Hawthorn extract is safe and has significant benefits for patients with congestive heart failure, according to a meta-analysis here.
By John Gever, Staff Writer, MedPage Today
Exeter, England, Jan. 23 — Hawthorn extract is safe and has significant benefits for patients with congestive heart failure, according to a meta-analysis here.
In most of the trials, patients were taking conventional cardiac medications such as diuretics, ACE inhibitors, and calcium antagonists along with the study medications. Concomitant medications were not mentioned in the other studies.
As a result, Dr. Pittler and colleagues wrote, it cannot be concluded definitively that the herbal remedy alone accounted for the results. On the other hand, it appears that hawthorn extract can be combined safely with conventional heart drugs.
The Cochrane analysis did not include results from SPICE, a large placebo-controlled trial presented at a major cardiology meeting last year that found equivocal benefits at best for hawthorn extract.
That still-unpublished study involved more than twice as many patients as all the trials included in the Cochrane study. SPICE found no difference after two years of treatment in a composite endpoint of cardiac events, including death, nonfatal myocardial infarction, and heart failure progression.
Dr. Pittler and colleagues included only studies published in medical journals through June 2006, thereby excluding the SPICE results.
Extracts made from leaves, flowers, and fruits of hawthorn, a shrub with the Latin name Crataegus laevigata, and also known as whitethorn, are a staple of alternative and complementary medicine. Hawthorn extract has been touted as a treatment for heart failure and hypertension.
Most of the trials included in the Cochrane analysi,s as well as SPICE, used a standardized product called WS-1442, with the others studying another product known as LI132. Doses ranged from 160 mg to 1,800 mg daily.
Maximal workload was the most frequent outcome measure used in the 14 included studies. Pooled data from trials involving 380 patients showed that hawthorn extract increased maximal workload by a weighted mean difference of 5.35 watts (95% CI: 0.71 to 10.00, P<0.02).
For pressure-heart rate product, pooled data from five trials and 264 patients found a weighted mean decrease of -19.22 mm Hg/min (95% CI: -30.46 to -7.98).
Exercise tolerance improved by a weighted mean difference of 122.76 watt-min (95% CI: 32.74 to 212.78) in trials involving 98 patients.
Two studies with 239 patients found a weighted mean decrease of -5.47 points (95% CI: -8.68 to -2.26) in dyspnea and fatigue scores.
Only one trial, involving 113 patients, tested for six-minute walk distance. It found no significant difference.
Dr. Pittler and colleagues sought data on mortality and cardiac events, but the included trials reported no analyzable data for these outcomes.
The most common adverse events with hawthorn extracts were dizziness and gastrointestinal complaints, both of which affected fewer than 10 patients in the included trials.
The researchers noted that post-marketing surveillance studies not included in their formal analysis also have found low rates for adverse effects. One study of 3,664 patients reported event rates of 1.3%.
“Our results suggest that, compared with placebo, hawthorn extract increases the maximal workload in patients with chronic heart failure,” Dr. Pittler and colleagues wrote. “This conclusion, however, is based on small numbers of studies and patients. Nevertheless, the secondary outcome measures support the findings and suggest that hawthorn extract is superior to placebo as an adjunctive treatment for patients with chronic heart failure.”
They added that future investigations are needed to determine whether hawthorn extract treatment affects the prognosis of heart failure.
They pointed out that, as with any systematic review, they may have excluded some relevant studies. Methodologies and degree of rigor varied among the included trials as well, the researchers said.
Gregg Fonarow, M.D., director of UCLA’s heart failure program, said he agreed with Dr. Pittler and his group that hawthorn extract is safe for heart failure patients. He said the review “does indeed demonstrate that it is not a harmful therapy.”
But he disputed the group’s conclusion that hawthorn is superior to placebo, citing the SPICE results reported last March at the American College of Cardiology’s annual meeting in New Orleans.
That study, conducted mainly in eastern Europe, tested WS-1442 against placebo in 2,618 heart failure patients. Christopher Holubarsch, M.D., of Median Kliniken Hospitals in Bad Krozingen, Germany, reported no difference after two years of treatment in the primary outcome measure. It was a composite of cardiac events including death, nonfatal myocardial infarction, and heart failure progression.
Significant reductions in relative risk for cardiac death in patients receiving hawthorn extract were seen at six and 18 months, but not at 12 or 24 months, according to the report.
Dr. Fonarow said these results impressed him more than the Cochrane review. He said hawthorn “is not particularly helpful” and would not recommend it for patients.
“It’s naturally attractive to think there is something over the counter or naturally occurring that may help improve outcome. Unfortunately, we’ve not been able to identify that so far,” he said.
The review was funded by the Videns-og forsknings-center for alternativ behandling (Denmark).
No financial conflicts of interest were reported.
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Cochrane Database of Systematic Reviews
Pittler M, et al “Hawthorn extract for treating chronic heart failure” Cochrane Database of Systematic Reviews 2008; Issue 1: DOI: 10.1002/14651858.CD005312.pub2.