Seven- and thirty-day mortality in digoxin poisoning: Results from the DIGITOX study

Background Digoxin poisonings are relatively common and potentially fatal, requiring immediate therapeutic intervention, with special attention to the patient's hemodynamic status and the presence of electrocardiographic and electrolytic disturbances. Objective To identify factors associated with seven-day and thirty-day mortality in digoxin poisoning. Design, settings and participants A retrospective, observational, multicenter study was conducted across 15 Hospital Emergency Departments (HED) in Spain. All patients over 18 years of age who presented to participating HEDs from 2015 to 2021 were included. The inclusion criteria encompassed individuals meeting the criteria for digoxin poisoning, whether acute or chronic. Outcomes measure and analysis To identify independent factors associated with 7-day and 30-day mortality, a multivariate analysis was conducted. This analysis included variables of clinical significance, as well as those exhibiting a trend (p < 0.1) or significance in the bivariate analysis. Main findings A total of 658 cases of digoxin poisoning were identified. Mortality rates were 4.5% (30 patients) at seven days and 11.1% (73 patients) at thirty days. Regarding 7-day mortality, the mean age of deceased patients was comparable to survivors (84.7 (8.9) vs 83.9 (7.9) years; p = ns). The multivariate analysis revealed that factors independently associated with 7-day mortality encompassed the extent of dependence assessed by the Barthel Index (BI 60–89 OR 0.28; 95% CI 0.10–0,77; p = 0.014 and BI>90 OR 0.22; 95% CI 0.08–0,63; p = 0.005), the identification of ventricular arrhythmias (OR 1.34; 95% CI 1.34–25.21; p = 0.019), and the presence of circulatory (OR 2.84; 95% CI 1.19–6.27; p = 0.019) and neurological manifestations (OR 2.67; 95% CI 1.13–6.27; p = 0.025). Factors independently associated with 30-day mortality encompassed extent of dependence (BI 60–89 OR 0.37; 95% CI 0.20–0.71; p = 0.003 and BI>90 OR 0.18; 95% CI 0.09–0.39; p < 0.001) and the identification of circulatory (OR 2.13; 95% CI 1.10–4.15; p = 0.025) and neurological manifestations (OR 2.39; 95% CI 1.25–3.89; p = 0.006). Conclusions The study identifies the degree of dependency assessed by the Barthel Index and the presence of cardiovascular and neurological symptoms as independent predictors of both 7-day and 30-day mortality. Additionally, the detection of ventricular arrhythmia is also an independent factor for 7-day mortality.