Short- and medium-term complications after emergency department treatment of patients with atrial fibrillation: design and internal validation of the CoSTuM risk scale.

Objectives: To design and validate a clinical risk scale for 90-day adverse events after emergency department (ED) discharge of patients with atrial fibrillation (AF).

Material And Methods: Prospective, observational CoSTuM (Spanish acronym for comorbidity, symptoms, treatments, and poor heart rate control) study of patients with AF. We recorded all adverse events occurring during follow-up and used multivariate logistic regression analysis to identify variables independently associated with the occurrence of any such event.