well, including diabetes, kidney failure, asthma, or other diseases. Despite these differences, there was no significant difference in one-month, six-month, or one-year survival rates for patients who were prescribed beta-blockers and those who were not.

Previous studies have shown mixed results about the effectiveness of beta-blockers in heart attack patients without heart failure. Because of this, European and US guidelines differ in their recommendations about beta-blocker as a treatment for these patients. Dondo and colleagues’ study provides clear evidence that beta-blockers are not a useful long-term treatment in these patients. However, this study did not address the role that beta-blockers may play in survival when they are administered during hospitalization. Further, heart failure may still occur after heart attack, in which case beta-blockers would significantly lower mortality.

Written by C. I. Villamil

Reference: Dondo et al. 2017. β-blockers and mortality after acute myocardial infarction in patients without heart failure or ventricular dysfunction. JACC 69:2710-2720.