Linkages between anxiety and outcomes in heart failure

Objective: We investigated the relationship between anxiety and event-free survival ( ie, composite endpoint of death, emergency department visits, or hospitalizations ) for patients with heart failure ( HF ), and examined whether behavioral and physiologic mechanisms mediate any association between anxiety and outcomes. Methods: In this longitudinal study, patients with HF completed the anxiety subscale of the Brief Symptom Inventory, and heart-rate variability and plasma norepinephrine levels were measured. Dietary adherence and medication adherence were measured according to 24-hour urine sodium level and the Medication Event Monitoring System, respectively. Patients were followed at least 1 year for event-free survival. Results: In total, 147 patients were enrolled. Patients with high anxiety had a shorter ( hazard ratio, 2.2; 95% confidence interval, 1.1-4.3; P = .03 ) period of event-free survival than patients with lower anxiety. Anxiety independently predicted adherence to medication ( P = .008 ), which in turn predicted event-free survival ( hazard ratio, 2.0; 95% confidence interval, 1.2-3.3; P = .008 ). The effect of anxiety ( P = .17 ) on event-free survival was less significant when the regression model included both anxiety and adherence to medication than when the model only included anxiety ( P = .03 ), indicating that adherence to medication mediated the relationship between anxiety and event-free survival. Conclusion: This is the first study to show that nonadherence to medication links anxiety and event-free survival for patients with HF. Interventions that reduce anxiety and improve adherence may benefit outcomes.