People at high risk of heart failure should consider reducing their intake of alcohol, even below that of current recommended guidelines, a new Irish study suggests.

According to the findings, the levels of alcohol consumption currently considered safe by some countries are linked with the development of heart failure.

While it is already recognised that long-term heavy alcohol use can cause a type of heart failure called alcoholic cardiomyopathy, evidence from Asian populations suggests that lower amounts may also be detrimental.

“As there are genetic and environmental differences between Asian and European populations, this study investigated if there was a similar relationship between alcohol and cardiac changes in Europeans at risk of heart failure or with pre-heart failure. The mainstay of treatment for this group is management of risk factors such as alcohol, so knowledge about safe levels is crucial,” explained the study’s author, Dr Bethany Wong, of St Vincent's University Hospital in Dublin.

The study included 744 adults over the age of 40 who were either at risk of developing heart failure due to risk factors, such as high blood pressure, diabetes and obesity, or they had pre-heart failure, meaning they had risk factors and heart abnormalities but no symptoms.

The average age of the participants was 66.5 years and 53% were women. Heart function was measured with echocardiography at baseline and follow up.

The study used the Irish definition of one standard drink (i.e. one unit), which is 10 grams of alcohol. Participants were categorised according to their weekly alcohol intake:

-None

-Low (less than seven units which is up to one 750ml bottle of 12.5% wine or three-and-a-half 500 ml cans of 4.5% beer)

-Moderate (7-14 units which is up to two bottles of 12.5% wine or seven 500ml cans of 4.5% beer)

-High (above 14 units which is more than two bottles of 12.5% wine or seven 500ml cans of 4.5% beer).

The researchers analysed the association between alcohol use and heart health over a median of 5.4 years. The results were reported separately for the at-risk and pre-heart failure groups. The analyses were adjusted for factors that can affect heart structure including age, gender, obesity, high blood pressure, diabetes and vascular disease.

Some 27% of patients reported no alcohol usage, 48% were low users and 25% had moderate or high intake. Compared to the low intake group, those with moderate or high use were younger, more likely to be male and had a higher body mass index.

In the pre-heart failure group, compared with no alcohol use, moderate or high intake was associated with a 4.5-fold increased risk of worsening heart health. The relationship was also observed when moderate and high levels were analysed separately.

In the at-risk group, there was no association between moderate or high alcohol use with progression to pre-heart failure or to symptomatic heart failure. No protective associations were found for low alcohol intake.

According to Dr Wong, the study suggests that drinking more than 70g of alcohol per week is associated with worsening pre-heart failure or progression to symptomatic heart failure in Europeans.

“We did not observe any benefits of low alcohol usage. Our results indicate that countries should advocate lower limits of safe alcohol intake in pre-heart failure patients.

“In Ireland, for example, those at risk of heart failure or with pre-heart failure are advised to restrict weekly alcohol intake to 11 units for women and 17 units for men. This limit for men is more than twice the amount we found to be safe,” she noted.

She said that more research is needed in Caucasian populations “to align results and reduce the mixed messages that clinicians, patients and the public are currently getting”.

“This study adds to the body of evidence that a more cautious approach to alcohol consumption is needed. To minimise the risk of alcohol causing harm to the heart, if you don’t drink, don’t start. If you do drink, limit your weekly consumption to less than one bottle of wine or less than three-and-a-half 500ml cans of 4.5% beer,” Dr Wong added.

This study was presented at Heart Failure 2022, a scientific congress of the European Society of Cardiology, which was recently held in Madrid, Spain.