Related Experiment Video
Updated: Oct 7, 2025
A Pre-Clinical Porcine Model of Orthotopic Heart Transplantation
Published on: April 27, 2019
Validation of existing risk scores for mortality prediction after a heart transplant in a Chinese population
Shanshan Zheng1, Hanwei Tang1, Zhe Zheng1
1Department of Cardiac Surgery, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing, China.
Insights
This study validated three heart transplant risk scores in China, finding they predicted mortality but overestimated actual outcomes with unsatisfactory discrimination for the Chinese cohort.
Area of Science:
- Cardiology
- Transplantation Medicine
- Health Outcomes Research
Background:
- Risk stratification is crucial for predicting outcomes after heart transplantation.
- Existing risk scores like IMPACT, UNOS, and RSSs are widely used but require validation in diverse populations.
- Assessing the performance of these scores in a Chinese cohort is essential for their clinical application.
Purpose of the Study:
- To validate the Index for Mortality Prediction After Cardiac Transplantation (IMPACT), United Network for Organ Sharing (UNOS), and Risk Stratification Scores (RSSs) in a Chinese heart transplant cohort.
- To evaluate the efficacy of these three risk scores in predicting 1-year mortality after heart transplantation.
- To assess the discriminative power and accuracy of these scores in a single-center Chinese population.
Main Methods:
- Retrospective analysis of 428 heart transplant patients from a single Chinese center (2015-2019).
- Application of IMPACT, UNOS, and RSSs to all patients.
- Comparison of observed versus predicted 1-year mortality, logistic regression for predictive accuracy, and AUC for discrimination.
Main Results:
- Observed 1-year mortality was 6.54%.
- Predicted mortality by IMPACT, UNOS, and RSSs were 10.59%, 10.74%, and 12.89%, respectively, indicating overestimation.
- All three scores (IMPACT, UNOS, RSS) were significant predictors of 1-year mortality (P < 0.001), with IMPACT showing the highest discriminative power (AUC 0.691).
Conclusions:
- The IMPACT, UNOS, and RSSs were validated as predictors of 1-year mortality post-heart transplant in this Chinese cohort.
- However, all three risk scores demonstrated unsatisfactory discriminative power and overestimated observed mortality.
- Further refinement of risk prediction models is needed for the Chinese heart transplant population.
Objectives:
The objectives of this study were to validate 3 existing heart transplant risk scores with a single-centre cohort in China and evaluate the efficacy of the 3 systems in predicting mortality.
Methods:
We retrospectively studied 428 patients from a single centre who underwent heart transplants from January 2015 to December 2019. All patients were scored using the Index for Mortality Prediction After Cardiac Transplantation (IMPACT) and the United Network for Organ Sharing (UNOS) and risk stratification scores (RSSs). We assessed the efficacy of the risk scores by comparing the observed and the predicted 1-year mortality. Binary logistic regression was used to evaluate the predictive accuracy of the 3 risk scores. Model discrimination was assessed by measuring the area under the receiver operating curves. Kaplan-Meier survival analyses were performed after the patients were divided into different risk groups.
Results:
Based on our cohort, the observed mortality was 6.54%, whereas the predicted mortality of the IMPACT and UNOS scores and the RSSs was 10.59%, 10.74% and 12.89%, respectively. Logistic regression analysis showed that the IMPACT [odds ratio (OR), 1.25; 95% confidence interval (CI), 1.15-1.36; P < 0.001], UNOS (OR, 1.68; 95% CI, 1.37-2.07; P < 0.001) and risk stratification (OR, 1.61; 95% CI, 1.30-2.00; P < 0.001) scores were predictive of 1-year mortality. The discriminative power was numerically higher for the IMPACT score [area under the curve (AUC) of 0.691)] than for the UNOS score (AUC 0.685) and the RSS (AUC 0.648).
Conclusions:
We validated the IMPACT and UNOS scores and the RSSs as predictors of 1-year mortality after a heart transplant, but all 3 risk scores had unsatisfactory discriminative powers that overestimated the observed mortality for the Chinese cohort.
