Tongxinluo (Tong xin luo or Tong-xin-luo) capsule for unstable angina pectoris

Abstract

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 0.01 to 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). 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. Copyright © 2006 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.