A type of drug used to help treat heart attacks does not work on the majority of patients and may actually contribute to hospitalization and death for women, new research has found.
Beta blockers are medicines that are used to lower blood pressure and cause the heart to beat more slowly and with less force and have been used to treat cardiovascular issues for years. They have been used as first-line treatment after heart attacks for decades, according to CNN.
However, a study published Saturday in the European Heart Journal found that women with little heart damage after suffering heart attacks who were treated with beta-blockers were significantly more likely to have another heart attack or be hospitalized for heart failure further down the line.
These women were also nearly three times more likely to die compared with women not given the drug, the study found. This was especially true for women receiving high doses of beta-blockers, according to lead study author Dr. Borja Ibanez.
Despite this, the same is not true for men, the research found.
Ibanez described the findings as “significant,” noting that the total number of women in the clinical trial was the largest ever included in a study testing beta-blockers after a heart attack.
The findings related to women with a left ventricular ejection fraction – the measurement used to determine how well the left side of the heart is pumping oxygenated blood – of above 50 percent. That is the level which is considered normal, according to the study.
For those with a score below 40 percent after a heart attack, beta-blockers will continue to be used due to their ability to calm abnormalities that could trigger a second event.
Dr. Andrew Freeman, director of cardiovascular prevention and wellness at National Jewish Health in Denver, told CNN that women being more susceptible to harm caused by beta blockers than men was “actually not surprising.”
“Gender has a lot to do with how people respond to medication,” Freeman told the outlet.
“In many cases, women have smaller hearts. They’re more sensitive to blood pressure medications. Some of that may have to do with size, and some may have to do with other factors we have yet to fully understand.”
Early research on heart disease was so focused on men that it took years for researchers to learn that symptoms presented differently in women, according to CNN. While men suffer from symptoms viewed as traditional, such as chest pain, women can have more unusual symptoms of a heart attack such as back pain and indigestion.
The analysis was part of a much bigger clinical trial called REBOOT — Treatment with Beta-Blockers after Myocardial Infarction without Reduced Ejection Fraction — which followed more than 8,000 men and women treated for heart attacks at 109 hospitals in Spain and Italy for nearly four years.
None of the patients had left ventricular ejection fraction below 40 percent, and the study, published in The New England Journal of Medicine, found “no benefit in using beta-blockers” in males or females who hearts were in such a condition, despite it still being the norm.
This, according to CNN, is in part down to advances in treatment.