Efficacy of Yuxintong capsule on cardiorespiratory fitness in patients with stable coronary heart disease: A multicentre, randomized, double-blind, placebo-controlled, parallel-group clinical trial

Ethnopharmacological relevance Yuxintong capsule, a traditional Chinese patent medicine, has been widely used in the treatment of coronary heart disease (CHD). However, whether it can improve cardiopulmonary fitness (CRF) in patients with CHD remains unclear. Aim of the study To evaluate the efficacy and safety of Yuxintong capsule in CRF in patients with stable CHD. Materials and methods A multicentre, randomized, double-blind, placebo-controlled, parallel-group trial was conducted in 13 hospitals in China from March 2021 to November 2021, and 404 patients with stable CHD were randomly assigned to receive either Yuxintong capsule and conventional Western medicine (Yuxintong group) or placebo and conventional Western medicine (placebo group) in a 1:1 ratio for 12 weeks (ChiCTR2000041293, December 23 2020). The primary outcomes were peak oxygen uptake (VO 2 peak) and anaerobic threshold (AT). The secondary outcomes were metabolic equivalents (METs), duration and onset time of 1-mm ST-segment depression on electrocardiography (ECG), and 36-Item Short Form Health Survey (SF-36) scores. The main safety indicators include complete blood count, urinalysis, liver function, renal function, coagulation function, and 12-lead electrocardiogram. And adverse events were recorded throughout the trial. Results 369 patients, 187 in the Yuxintong group and 182 in the placebo group, were finally included for analysis. Compared with placebo group, 12-week treatment with Yuxintong showed an improvement in AT (0.98 ± 2.88 vs. 0.12 ± 2.79 mL·kg -1 ·min -1 ; LSMD, 0.80 [95% CI: 0.28 to 1.32]; P < 0.025) , and general health (13.61 ± 15.13 vs. 8.29 ± 14.14; LSMD 5.30, [95% CI: 2.33 to 8.31]; P < 0.05) and vitality scores (12.46 ± 11.32 vs. 6.01 ± 11.41; LSMD 6.43, [95% CI: 4.13 to 8.31]; P < 0.05) on SF-36 scale. The other outcomes did not significantly differ between the two groups. The adverse events were similar between the two groups. Conclusions Yuxintong capsule, as an adjunctive therapy to conventional treatment, improved AT, and general health and vitality scores on SF-36 scale in patients with stable CHD. However, the improvements in VO 2 peak, METs, and the duration and onset time of 1-mm ST-segment depression on ECG were not statistically significant.