Scholarly article on topic 'Acupuncture therapy for angina pectoris: a systematic review'

Acupuncture therapy for angina pectoris: a systematic review Academic research paper on "Basic medicine"

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Abstract of research paper on Basic medicine, author of scientific article — Ji Chen, Yulan Ren, Yong Tang, Zhengjie Li, Fanrong Liang

Abstract Objective To assess the effectiveness and safety of acupuncture therapy for angina pectoris. Methods Randomized controlled trials (RCTs) concerned with acupuncture treatment of angina pectoris were identified by searching Academic Source Premier, MEDLINE, Science Citation Index Expanded, and three Chinese databases (China biology medicine database, China national knowledge infrastructure, and VIP database for Chinese technical periodicals). The valid data were extracted in accordance with our inclusion and exclusion criteria. The main outcomes of the included studies were synthesized using Revman 5.1. Results Twenty-one articles on 16 individual studies were included and evaluated as having high or moderate risk of bias according to the standards of the Cochrane Collaboration. Meta-analysis indicated that acupuncture combined with conventional drugs (ACCD) was superior to conventional drugs alone in reducing the incidence of acute myocardial infarction (AMI) [OR=0.18, 95% CI (0.04, 0.84), P=0.03]. Moreover, ACCD was superior to conventional drugs in the relief of angina symptoms [OR=4.23, 95% CI (2.73, 6.56), P<0.00001], and improvement of electrocardiography (ECG) [OR=2.61, 95% CI (1.83, 3.73), P<0.00001]. Acupuncture by itself was also superior to conventional drugs for angina symptoms [OR=3.59, 95%C/(1.76, 7.92), P=0.0004] and ECG improvement [OR=3.07, 95%CI (1.54, 6.10), P=0.001]. ACCD was superior to conventional drugs in shortening the time to onset of angina relief [WMD=−1.40, 95% CI (−1.65, −1.15), P< 0.00001]. However, the time to onset was significantly longer for acupuncture treatment than for conventional treatment alone [WMD=2.43, 95% CI (1.63, 3.23), P<0.000 01]. Conclusion ACCD reduced the occurrence of AMI, and both acupuncture and ACCD relieved angina symptoms and improved ECG. However, compared with conventional treatment, acupuncture showed a longer delay before its onset of action. This indicates that acupuncture is not suitable for emergency treatment of heart attack. Owing to the poor quality of the current evidence, the findings of this systematic review need to be verified by more RCTs to enhance statistical power.

Academic research paper on topic "Acupuncture therapy for angina pectoris: a systematic review"

JTCM

Online Submissions: http://www.journaltcm.com info@journaltcm.com

JTradit Chin Med 2012 December 15; 32(4):494-501

ISSN 0255-2922 © 2012 JTCM. All rights reserved.

EVIDENCE-BASED STUDY

Acupuncture therapy for angina pectoris: a systematic review

Ji Chen,Yulan Ren, Yong Tang, Zhengjie Li, Fanrong Liang

Ji Chen, Yulan Ren, Yong Tang, Zhengjie Li, Fanrong Liang, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, Sichuan, China

Supported by the National Basic Research Program of China (973 Program) for "Basic Research on Acupoint Specificity Along Medians and its Crucial Influential Factors" (No. 2012CB518501)

Correspondence to: Prof. Fanrong Liang, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, Sichuan, China. LFR@cdutcm.edu.cn Telephone: +86-28-61800006 Accepted: June 11,2012

Abstract

OBJECTIVE: To assess the effectiveness and safety of acupuncture therapy for angina pectoris.

METHODS: Randomized controlled trials (RCTs) concerned with acupuncture treatment of angina pectoris were identified by searching Academic Source Premier, MEDLINE, Science Citation Index Expanded, and three Chinese databases (China biology medicine database, China national knowledge infrastructure, and VIP database for Chinese technical periodicals). The valid data were extracted in accordance with our inclusion and exclusion criteria. The main outcomes of the included studies were synthesized using Revman 5.1.

