The influence of digoxin on outcomes in remotely monitored patients with implantable cardioverter-defibrillators

Background Despite advances in device technology and pharmacotherapy, the long-term prognosis of patients with heart failure (HF) and implantable cardioverter-defibrillators (ICD) or cardiac resynchronisation therapy-defibrillators (CRT-D) remains poor. Evidence on the influence of digoxin in this population is conflicting. Purpose To evaluate the impact of digoxin prescribed at discharge on mortality and device therapies in remotely monitored HF patients with ICD/CRT-D. Methods Patients from the prospective COMMIT-HF registry were included if enrolled in the remote monitoring programme after ICD/CRT-D implantation. Subjects were stratified according to digoxin prescription at discharge. Propensity score matching (PSM) was applied to balance baseline differences. Outcomes included all-cause mortality and appropriate and inappropriate ICD/CRT-D therapies. Event rates were assessed using Kaplan-Meier curves and Cox regression during a median follow-up of 6.6 years (Q1–Q3: 3.8–8.4). Results Among 1,297 patients, 266 (20.5%) were discharged with digoxin, displaying a more adverse clinical profile. In the unmatched cohort, digoxin independently predicted both appropriate and inappropriate device therapies. After PSM, digoxin was associated with higher all-cause mortality (HR 1.411, 95% CI 1.019–1.954, p=0.038) and increased risk of inappropriate ICD therapies (HR 1.440, 95% CI 1.039–1.996, p=0.029). No independent association was observed for appropriate therapies after matching. Conclusions In a large real-world cohort of remotely monitored HF patients with ICD/CRT-D, digoxin use at discharge was associated with increased risk of death and inappropriate device interventions. Digoxin prescription may therefore identify a subgroup with poorer prognosis, warranting closer surveillance and optimised therapeutic strategies.