Prevalence and predictors of digoxin utilization among heart failure patients with reduced ejection fraction in Qatar

Background Digoxin is a cardiac glycoside that is recommended by clinical practice guidelines to be used in patients with heart failure with reduced ejection fraction (HFrEF) who still have persistent symptoms despite optimal medical therapy. However, this recommendation is based on limited and old trial data. Moreover, pharmacoepidemiologic studies are important in determining the prevalence of digoxin use and factors influencing this. Objective This study aimed to determine the prevalence and the predictors of digoxin utilization among patients with HFrEF with or without atrial fibrillation (AF) in Qatar. Setting Heart Hospital, a specialized tertiary care center in Qatar. Methods A retrospective observational study was conducted using Cerner electronic medical records. Subjects included 736 patients admitted between January 1, 2013 and December 31, 2014 with the diagnosis of HFrEF with or without AF. Two groups of patients were studied: digoxin users and digoxin non-users at index hospitalization until discharge. Univariate and multivariate binary logistic regression analyses were conducted to determine the predictors of digoxin prescription. Data analyses were performed using IBM SPSS^® version 23.0. Main outcome measures Prevalence and predictors of digoxin prescriptions among HFrEF patients measured in percentages and odds rations, respectively. Results A total of 736 patients who met the inclusion criteria were analyzed for digoxin prevalence, including 80 patients (11%) who were newly prescribed digoxin during the index hospitalization. After adjusting for patient demographics and clinical characteristics, the use of thiazide diuretics (aOR = 10.14, CI 2.31-44.6, p value = 0.002), concurrent AF (aOR = 8.2, CI 3.11-21.7, p < 0.001), and an ejection fraction (EF) <25% (aOR = 3.2, CI 1.5-6.8, p value = 0.002) significantly predicted digoxin prescriptions among patients with HFrEF. Conclusion The rate of digoxin prescription among patients with HFrEF in Qatar is relatively low. The strongest predictors of digoxin use in HFrEF patients were the concomitant use of thiazide diuretics and concurrent diagnosis of AF. The findings may potentially serve as useful guides for the rational utilization of digoxin in patients with HFrEF.