Back in the 1980s, several clinical trials showed that there was a small but significant benefit by "blocking" the effect of adrenaline, which can induce the lethal disturbance of heart rhythm ventricular fibrillation.

Since then, there has been a longstanding dispute of whether the routine long-term prescription of beta-blockers following a heart attack or bypass should be done or not.

However a new study from the University of Leeds has suggested that many patients given beta blockers after a heart attack may not benefit from being on the drugs after all.

Addressing the dispute of beta-blocker prescriptions

For decades, it was recommended that people who have had a heart attack should be prescribed beta blockers to reduce the activity of the heart and lower blood pressure.

Indeed, they are necessary for people who have suffered a heart attack with heart failure, as the heart muscle is damaged and stops working properly. Beta blockers help the heart work more effectively.

However 95% of heart attack patients who did not have heart failure are also prescribed beta blockers and it has been found that the drugs do not help them live longer.

Not all heart attacks result in heart failure, therefore the study focused on patients who did not suffer from the complication.

No statistical difference in death rates found between the two groups

The team analysed anonymous data from the UK's national heart attack register and looked at 179,810 people who were hospitalised with a heart attack between 2007 and 2013, but did not suffer from heart failure.

The chances of being alive a year later after being put on beta blockers were looked at.

There was no statistical difference in death rates within a year of the patients suffering their heart attack between those who had been prescribed beta blockers and those who were not.

"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 who had not," said Dr Marlous Hall, lead investigator and senior epidemiologist at the Leeds Institute of Cardiovascular and Metabolic Medicine.

This suggested that the drugs – which can have side-effects, like dizziness and tiredness – are over-prescribed and burdening patients.

Psychological effects of beta blockers can be fatal as well

Not to mention the adverse psychological effects caused by beta blockers which pile on to the depression experienced by many, following cardiac surgery.

"I felt like a zombie," writes a man in his sixties, who "completely lost" any zest for his previously sociable life. This could lead to subsequent cardiac events, such as angina and even "sudden death".

"This study suggests that there may be no mortality advantage associated with the prescription of beta blockers," said Chris Gale, Professor of Cardiovascular Medicine at the University of Leeds and Consultant Cardiologist at York Teaching Hospital Trust.

However, the researchers agree that patient trials were needed to support the findings and examine other issues such as whether beta blockers prevent future heart attacks, to help "personalise" medications after a heart attack.

The study was funded by the British Heart Foundation. MIMS

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