Psychocardiological impact of depression on medication adherence, ventricular function, and readmission in heart failure: A retrospective cohort study

BACKGROUND Depression is a highly prevalent and clinically significant psychiatric comorbidity in patients with heart failure (HF), exerting multidimensional effects that extend beyond emotional symptoms to influence physiological outcomes and disease progression. Emerging evidence in psychocardiology highlights the bidirectional interplay between mood disorders and cardiovascular dysfunction through neuroendocrine, autonomic, and behavioral pathways. This study aims to explore the real-world effect of depression severity - measured by the Patient Health Questionnaire-9 (PHQ-9) - on left ventricular systolic function and one-year cardiovascular readmission in patients with HF, providing insights into its prognostic relevance within a psychocardiological framework. AIM To investigate the impact of depression severity on medication adherence, ventricular function, and readmission in patients with HF. METHODS A total of 160 patients hospitalized for HF between January 2020 and December 2023 were included in this real-world retrospective cohort study. Depression severity was assessed by using the PHQ-9, with scores ≥ 10 indicating moderate-to-severe depression. Cardiac function was evaluated through transthoracic echocardiography to determine left ventricular ejection fraction (LVEF). Medication adherence was assessed at three and six months postdischarge by employing the four-item Morisky Medication Adherence Scale (MMAS-4) and categorized as high (score = 0), moderate (1-2), or low (3-4). Data on antidepressant or anxiolytic prescriptions and psychological interventions during hospitalization were collected. Patients were followed up for one year to capture cardiovascular-related readmissions. Kaplan-Meier analysis was employed to estimate event-free survival, and Cox regression identified independent predictors of readmission. RESULTS Patients with moderate-to-severe depression (PHQ-9 ≥ 10) presented with significantly lower LVEF at baseline, higher N-terminal pro-B-type natriuretic peptide levels, and more severe HF symptoms than other patients. They also demonstrated poorer medication adherence postdischarge, with a higher proportion classified as low adherence on the MMAS-4 scale, and were less likely to receive β-blockers or angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker at discharge than other patients. At three and six months postdischarge, PHQ-9 and MMAS-4 scores were inversely correlated with LVEF, suggesting a behavioral pathway linking depression to impaired cardiac recovery. During the one-year follow-up period, 30.0% of patients experienced cardiovascular-related readmissions, predominantly due to worsening HF (54.2%). In multivariable Cox regression analysis, high PHQ-9 scores, reduced LVEF, old age, elevated N-terminal pro-B-type natriuretic peptide levels, New York Heart Association class IV, and absence of β-blocker therapy were independently associated with readmission risk. CONCLUSION In patients with HF, depression severity independently predicts impaired ventricular function, low medication adherence, and increased one-year cardiovascular readmission. These findings highlight the psychocardiological relevance of depression screening and behavioral intervention in optimizing adherence and clinical outcomes in routine HF care.