The results of the pivotal DIGIT-HF trial show significant new evidence for a long-used cardiac glycoside. Therefore, clinicians must review the potential role of Digitoxin HFrEF management. Adding digitoxin to standard guideline-directed medical therapy (GDMT) significantly improved outcomes for patients with symptomatic Heart Failure with reduced Ejection Fraction (HFrEF). The trial followed patients for a median of 36 months.
Key Findings on Digitoxin HFrEF Efficacy
The DIGIT-HF trial randomly assigned 1,212 patients with symptomatic HFrEF to receive either low-dose digitoxin or a placebo. All participants were already on optimal GDMT. The study’s primary endpoint was a composite of all-cause death or the first hospitalization for worsening heart failure. Significantly, digitoxin reduced this composite outcome by a relative risk reduction of 18% compared to placebo. Consequently, the absolute risk reduction was 4.6% over the trial period. The final hazard ratio was 0.82 (95% CI, 0.69 to 0.98; p=0.03).
Researchers noted the beneficial effect of digitoxin was consistent across pre-specified subgroups. For the individual components, death from any cause occurred in 27.2% of the digitoxin group versus 29.5% in the placebo group. A first heart failure hospitalization occurred in 28.1% of the digitoxin group versus 30.4% in the placebo group. Thus, both components showed a trend towards benefit, though the trial powered the study for the composite endpoint.
Why Digitoxin Differs from Digoxin
Both digitoxin and digoxin are cardiac glycosides used in heart failure management. However, digitoxin offers important pharmacokinetic advantages. Digitoxin is not primarily excreted by the kidneys. This key difference means that serum concentrations remain more stable, even in patients who have renal dysfunction. Furthermore, impaired kidney function is common in the advanced heart failure population. This stability likely allows for a wider therapeutic window and a simpler dosing protocol. Importantly, researchers designed the DIGIT-HF trial to target low serum concentrations (8–18 ng/mL) using a simple dose-titration schedule. Conversely, previous trials with digoxin found that higher serum concentrations increased mortality risk.
The DIGIT-HF study population included patients with advanced chronic heart failure (LVEF ≤40% and NYHA class III/IV, or LVEF ≤30% and NYHA class II). They represented a sicker patient group who often have challenges tolerating or responding optimally to all pillars of GDMT. Therefore, the new findings suggest that digitoxin provides an additional, much-needed therapeutic option.
Safety Profile and Dosing in HFrEF
Treatment with digitoxin was generally safe in the trial. Serious adverse events (SAEs) occurred in 4.7% of the digitoxin group versus 2.8% in the placebo group. Predominantly, these SAEs included cardiac disorders. The standard protocol started with a 0.07 mg once-daily dose, with adjustments up or down to 0.05 mg or 0.1 mg to maintain the target serum level. Therefore, clinicians should use a simple, standardized dosing approach when considering digitoxin as an adjunct therapy for symptomatic HFrEF.
Frequently Asked Questions
Q1: What was the primary finding of the DIGIT-HF trial?
The trial found that adding digitoxin to guideline-directed medical therapy for HFrEF significantly reduced the composite risk of all-cause death or first hospitalization for worsening heart failure by 18% over a median of 36 months.
Q2: How does digitoxin’s use differ from digoxin in heart failure?
Digitoxin has pharmacokinetic advantages over digoxin, primarily because it is not renally excreted. This results in more stable serum drug concentrations, even in patients with kidney dysfunction, which is crucial for safety and efficacy in the heart failure population.
Q3: Which patients may benefit most from adding digitoxin?
The study suggests that digitoxin is an additional option for symptomatic HFrEF patients, especially those who have atrial fibrillation, higher heart rates, low blood pressure, or impaired kidney function, or those who cannot tolerate other GDMT components.
References
- Kumar S et al. In HFrEF, adding digitoxin to standard care reduced a composite of death or first worsening HF hospitalization at a median 36 mo. Ann Intern Med. 2026 Jan 06. doi: 10.7326/ANNALS-25-05015-JC. PMID: 41490511.
- Bavendiek U, Großhennig A, Schwab J, et al. Digitoxin in Patients with Heart Failure and Reduced Ejection Fraction. N Engl J Med 2025.
- ESC Congress 2025. Digitoxin improves outcomes in advanced heart failure. European Society of Cardiology. August 29, 2025.