Coronary heart disease (CHD) is the leading cause of death and disability in the world. Percutaneous coronary intervention (PCI) with stent placement is the standard nonsurgical treatment for CHD. However, its main limitation is the repeated blocking of blood vessels following a stent procedure. Data from experimental and human studies have suggested that Xiongshao capsule, a Chinese herbal medicine product, may be beneficial in preventing restenosis of blood vessels after a PCI procedure. We systematically reviewed currently available evidence with the goal of performing a reliable assessment of the effects and safety of Xiongshao in repeated blocking of blood vessels after PCI.
We identified four trials that tested treatments based on Xiongshao capsule. Two trials compared Xiongshao capsule plus conventional western medicine with the same conventional western medicine plus placebo; the other two trials compared Xiongshao capsule plus conventional western medicine with the same conventional western medicine alone for preventing restenosis after a PCI procedure in CHD patients. These trials reported that use of Xiongshao capsule caused a significant reduction in the incidence rates of restenosis, recurrence angina pectoris, and serious cardiovascular adverse events with no substantive adverse effects following a PCI procedure. Therefore Xiongshao capsule may represent a choice for the prevention of in-stent restenosis following a PCI procedure. However, although summary estimates indicate a protective effect of Xiongshao on restenosis, evidence is derived in part from small randomised trials, all conducted in China, with some methodological limitations that undermine the validity of the findings. Additional high-quality research trials with sufficient sample size are required.
The summary estimates indicate a protective effect of Xiongshao on restenosis and suggest that Xiongshao capsule may be used to prevent restenosis after a PCI procedure in CHD patients. However, this evidence is derived from small randomised trials, all conducted in China, and two of the included trials showed important methodological limitations that undermine the validity of the findings. Additional high-quality research trials with sufficient sample size are required.
Percutaneous coronary intervention (PCI) with stent placement is a standard treatment for coronary heart disease (CHD). In-stent restenosis after PCI remains an important clinical problem. Xiongshao capsule has been reported to be beneficial in preventing restenosis after PCI in CHD patients. However, the strength of evidence to support its use is unclear.
To systematically assess the efficacy and safety of Chinese herbal medicine Xiongshao capsule in preventing restenosis after PCI in patients with CHD.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (Issue 3 of 2012), MEDLINE (OVID) (1948 to week 1 March 2012), EMBASE (OVID) (1980 to week 10 2012), ISI Web of Science with Conference Proceedings (1970 to 14 March 2012), LILACS (1982 to 15 March 2012), Chinese biomedical literature database (1980 to May 2012), China National Knowledge Infrastructure (1994 to May 2012), Chinese Medical Current Contents (1994 to May 2012), VIP Database for Chinese Technical Periodicals (1989 to May 2012), Chinese Master's Theses Full-Text Database (1994 to May 2012), China Doctor Dissertation Full-Text Database (1994 to May 2012), and China Proceedings of Conference Full-Text Database (1994 to May 2012). We also searched ongoing trials and research registries.
All randomised controlled trials comparing Xiongshao capsule alone/plus conventional western medicine with the same conventional western medicine alone/plus placebo in participants with CHD who met the recognised diagnostic criteria and had successfully undergone a PCI procedure were included.
Two review authors independently selected trials and extracted data. Two review authors independently assessed the risk of bias of included trials using The Cochrane Collaboration tool, and any disagreements were resolved by discussion with a third review author. Data were pooled for meta-analysis using the fixed-effect model, and the results were expressed as risk ratios (RRs) with 95% confidence intervals (CIs).
Four trials involving 649 participants were included in this review. Two of these trials (459 participants) were designed as randomised, double-blind, placebo-controlled trials with an adequate methodological description; the other two trials (190 participants) described an inadequate methodological design. All four trials with 649 participants were included in the meta-analysis. Significant differences were noted in rates of restenosis, recurrence angina pectoris, and serious cardiovascular adverse events between Xiongshao capsule plus conventional western medicine and the same conventional western medicine alone; RR values (95% CIs) were 0.41 (0.22 to 0.75), 0.47 (0.31 to 0.72), and 0.47 (0.25 to 0.90), respectively. Xiongshao capsule plus conventional western medicine showed more significant reductions in restenosis (RR 0.52, 95% CI 0.33 to 0.80), recurrence angina pectoris (RR 0.26, 95% CI 0.18 to 0.38), and serious cardiovascular adverse events (RR 0.45, 95% CI 0.28 to 0.70) than the same conventional western medicine plus placebo. Safety outcomes and adverse events of the Xiongshao capsule were reported in two trials, which reported no adverse events.