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CoQ10 supplementation benefits patients with heart failure, Q-SYMBIO study shows


  • Randomized, double-blind, placebo-controlled, multi-center clinical trial
  • Participants include 420 patients with moderate-to-severe chronic heart failure
  • CoQ10, added to standard therapy, significantly reduces symptoms and major adverse cardiovascular events
  • Effective dosage is 100 mg, 3 times daily, for 2 years


This randomized, double-blind, placebo-controlled, multi-center study (Q-SYMBIO study) evaluated the use of coenzyme Q10 (CoQ10) supplementation as an adjunct treatment in patients with chronic heart failure (HF). Patients were enrolled in 17 European, Asian, and Australian centers from 2003 to 2010.

For this study, researchers enrolled 420 patients with moderate-to-severe HF who were randomly assigned to one of two treatment groups for 2 years: CoQ10 supplementation (100 mg, 3 times daily) or placebo, in addition to standard therapy.

The primary short-term endpoints (at 16 weeks) were changes in the New York Heart Association (NYHA) functional classification, 6-min walk test, and levels of N-terminal pro-B type natriuretic peptide. The primary long-term endpoint (at 2 years) was composite major adverse cardiovascular events (MACE) as determined by a time to first event analysis.

Of the 420 patients enrolled, 36 dropped out (22 in the CoQ10 group; 14 in the placebo group) with no between-group difference in reasons for withdrawal. (Withdrawals were not removed from the intention-to-treat analysis.) By the end of the study, the survival status of all patients was known, except for 4 patients in each treatment group who were classified as lost to follow-up. A total of 87 patients had reached the primary endpoint (MACE), and 60 patients had died.

Results indicate no significant changes in short-term endpoints. The primary long-term endpoint was reached by 15% of the patients in the CoQ10 group vs. 26% in the placebo group (hazard ratio: 0.50; 95% confidence interval: 0.32 to 0.80; P=.003) by intent-to-treat analysis. The following secondary endpoints were significantly lower in the CoQ10 group vs. the placebo group: cardiovascular mortality (9% vs. 16%, P=.026), all-cause mortality (10% vs. 18%, P=.018), and incidence of hospital stays for HF (P=.033). In addition, a significant improvement of NYHA class was found in the CoQ10 group after 2 years (P=.028).

These findings indicate that long-term CoQ10 treatment (100 mg, 3 times daily, for 2 years) in addition to standard therapy is safe, well tolerated, and associated with a reduction in symptoms and major adverse cardiovascular events in patients with moderate-to-severe HF.


Mortensen SA, Rosenfeldt F, Kumar A, et al.; Q-SYMBIO Study Investigators. The effect of coenzyme Q10 on morbidity and mortality in chronic heart failure: results from Q-SYMBIO: a randomized double-blind trial. JACC Heart Fail. 2014;2(6):641-9.

PMID: 25282031