Coenzyme Q10 and chronic heart failure
Chronic heart failure (CHF) is on the rise. The connection between CHF, coenzyme Q-10 (CoQ- 10) and statins is discussed frequently outside of mainstream medicine since statins inhibit the synthetic pathway for the endogenous synthesis of this enzyme.
A study has just been reported in the Journal of the American College of Cardiology which investigated the relationship between CoQ-10 and survival in patients with CHF. It was found that plasma CoQ-10 was an independent predictor of mortality in a group of 236 patients admitted to hospital with CHF.
When a cut-point of 0.73 micromol/L was used, the group above this plasma level had approximately a 65% 5-year survival whereas for those below this level, it was 40%.
The authors comment that there had been previously reported an independent inverse association between plasma cholesterol and total mortality and that the myocardium in patients with heart failure is deficient in CoQ-10.
The authors cite 12 clinical studies which suggest benefits from CoQ-10 supplementation.
In a meta-analysis of 8 studies, it was found that CoQ-10 supplementation significantly improved stroke volume, ejection fraction, cardiac output, and two other indices of cardiac function.
Another meta-analysis found improvements in ejection fraction and cardiac output.
Some of these studies may underestimate the benefits of CoQ-10 supplementation in that there are considerable differences in bioavailability (biologische beschikbaarheid)among various formulations of this enzyme.
The authors also comment that a multicenter intervention trial of CoQ-10 as an adjunctive treatment for CHF is underway which is randomized and double blind. However, examination of the description of the trial fails to reveal the nature of the enzyme preparation, only the dose which is 300 mg.
Since bioavailability can vary by a factor of 2 or 3, this may be an issue when it comes to interpreting the results, i.e. was the dose high enough?
Molyneux SL, et al. Coenzyme Q10: An independent predictor of mortality in chronic heart failure. Journal of the American College of Cardiology, Vol. 52, No. 18, October 28, 2008, pp. 1435-41