Atzema CL, et al. - In this retrospective cohort study, researchers aimed at proposing and validating a predictive tool for a composite of 30-day mortality and return cardiovascular hospitalizations for atrial fibrillation (AF) patients seen in the emergency department. They successfully derived and validated such a tool by using a population-based sample. The utility of this tool lies in its ability to provide information regarding the risk of death and re-hospitalization in this patient population. Furthermore, the tool can help identify patient groups for future targeted interventions focused on avoiding these outcomes.

Methods

• This retrospective cohort study was conducted at 24 emergency departments in Ontario, Canada.
• Participants were patients with a primary diagnosis of AF who were seen between April 2008 and March 2009.
• Researchers evaluated a composite outcome of 30-day mortality and ensuing hospitalizations for a cardiovascular issue, including stroke.

Results

• A total of 3,510 patients were included; 2,343 were randomly selected for the derivation cohort, leaving 1,167 in the validation cohort.
• The incidence of the composite outcome was noted in 227 (9.7%) patients in the derivation cohort and 125 (10.7%) patients in the validation cohort.
• Findings demonstrated an independent association of 11 variables with the outcome: older age, not taking anticoagulation, HAS-BLED score ≥ 3, three lab results (positive troponin, supratherapeutic INR, and elevated creatinine), emergency department administration of furosemide, and four patient comorbidities (heart failure, COPD, cancer, dementia).
• They found that the observed 30-day outcomes in the five risk strata that were defined using the derivation cohort were 2.0%, 6.6%, 10.7%, 12.5% and 20.0% in the validation cohort.
• In the derivation and validation cohort, the observed c-statistic was 0.73 and 0.69, respectively.