Acupuncture for Angina? Chinese Study Backs Targeted Approach

Acupuncture can reduce the frequency of chest pain episodes in patients with chronic stable angina when added to medical therapy, according to data from a randomized clinical trial conducted in China.

Unlike earlier, failed attempts to show a benefit with acupuncture in this setting, the current study specified exactly how the therapy should be administered, focusing on acupoints on the disease-affected meridian (DAM). Patients in the four-arm trial who were treated in the DAM had fewer angina attacks than those who were treated in nonaffected meridian (NAM) or received sham acupuncture or no treatment beyond medical therapy.

This is hardly the first high-quality study to be done in China on the use of traditional Chinese medicine (TCM) for angina, lead author Ling Zhao, PhD, and senior author Fanrong Liang, MD (both from Chengdu University of Traditional Chinese Medicine, China), told TCTMD in a jointly written email. But, they said, the current report has the largest sample size.

Indeed, acupuncture is already in use for this indication, Zhao and Liang noted. “Because of limited medical resources and controversial benefits from percutaneous coronary intervention, Chinese clinicians choose acupuncture in addition to antianginal treatment for chronic stable angina. Acupuncture has been used as a nonpharmacologic treatment in TCM hospitals for several decades, especially to relieve symptoms of myocardial ischemia, improve cardiac function, and prevent recurrence in clinic.”

Shaista Malik, MD, PhD (University of California, Irvine), whose own research focuses on the use of acupuncture in CV medicine, particularly hypertension, said: “This is an excellent and well-done study because it actually looked at using targeted acupoints for a very specific indication.”

A lot needs to be worked out for acupuncture to be adopted as an angina treatment in the United States, Malik commented to TCTMD. “But over half of our population uses complementary medicine approaches including acupuncture. Unfortunately, in our mainstream medical system we don’t ask about it, patients are hesitant to talk about it. In the end, I don’t see this as an alternative therapy [but rather] used as an adjunctive strategy. [This] is going to lead to wider acceptance because cardiologists such as myself are hesitant to tell patients, ‘You’re going to rely on something and we don’t know how frequently you’re going to need it again.’”

On the backdrop of a medical therapy “safety net,” acupuncture might allow patients to be on fewer medications or take them at a lower dose, thus reducing side effects, Malik suggested. “I think this is a really powerful tool.”

Nieca Goldberg, MD (NYU Langone Medical Center, New York, NY), described acupuncture in this setting as an “interesting concept.”

“There are millions of people who live with chronic heart disease across our country” but for whom medication may produce side effects or not completely resolve symptoms, she pointed out, noting that patients are often curious about alternative medicine. One unknown, though, is how these China-based results might extend to other populations.

Nonetheless, “it’s great that we’re starting to think out of the box in terms of treatment options for our patients,” Goldberg concluded.

Targeted Acupoints

Zhao and colleagues enrolled 404 patients with chronic stable angina who had at least twice-weekly attacks at five centers between October 10, 2012, and September 19, 2015. Practitioners were licensed acupuncturists with more than 3 years’ experience.

All study participants received guideline-directed antianginal therapy, including beta-blockers (or calcium channel blockers), aspirin (or clopidogrel), statins, and ACE inhibitors. Those randomized to the DAM, NAM, and sham groups underwent acupuncture treatment three times per week for 4 weeks. Follow-up was then maintained for an additional 12 weeks, during which patients recorded details on their angina attacks in diaries.

In an intention-to-treat analysis of 398 individuals (mean age 63 years; 64% women), baseline characteristics were similar across the four groups. Mean frequency of angina attacks during the initial 4 weeks was 13.31. Between weeks 4 and 16, patients who received DAM acupuncture had a greater reduction in angina frequency than any of the other three groups.

Mean Change in Frequency of Angina Attacks With Acupuncture

Further study is needed to better understand the durability of acupuncture’s effects beyond 12 weeks, Zhao and Liang noted to TCTMD, suggesting that patients might need to return for additional sessions after a gap of around 3 to 6 months. There may also be the potential for “portable and wearable acupoint-stimulation devices to simulate acupuncture,” they said.

An Achilles’ heel of acupuncture therapy, Malik said, is that “you actually have to find an acupuncturist, you have to go to a physical location versus being able to take a pill at home. However, how far out do you have to go? What is the maintenance regimen?” Answering these questions and others related to “perceived patient burden” will be key to the therapy’s clinical adoption, she added.

As to the mechanism, Malik said “it has to do with neuromodulation and neurostimulation. Not every acupoint’s like that, but about 70% to 80% are associated with a large accumulation of nerve bundles in that one spot. It’s interesting, our sensory nerves are distributed unevenly over the body. . . . These acupoints have those nerve bundles and they have lower electrical impedance than the surrounding tissue at that [location]. The stimulation of these small-diameter nerve fibers or nerve path causes a peripheral to central nervous system response.”

Animal models have shown that the signal goes to the brain stem and hypothalamus, which are involved in regulation of blood pressure, with a mechanism involving the endogenous opioid system, she explained. “That makes a lot of sense with angina and pain.”

Funding in this area is difficult to come by, since there are no devices or drugs to capture the attention of manufacturers, Malik observed, adding that advocacy for continued National Institutes of Health funding is critical.