The Evolution of Digoxin in Heart Failure and Atrial Fibrillation: An Update in Role, Dosing, and Toxicity.

Digoxin has been recognized as a time-old therapy in cardiovascular medicine and its use has persisted in heart failure (HF) and atrial fibrillation (AF). However, whether digoxin is beneficial or harmful is still debated with a long history of conflicting data regarding the association between digoxin use and mortality in these patient populations. Recent studies on the impact of digoxin on clinical outcomes in observational and randomized controlled trials clarify the role and expectations of digoxin and the importance of digoxin levels in various clinical scenarios. Digoxin with dosing maintained at 0.5 - 0.8 ng/mL is recommended in the setting of HF with reduced ejection fraction (HFrEF) with normal sinus rhythm, particularly in NYHA class III–IV, LVEF < 25%, or cardiothoracic ratio (CTR) > 55% for symptomatic improvement and to decrease hospitalizations for heart failure exacerbations, as an adjunct to goal directed medical therapy. In AF patients already on long term digoxin, therapy should be continued at dosing < 1.2 ng/mL, otherwise initiation of digoxin therapy is not favored. In both patient subsets, periodic serum digoxin concentration (SDC) monitoring is important especially in those at risk for labile levels. With the use of digoxin, toxicity remains a risk and digoxin-specific antibody fragments (DIF) may begin to be used more liberally. Hence, this paper reports and evaluates the changing data surrounding this drug and addends its use in clinical practice.