Objective estimates improve risk stratification for primary graft dysfunction after lung transplantation

Primary graft dysfunction (PGD) is a major cause of early mortality after lung transplant. We aimed to define objective estimates of PGD risk based on readily available clinical variables, using a prospective study of 11 centers in Lung Transplant Outcomes Group (LTOG). Derivation included 1255 subjects from 2002–2010; with separate validation in 382 subjects accrued from 2011–2012. We used logistic regression to identify predictors of grade 3 PGD at 48/72 hours, and decision curve methods to assess impact on clinical decisions. 211/1255 subjects in the derivation and 56/382 subjects in the validation developed PGD. We developed 3 prediction models, where low-risk recipients had a normal BMI (18.5–25 kg/m2), COPD/CF, and absent or mild PH (mPAP< 40mmHg). All others were considered higher-risk. Low-risk recipients had a predicted PGD risk of 4–7%, and high-risk a predicted PGD risk of 15–18%. Adding a donor-smoking lung to a higher-risk recipient significantly increased PGD risk, although risk did not change in low-risk recipients. Validation demonstrated that probability estimates were generally accurate and that models worked best at baseline PGD incidences between 5–25%. We conclude that valid estimates of PGD risk can be produced using readily-available clinical variables.