RESULTS: Twenty-one articles on 16 individual studies were included and evaluated as having high or moderate risk of bias according to the standards of the Cochrane Collaboration. Meta-analysis indicated that acupuncture combined with conventional drugs (ACCD) was superior to conventional drugs alone in reducing the incidence of acute myocardial infarction (AMI) [0R=0.18, 95% CI (0.04,

0.84), P=0.03]. Moreover, ACCD was superior to conventional drugs in the relief of angina symptoms [OR=4.23, 95% CI (2.73, 6.56), P<0.00001], and improvement of electrocardiography (ECG) [OR=2.61, 95%CI (1.83, 3.73), P<0.00001]. Acupuncture by itself was also superior to conventional drugs for angina symptoms [OR=3.59,95%CI (1.76,7.92), P=0.0004] and ECG improvement [0R=3.07, 95%CI (1.54, 6.10), P=0.001]. ACCD was superior to conventional drugs in shortening the time to onset of angina relief [WMD=-1.40, 95% CI (-1.65,-1.15), P< 0.00001]. However, the time to onset was significantly longer for acupuncture treatment than for conventional treatment alone [WMD=2.43, 95% CI (1.63, 3.23), P<0.000 01].

CONCLUSION: ACCD reduced the occurrence of AMI, and both acupuncture and ACCD relieved angina symptoms and improved ECG. However, compared with conventional treatment, acupuncture showed a longer delay before its onset of action. This indicates that acupuncture is not suitable for emergency treatment of heart attack. Owing to the poor quality of the current evidence, the findings of this systematic review need to be verified by more RCTs to enhance statistical power.

© 2012 JTCM. All rights reserved.

Key words: Acupuncture therapy; Randomized controlled trial; Efficacy; Review; Meta-analysis

INTRODUCTION

Coronary artery disease (CAD) commonly results from atherosclerotic obstruction of coronary arteries and mostly manifests as angina pectoris and acute myocar-

dial infarction. An ischemic heart disease, it is likely to attack people over 40 years of age. It has been reported that the incidence of angina pectoris is 0.1%-1% in European women aged 40%-54% years, and 2%-5% in men of the same age group. The incidence is 10%-15% in females and 10%-20% in males in people aged 65 to 74 years.1 With the rapid development of the Chinese economy, ischemic heart disease has become increasingly common in recent years. According to a survey of a community in Beijing, the incidence of angina pectoris and myocardial infarction is 30.7% (male 26.2%, female 33.7%) and 2.9% (male 4.8%, female 1.7%), respectively.2 It has been estimated that the global mortality of CAD will rise from 6.3 million in 1990 to 11 million by the end of 2020, and that the mortality will increase to 74.6% in the coming thirty

years.

Modern treatments to reduce ischemic symptoms and improve prognosis of angina pectoris include nitrates, beta blockers, calcium antagonists, aspirin, and ACE inhibitors. These drugs can have undesirable effects. For instance, nitrate treatment carries the risks of tolerance and rebound, and can cause headaches, flushed cheeks and other adverse reactions.4,5 Acupuncture was recorded in Huang Di Nei Jing over two thousand years ago to work well in the treatment of chest Bi syndrome (precordial pain). In more recent years, acupuncture therapy for angina has occasionally been reported outside China. A non-randomized controlled trial in Denmark indicated that integrated rehabilitation dominated by acupuncture reduced the risk of death in patients with coronary heart disease and decreased their economic burden.7,8

Currently available randomized controlled trials (RCTs) have had small sample sizes and shown diverse outcomes. The assessment and integration of these trials using an evidence-based approach to guide clinical treatment are of global priority. Therefore, in this systematic review we synthesize the results of available RCTs to assess the effectiveness and safety of acupuncture therapy for angina pectoris.

METHODS

Inclusion criteria for studies

All RCTs, except those containing inaccurate or incomplete data, were included.

Inclusion criteria for participants

Participants had been diagnosed with angina pectoris since at least three months. Participants were excluded if they had acute myocardial infarction, severe arrhythmia, heart failure, hepatic failure or renal failure.

Inclusion criteria for the interventions

This review included trials that made a comparison between an acupuncture-dominated therapy and nitrates. The acupuncture-dominated treatments included acu-

puncture combined with conventional drugs (ACCD) and acupuncture itself. ACCD or acupuncture therapy consisted of manipulations such as stimulation with filiform needles, and cupping after needling, and the duration of treatment was >10 days. We included studies that predominantly used nitrates as the conventional treatment. If they used other antianginal drugs, such as beta-blockers or calcium antagonists, we included the trial as long as the drugs were used equally across the control and experimental groups.

