A double-blinded, placebo-controlled randomized trial evaluating the efficacy and safety of Zhigancao Tang granules for treating HFpEF: study protocol for a randomized controlled trial

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is a clinical syndrome characterized by diastolic dysfunction. Despite the increasing incidence of HFpEF, there is no available therapy that reduces the mortality rate of HFpEF. Zhigancao Tang has been used traditionally for the treatment of cardiovascular diseases in China. The use of traditional Chinese medicine (TCM) is associated with improvements in clinical syndromes and quality of life of patients. A randomized clinical trial should be conducted to provide clear evidence regarding the efficacy and safety of Zhigancao Tang granules for the treatment of HFpEF. METHODS: A randomized, double-blinded, placebo-controlled clinical trial was proposed. A total of 122 patients with HFpEF will be randomly assigned to receive Zhigancao Tang granules or placebo for 12 weeks. The primary outcome measure is cardiac function. The secondary outcomes include measurement of the integral TCM syndrome score, echocardiography, 6-min walk test, N-terminal-pro hormone B-type natriuretic peptide level, atrial natriuretic peptide level, Minnesota Living with Heart Failure scale, and Lee’s scale. The outcome measures will be evaluated at baseline, 4 weeks, and 12 weeks. Adverse events will be evaluated from baseline till the 12-week follow-up period. DISCUSSION: The results of this trial will demonstrate whether Zhigancao Tang granules are effective and safe for treating HFpEF. TRIAL REGISTRATION: ClinicalTrials.gov NCT04317339. Registered on 23 March 2020. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-021-05232-6.