Ubiquinol Improves Endothelial Function in Patients with Heart Failure with Reduced Ejection Fraction: A Single-Center, Randomized Double-Blind Placebo-Controlled Crossover Pilot Study

Abstract

Background: Endothelial dysfunction is reportedly associated with worse outcomes in patients with chronic heart failure. Ubiquinol is a reduced form of coenzyme Q10 (CoQ10) that may improve endothelial function.

Objective: We assessed the hypothesis that ubiquinol improves peripheral endothelial function in patients with heart failure with reduced ejection fraction (HFrEF).

Methods: In this randomized, double-blind, placebo-controlled, crossover pilot study, 14 patients with stable HFrEF were randomly and blindly allocated to ubiquinol 400 mg/day or placebo for 3 months. After a 1-month washout period, patients were crossed over to the alternative treatment. Before and after each treatment, we assessed peripheral endothelial function using the reactive hyperemia index (RHI) and analyzed it using the natural logarithm of RHI (LnRHI).

Results: Peripheral endothelial function as assessed by LnRHI tended to improve with ubiquinol 400 mg/day for 3 months (p = 0.076). Original RHI values were also compared, and RHI significantly improved with ubiquinol treatment (pre-RHI 1.57 [interquartile range (IQR) 1.39-1.80], post-RHI 1.74 [IQR 1.63-2.02], p = 0.026), but not with placebo (pre-RHI 1.67 [IQR 1.53-1.85], post-RHI 1.51 [IQR 1.39-2.11], p = 0.198).

Conclusions: Ubiquinol 400 mg/day for 3 months led to significant improvement in peripheral endothelial function in patients with HFrEF. Ubiquinol may be a therapeutic option for individuals with HFrEF. Large-scale randomized controlled trials of CoQ10 supplementation in patients with HFrEF are needed.

Clinical trial registration: Japanese University Hospital Medical Information Network (UMIN-ICDR). Clinical Trial identifier number UMIN000012604.