A Risk Score for Adults With Congenital Heart Disease Undergoing Heart Transplantation.

Background: This study derived and validated a risk score for 1-year mortality in patients with adult congenital heart disease (ACHD) undergoing orthotopic heart transplantation (OHT).

Methods: The United Network for Organ Sharing registry identified patients with ACHD (≥18 years of age) who underwent OHT between 1987 and 2018. The primary outcome was 1-year mortality. Associated covariates (univariate P < .2) were entered into a multivariable logistic regression model. Variable inclusion in the model was assessed by improvement in the McFadden pseudo-R, likelihood ratio test, and C-index. A risk score was created using the absolute magnitude of the odds ratios from the derivation cohort, and its ability to predict 1-year mortality was tested in the validation cohort.

Results: A total of 1388 recipients were randomly divided into derivation (66.7%, n = 950) and validation (33.3%, n = 438) cohorts. A 13-point risk score incorporating 4 pretransplant variables (age, dialysis dependence, serum bilirubin level, and mechanical ventilation) was created. The predicted 1-year mortality ranged from 14.6% (0 points) to 49.9% (13 points) (P < .001). In weighted regression analysis, there was a strong correlation between predicted 1-year mortality and observed 1-year mortality in the validation cohort (r = 0.85, P < .001). Logistic regression also demonstrated a significant association (odds ratio, 1.18; 95% confidence interval, 1.1-1.3; P = .004). The Brier score of the composite score in the validation cohort was 0.14. Kaplan-Meier analysis demonstrated that risk scores of 4 points or higher portended worse survival at 1-year posttransplant (P < .001).

Conclusions: This 13-point risk score for ACHD is predictive of mortality within 1 year after OHT and has potential utilization in improving recipient selection for OHT in adult patients with CHD.