Two Centuries On, Foxglove Still Has More to Teach Us

Foxglove’s value in heart failure is hardly a new discovery. Digitalis preparations have been used for more than two centuries, and their purified cardiac glycosides have been studied for decades. For example, in the landmark 1997 DIG trial digoxin reduced hospital admissions for worsening heart failure but did not reduce overall mortality. The question addressed by the new DIGIT-HF trial was could a different foxglove glycoside, digitoxin, still improve outcomes when added to contemporary treatment for heart failure with reduced ejection fraction (HFrEF)?

For ten years, researchers led by Professor Dr Johann Bauersachs, Director of the Department of Cardiology and Angiology at Hanover Medical School (MHH), and senior physician Professor Dr Udo Bavendiek thoroughly investigated the safety and efficacy of digitoxin in a clinical study involving more than 1,200 participants.

The large-scale DIGIT-HF study was coordinated by them and involved more than 50 centres in Germany, Austria and Serbia. It has now been completed and delivers a clear result: adjunctive therapy with digitoxin reduces mortality and the number of hospitalisations for heart failure in patients with advanced HFrEF. The results have been published in the New England Journal of Medicine, one of the world's leading medical journals.

Over a median of three years, death from any cause or a first admission for worsening heart failure occurred in 39.5% of the digitoxin group and 44.1% of the placebo group (hazard ratio 0.82; 95% CI 0.69–0.98). That is a meaningful result for an inexpensive, established drug.

Currently, digitoxin is only produced as a generic drug. ‘However, it remains the most commonly used digitalis preparation in Germany, so far, however, without any scientifically proven evidence of its effectiveness,’ notes Professor Bavendiek.

This has now been proven. ‘In the DIGIT-HF study, we examined patients who had exhausted all conventional treatment options,’ says Professor Bauersachs. ‘We were surprised ourselves that we were able to achieve such a significant improvement with the additional digitoxin treatment in these very well-treated study participants.’

If a compound from foxglove can reveal a significant new therapeutic value after 200 years of use, we have probably only explored the tip of the iceberg of plant medicine. Beneath the surface lies a vast reserve of compounds and their intelligent mixtures whose healing potential remains to be uncovered. Big pharma may invest in a plant compound it can turn into a proprietary drug, but it is unlikely to fund the research needed to investigate whole herbs and intelligent mixtures that cannot be readily patented. That work will depend on public funding, independent researchers and a herbal industry willing to invest in the evidence for its own medicines.

For more information see Scientifically proven for the first time: active ingredient from red foxglove helps with heart failure - Safe and cost-effective and Digitoxin in Patients with Heart Failure and Reduced Ejection Fraction - PubMed