Relationship between multimorbidity and outcomes in atrial fibrillation

Background: Multimorbidity is common in atrial fibrillation (AF) patients. Charlson comorbidity index (CCI) is used to evaluate multimorbidity in the general population. Limited long-term data are available on the relationship between CCI and AF. We examined the association between CCI, anticoagulation control and outcomes in AF patients. Methods: We studied 1956 from the FANTASIIA registry, an observational Spanish nationwide study on anticoagulated AF patients. Time in therapeutic range (TTR) was used to evaluate anticoagulation control. Stroke/TIA, major bleeding, cardiovascular (CV) death and all-cause death were study outcomes. Results: Mean ± SD CCI was 1.1 ± 1.2. Based on CCI quartiles, patients were categorised in four groups: 676 (34.6%) in Q1 (CCI 0); 683 (34.9%) in Q2 (CCI 1); 345 (17.6%) in Q3 (CCI 2); and 252 (12.9%) in Q4 (CCI ≥3). In vitamin K antagonist treated patients, the highest CCI quartile was inversely associated with TTR >70% (odds ratio:0.67, 95% confidence interval (CI):0.45–0.99). During observation, a progressively higher rate of major bleeding, CV death and all-cause death was found across the quartiles (all p < 0.001). The final Cox multivariable regression analysis showed an association with increasing risk for major bleeding occurrence in Q3 and Q4 (hazard ratio (HR):1.69, 95%CI:1.00–2.87 and HR:1.92, 95%CI:1.08–3.41). An increasing risk for all-cause death and CV death was found across CCI quartiles. Conclusions: In a nationwide contemporary cohort of AF anticoagulated patients, multimorbidity was inversely associated with good anticoagulation control. A progressively higher risk for major bleeding, CV death and all-cause death was found across CCI quartiles.