CONGESTIVE HEART FAILURE
There is considerable experimental and clinical evidence supporting the use of hawthorn as an effective treatment for congestive cardiac failure in patients with slight, mild limitation of activity who are comfortable at rest or with mild exertion (i.e. NYHA class II).
A meta-analysis of rigorous clinical trials of the use of hawthorn extract to treat patients with chronic heart failure (NYHA classes I-III) included eight trials involving 632 subjects. The results of the meta-ana lysis showed that treatment with standardised hawthorn extracts produced significant improvement in maximal workload, pressure-heart rate product, as well as symptoms such as dyspnoea and fatigue as compared with placebo. The hawthorn extract most commonly used in these trials was WS 1442, which is standardised to 18.8% oligomeric procyanidins. In some cases, hawthorn extract was used as an adjunct to standard therapy (such as diuretics) and the daily dose ranged from 160 mg to 1800 mg.
A review of the results of 13 clinical trials published from 1981 to 1996, involving over 839 patients, suggests that a daily dose of 900 mg hawthorn extract improves exercise tolerance, anaerobic threshold and ejection fraction, as well as subjective symptoms. Studies comparing hawthorn extract LI 132 (Crataegutt novo 450, 1 tablet twice daily) to the ACE inhibitor captopril suggests that the LI 132 extract is comparable in effectiveness to a dose of 37.5 mg captopril, but may be better tolerated.
These findings are supported by the results of more recent studies. A recent prospective, cohort study involving 952 patients with NYHA stage II heart failure compared the use of the WS 1442 extract of hawthorn either alone or in conjunction with conventional therapy to conventional medication. After 2 years, the hawthorn cohort was found to have similar or more pronounced improvements than the conventional medication group with reduced fatigue, stress dyspnoea, and palpitations along with marked reduction in the use of drugs such as ACE inhibitors, cardiac glycosides, diuretics and beta-blockers.
In two further double-blind studies of NYHA class II patients, one using the WS 1442 extract in 40 patients and another using the Rob 10 standardised extract of fresh hawthorn berries in 88 patients, 3 months’ treatment with hawthorn led to significantly improved exercise tolerance, reduced subjective symptoms, and was found to be safe and well tolerated. In 2003, another placebo-controlled, randomised, parallel-group, multicentre trial confirmed the efficacy and safety of a standardised extract of fresh berries of Crataegus oxyacantha L. and C. monogyna Jacq. (crataegisan) in patients with cardiac failure NYHA class II. This study of 143 patients (mean age 64.8 years) used a dose of 30 drops of the extract taken three times daily for 8 weeks and found a significant increase in exercise tolerance, but no difference in symptoms or blood pressure-heart rate product. Researchers suggested that dyspnoea and fatigue do not occur until a significantly higher wattage had been reached in the bicycle exercise testing and that further improvements were likely to occur if treatment time was extended.
In another RCT of patients with marked limitation of activity, who were comfortable only at rest (NYHA class III), 209 patients received standardised extract WS 1442 at doses of either 900 mg or 1800 mg or placebo in addition to pre-existing diuretic treatment. After 16 weeks, significant dose-dependent improvements in exercise capacity and clinical signs and symptoms were seen with the herbal extract, with patients on the higher dosage experiencing less adverse events such as dizziness and vertigo. A large, international, multicentre double-blind study is investigating the influence of the WS 1442 extract on mortality of up to 2300 cardiac patients over 24 months.
In an observational cohort study of 212 patients, a homeopathic hawthorn preparation was found to be non-inferior to standard treatment (ACE inhibitor/diuretics) for mild cardiac insufficiency in all parameters except blood pressure reduction.
As well as being shown to be effective when used alone, hawthorn is effective in reducing symptoms of congestive heart failure when used in combination with other herbs such as camphor. This was demonstrated in an open study of 319 patients, as well as in a double-blind study of 190 patients.
Commission E supports the use of hawthorn leaf and flower to treat decreased cardiac output (NYHA class II).
ARRHYTHMIAS, HYPERTENSION AND ATHEROSCLEROSIS
In addition to treating congestive cardiac failure, hawthorn has traditionally been used to treat arrhythmias, hypertension and atherosclerosis, with some evidence to support these uses, although large controlled clinical studies are required.
In one double-blind RCT of 92 subjects aged 40-60 years, a hydro-alcoholic extract of Iranian hawthorn (C. curvisepala Lind) given three times daily was found to produce a significant decrease in both systolic and diastolic blood pressure after 3 months. Antihypertensive activity was also observed in one uncontrolled study that used hawthorn berry tincture (equivalent to 4.3 g/day of berry), whereas three randomised, double-blind, placebo-controlled, clinical trials have shown that a combination of natural D-camphorand an extract from fresh hawthorn berries was effective in treating orthostatic hypotension.
One study that focused primarily on mild hypertension compared the hypotensive effect of low dose hawthorn extract (500 mg) and magnesium supplements, individually and in combination, to placebo. Walker et al found hawthorn treatment significantly reduced resting diastolic blood pressure at week 10 compared with the other groups. In addition, a trend towards a reduction in anxiety was also observed with hawthorn treatment, which is an interesting observation as sedative effects have been observed in animal models.
Hawthorn fruit extract has been reported to reduce serum lipid levels, as well as to reduce lipid deposits in the liver and aortas of rats and rabbits fed a hyperlipidaemic diet. In combination with other traditionally used Chinese herbs, hawthorn has been shown to also reduce serum lipid levels in both animals and humans.
The results of a double-blind trial of 182 people suggest that hawthorn in combination with other herbs such as passiflora and Valeriana may be beneficial for people with adjustment disorder with anxious mood. Another double-blind trial of 264 people found that a combination containing Crataegus oxyacantha and Eschscholtzia californica along with magnesium was effective in treating mild-to-moderate anxiety disorder.
As it has a high flavonoid content, hawthorn is also used to strengthen connective tissue, decrease capillary fragility, and prevent collagen destruction of joints and therefore may be beneficial in the treatment of certain connective tissue disorders. Hawthorn has been traditionally used as a diuretic and to treat kidney and bladder stones. In practice, it is also used at the first signs of a herpes simplex infection, to prevent lesion formation and halt infection.