Aims: Hawthorn's efficacy when added to contemporary evidence-based heart failure therapy is unknown. We aimed to determine whether hawthorn increases submaximal exercise capacity when added to standard medical therapy.
Methods and results: We performed a randomized, double-blind, placebo-controlled trial in 120 ambulatory patients aged > or = 18 years with New York Heart Association (NYHA) class II-III chronic heart failure. All patients received conventional medical therapy, as tolerated, and were randomized to either hawthorn 450 mg twice daily or placebo for 6 months. The primary outcome was change in 6 min walk distance at 6 months. Secondary outcomes included quality of life (QOL) measures, peak oxygen consumption, and anaerobic threshold during maximal treadmill exercise testing, NYHA classification, left ventricular ejection fraction (LVEF), neurohormones, and measures of oxidative stress and inflammation. There were no significant differences between groups in the change in 6 min walk distance (P = 0.61), or on measures of QOL, functional capacity, neurohormones, oxidative stress, or inflammation. A modest difference in LVEF favoured hawthorn (P = 0.04). There were significantly more adverse events reported in the hawthorn group (P = 0.02), although most were non-cardiac.
Conclusion: Hawthorn provides no symptomatic or functional benefit when given with standard medical therapy to patients with heart failure. This trial is registered in ClinicalTrials.gov ID: NCT00343902.