CHADS ₂ and CHA ₂DS ₂-VASc risk factors to predict first cardiovascular hospitalization among atrial fibrillation/atrial flutter patients

Limited data exist concerning risk factors for cardiovascular (CV) hospitalization in patients with atrial fibrillation (AF) or atrial flutter (AFL). The aim of this retrospective cohort evaluation was to assess whether patient characteristics and risk factors, including CHADS ₂ (congestive heart failure, hypertension, age <75 years, type 2 diabetes, and previous stroke or transient ischemic attack [doubled]) and CHA ₂DS ₂-VASc (congestive heart failure; hypertension; age <75 years [doubled]; type 2 diabetes; previous stroke, transient ischemic attack, or thromboembolism [doubled]; vascular disease; age 65 to 75 years; and sex category) scores, identified patients with AF or AFL at risk for CV hospitalization. Claims data (January 2003 to June 2009) were evaluated to identify patients aged <40 years with <1 inpatient or <2 (within 30 days of each other) outpatient diagnoses of AF or AFL and an absence of diagnosis codes related to cardiac surgery within 30 days of AF or AFL diagnosis. Risk factors for first CV hospitalization in the 2-year period after diagnosis were assessed using univariate and multivariate analyses. Overall, 377,808 patients (mean age 73.9 ± 12.1 years) were identified, of whom 128,048 had CV hospitalizations. CHADS ₂ and CHA ₂DS ₂-VASc scores were the top 2 predictors of first CV hospitalization after AF or AFL diagnosis. Hospitalization risk was increased 2.3- to 2.7-fold in patients with CHADS ₂ scores of 6 and approximately 3.0-fold in patients with CHA ₂DS ₂-VASc scores of 9 compared to patients with a score of 0. These increases were maintained essentially unchanged throughout the 2-year follow-up period. In conclusion, CHADS ₂ and CHA ₂DS ₂-VASc scores were predictive of first CV hospitalization in patients with AF or AFL and may be helpful in identifying "at-risk" patients and guiding therapy.