Primary and secondary outcomes

Primary outcome: incidence of myocardial infarction. Secondary outcomes: 1) improvement of angina symptoms; 2) time to onset of angina relief in response to treatment; and 3) electrocardiography (ECG) improvement.

Search methods

We searched the following databases: Academic Source Premier (1975 to August 2011), MEDLINE (1993 to August 2011), Science Citation Index Expanded (1973 to August 2011) and the three Chinese databases China biology medicine (1978 to August 2011), China national knowledge infrastructure (1979 to August 2011) and VIP database for Chinese technical periodicals (1989 to August 2011). Studies published in both English and Chinese were retrieved. Further, studies included in reference lists of relevant trials and reviews were also identified. The following key words were used in the search: angina, angina pectoris, coronary heart disease, acupuncture, and electroacupuncture. A sample retrieval strategy for MEDLINE is shown below.

1) acupuncture therapy.mp. or exp Acupuncture Therapy

2) electroacupuncture. mp. or exp Electroacupuncture

3) electric acupuncture. mp. or exp Electric Acupuncture

4) electric stimulat$.tw.

5) transcutaneous electrical nerve stimulation

6) tens.mp

7) or/1)-6)

8) angina pectoris.mp. or exp Angina Pectoris

9) angina.mp.

10) stable angina.mp.

11) unstable angina.mp.

12) or/8)-11)

13) 7) and 12)

14) randomized controlled trial.pt.

15) controlled clinical trial.pt.

16) randomized controlled trials.sh.

17) random allocation.sh.

18) double blind method.sh.

19) single-blind method.sh.

20) or/14)-19)

21) (animals not human).sh.

22) 20 not 21

23) clinical trial.pt.

24) exp clinical trials

25) (clin$ adj25 trial$).ti,ab.

26) ((singl$ or doubl$ or trebl$ or tripl$) adj25 (blind $ or mask$)).ti,ab.

27) random$.ti,ab.

28) research design.sh.

29) or/23-28

30) 29) not 21)

31) 30) not 21)

32) comparative study.sh.

33) exp evaluation studies

34) follow up studies.sh.

35) prospective studies.sh.

36) (control$ or prospectiv$ or volunteer$).ti,ab.

37) or/32)-36)

38) 37) not 21)

39) 38) not 22) or 31)

40) 22) or 31) or 39)

41) 13) and 40)

Data collection and extraction

RCTs evaluating the efficacy of acupuncture-dominated therapy for angina pectoris were included. Titles and abstracts of searched studies were screened for further review. Those that appeared eligible were determined eligible by review of the full text. The inclusion criteria were applied by two authors independently. Disagreements were resolved by discussion and by consultation with other authors of our group, and a judgment was made based on consensus. Data were collected independently by two authors using a piloted data extraction form. The following characteristics of the trials were recorded on the form: design, methods, participants, interventions, and outcomes. Any disagreements were resolved by referring to the trial report and by discussion. The standards advised by the Cochrane handbook9 in terms of randomization, allocation concealment, binding, complete data and selective reporting were employed to evaluate the quality of the RCTs. "Yes", "No" or "not-reported" were used to determine the standards mentioned above. The quality of each study was assessed as low risk of bias (one or more criteria not met), as moderate risk of bias (one or more criteria partly met), or as high risk of bias (all of the criteria met). For dichotomous outcomes, the number of participants experiencing the event in each group was recorded. For continuous outcomes, the means and standard deviations for each group were extracted. Data entries in RevMan 5.1 (free software downloadable from http: //ims.cochrane.org/revman/download) were double-checked.

Statistical analysis

Data were used for a meta-analysis if they were available, of sufficient quality and sufficiently similar. Dichotomous data were expressed as relative risks (OR). Continuous data were expressed as weighted mean differences (WMD). Overall results were calculated based on the fixed effects model when no heterogeneity was found among pooled studies. Where heterogeneity existed, the random effects model was used. Heterogene-

ity was tested using the Z score and the Chi-square statistics with significance set at P<0.1. Possible sources of heterogeneity were assessed by sensitivity and subgroup analyses as described below.

RESULTS

Description of included studies

We selected 21 studies out of the 296 relevant references by screening titles and reviewing full texts. The data of the included studies were extracted using a form that included study design, sample size, intervention and outcome measure (Figure 1).

