CLINICAL CHARACTERISTICS, CAUSES, AND OUTCOMES OF 30-DAY READMISSION FOLLOWING HOSPITALIZATION FOR HEART FAILURE: A RETROSPECTIVE COHORT STUDY

Abstract

Background: Heart failure is associated with frequent hospitalizations and substantial early post-discharge morbidity. Thirty-day readmission remains an important indicator of clinical instability and healthcare utilization, particularly among patients with multiple comorbidities. Objective: To evaluate the clinical characteristics, causes, outcomes, and predictors of 30-day readmission following hospitalization for heart failure. Methods: This retrospective cohort study was conducted at Army Cardiac Hospital, Lahore, Pakistan from August 2025 to February 2026, included 300 adult patients hospitalized with acute or acute-on-chronic heart failure. Patients were classified according to whether they experienced an unplanned readmission within 30 days after discharge. Demographic characteristics, comorbidities, laboratory parameters, previous emergency department visits, length of index hospitalization, timing and causes of readmission, and clinical outcomes were recorded. Results: Of 300 patients, 49 (16.3%) were readmitted within 30 days. Readmitted patients were older than non readmitted patients (70.4±11.3 vs. 66.1±12.0 years; p=0.021) and had higher mean blood urea nitrogen (35.8±16.2 vs. 27.1±13.4 mg/dL; p<0.001), serum creatinine (1.65±0.79 vs. 1.31±0.62 mg/dL; p=0.001), and index hospital stay (6.8±3.0 vs. 5.1±2.5 days; p<0.001). Worsening heart failure was the most common cause of readmission, accounting for 21 (42.9%) cases, followed by renal disorders in 7 (14.3%). Among readmitted patients, 11 (22.4%) required ICU admission, 9 (18.4%) developed acute kidney injury, and 4 (8.2%) died during readmission. Conclusion: It is concluded that 30-day readmission after heart failure hospitalization was common and was most frequently related to recurrent heart failure. Chronic kidney disease, previous emergency department utilization, elevated blood urea nitrogen, and prolonged hospitalization were important independent predictors of early readmission.