Abstract 17353: Effectiveness and Safety of Digoxin in Adults with Incident Systolic Heart Failure

Abstract

Background: Current clinical guidelines endorse digoxin use for patients with symptomatic systolic heart failure (HF) on optimal medical therapy, but this recommendation is based on limited, older clinical trial data. We sought to evaluate the effectiveness and safety of digoxin in a contemporary cohort of patients with incident systolic heart failure and stratified by patient sex and serum digoxin concentration (SDC). Methods: We identified patients with incident systolic HF between 2006 and 2008 in the Kaiser Permanente of Northern California health system. We used multivariable extended Cox regression to examine the association between incident digoxin use and death and hospitalization for HF, controlling for patient medical history, physical exam, diagnostic tests, laboratories, and medications. Longitudinal drug use, patient characteristics and outcomes were identified based on validated algorithms using health plan automated databases. Analyses were also conducted stratifying by sex and SDC. Results: Among 2891 patients with incident systolic HF followed for a mean 2.4 years, digoxin users had higher rates of death (14.2% vs 11.3%) and HF hospitalization (28.2% vs 24.4%). In adjusted analysis, digoxin was associated with excess mortality (odds ratio (OR) 1.60, 95% confidence interval (CI) 1.18-2.17) and HF hospitalization (OR 1.40, 95% CI 1.05-1.86). Compared with non-use, new digoxin use with SDC ≥1.2 ng/mL had higher odds of HF hospitalization and borderline higher odds of death (Table); SDC ≤0.8 ng/mL had higher odds of death. Digoxin use was associated with higher adjusted rates of HF hospitalization and death in men but not in women (Table). Conclusions: Digoxin was associated with a higher risk of death and HF hospitalization, however these risks were dependent on SDC. Digoxin was linked to a higher risk of adverse events in men but not significantly so for women.