General data of included studies

Sixteen independent studies were reported in the 21 included articles. The treatment groups received either ACCD or acupuncture therapy, while the control groups were treated with conventional drugs. The number of participants varied from 49 to 200 and the duration of treatment was between 10 days and 6 weeks (Table 1).

Quality assessment of included studies

Six of the included articles reported their method of randomization, whereas none mentioned allocation concealment, blinding, loss of follow-up or drop-out, or selective report. All studies were assessed as having a high or moderate risk of bias (Table 2).

Effect of ACCD on the incidence of myocardial infarction

Two papers reported their follow-up of participants with myocardial infarction.21,26 In those trials, the patients received ACCD together with the same conventional drugs as the control group, and there was little heterogeneity between the two studies (P=1.00, I= 0%). Meta-analysis was conducted using the fixed effect model. The result indicated that ACCD was better than conventional treatment for preventing acute myocardial infarction [0R=0.18, 95% CI (0.04, 0.84), P=0.03] (Figure 2).

Effects of ACCD and acupuncture on angina symptoms

Ten studies reported the effective rate of angina relief by ACCD.11'13 1620'222630 There was little heterogeneity among these studies (P=0.95, I =0%), so meta-analysis was conducted using the fixed effect model. The result indicated that ACCD was superior for improvement of angina symptoms compared to the conventional treatment [OR=4.23,95%CI(2.73,6.56),P<0.00001] (Figure 3). Two studies reported the effective rate of angina relief by acupuncture.27,28 There was little heterogeneity between the two studies (P=0.35, P= 0%), so meta-analy-sis was conducted using the fixed effect model. The result indicated that acupuncture was superior compared

able 1 Characteristics of included studies

Study n T C Intervention TC Drugs employed as conventional treatment Course

Yuan ZJ10 30 28 A+CT CT isosorbide 5-mononitrate 4 weeks

WangX11 28 21 A+CT CT isosorbide 5-mononitrate, betaloc, aspirin 2 weeks

CaoJP12 30 21 A+CT CT isosorbide dinitrate, aspirin 3weeks

Liu WP13 32 31 A+CT CT isosorbide dinitrate 8 weeks

Liu WP14 32 30 A+CT CT isosorbide 5-mononitrate, diltiazem hydrochloride, aspirin 4 weeks

Liu WP15 32 30 A+CT CT isosorbide 5-mononitrate, diltiazem hydrochloride, aspirin 4 weeks

Chang PF16 30 22 A+CT CT nitrates, betaloc 2 weeks

TongYH18 120 80 A+CT CT isosorbide 5-mononitrate, betaloc, simvastatin, aspirin 6 weeks

TongYH19 80 60 A+CT CT isosorbide 5-mononitrate, betaloc, simvastatin, aspirin 6 weeks

TongYH20 120 80 A+CT CT isosorbide 5-mononitrate, betaloc, simvastatin, aspirin 6 weeks

Huang FQ17 80 60 A+CT CT isosorbide 5-mononitrate, betaloc, simvastatin, aspirin 6 weeks

Xu FH21 35 35 A+CT CT nitrates, beta-blocker, calcium antagonist, aspirin 10 days

Yu SH22 33 30 A+CT CT Nitrates 2 weeks

Li CP23 36 34 A+CT CT isosorbide 5-mononitrate, betaloc, aspirin 24 sessions

Xu GD25 120 80 A+CT CT isosorbide 5-mononitrate, betaloc, simvastatin, aspirin 6 weeks

Liu WP24 32 30 A+CT CT isosorbide 5-mononitrate, diltiazem hydrochloride , aspirin 4 weeks

Zhou W27 72 56 A CT isosorbide dinitrate, betaloc, aspirin 6 weeks

Zhai WS26 35 35 A+CT CT nitrates, beta-blocker, calcium antagonist, aspirin 10 days

Yin LH28 40 38 A CT isosorbide 5-mononitrate 30 sessions

Yin LH29 40 38 A CT isosorbide 5-mononitrate 30 sessions

Lin Z30 35 30 A+CT CT isosorbide 5-mononitrate, aspirin 4 weeks

Notes: A: acupuncture; CT: conventional treatment; T: treatment group; C: control group.

