Leeds, UK—Beta-blockers are routinely prescribed to patients who have survived a heart attack. A new study raises questions about that common practice, however.
The report, published in the Journal of the American College of Cardiology, questions guidelines directing that all heart attack patients be on beta-blockers.
For the study, University of Leeds–led researchers focused on acute myocardial infarction (AMI) patients who did not also have heart failure (HF). They determined that the cohort —95% of whom were prescribed beta-blockers—got no survival benefit from the medication.
English and Welsh registry data from the Myocardial Ischaemia National Audit Project were used for the cohort study and involved 179,810 survivors of hospitalization with AMI without HF or left ventricular systolic dysfunction (LVSD) between January 1, 2007, and June 30, 2013. With a final follow-up on December 31, 2013, survival-time inverse probability–weighting propensity scores and instrumental variable analyses were used to investigate the association between the use of beta-blockers and 1-year mortality.
Results indicate that, of 91,895 patients with ST-segment elevation myocardial infarction and 87,915 patients with non–ST-segment elevation myocardial infarction, 88,542 (96.4%) and 81,933 (93.2%) received beta-blockers, respectively.
With 9,373 deaths overall, unadjusted 1-year mortality was lower for patients who received beta-blockers compared with those who did not—4.9% versus 11.2%. After weighting and adjustment, however, the researchers determined that there was no significant difference in mortality between those with and without beta-blocker use. Similar results occurred with ST-segment elevation myocardial infarction and non–ST-segment elevation myocardial infarction.
Some international treatment guidelines recommend that beta-blockers be prescribed to all patients who have had an AMI, whether or not they have heart failure.
“If you look at the patients who had a heart attack but not heart failure—there was no difference in survival rates between those who had been prescribed beta-blockers and those that had not,” pointed out lead investigator Marious Hall, PhD, senior epidemiologist at the Leeds Institute of Cardiovascular and Metabolic Medicine.
Hall notes that the study was observational and called for a randomized patient trial evaluating the use of beta-blockers.
“There is uncertainty in the evidence as to the benefit of beta-blockers for patients with heart attack and who do not have heart failure,” explained Chris Gale, MD, professor of cardiovascular medicine at the University of Leeds. “This study suggests that there may be no mortality advantage associated with the prescription of beta-blockers for patients with heart attack and no heart failure.”
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