Coenzyme Q 10 and exercise training in chronic heart failure
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 VO2þ 9%, EDDBA þ38%, systolic wall thickening score index (SWTI) 212%; 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.