An herbal medicine used to treat cardiovascular diseases in China may improve symptoms of chest pain when used in conjunction with traditional treatments, according to a new systematic review.

In several studies included in the review, taking tongxinluo improved angina patients’ electrocardiogram results. Overall, though, the review did not provide solid evidence that the medicine routinely benefits cardiac patients with angina.

“Tongxinluo is one of the most successful traditional Chinese medicines on the market in China,” said lead author Wu Taixiang.

Tongxinluo, widely used in parts of Asia, is composed of eight herbs and insects, which are mixed together, ground to a fine powder and enclosed in capsules. Patients taking it for cardiovascular conditions typically consume three to four capsules, three to four times daily, for four weeks.

Because of the medicine’s popularity, Taixiang, an associate professor at Sichuan University, West China Hospital, in Chengdu, Sichuan, and his coauthors say they felt a “social responsibility” to investigate possible clinical benefits.

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 draw evidence-based conclusions about medical practice after considering both the content and quality of existing trials on a topic.

The meta-analysis compiled data from 18 randomized controlled trials, all conducted in China, comprising 1,413 patients ranging in age from 25 to 88. Most of the trials examined the effect of tongxinluo when used in conjunction with traditional angina treatments compared to traditional treatments alone.