Psychiatric Comorbidity in Heart Failure: Associations With Length of Stay, Costs, and Mortality in a National Cohort

Objective To evaluate how specific psychiatric comorbidities relate to index length of stay (LOS), hospital costs, and in-hospital mortality during readmissions after HF hospitalization. Methods A retrospective cohort study was conducted using the 2016-2022 Nationwide Readmissions Database. Adults with a principal HF diagnosis were included. Psychiatric comorbidities were depression, anxiety, bipolar disorder, schizophrenia/psychotic disorders, post-traumatic stress disorder (PTSD), and substance use disorder (SUD). Outcomes were index LOS, inflation-adjusted costs, and in-hospital mortality during readmissions within 30 days and up to 1 year after discharge. Survey-weighted multivariable models adjusted for demographics, socioeconomic factors, hospital characteristics, discharge disposition, and comorbidity burden; P ≤ 0.001 was prespecified as the level of statistical significance. Results Among 31,886,859 weighted HF hospitalizations, psychiatric comorbidity was common. Anxiety was associated with longer LOS (β = 0.88 days; P < 0.001) and higher costs (β = $2779; P < 0.001) but there were no differences in 30-day or 1-year mortality. However, several diagnoses were associated with lower mortality, including depression (30-day OR = 0.86; 1-year OR = 0.86), bipolar disorder (0.66; 0.68), schizophrenia/psychotic disorders (0.68; 0.72), PTSD (0.73; 0.78), and SUD (0.87; 0.92) (all P < 0.001). Bipolar disorder showed the largest cost reduction ( β = −$1320; P < 0.001) compared to HF patients without bipolar disorder. Conclusion Psychiatric comorbidity in HF is common. Anxiety is associated with increased hospital utilization, but is not associated with mortality, whereas several other diagnoses are associated with lower mortality. Costs were lower for depression and bipolar disorder. These diagnosis-specific patterns support targeted screening, early consultation, and integrated consultation-liaison care pathways during HF hospitalization.