Risk Factors for Readmission of Heart Transplant Recipients: A Retrospective Case-Control Study

Abstract

Purpose: The purpose of this study was to identify factors influencing the readmission of heart transplant recipients through survival analysis. Methods: We collected data from heart transplant recipients who were discharged after surgery between November 2005 and September 2020 from the electronic medical records of Y University Hospital in Seoul. The Kaplan-Meier estimation was utilized to calculate the survival rate, and Cox's proportional hazards model was employed to determine the factors influencing readmission within 1 year. Results: Out of 150 heart transplant recipients, 81 (54.0%) were readmitted within one year. The median time to readmission was 231 days. An increased duration of postoperative days was associated with a higher risk of readmission (p=.016). Groups with abnormal sodium levels (p<.001), those requiring postoperative hemodialysis (p=.013), patients with chronic kidney disease (p=.002), dyslipidemia (p=.040), or diabetes mellitus (p=.045) also faced higher readmission risks. In the final model, sodium levels (hazard ratio [HR]=2.31, p<.001) and chronic kidney disease (HR=1.67, p=.045) were significant risk factors for readmission (χ2=31.90, p<.001). Conclusion: Interventions to improve kidney function and a multidisciplinary approach are needed to reduce readmission of heart transplant recipients.