A popular herbal remedy may boost the physical capacity of patients with chronic heart failure and ease some symptoms, suggests a systematic review from the Cochrane Collaboration.
Researchers from the Peninsula Medical School in Exeter pooled the data of 14 randomised clinical trials, which assessed the impact of hawthorn extract in patients with mild to moderate chronic heart failure.
Hawthorn, a member of the rose family, is a herbal remedy that has been used since the Middle Ages for its medicinal properties.
Ten of these trials, which included 855 patients, evaluated the use of hawthorn extract in addition to conventional medicine, and compared it with the use of medicine plus placebo.
Those taking the hawthorn supplement increased the levels of physiological stress put on their hearts (physiological workload) and reduced the amount of oxygen required.
Exercise tolerance and symptoms of shortness of breath and fatigue also significantly improved compared with those taking the placebo.
The herb seemed to boost the strength of heart contractions, increase blood flow through the arteries and reduce irregular heartbeats.
Side effects were rare and mild, and there did not seem to be any interactions with conventional medicines.
But lead author Dr Max Pittler told OnMedica that the trials on which the review was based did not specifically look at potential interactions, nor did they assess impact on death rates.
And side effects might be more severe in those with more advanced disease who are taking stronger conventional medicines.
The 14 studies did not include a large clinical trial, due to be published later this year, which apparently suggests that the extract has a limited impact on lifespan.
“The results were significant when compared with placebo, but they were not very dramatic,” Dr Pittler told OnMedica.
“But they improved energy output, and that could translate into improved mobility, or the capacity to carry a bag of shopping. And that could have an effect on quality of life,” he said.
So should GPs recommend hawthorn extract to their heart failure patients?
“I think healthcare professionals should at least consider the evidence and take into account that hawthorn was better than placebo,” he responded.
No one single constituent had been identified as the active ingredient, he said.
“There are few herbal remedies which have had 14 good quality trials, so that’s quite significant in itself,” he added.
Hawthorn Extract for Treating Chronic Heart Failiure. Cochrane Database of Systematic Reviews 2008, Issue 1. www.cochrane.co.uk