Relevant reference(n=296) ASP (n=13) MEDILINE(n=19) SCI-E (n=14) CBM (n=35) CNK((n=184) VIP (n=31)

-+ r Review titles and abstract: duplication-elimination(n-62) non-conforming articles (n-181)

Articles proposed to include (n=53)

-» In-depth review of the full-text: non-conforming articles(n-32)

Final included studies (n=21)

Figure 1 Flow diagram of the search method and selection process

ASP: academic source premier; SCI-E: science citation index expanded; CBM: China biology medicine; CNKI: China national knowledge infrastructure; VIP: VIP database for Chinese technical periodicals.

Experimental Control Study or Subgroup Events Total Events Total Weight

Odds Ratio M-H. Fixed. 95% CI

Odds Ratio M-H. Fixed. 95% CI

XuFH 2005 Zhai WS 2007

35 50.0% 35 50.0%

0.18 [0.02,1.60] 0.18 [0,02,1.60]

Total (95% CI)

Total events 2 10

Heterogeneity: Chi3 = 0.00, df= 1 (P = 1.00); I3 = 0% Test for overall effect: Z = 2.18 (P = 0.03)

Figure 2 Forest plot of ACCD for acute myocardial infarction ACCD: acupuncture combined with conventional drugs.

70 100.0% 0.18 [0.04,0.84]

I-1--1-1

0.001 0.1 1 10 1000 Favours experimental Favours control

able 2 Methodological quality assessment of included studies

Study Method of randomization allocation concealment blinding Loss of follow-up or drop-out Selective report Quality assess ment

Yuan ZJ 10 Unclear not reported not reported non non high risk

Wang X 11 Unclear not reported not reported non non high risk

CaoJP 12 Yes (coin toss) not reported not reported non non moderate risk

Liu WP13 Unclear not reported not reported non non high risk

Liu WP14 Yes (random number table) not reported not reported non non moderate risk

Liu WP15 Yes (random number table) not reported not reported non non moderate risk

Chang PF16 Unclear not reported not reported non non high risk

Huang FQ17 Unclear not reported not reported non non high risk

TongYH18 Unclear not reported not reported non non high risk

TongYH19 Unclear not reported not reported non non high risk

TongYH20 Unclear not reported not reported non non high risk

Xu FH21 No (medical record number) not reported not reported non non high risk

Yu SH22 Unclear not reported not reported non non high risk

Li CP23 Yes (random number table) not reported not reported non non moderate risk

Liu WP24 Unclear not reported not reported non non high risk

Xu GD25 Unclear not reported not reported non non high risk

Zhai WS26 Unclear not reported not reported non non high risk

Zhou W27 Yin LH28 Yin LH29 Unclear Yes (computer-generating random numbers) Yes (computer-generating random numbers) not reported not reported not reported not reported not reported not reported non non non non non non high risk moderate risk moderate risk

Zhang L30 Unclear not reported not reported non non high risk

with the conventional treatment in reducing angina symptoms [0^=3.59, 95% CI (1.76, 7.92), P=0.0004] (Figure 4).

Effect of ACCD and acupuncture on the time to onset of angina relief

Two studiesreported the time to onset of angina relief provided by ACCD.11,22 There was little heterogeneity between the two studies (P= 1.00, P=0%), so meta-analysis

was conducted usingthe fixed effectmodel. The resultindi-cated that ACCD shortened the time to onset of anginarelief compared with conventional treatment [WMD= -1.40, 95%CI (-1.65, -1.15), P<0.00001] (Figure 5). Only one study reported the effect of acupuncture on the time to onset of angina relief.27 The fixed effect model was employed to conduct meta-analysis in which no combined effect was applied. The result showed that acupuncture had a slower onset of action

