Overview on coenzyme Q_{10} as adjunctive therapy in chronic heart failure. Rationale, design and end-points of "Q-symbio" – A multinational trial

Issue title: The Third Conference of the International CoQ10 Association

Article type: Research Article

Authors: Mortensen, Svend Aage

Affiliations: The Heart Centre, Medical Department B, Copenhagen University Hospital, Denmark. E-mail: [email protected]

Abstract: Energy starvation of the myocardium is probably a dominant feature of heart failure and attention has been directed towards agents which may stabilize myocardial metabolism and maintain adequate energy stores. A reduced myocardial tissue content of the essential redox-component and natural antioxidant Coenzyme Q_{10} (CoQ_{10}) has been detected in patients with heart failure and the observed level of CoQ_{10} deficiency was correlated to the severity of heart failure. CoQ_{10} fulfills various criteria of an obvious adjunct in patients with symptomatic heart failure: it is devoid of significant side effects and it improves symptoms and quality of life. Till this date, several double-blind placebo-controlled trials with CoQ_{10} supplementation in more than 1000 patients have been positive and statistically significant with respect to various clinical parameters, e.g. improvement in NYHA Class, exercise capacity and reduced hospitalisation frequency. Also treatment with CoQ_{10} led to a significant improvement of relevant hemodynamic parameters. In only 3 out of 13 double-blind studies comprising 10% of the total number of patients treated the results were neutral. Thus, based on the available controlled data CoQ_{10} is a promising, effective and safe approach in chronic heart failure. This is why a double-blind multicenter trial with focus on morbidity and mortality has been planned to start in 2003: Q-SYMBIO. Patients in NYHA classes III to IV (N=550) receiving standard therapy are being randomized to treatment with CoQ_{10} 100 mg t.i.d. or placebo in parallel groups. End-points in a short-term evaluation phase of 3 months include symptoms, functional capacity and biomarker status (BNP). The aim of a subsequent 2-year follow-up study is to test the hypothesis that CoQ_{10}may reduce cardiovascular morbidity (unplanned cardiovascular hospitalisation due to worsening heart failure) and mortality as a composite endpoint. This trial should help to establish the future role of CoQ_{10} as part of a maintenance therapy in patients with chronic heart failure.

Keywords: coenzyme Q[TeX:] _{10}, heart failure, clinical trials, efficacy, safety

Journal: BioFactors, vol. 18, no. 1-4, pp. 79-89, 2003