Atrial Fibrillation Is Associated With Increased In-Hospital and 1-Year Mortality in Patients Receiving Hemodialysis With ST Elevation Myocardial Infarction: A Retrospective Cohort Study

Rationale & Objective: Atrial fibrillation (AF) is highly prevalent among patients receiving maintenance hemodialysis (HD) and patients with ST elevation myocardial infarction (STEMI). We investigated the association of AF with in-hospital mortality, 1-year mortality, and 1-year readmission for acute myocardial infarction (AMI) in HD patients admitted with STEMI. Study Design: Retrospective cohort study based on a large administrative database. Setting & Participants: 138,939 patients admitted with STEMI from 2003-2018, of whom 1,185 (8.5%)receiving HD, followed from the date of admission until death, migration, or 1 year after discharge. Exposures: STEMI (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] 410.x) as the primary discharge diagnosis, maintenance HD (ICD-9-CM 39.95; 54.98; V560; V5 63.1; V563.2), and AF (ICD-9-CM 427.31). Outcomes: In-hospital all-cause mortality (primary outcome), 1-year all-cause mortality, and 1-year readmission for AMI (secondary outcomes). Analytical Approach: Multivariable logistic regression and multivariable Cox regression. Results: One hundred and ninety-five out of 1,185 (16.5%) patients had AF at admission or developed AF during hospitalization. After adjusting for possible confounders, AF versus sinus rhythm was associated with higher in-hospital mortality (odds ratio [OR] = 1.57; 95% confidence interval [CI], 1.11-2.22). AF was associated with higher 1-year mortality (hazard ratio [HR] = 1.45; 95% CI, 1.18-1.76), whereas it was not associated with higher 1-year readmission for AMI (HR = 1.05; 95% CI, 0.72-1.53). Less than 20% of patients with AF discharged alive were prescribed oral anticoagulant therapy. In this subgroup, oral anticoagulant therapy was associated with lower 1-year mortality (HR = 0.46; 95% CI, 0.24-0.89). Limitations: Potential bias due to incorrect or incomplete coding, retrospective design, incidence of thromboembolic events after discharge, and cause of 1-year mortality unknown. Conclusions: AF is highly prevalent and associated with adverse short-and long-term outcomes in HD patients admitted with STEMI.