Efficacy and safety of Guhong injection for treating coronary microvascular disease: study protocol for a randomized controlled trial

BACKGROUND: Coronary microvascular disease (CMVD) can be described as one of the cardiovascular diseases with normal coronary angiography but evidence of myocardial ischemia or microcirculatory lesions, often presenting as angina pectoris attacks. Coronary artery microtubular dysfunction is one of the pathogenic features of coronary heart disease, but its occurrence and development and the current CMVD-intervention therapy needs further research. Chinese traditional medicine (TCM) has advantages for the treatment of cardiovascular diseases. Hence, this article describes an ongoing randomized controlled clinical trial based on the theory of TCM for the purpose of evaluating the efficacy and safety of Guhong injection versus placebo in patients with CMVD. METHODS/DESIGN: This is a multicenter, randomized, parallel-arm, open-label, double-blind, placebo-controlled clinical trial. A total of 260 eligible patients will be allocated and randomly assigned, in a ratio of 1:1, to either the experimental group or the control group. The treatment course is 10 consecutive days, and with an 8-week follow-up. The primary outcome is therapeutic efficacy. Secondary outcomes include the quantitative score of TCM syndromes (a series of TCM symptoms and signs of coronary heart disease), the average frequency of anginal attacks, electrocardiogram (ECG) changes, inflammatory response, endothelial function indicators and myocardial metabolites. DISCUSSION: This trial is strictly designed in accordance with principles and regulations issued by the China Food and Drug Administration (CFDA). The results should provide high-quality evidence on the efficacy and safety of Guhong injection in the treatment of CMVD. TRIAL REGISTRATION: Chinese Clinical Trials Registry, ID: ChiCTR1900022902. Registered on 27 April 2019.