Randomised double-blind, placebo-controlled trial of coenzyme Q10 therapy in class II and III systolic heart failure

Anne Keogh, Steve Fenton, Christina Leslie, Christina Aboyoun, Peter Macdonald, Yi Chen Zhao, Michael Bailey, Franklin Rosenfeldt

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43 Citations (Scopus)


Background: Coenzyme Q10 (CoQ10) supplementation has been reported to improve symptoms of heart failure and quality of life, and to reduce hospitalisation. Most prior trials have been open-label and in some, only 50% of patients took angiotensin converting enzyme inhibitors (ACEI). Aim: To determine the effects of CoQ10 in patients with a New York Heart Association (NYHA) Class II or III heart failure due to ischaemic or dilated cardiomyopathy who have been treated with ACEI but not beta-blockers. Methods: Thirty-nine patients in NYHA Class II or III heart failure were randomised in a double-blind, placebo-controlled study with 150 mg/day of oral CoQ10 or placebo. Results: Thirty-five patients completed the trial. After 3 months of therapy, the NYHA class in the CoQ10 group (n = 17) showed a significant improvement of 0.5 class compared with the placebo (n = 18) (P = 0.01). Specific Activities Scale class showed a significant (P = 0.004) improvement in the CoQ10 group, but no change in the placebo group. The 6-min walk-test distance showed a significant (P = 0.047) increase in the CoQ10 group with no change in the placebo group (between-group difference P = 0.29). For the Naughton exercise test times the difference in increase in exercise time approached significance in favour of the CoQ10 group (P = 0.056). There was a correlation between the increase in exercise time and the increase in serum CoQ10 level (P = 0.024). There was a threefold increase in the CoQ10 level in the treated group (0.7± 0.4 to 2.1 ± 0.3 μg/mL), but no change in the placebo group. Conclusions: This pilot study accords with published data suggesting that CoQ10 therapy improves cardiac functional status in patients with moderately severe dilated cardiomyopathy receiving maximal non beta-blocker therapy. Future multicentre studies with larger numbers are indicated.

Original languageEnglish
Pages (from-to)135-141
Number of pages7
JournalHeart Lung and Circulation
Issue number3
Publication statusPublished - 1 Jan 2003


  • Coenzyme Q
  • Heart failure
  • Systolic heart failure
  • Ubiquinone

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