Dan shen’s effect for stroke patients lacks strong evidence

Health Behavior News Service, by Bruce Sylvester – The traditional Chinese medicine dan shen (丹参, Salviae miltiorrhizae), a standard treatment for ischemic stroke in China, lacks strong scientific evidence to support such use, according a new review of studies.Nevertheless, based on the available data, dan shen treatment showed a tendency to improve short-term neurological deficits in stroke patients, say researchers at Sichuan University in Chengdu, China.

However, the short-term result “should be interpreted cautiously because of the poor methodological quality of included trials and the small numbers of patients,” said review co-author and neurology professor Ming Liu.

The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates research in all aspects of health care. Systematic reviews drawevidence-based conclusions about medical practice after considering both the content and quality of existing trials on a topic.

Obstruction of a blood vessel supplying blood to the brain can result in ischemic stroke, which accounts for about 83% of all strokes.

In China, post-stroke use of herbal medicine is part of standard care in both Western-style hospitals and in traditional Chinese medicine hospitals. Dan shen, in various pill, tablet and injection formulations, is the herb most commonly given for ischemic stroke; its use in that context spans more than three decades.

However, few researchers have tested the herb’s effectiveness in rigorous clinical trials that approach current international standards.

The reviewers found six studies that met inclusion criteria for the review — randomized or quasi-randomized and controlled — involving 494 acute ischemic stroke patients.

The Cochrane reviewers found that methods of randomly assigning study subjects to dan shen or placebo were unclear, and that this could have led to results exaggerating a positive treatment effect by 30% to 41%. “It is therefore plausible that dan shen is truly ineffective and the apparent benefits are simply due to bias arising from the methodological weaknesses of the studies,” they say.

Since treatment and follow-up in these studies ranged from 14 to 28 days, it was not possible to assess the long-term effects of dan shen.

“We found no evidence to support the routine use of dan shen agents for ischemic stroke,” Liu said. “However, if the apparently beneficial effects on neurological impairment were confirmed in methodologically rigorous trials, it would lead to a useful treatment for stroke being identified,” she added.

Ted Kaptchuck, O.M.D., associate professor of medicine at Harvard Medical School, said, “in Chinese society, at this time, basic science and laboratory evidence seems to be enough to gain widespread acceptance and adoption for the use herbal and other medications. In the West, we think it is a long shot to go from basic laboratoryevidence to demonstrated clinical efficacy in randomized trials. We are not at the point where it is clear that a traditional Chinese herb has a major role in health care.”

Liu agreed: “The designs of these trials need to be improved in the future research, not only in the clinical trials on dan shen agents, but also in trials on other Chinese herbal medicine.”

[Dan Shen agents for acute ischaemic stroke (Review). Cochrane Database of Systematic Reviews 2007, Issue 2.]

The Cochrane Collaboration is an international nonprofit, independent organization that produces and disseminates systematic reviews of health care interventions and promotes the search forevidence in the form of clinical trials and other studies of interventions.

Stroke: Surgery Safer Than Angioplasty?

Stroke: Surgery Safer Than Angioplasty?

Better Long-Term Outcomes Seen With Carotid Artery Surgery, Study Shows

By Salynn Boyles
WebMD Health News

Reviewed By Louise Chang, MD

Aug. 28, 2009 — Surgery is safer and slightly more effective than balloon angioplasty for preventing strokes, new research shows.

Two newly published investigations join a growing body of research showing worse outcomes in patients who have balloon angioplasty to clear the clogged neck arteries that supply oxygen-rich blood to the brain.

The findings could have a big impact on clinical practice, especially in the United States where balloon angioplasty is now performed far more often than surgery to open blocked or narrowed carotid arteries.

Both procedures carry their own risk of stroke, but it has not been clear if one was safer or worked better than the other.

“Taking all the studies together, the risk of stroke is now clearly higher with angioplasty,” stroke researcher Peter M. Rothwell, MD, PhD, tells WebMD. “What these two (new) papers now also show is that the long-term outcome is also worse with angioplasty. This is therefore a double-blow for angioplasty.”

Angioplasty Considered Safer

Narrowing of the carotid artery because of buildup of fatty plaque is one of the main risk factors of stroke.

The plaque can either be removed surgically or the narrowed artery can be opened by inflating a tiny balloon threaded up to the neck through a narrow catheter inserted into a groin artery. These days, a wire mesh stent is almost always inserted during angioplasty to keep the artery open.

Balloon angioplasty with stenting has become the procedure of choice in the U.S. in recent years, largely because it has been considered safer than surgery, says Larry B. Goldstein, MD, who directs Duke University Medical Center’s stroke center.

It is now clear that this is not the case, Goldstein tells WebMD.

The new studies, both performed by the same international research team, include the longest follow-up yet of patients treated with surgery or angioplasty for coronary artery disease.

Researchers followed 251 patients who had surgery and 253 who had angioplasty for up to 11 years, lead investigator Martin M. Brown, MD, tells WebMD.

Eight years later, slightly more angioplasty patients than surgery patients (11.3% vs. 8.6%) had experienced strokes, although the difference wasn’t statistically significant.

The angioplasty group also had more minor strokes within the first 30 days of having the procedure, compared to the surgery group (eight vs. one). The surgery group had more cases of cranial nerve palsy (22 vs. zero), a temporary nerve injury, and hematoma that needed surgery or longer stay in the hospital (17 vs. three).

In the second study, the researchers used ultrasound imaging to look for plaque buildup in the carotid arteries of 213 patients following surgery and 200 following angioplasty.

After five years, three times as many angioplasty patients had severe artery blockage (31% vs. 10%). “Patients who had angioplasty with stents had a lower risk of plaque recurrence than those who had angioplasty alone.

“The trials make it clear that surgery is the best option, but it is important to understand that the difference is not that great,” lead investigator Martin M. Brown, MD, tells WebMD. “Patients who can’t have surgery or don’t want it are still likely to do well.”

Surgery, Angioplasty or No Treatment

Because recruitment for the trials occurred before stents were routinely used with angioplasty, the results are not all that relevant to patients who have the procedure today, Goldstein says.

“One criticism is that the procedures used then are somewhat outdated, but this is an issue with any long-term interventional study,” he says. “The technology tends to move faster than the sciences.”

Another pressing question is whether too many procedures to clear clogged carotid arteries are being performed in the United States, he says.

The benefits of treatment are well established for patients with symptoms associated with carotid artery disease, but this is not the case for patients who have no symptoms, Goldstein says.

“If you have symptomatic high-grade narrowing of the carotid arteries, the risk of stroke can be as high as 26% over two years with no intervention,” he says. “The stroke risk for someone with asymptomatic disease is on the order of 1% to 2%.”

He tells WebMD that in the U.S. the majority of angioplasty with stenting procedures for carotid artery disease are performed on asymptomatic patients.

“The question now is who, if anybody, with asymptomatic disease should have anything done to their carotid artery, because the risk of causing harm is not small,” he says.

SOURCES: The Lancet Neurology, Aug. 29, online. Larry B Goldstein, MD, professor of medicine, director, Duke Stroke Center, Duke University Medical Center. Peter M. Rothwell, MD, PhD, John Radcliffe Hospital, Oxford, England. Martin M. Brown, MD, The National Hospital for Neurology and Neurosurgery, London. News release, The Lancet Neurology. WebMD Medical Reference: “Carotid Artery Disease.”

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