Tongxinluo (a traditional Chinese medicine) capsules may help patients suffering from unstable angina

Tongxinluo, in capsule form, is a traditional Chinese medicine which consists of herbs and insects. Traditionally it has been thought to have clinical benefits for patients with angina, including the reduction of the occurrence of acute myocardial infarction (AMI), and complications of some types of heart surgery. Some studies also suggest a possible benefit in reducing the frequency and severity of angina attacks and improving symptoms. However, none of these individual studies have been reviewed systematically.

The review authors systematically reviewed evidence from 18 randomised controlled trials for the benefit of tongxinluo with or without other treatments, including routine care or placebo, for patients with unstable angina. All the trials were conducted in China. The total number of participants was 1413, ranging in age from 25 to 88 years. Most studies randomised patients to receive tongxinluo with conventional medication or conventional medications alone.

There was some evidence from seven studies that tongxinluo improved the electrocardiogram (ECG) changes indicating ischaemia and reduced the number of people with no improvement or worsening of ECG (six studies). Some improvement in angina symptoms (10 studies) and reduced numbers of people showing no improvement or worsening of symptoms were apparent with tongxinluo. Tongxinluo appeared to be as effective as isosorbide mononitrate in three studies. A few cases of slight gastrointestinal discomfort were reported after giving tongxinluo in seven studies and three cases of breaking of tiny blood vessels under the skin (ecchymosis) in one study.

The evidence suggested possible benefits relating to a range of outcomes among patients with unstable angina but all the studies were of poor quality and neither blinding nor allocation concealment were used. This makes it impossible to reach firm conclusions about the benefit of this treatment. 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.

Authors' conclusions: 

Tongxinluo in combination with routine angina therapy appears to reduce the risk of subsequent AMI, PTCA or CABG, angina attacks and severity, as well as improving symptoms and ischaemic changes on the electrocardiogram (ECG). Due to the methodological limitations of the studies, the evidence is insufficient to make any conclusive recommendations about the use of this treatment for patients presenting with unstable angina. Large high quality randomised controlled trials are warranted.

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Background: 

Tongxinluo capsule is a medicine consisting of traditional Chinese herbs and insects used for cardiovascular diseases in China and some other Asian countries. To date the evidence of its effect has not previously been subject to systematic review, making it difficult to derive robust conclusions about its actual benefits, and indeed, possible harms.

Objectives: 

To assess systematically the effects of tongxinluo capsule in people with unstable angina pectoris.

Search strategy: 

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library, Issue 4 2004, MEDLINE, EMBASE, Chinese Biomedical Database , China National Knowledge Infrastructure , Japana Centra Revuo Medicina (all 1995 to 2005). We also handsearched the relevant Chinese journals, checked with manufacturers and registers of ongoing studies.

Selection criteria: 

Randomised trials comparing either tongxinluo capsule only or standard treatment plus tongxinluo capsule with standard treatment or other anti-angina pectoris drugs, placebo or no intervention.

Data collection and analysis: 

Two authors identified relevant studies for the review independently and went on to abstract data, and assess trial quality. Authors of included studies were contacted to obtain further information as required.

Main results: 

18 short term follow-up trials involving 1413 people were included. The studies did not provide strong support of a benefit of tongxinluo for reducing the combined outcome of acute myocardial infarction, angioplasty (PTCA) coronary artery bypass graft (CABG) and sudden death or all-cause mortality (RR 0.42, 95%CI 0.07 to 2.59, P=0.35; RR 0.33, 95%CI 0.01to 7.78, P=0.49, respectively). Tongxinluo reduced the frequency of acute angina attacks (WMD -1.20, 95%CI -1.38 to -1.02, P<0.00001 and RR -2.36, 95%CI -2.53 to -2.18, P<0.00001, respectively), improved ECG (RR 1.31, 95%CI 1.08 to 1.57, P=0.005) and angina symptoms (RR 1.21, 95% CI 1.06 to 1.40; P=0.007).

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