Coenzyme Q₁₀ and exercise training in chronic heart failure

Abstract

Aims There is evidence that plasma coenzyme Q₁₀ (CoQ₁₀) levels decrease in patients with advanced chronic heart failure (CHF). However, it is not known whether oral CoQ₁₀ supplementation may improve cardiocirculatory efficiency and endothelial function in patients with CHF.

Methods and results We studied 23 patients in NYHA class II and III (20 men, three women, mean age 59±9 years) with stable CHF secondary to ischaemic heart disease [ejection fraction 37±7%], using a double-blind, placebo-controlled cross-over design. Patients were assigned to each of the following treatments: oral CoQ₁₀ (100 mg tid), CoQ₁₀ plus supervised exercise training (ET) (60% of peak VO₂, five times a week), placebo, and placebo plus ET. Each phase lasted 4 weeks. Both peak VO₂ and endothelium-dependent dilation of the brachial artery (EDDBA) improved significantly after CoQ₁₀ and after ET as compared with placebo. CoQ₁₀ main effect was: peak VO₂+9%, EDDBA +38%, systolic wall thickening score index (SWTI) −12%; ET produced comparable effects. CoQ₁₀ supplementation resulted in a four-fold increase in plasma CoQ₁₀ level, whereas the combination with ET further increased it. No side effects were reported with CoQ₁₀.

Conclusions Oral CoQ₁₀ improves functional capacity, endothelial function, and LV contractility in CHF without any side effects. The combination of CoQ₁₀ and ET resulted in higher plasma CoQ₁₀ levels and more pronounced effects on all the abovementioned parameters. However, significant synergistic effect of CoQ₁₀ with ET was observed only for peak SWTI suggesting that ET amplifies the already described effect of CoQ₁₀ on contractility of dysfunctional myocardium.

Coenzyme Q₁₀, Chronic heart failure, Endothelium-dependent relaxation, Peak oxygen uptake, LV contractility