Acupuncture as Adjunctive Therapy for Chronic Stable Angina: A Randomized Clinical Trial

This multicenter randomized controlled trial evaluated the efficacy of acupuncture as adjunctive therapy for chronic stable angina, a condition characterized by chest pain caused by reduced blood flow to the heart. The research was conducted at five clinical centers in China between October 2012 and September 2015, including 404 participants aged 35 to 80 years. The main objective was to investigate whether acupuncture could reduce the frequency of angina attacks when used in conjunction with standard medication treatment. The study design was particularly rigorous, comparing four groups: acupuncture at the meridian affected by the disease (DAM), acupuncture at the non-affected meridian (NAM), sham (placebo) acupuncture, and a control group with medication only.

All participants received standard antianginal therapy according to medical guidelines, including beta-blockers, aspirin, statins, and ACE inhibitors. The acupuncture groups received 12 treatment sessions (3 times a week for 4 weeks), with each session lasting 30 minutes. The DAM group received acupuncture at points PC-6 and HT-5 bilaterally, located on the pericardium and heart meridians, respectively. The NAM group received acupuncture at points LU-9 and LU-6, located on the lung meridian.

Electroacupuncture with a frequency of 2 Hz and intensity adjusted for patient comfort was used. The results were notably positive for the DAM group. The mean frequency of angina attacks decreased significantly more in the DAM group compared to the other groups. Specifically, there was a reduction of 7.96 attacks in the DAM group versus only 3.89 in the NAM group, 2.78 in the sham group, and 2.33 in the control group during the 4-week period.

The differences were statistically significant (P < 0.001) and clinically relevant, with the DAM group having 4.07 fewer attacks than the NAM group, 5.18 fewer attacks than the sham group, and 5.63 fewer attacks than the control group. The benefits were maintained throughout the 16-week follow-up period. In addition to the primary endpoint, the study also demonstrated significant improvements in several secondary endpoints. Anginal pain intensity, measured by visual analog scale, was consistently lower in the DAM group.

The Seattle Angina Questionnaire showed improvements in scores for angina stability, frequency, and treatment satisfaction. The 6-minute walk test also showed better results in the DAM group. Importantly, the beneficial effects were maintained for 12 weeks after treatment ended, suggesting lasting benefits of acupuncture. From a safety standpoint, acupuncture was well tolerated.

Only 16 patients reported acupuncture-related adverse events, all classified as mild to moderate, including subcutaneous hemorrhage and tingling sensation. No event required special medical intervention. The clinical implications of this study are significant. The results suggest that acupuncture, specifically when applied at points related to the cardiovascular system according to traditional Chinese medicine theory, can be a valuable complement to standard medication treatment of chronic stable angina.

The specificity of acupuncture points appears important, as there were clear differences between the DAM and NAM groups, indicating that point location influences treatment efficacy. This finding has relevance for both clinical practice and understanding of acupuncture's mechanisms of action. The study has several limitations that should be considered. First, a standardized acupuncture point prescription was used, not allowing individualization of treatment based on the clinical experience of the acupuncturist.

Second, although rescue medication use was measured, dosages were not analyzed in detail. Third, subgroup analyses for patients with different baseline characteristics were not performed. Finally, long-term follow-up beyond 16 weeks was not evaluated, limiting understanding of the duration of benefits. Despite these limitations, this study represents an important contribution to the scientific evidence on acupuncture in cardiology, demonstrating that acupuncture can be considered a safe and effective adjunctive therapeutic option for patients with mild to moderate chronic stable angina.