Efficacy and safety of acupuncture for coronary microvascular disease: study protocol for a pilot randomized controlled trial

Background Coronary microvascular disease (CMVD), particularly ischemia with non-obstructive coronary arteries (INOCA)-related CMVD, is associated with recurrent angina, impaired quality of life, and an increased risk of adverse cardiovascular outcomes. Although recognition of this condition is increasing, treatment options remain limited, and many patients continue to have symptoms despite conventional medical therapy. Acupuncture has shown potential as an adjunctive therapy for angina-related symptoms and other cardiovascular conditions. However, high-quality evidence for INOCA-related CMVD remains scarce. This trial aims to evaluate the efficacy and safety of acupuncture as an adjunct to conventional medical therapy in patients with INOCA-related CMVD. Methods This prospective, single-center, randomized, sham-controlled, parallel-group pilot trial will recruit 60 participants with INOCA-related CMVD at Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China. Eligible participants will be randomly assigned in a 1:1 ratio to an acupuncture group or a sham acupuncture group. Both groups will continue guideline-directed conventional medical therapy. The acupuncture group will receive true acupuncture at Dabao (SP21), Neiguan (PC6), Danzhong (CV17), Xinshu (BL15), and Geshu (BL17), while the sham group will receive non-penetrating sham acupuncture at the same acupoints with the same schedule. Treatment will be given three times weekly for 4 consecutive weeks, followed by a 4-week follow-up. The primary outcome is the response rate at week 4, defined as the proportion of participants with an increase of at least 5 points in the Seattle Angina Questionnaire summary score from baseline. Secondary outcomes include changes in SAQ scores, angina attack frequency, EuroQol 5-Dimension 5-Level questionnaire, traditional Chinese medicine syndrome score, nitric oxide, endothelin-1, and high-sensitivity C-reactive protein. Additional assessments include Clinical Global Impression–Improvement, expectancy and credibility assessments, and blinding assessment. Safety evaluation includes monitoring adverse events and serious adverse events throughout the trial. Discussion This pilot trial will provide preliminary evidence on the safety and potential efficacy of acupuncture for INOCA-related CMVD and may help clarify its effects on angina-related health status, quality of life, and selected endothelial and inflammation-related markers. The findings are expected to inform future larger multicenter confirmatory trials. Clinical Trial Registration International Traditional Medicine Clinical Trial Registry ( http://itmctr.ccebtcm.org.cn/ ), Identifier ITMCTR2026000515.