-Chest pain frequency significantly reduced in patients with stable angina; improvement in depression and anxiety too
Study Authors: Ling Zhao, Dehua Li, et al.
Target Audience and Goal Statement:
Cardiologists, internists, family medicine specialists, pain management specialists, public health specialists/epidemiologists
The goal of this study was to test traditional acupuncture as an adjunctive therapy versus sham or no acupuncture in patients with chronic stable angina in order to reduce frequency of angina attacks.
Questions Addressed:
- What effect/s did traditional acupuncture as adjunctive therapy have, if any, in reducing episodes of angina in patients with chronic stable angina, compared with patients undergoing sham acupuncture, acupuncture on the nonaffected meridian, or none at all, in a 20-week study?
- What effect/s did traditional acupuncture have on the severity of attacks, if any?
Study Synopsis and Perspective:
Traditional acupuncture administered as adjunctive therapy reduced the frequency of chest pain episodes among Chinese patients with chronic stable angina in a randomized sham-controlled trial.
Patients assigned to receive 4 weeks of acupuncture on the acupoints on the disease-affected meridian (DAM) had roughly eight fewer angina attacks per 4-week interval during the subsequent 16 weeks, from a pretreatment baseline of 13.5 attacks per 4 weeks, according to Fanrong Liang, MD, of the Acupuncture and Tuina School at Chengdu University of Traditional Chinese Medicine in China, and colleagues.
Such a reduction from baseline was significantly better than what was found in three control arms, according to the researchers’ study, which appeared in Jama Internal Medicine:
- Acupuncture on the nonaffected meridian (NAM): about four fewer attacks per 4 weeks
- Sham acupuncture: about three fewer attacks
- No acupuncture (patients remained on wait list [WL]): about two fewer attacks
The differences from baseline in the DAM acupuncture group were significantly greater compared with each control group at P<0.001.
Results from the 6-minute walk distance test, Canadian Cardiovascular Society angina grade, and most metrics of the Seattle Angina Questionnaire were also better with acupuncture on the DAM, Liang’s group noted.
“I think that this appears to be a well-done study, with appropriate levels of sham procedures. You clearly observe that there is some placebo effect — with both the sham and NAM procedures, which have similar outcomes — but the effect of DAM appears to be real,” commented Suzanne Arnold, MD, of Saint Luke’s Hospital in Kansas City, Missouri, who was not involved in the study.
“Angina is a complicated symptom that can be impacted by many things other than just pure myocardial ischemia. For example, both depression and anxiety have been shown to be associated with increased anginal burden independent of the degree of ischemia. As such, it isn’t completely crazy to think that some treatment, that is not directly associated with increased myocardial blood flow, might be associated with less angina,” Arnold told MedPage Today.
If these findings are replicated, acupuncture would potentially be a good option for symptom relief for many patients, Arnold said.
To study the potential effects of acupuncture on episodes of angina, researchers conducted the trial at five centers across China in 398 adult patients with chronic stable angina who averaged 13.3 chest pain episodes over a 4-week baseline period, randomized in equal numbers to the four treatment arms. Patients included in the study had to have angina for more than 3 months, with attacks occurring at least twice weekly, and no significant change in the frequency, extent, nature, and inducing and alleviation factors of angina attacks at baseline. Exclusion criteria included previous MI, severe heart failure, valvular heart disease, atrial fibrillation, poorly controlled blood pressure or blood glucose, severe arrhythmias, and other severe primary disease not effectively controlled.
The four patient groups shared similar baseline characteristics. Mean age was 62.6 years; nearly two-thirds of the cohort were women.
Patients in the DAM, NAM, and sham acupuncture groups received treatment over 12 sessions (thrice weekly for 4 weeks, with each session lasting 30 minutes). Acupuncture was administered by licensed acupuncturists with at least 3 years of experience.
All patients stayed on their usual antianginal therapies — including beta-blockers, aspirin, statins, and angiotensin-converting enzyme inhibitors — during the course of the trial. Patients experiencing an acute angina episode were told to take rescue medication to relieve discomfort, with physicians providing nitroglycerin or nifedipine tablets, or a traditional Chinese medicine product. All use of such rescue medications was recorded in angina diaries that patients kept.
Sixteen adverse events were reported after acupuncture, all deemed mild or moderate; they included subcutaneous hemorrhage, tingling sensation, and sleeplessness.
A limitation of the study was the use of rescue medication for acute pain, which was not quantified in the study, but simply recorded as yes or no by patients, Liang’s team said. Also, participants did not have heavy comorbidity burdens, and there was a lack of longer-term data.
Ultimately, the study is interesting but small, “meaning it needs to be replicated,” said David Brown, MD, of Washington University School of Medicine in St. Louis.
Source Reference: JAMA Internal Medicine 2019; DOI: 10.1001/jamainternmed.2019.2407
Study Highlights: Explanation of Findings
This study comparing traditional Chinese acupuncture versus two types of sham treatment or no treatment in patients with stable angina found that “angina stability scores and angina frequency improved significantly more in the DAM group than in other groups,” over 16 weeks of treatment and 20 weeks overall. Adjunctive acupuncture was superior to antianginal therapy alone. Importantly, compared with sham acupuncture, acupuncture on the DAM resulted in a better regulation of anxiety and depression within the 12 weeks after treatment than at the end of the treatment period.
This study is the largest multicenter trial to demonstrate the benefit of true acupuncture as an adjunctive treatment for chronic stable angina within 16 weeks, and is also the first to explore “acupoint specificity” in cardiology, the authors wrote.
The mean changes in angina attacks differed significantly across the four groups at 16 weeks: they found a greater reduction in angina episodes in the DAM group versus the NAM group (4.07 fewer attacks), in the DAM group versus the sham acupuncture group (5.18 fewer attacks), and in the DAM group versus the WL group (5.63 fewer attacks). In contrast, at baseline, the mean frequency of angina attacks was 13.31 during the initial 4 weeks before treatment began.
The frequency decreased by 7.96 attacks in the DAM group, by 3.89 attacks in the NAM group, by 2.78 attacks in the sham acupuncture group, and by 2.33 attacks in the WL group. Notably, there was no difference in the number of patients using rescue medication among the four groups once acupuncture treatment began. Also of interest, on the 6-minute walk distance test, patients in the DAM group walked longer distances than those in the sham acupuncture and WL groups at the end of the fourth week of treatment, but not longer than patients in the NAM group.
Regarding the physiology of treatment with acupuncture for this indication, the authors stated that “acupuncture on the DAM causes autonomic remodeling by improving the balance between the vagus nerve and sympathetic nervous system during treatment.”
Chronic stable angina affects a mean of 3.4 million people older than age 40 each year, a prevalence of 9.6% in China. According to the authors, the current aim of pharmacologic treatment is to “prevent myocardial ischemia episodes, control symptoms, improve quality of life, and prevent cardiovascular events,” but due to a dearth of sufficient medical resources and a lack of improvement in angina with percutaneous intervention, acupuncture has commonly been employed for decades as an adjunctive to medication and/or surgery in China. They noted that there are some small studies showing that acupuncture was beneficial in treating angina, with others showing discrepancies concerning the efficacy of sham versus true acupuncture treatment, which they said may be a result of differences in study design, as well as insufficient numbers of patients in these studies.
Study Authors: Ling Zhao, Dehua Li, et al.
