Digitalis has been used to treat heart failure for more than 200 years. The drug digitoxin also belongs to this group of active ingredients known as cardiac glycosides. Although there were indications that digitalis was beneficial in heart failure, it has only now been scientifically proven that digitoxin has a significant positive effect in heart failure due to reduced pumping function and insufficient emptying of the left ventricle—known in medical terms as HFrEF (heart failure with reduced ejection fraction). For 10 years, researchers thoroughly investigated the safety and efficacy of the active ingredient in a clinical study involving more than...