Acupuncture shows potential as adjunctive treatment for angina
Acupuncture effectively alleviates angina in terms of frequency and pain intensity when used as an adjunctive treatment to conventional antianginal therapies, a study finds.
“Acupuncture has been used as nonpharmacologic treatment for several decades, especially to relieve symptoms of myocardial ischaemia, improve cardiac function, and prevent recurrence,” the researchers stated.
“Because of limited medical resources and lack of obvious improvement to angina with percutaneous coronary intervention, Chinese clinicians choose traditional Chinese medicine and acupuncture in addition to antianginal treatment for chronic stable angina [CSA],” they added.
In the multicentre study, 398 participants aged 35–80 years with CSA (mean age 62.6 years, 63.6 percent women, angina frequency of ≥2 weekly) were randomized 1:1:1:1 to receive acupuncture on the disease-affected meridian (DAM) or nonaffected meridian (NAM) acupoints, sham acupuncture (SA), or be on the waitlist group (no acupuncture), in addition to their background guideline-recommended antianginal therapies. The first three groups underwent 30-minute acupuncture sessions thrice weekly for 4 weeks. [JAMA Intern Med 2019;doi:10.1001/jamainternmed.2019.2407]
Among the four groups, the DAM group had the greatest reduction in the primary endpoint of frequency of angina attacks at week 16 (p<0.001).
In pairwise comparisons, reductions in angina frequency were greater in the DAM group by 4.07 attacks (p<0.001) when compared with the NAM group, by 5.18 attacks (p<0.001) compared with the SA group, and by 5.63 attacks (p<0.001) compared with the waitlist group.
“We speculate that the varied efficacy between the DAM and NAM and the benefit of acupuncture on the DAM relate to acupoint specificity,” said the researchers. The acupoints chosen for the DAM group were PC6 on the pericardium meridian and HT5 on the heart meridian.
The DAM group also reported significantly lower pain score on the visual analogue scale for angina severity compared with the other groups across all time points from weeks 8–16 (p=0.007), weeks 9–12 (p<0.001), and weeks 13–16 (p<0.001).
In addition, physical limitation, angina stability, and angina frequency scores were also better with acupuncture on the DAM compared with the other interventions at week 16 (p<0.001 for all measures), as assessed using the Seattle Angina Questionnaire.
Anxiety and depression scores on the Zung self-rating scale were also better in the DAM group compared with the other groups at week 16, although the benefits were not immediately obvious after treatment at weeks 5–8.
Adverse events (AEs) occurred in 16 patients, of which eight were related to acupuncture — comprising five cases of subcutaneous haemorrhage at needle insertion sites and three cases of tingling sensation after needle insertion. According to the researchers, all AEs were mild or moderate, with none leading to study discontinuation.
“Acupuncture should be considered as [an] option for adjunctive treatment in alleviating angina,” said the researchers.
“Acupuncture on the DAM causes autonomic remodelling by improving the balance between the vagus nerve and sympathetic nervous system during treatment,” they explained, with regard to the possible mechanism mediating the beneficial effects of acupuncture on angina.
As the current study involved patients who were relatively healthy at baseline, the researchers cautioned against generalizing the results to a sicker population. The study was also limited by small sample size and short duration, and thus, long-term relief beyond the studied period of 16 weeks remained unknown.