Impact of digoxin on risk of death in heart failure patients treated with b-blockers. Results from Polish part of ESC Heart Failure Long-Term Registry.

BACKGROUND: Digoxin is used in the treatment of atrial fibrillation (AF) and heart failure (HF). It was reported to increase the risk of death in HF. Studies on digoxin are based mainly on patients treated some years ago, before the era of common b-blocker use. AIM: This study aims to show the influence of digoxin in a modern cohort of HF patients on top of the contemporary guideline-directed treatment. METHODS: This study retrospectively analyses the Polish part of the European Society of Cardiology Heart Failure Long-Term Registry. It includes 912 patients treated for HF between February 2012 and January 2013, and followed until May 2014. At baseline, 19.1% took digoxin, 89.6% angiotensin convertase enzyme inhibitors or angiotensin receptor blockers, 91.9% b-blockers, and 69.4% mineralocorticoid receptor antagonists. RESULTS: Digoxin is associated with increased risk of death after adjustment for significant covariates in patients who have HF with reduced ejection fraction (HFrEF) but no AF history (hazard ratio [HR] 2.52, 95% confidence interval [CI] 1.23-5.19; p = 0.011), and it does not influence significantly the risk of hospitalisation (adjusted HR 1.46, 95% CI 1.05-1.72; p = 0.11). Digoxin use shows no significant association with the risk of death or hospitalisation in patients with AF and HFrEF or HF with preserved ejection fraction (HFpEF). Patients on digoxin present a significantly worse clinical status with lower left ventricular ejection fraction and higher New York Heart Association class, and fewer of them received the guideline-directed treatment. CONCLUSIONS: Digoxin is associated with increased risk of death in HFrEF patients without AF history receiving the guideline- -directed treatment. Digoxin seems to be employed in patients with worse clinical status, which may at least partially explain its association with increased risk of death.