Center Differences in PreTransplant Functional Status and Its Association With Survival After Heart Transplantation

Area of Science:

• Cardiology
• Transplantation Medicine
• Health Outcomes Research

Background:

• The Karnofsky Performance Scale (KPS) is a standard tool for assessing functional status in heart transplantation (HT) candidates.
• Concerns exist regarding the consistency and prognostic accuracy of KPS scores due to its subjective nature.
• Variability in KPS scoring across different transplant centers may impact risk stratification.

Purpose of the Study:

• To evaluate the center-level variability in Karnofsky Performance Scale (KPS) assignment among heart transplantation candidates.
• To determine the association between KPS scores and 1-year posttransplant mortality.
• To assess if center-specific KPS scoring influences the prediction of short-term mortality.

Main Methods:

• Analysis of adult patients undergoing first-time single-organ HT from November 2018 to June 2024 using the United Network for Organ Sharing database.
• Exclusion of patients with prior transplants, multi-organ transplants, missing data, or loss to follow-up before 1 year.
• Application of hierarchical linear and logistic regression models with center-level random effects to analyze KPS variability and its association with 1-year mortality.

Main Results:

• A total of 13,726 patients were included, with a median KPS of 30, and 60% in the low range (0-30).
• Adjusted models revealed that 28% of KPS variance was attributable to inter-center differences.
• KPS was not significantly associated with 1-year posttransplant mortality (OR 1.00, p = 0.564), with no detected heterogeneity in this association across centers.

Conclusions:

• Karnofsky Performance Scale (KPS) demonstrates considerable variability in assignment across different heart transplant centers.
• KPS scores are not associated with 1-year mortality following heart transplantation.
• The findings suggest that KPS should be used with caution for short-term risk stratification in heart transplant recipients.