ABSTRACT
BACKGROUND: Chronic heart failure is a debilitating condition that accounts for an annual NHS spend of £2.3B. Low levels of endogenous coenzyme Q10 may exacerbate chronic heart failure. Coenzyme Q10 supplements might improve symptoms and slow progression. As statins are thought to block the production of coenzyme Q10, supplementation might be particularly beneficial for patients taking statins. OBJECTIVES: To assess the clinical effectiveness and cost-effectiveness of coenzyme Q10 in managing chronic heart failure with a reduced ejection fraction. METHODS: A systematic review that included randomised trials comparing coenzyme Q10 plus standard care with standard care alone in chronic heart failure. Trials restricted to chronic heart failure with a preserved ejection fraction were excluded. Databases including MEDLINE, EMBASE and CENTRAL were searched up to March 2020. Risk of bias was assessed using the Cochrane Risk of Bias tool (version 5.2). A planned individual participant data meta-analysis was not possible and meta-analyses were mostly based on aggregate data from publications. Potential effect modification was examined using meta-regression. A Markov model used treatment effects from the meta-analysis and baseline mortality and hospitalisation from an observational UK cohort. Costs were evaluated from an NHS and Personal Social Services perspective and expressed in Great British pounds at a 2019/20 price base. Outcomes were expressed in quality-adjusted life-years. Both costs and outcomes were discounted at a 3.5% annual rate. RESULTS: A total of 26 trials, comprising 2250 participants, were included in the systematic review. Many trials were reported poorly and were rated as having a high or unclear risk of bias in at least one domain. Meta-analysis suggested a possible benefit of coenzyme Q10 on all-cause mortality (seven trials, 1371 participants; relative risk 0.68, 95% confidence interval 0.45 to 1.03). The results for short-term functional outcomes were more modest or unclear. There was no indication of increased adverse events with coenzyme Q10. Meta-regression found no evidence of treatment interaction with statins. The base-case cost-effectiveness analysis produced incremental costs of £4878, incremental quality-adjusted life-years of 1.34 and an incremental cost-effectiveness ratio of £3650. Probabilistic sensitivity analyses showed that at thresholds of £20,000 and £30,000 per quality-adjusted life-year coenzyme Q10 had a high probability (95.2% and 95.8%, respectively) of being more cost-effective than standard care alone. Scenario analyses in which the population and other model assumptions were varied all found coenzyme Q10 to be cost-effective. The expected value of perfect information suggested that a new trial could be valuable. LIMITATIONS: For most outcomes, data were available from few trials and different trials contributed to different outcomes. There were concerns about risk of bias and whether or not the results from included trials were applicable to a typical UK population. A lack of individual participant data meant that planned detailed analyses of effect modifiers were not possible. CONCLUSIONS: Available evidence suggested that, if prescribed, coenzyme Q10 has the potential to be clinically effective and cost-effective for heart failure with a reduced ejection fraction. However, given important concerns about risk of bias, plausibility of effect sizes and applicability of the evidence base, establishing whether or not coenzyme Q10 is genuinely effective in a typical UK population is important, particularly as coenzyme Q10 has not been subject to the scrutiny of drug-licensing processes. Stronger evidence is needed before considering its prescription in the NHS. FUTURE WORK: A new independent, well-designed clinical trial of coenzyme Q10 in a typical UK heart failure with a reduced ejection fraction population may be warranted. STUDY REGISTRATION: This study is registered as PROSPERO CRD42018106189. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 4. See the NIHR Journals Library website for further project information.
People living with chronic heart failure suffer from shortness of breath, ankle swelling, tiredness, frequent stays in hospital and reduced quality of life and have shorter lives. The NHS spends over £2 billion each year managing chronic heart failure. Coenzyme Q10 is a vitamin-like substance made by the body that helps cells produce energy. Low levels of coenzyme Q10 in heart muscle may lead to, or exacerbate, chronic heart failure. Taking coenzyme Q10 supplements might improve symptoms or slow deterioration. To the best of our knowledge, we found all randomised clinical trials of coenzyme Q10 in patients with the type of chronic heart failure caused by muscle weakness (i.e. heart failure with reduced ejection fraction, where the heart's pumping function is weaker than normal). We asked the research groups responsible for these trials to provide the patient data that they had collected in their trials. Most research groups did not share their data and so we mainly used information from published trial reports. This limited our planned analyses. We found that taking coenzyme Q10 alongside usual treatment for heart failure with reduced ejection fraction potentially reduced deaths by approximately one-third and reduced readmission to hospital by around 40%. However, these results were uncertain. Side effects were not increased. We had some concerns about how reliable the data were, and it is not clear how well the results apply to UK patients. We also worked out what the benefits and costs to the NHS would be if coenzyme Q10 became available on prescription for patients with heart failure with reduced ejection fraction. Our model found that prescription could be worthwhile; however, a new trial is needed first to make sure that coenzyme Q10 improves outcomes for patients. A new trial would be particularly important because coenzyme Q10 has not been assessed in the same way as prescribed medicines. A new trial could make sure that there is better evidence about whether or not prescribing would be a good use of NHS resources.