Depression and Uptake of Oral Anticoagulation Therapy in Patients With Atrial Fibrillation: A Danish Nationwide Cohort Study.

Background: Oral anticoagulation therapy (OAT) in patients with atrial fibrillation (AF) is a highly important preventive intervention, perhaps especially in those with comorbid depression, who have a worse prognosis. However, OAT may pose particular challenges in depressed patients.

Objectives: To assess whether AF patients with depression have lower OAT uptake.

Methods: This nationwide register-based 2005-2016 cohort study of all Danes with AF and OAT indication (CHA2DS2VASc stroke risk score ≥2) assessed OAT initiation within 90 days in those with incident AF (N=147,162) and OAT prevalence in those with prevalent AF (N=192,656). The associations of depression with both outcomes were estimated in regression analyses with successive adjustment for socioeconomic characteristics and somatic and psychiatric comorbidity.

Results: Comorbid depression was significantly associated with lower frequency of OAT initiation in incident AF patients {adjusted proportion differences (aPDs): -6.6% [95% confidence interval (CI), -7.4 to -5.9]} and lower prevalence of OAT [aPD: -4.2% (95% CI, -4.7 to -3.8)] in prevalent AF patients. Yet, the OAT uptake increased substantially during the period, particularly in depressed patients [aPD for OAT prevalence in 2016: -0.8% (95% CI, -1.6 to -0.0)].

Conclusions: Comorbid depression was associated with a significantly lower OAT uptake in patients with AF, which questions whether depressed patients receive sufficient support to manage this consequential cardiac condition. However, a substantial increase in the overall OAT uptake and a decrease of the depression-associated deficit in OAT were seen over the period during which OAT was developed through the introduction of new oral anticoagulation therapy.