The established practice that all heart attack patients should routinely receive beta-blockers has been challenged by UK researchers.
They found no benefit from the drugs in patients who experienced a myocardial infarction but did not have heart failure as a complication.
“There may be no mortality advantage associated with the prescription of beta-blockers”
MI patients who did not have heart failure did not live any longer after being given beta-blockers, despite around 95% of such patients usually being given the medication.
The study authors, from the University of Leeds, noted that beta-blockers could have unwanted side-effects for some patients such as dizziness and tiredness.
Their findings raised the possibility that the drugs were being over prescribed, and may burden patients and the NHS with unnecessary costs, they said.
NHS guidelines, published by the National Institute for Health and Care Excellence in 2013, recommend that beta-blockers should be prescribed to all patients who have had an MI.
However, the researchers stated that, internationally, clinical guidance differed regarding prescribing beta-blockers to MI patients without heart failure.
The research team analysed data from the UK’s national heart attack register, which collects information on patients admitted to hospital following a heart attack.
“What we need now is a randomised patient trial”
They looked at anonymised data from more than 179,000 patients who had a heart attack between January 2007 and June 2013, but without heart failure or left ventricular systolic dysfunction (LVST).
Of 91,895 patients with ST-segment elevation MI (STEMI) and 87,915 patients with non-ST-segment elevation MI (NSTEMI), 96.4% and 93.2% received beta-blockers, respectively.
For the entire cohort, there were 9,373 deaths (5.2%) within a year of the patients having a heart attack.
But the researchers said they found no statistical difference between those who had been prescribed the drugs and those who had not.
The study authors said: “Among patients who survived hospitalisation in England and Wales with STEMI and NSTEMI without heart failure or LVSD, beta-blocker use was not associated with lower all-cause mortality at any time point up to one year.
“This result adds to the increasing body of evidence that the routine prescription of beta-blockers might not be indicated in patients with a normal ejection fraction or without heart failure after acute myocardial infarction,” they said in the Journal of the American College of Cardiology.
Lead study author and senior epidemiologist Dr Marlous Hall said: “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.
“This was an observational study based on robust statistical analysis of large scale patient data,” he said. “What we need now is a randomised patient trial. A trial would allow researchers to substantiate these findings and also look at other outcomes, such as whether beta blockers prevent future heart attacks.
“This work would have implications for personalising medications after a heart attack,” he added.
Professor Chris Gale, a consultant cardiologist at York Teaching Hospital NHS Foundation Trust, said: “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.
“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,” he said. “A necessary next step is the investigation of beta-blockers in this population in a randomised controlled trial.”