Identifying High-Risk Psychiatric Subgroups for Readmission Among Heart Failure Patients: A Seven-Year National Analysis in the United States

Background Psychiatric comorbidities are common among patients with heart failure (HF) and may significantly influence hospital readmissions. While prior studies have linked mental illness to readmission risk, few have clarified which specific psychiatric diagnoses confer the greatest risk, limiting the development of diagnosis-specific interventions. Leveraging the nationally representative Nationwide Readmissions Database (NRD), this study aimed to define these associations and inform diagnosis-specific interventions. Methods We conducted a retrospective cohort study using the 2016-2022 NRD. Adults hospitalized for HF were identified using ICD-10-CM codes. Patients who died, left against medical advice, were transferred, had planned readmissions, or had missing critical data were excluded. Psychiatric comorbidities were defined using ICD-10 codes (primary and secondary diagnoses) for depression, anxiety disorders, bipolar disorder, schizophrenia/psychotic disorders, post-traumatic stress disorder (PTSD), and substance use disorder (SUD). The primary outcome was unplanned all-cause readmission at 30 days and one year. We used multivariable Cox proportional hazards models adjusted for age, sex, insurance type, income quartile, hospital characteristics, discharge disposition, and the Charlson Comorbidity Index. Adjusted HRs and 95% CIs were reported. Results Among 31,886,859 weighted HF hospitalizations, schizophrenia or psychotic disorders (HR: 1.05; 95% CI: 1.05-1.06), bipolar disorder (HR: 1.03; 95% CI: 1.02-1.04), PTSD (HR: 1.03; 95% CI: 1.02-1.04), and SUD (HR: 1.02; 95% CI: 1.02-1.03) were each independently associated with increased 30-day all-cause readmission (p < 0.001 for all), while depression (HR: 0.99; 95% CI: 0.98-0.99; p < 0.001) was associated with reduced risk, and anxiety (HR: 0.99; 95% CI: 0.97-1.02; p = 0.86) showed no significant association. At one year, schizophrenia or psychotic disorders (HR: 1.09; 95% CI: 1.08-1.10), bipolar disorder (HR: 1.06; 95% CI: 1.05-1.07), PTSD (HR: 1.05; 95% CI: 1.04-1.06), and SUD (HR: 1.04; 95% CI: 1.03-1.04) remained significantly associated with increased risk (p < 0.001 for all), whereas depression (HR: 0.99; 95% CI: 0.99-1.01; p = 0.69) and anxiety (HR: 1.00; 95% CI: 0.98-1.01; p = 0.99) were not. Conclusions Schizophrenia, bipolar disorder, PTSD, and SUD were independently associated with elevated short- and long-term all-cause readmission following HF hospitalization. These findings underscore the importance of incorporating psychiatric risk factors into diagnosis-specific transitional care strategies for adults hospitalized with HF.