Experimental

Control

Odds Ratio

Study or Subtiroun Events Total Events Total Wei a (it M-H. Fixed. 95% CI Year

Wang X 2000 27 28 16 21 3.1% 8.44 [0.90, 78.81] 2000

Cao JP2002 27 30 15 21 8.5% 3.60 [0.79,16.51] 2002

Liu WP1 2004 30 32 25 30 7.7% 3.00(0.54,16.81] 2004

Yu SH 2005 30 33 25 30 11.4% 2.00 [0.43, 9.20] 2005

XuFH 2005 31 35 21 35 11.5% 5.17 (1.49,17.88] 2005

Chang PF 2005 27 30 18 22 9.9% 2.0010.40,10.02] 2005

Li CP 2005 31 36 21 34 14.4% 3.84 (1.19,12.38] 2005

Tong YH3 2005 116 120 64 80 12.3% 7.25 (2.32,22.61] 2005

ZhaiWS 2007 31 35 21 35 11.5% 5.17(1.49, 17 88] 2007

Zhang L2011 32 35 22 30 9.7% 3.88 {0.92,16.27] 2011

Total (95% CI) 414 338 100.0% 4.23 (2.73, 6.56]

Total events 382 248

Heterogeneity: ChP = 3.42, df= 9 (P= 0. 95); F = 0%

Test for overall effect: Z-6.45 (P <0.00001)

Odds Ratio M-H. Fixed. 95% CI

0.01 0.1 1 Favours control

10 100 Favours experiments

Figure 3 Forest plot of ACCD for effective improvement of angina symptoms ACCD: acupuncture combined with conventional drugs.

Experimental Control Odds Ratio

Study or Subgroup Events Total Events Total Weight M-H. Fixed, 95% CI

Odds Ratio M-H. Fixed. 95% CI

Zhou W 2007 56 72 30 56 90,4% 3.03 [1.41,6.521 2007

Yin LH1 2009 39 40 31 38 96% 8.81 [1.03, 75.43] 2009

Total (95% CI) 112 94 100.0% 3.59 [1.7fi, 7.29]

Total events 95 61

Heterogeneity: Chi3 = 0.86, df= 1 (P = 0.35); P= 0% Test for overall effect: Z = 3.53 (P = 0.0004)

Figure 4 Forest plot of acupuncture for effective improvement of angina symptoms

Experimental Control Mean Difference

Study or Suhoroui) Mean SD Total Mean SD Total Weiiiht IV. Fixed. 95% CI

0.001 0.1 1 10 1000 Favours control Favours experiments

Mean Difference IV. Fixed. 95% CI_

Wang X 2000 Yu SH 2005

2.6 2 6

0.9 0.9

50,0% 50.0%

-1.40 [-1.75,-1.05] -1.40 [-1.75,-1.05]

Total (95% CI) 61

Heterogeneity: Chi= = 0.00, df = 1 (P = 1.00); l* = Test for overall effect: Z= 11.09 (P <s 03)0001)

61 100.0% -1.40 [-1.65,-1.15]

-2-10 1 2 Favours experimental Favours control

Figure 5 Forest plot of the effect of ACCD in reducing the time to onset of angina relief ACCD: acupuncture combined with conventional drugs.

Experimental Control Mean Difference

Study or Subgroup Mean SD Total Mean SP Total Weight IV. Fixed, 95% CI

Mean Difference IV. Fixed. 95% CI

ZhouW2007

6.57 3 18 72 4.14 1.21

Total (95% CI)

Heterogeneity: Not applicable

Test for overall effect: Z = 5.95 (P < 0.00001)

56 100 0% 2.43 (1.63,3 23] 56 100.0% 2.43(1.63,3.23]

Figure 6 Forest plot of the effect of acupuncture on the time to onset of angina relief

Experimental

Control

Odds Ratio

Study or Subaroup Events Total Events Total Weitiirt M-H. Fixed. 95% CI rear

Yuan ZJ 1999 21 30 16 28 13.1% 1.75 [0.59, 5.16] 1999

Wang X 2000 4 28 2 21 5.2% 1.53 [0.26, 9.59] 2000

Cao JP 2002 23 30 14 21 10 1% 1 64 ¡0.48,5.68] 2002

Liu WP1 2004 30 32 23 30 3.9% 4.57(0,87,24.07] 2004

Chang PF 2005 28 30 14 22 2.8% 0.00(1 50, 42.80] 2005

Li CP 2005 27 36 16 34 10.8% 3.38 ¡1.23, 9.28] 2005

Xu FH 2005 22 35 23 35 22.5% 0.88 ¡0.33, 2.35] 2005

Tong YH3 2005 112 120 64 ao 13.5% 3.50 ¡1.42,8.63] 2005

ZhaiWS 2007 22 35 11 35 10.8% 3.69 ¡1.37, 9.93] 2007

Zhang L2011 30 35 10 30 7.3% 4.00 [1.21,13,22] 2011

Total (95% CI) 411 336 100.0% 2.61 (1.83, 3.73]

