Long-Term Relationship Between Atrial Fibrillation, Multimorbidity and Oral Anticoagulant Drug Use

Objectives: To analyze the relationship between atrial fibrillation (AF) and Charlson comorbidity index (CCI) in a population-based cohort study over a long-term follow-up period, in relation to oral anticoagulant (OAC) prescriptions and outcomes. Patients and Methods: We used data from the administrative health databases of Lombardy. All patients with AF and age 40 years and older and who were admitted to the hospital in 2002 were considered for analysis and followed up to 2014. AF diagnosis and CCI were established according to codes from the International Classification of Diseases, Ninth Revision. Results: In 2002, 24,040 patients were admitted with a diagnosis of AF. CCI was higher in patients with AF than in those without AF (1.8±2.1 vs 0.2±0.9; P<.001). Over 12 years of follow-up, AF was associated with an increased risk of higher CCI (beta coefficient, 1.69; 95% CI, 1.67-1.70). In patients with AF, CCI was inversely associated with OAC prescription at baseline (P<.001) and at the end of the follow-up (P=.03). Patients with AF and a high CCI (≥4) had a higher cumulative incidence of stroke, major bleeding, and all-cause death (all P<.001), compared with those with low CCI (range, 0-3). Adjusted Cox regression analysis revealed that time-dependent continuous CCI was associated with an increased risk for stroke, major bleeding, and all-cause death (all P<.001). Conclusions: In hospitalized patients, AF is associated with an increase in CCI that is inversely associated with OAC prescriptions during follow-up. CCI is independently associated with an increased risk of stroke, major bleeding, and all-cause death.