The Effect of Coenzyme Q(10) on Morbidity and Mortality in Chronic Heart Failure Results From Q-SYMBIO: A Randomized Double-Blind Trial

{OBJECTIVES This randomized controlled multicenter trial evaluated coenzyme Q(10) (CoQ(10)) as adjunctive treatment in chronic heart failure (HF). BACKGROUND CoQ(10) is an essential cofactor for energy production and is also a powerful antioxidant. A low level of myocardial CoQ(10) is related to the severity of HF. Previous randomized controlled trials of CoQ(10) in HF were underpowered to address major clinical endpoints. METHODS Patients with moderate to severe HF were randomly assigned in a 2-year prospective trial to either CoQ(10) 100 mg 3 times daily or placebo, in addition to standard therapy. The primary short-term endpoints at 16 weeks were changes in 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 as determined by a time to first event analysis. RESULTS A total of 420 patients were enrolled. There were no significant changes in short-term endpoints. The primary long-term endpoint was reached by 15% of the patients in the CoQ(10) group versus 26% in the placebo group (hazard ratio: 0.50; 95% confidence interval: 0.32 to 0.80; p = 0.003) by intention-to-treat analysis. The following secondary endpoints were significantly lower in the CoQ(10) group compared with the placebo group: cardiovascular mortality (9% vs. 16%