A review of published studies suggests that a Chinese herbal medicine may improve angina (chest pain) symptoms when combined with conventional therapy.

However, lead researcher Dr Wu Taixiang, from Sichuan University in Chengdu, China, and colleagues stress that further research is needed to provide solid evidence of the benefits of the herbal medicine, called tongxinluo, for the treatment of angina before it can be recommended for patients with the condition.

Tongxinluo is widely used in parts of Asia, and is composed of eight herbs and insects. Patients who use the medication for cardiovascular disorders typically take three to four capsules, three to four times daily for 4 weeks.

Because of Tongxinluo's popularity in Asia, the researchers conducted a review of 18 published studies, including more than 1400 participants, which investigated its effectiveness in the treatment of angina. Most of these studies examined the effects of tongxinluo in combination with conventional treatment and compared this with conventional treatment alone.

The results of the review indicated that tongxinluo reduced the frequency of angina symptoms such as chest pain and discomfort attacks, with significant improvements in patients' electrocardiogram results, which indicate heart health by measuring the electrical activity of the heart.

However, the researchers comment: "Although this review shows that there appears to be some benefit from the use of tongxinluo, the results should be interpreted with caution because of the poor methodology of the included studies."

They conclude: "Large, high quality, randomised controlled trials are needed to confirm the possible benefit of tongxinluo for unstable angina and to suggest appropriate future use of this herbal medicine."

The review appears in the current edition of The Cochrane Library.