Total events 319 201

Heterogeneity: Chf = 9.83, df= 9 (P= 0.36); l' = 8%

Test for overall effect: Z= 5.27 (P< 0.00001)

-4 -2 0 2 4 Favours experimental Favours control

Odds Ratio M-H. Fixed. 95% CI

0.02 0.1 1 Favours control

10 50 Favours experiments

Figure 7 Forest plot of the efficacy of ACCD in improving ECG

ACCD: acupuncture combined with conventional drugs; ECG: electrocardiography.

Study or Subgroup

Experimental Events Total

Control Events Total

Odds Ratio Weight M-H, Fixed, 95% CI

Odds Ratio M-H. Fixed. 95% CI

Zhou W 2007 Yin LH1 2009

69.6% 30.4%

3.00(1.32, 6 83] 3.21 [0.91,11.34]

2007 2009

10G.0% 3.07 [1.54, 6.10]

Total (95% CI) 112 94

Total events 96 63

Heterogeneity: Chi= = 0.01. df= 1 (P= 0.93); Is = 0% Test for overall effect: 2 = 3.19 (P = 0.001 )

Figure 8 Forest plot of the effect of acupuncture on ECG improvement ECG: electrocardiography.

0.01 0.1 1 10 100 Favours control Favours experimenta

SE (log[OR]) \

□ qt¡ h n \

□ □

! □ \ OR

0.02 0.1 1 10 50

Figure 9 Funnel plot of the included studies on the effects on ECG improvement ECG: electrocardiography.

compared to nitrates [WMD=2.43, 95% CI(1.63, 3.23), P<0.000 01] (Figure 6).

Effects ofACCD and acupuncture on ECG improvement

Ten studies reported the efficacy of ACCD on ECG improvement.10-12,16,20,21,23,26,30 There was little heterogeneity among these studies (P=0.36, I=8%), so meta-analysis was conducted using the fixed effect model. The result indicated that ACCD was superior compared to the conventional treatment for the improvement of ST segment ischemia [OR=2.61, 95% CI (1.83, 3.73), P<0.000 01] (Figure 7).

Two studies reported the efficacy of acupuncture in ECG improvement.27,28 There was little heterogeneity among these studies (P=0.93, I2=0%), so meta-analysis was conducted using the fixed effect model. The result indicated that acupuncture was superior compared with the conventional treatment for the improvement of ST segment ischemia [0R=3.07, 95% CI (1.54, 6.10), P=0.001] (Figure 8).

Assessment of publication bias

udging from to the symmetry of the funnel plot, no apparent publication bias was found in the meta-analysis, indicating that the results are reliable (Figure 9).

Adverse effect

None of the studies reported any adverse effects associated with acupuncture therapy.

DISCUSSION

All current randomized controlled trials were conduct-

ed in China, and all patients were Chinese. The articles were all published in Chinese journals. Nitrate treatment was given to all control groups. This typical and popular vasodilator has been proven to be effective in the treatment of angina pectoris, as reported by a systematic review abroad.31 Based on our analysis, acupuncture-dominated therapy appears beneficial for treating angina pectoris, as it relieves symptoms, provides pain relief, and promotes ECG restoration. However, acupuncture shows a slower time to onset than conventional treatment and is therefore not advised for the emergency treatment of ischemic disease. The main shortcoming of the conclusions of our study is the poor quality of the original studies, as this is likely to influence the reliability of our results. It also suggests that there is a need for medical staff in China to implement further improvements in terms of the design and methodology of clinical studies. Moreover, more RCTs with larger samples are needed to validate the use of acupuncture in angina treatment. Our study indicates that ACCD can play an active role in preventing acute myocardial infarction, which would lead to improvements in the life quality of patients. In addition, when compared to the control group, ACCD or acupuncture treatment increased the overall efficacy in terms of symptom relief and ECG improvement. When the time to onset of angina relief was used as an outcome measure, ACCD was superior to the conventional treatment alone, whereas acupuncture showed a slower onset of action. In conclusion, acupuncture therapy is indicated for treating stable angina pectoris, but it is unsuitable for the treatment of patients with an acute ischemic heart event.

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