Beta blockers may be ineffective following heart attack
Beta blocker drugs have formed part of the standard treatment for heart attacks for over 30 years to reduce the risk of new attacks. However, a new study involving more than 43,000 Swedish heart attack patients now indicates that these drugs have no effect after one year in the vast majority of cases.
“These beta blocker drugs were studied in the 1960s, 70s and 80s, when they proved to be effective in patients suffering from a heart attack, but since then a lot has happened in heart attack care. Among other things, we do more balloon angioplasty and stents and provide other treatments, such as lipid-lowering and more potent blood-thinning drugs that mean that beta blockers may no longer be needed,” explains Gorav Batra, Researcher at the Department of Medical Sciences and Uppsala Clinical Research Centre (UCR).
Fewer suffers from heart failure
The chances of surviving a heart attack are much better today than in the past. Previously, heart failure was also a very common complication of heart attacks and beta blockers are proven to be effective in such cases. However, significantly fewer heart attack patients are now suffering from heart failure thanks to faster care and treatment.
“It may be that beta blockers are useful in the short initial period, but not in the longer term. This is why we started looking at heart attack patients one year after the attack. We looked at those who were on beta blockers compared to those who were not. Then we looked at the combined outcome that included death, new heart attack, new revascularisation, that is, a new angioplasty, or whether they were admitted due to heart failure, because these are serious diseases that we want to avoid. We noted that beta blockers had no effect on this overall outcome,” explains Batra.
A register study
The study followed more than 43,000 heart attack patients from the national Swedish registry for coronary heart disease, SWEDEHEART. They had suffered a heart attack in 2005-2016 and none had developed heart failure at the start of the study. The researchers also collected information from the Patient Register, the Cause of Death Register and the National Prescribed Drug Register to see what treatment the patients received and whether they were hospitalised or died during the four and a half years in which they were monitored.
As this was a register study, the researchers could not investigate whether there were differences in quality of life between patients who took beta blockers and those who did not. Like other medicines, they have known side effects.
“It’s mainly fatigue – that’s what some of my patients experience. Some may feel depressed and some patients may have nightmares. It’s not a large number, but sometimes we do see that,” notes Batra.
Some patients also experience a decline in fitness, which can lead to them not being as physically active as they should be
Large randomised trials
Although the results of the study clearly indicate that beta blockers do not have a long-term effect on patients who have had a heart attack but have not developed heart failure, no far-reaching conclusions can be drawn from a single study. Randomised clinical trials showing the same results are needed before any change in the recommendations could be considered.
“Fortunately, there are large randomised trials in this area, including one in Sweden that randomly assigns patients to receive either beta blockers or no such treatment. We in Uppsala are also involved in including patients in this study. We should have results from this study pretty soon,” adds Batra.