Predicting Primary Graft Dysfunction in Systemic Sclerosis Lung Transplantation Using Machine-Learning and CT...

Primary graft dysfunction (PGD) is a significant barrier to survival in lung transplant (LTx) recipients. PGD in patients with systemic sclerosis (SSc) remains especially underrepresented in research.

We investigated 92 SSc recipients (mean age 51 years ± 10) who underwent bilateral LTx between 2007 and 2020. PGD was defined as grade 3 PGD at 72 h post-LTx. A comprehensive set of CT image features was automatically computed from recipient chest CT scans using deep learning algorithms. Volumetric analysis of recipients' lungs and chest cavity was used to estimate lung-size matching. Four machine learning (ML) algorithms were developed to predict PGD, including multivariate logistic regression, support vector machine (SVM), random forest classifier (RFC), and multilayer perceptron (MLP).

PGD was significantly associated with BMI >30 kg/m² (p = 0.009), African American race (p = 0.011), lower Preop FEV1 (p = 0.002) and FVC (p = 0.004), longer waitlist time (p = 0.014), higher lung allocation score (LAS) (p = 0.028), and interstitial lung disease (p = 0.050). From CT analysis, PGD was significantly associated with decreased lung volume (p < 0.001), increased heart-chest cavity volume ratio (p < 0.001), epicardial (p = 0.033) and total heart (p = 0.049) adipose tissue, and five cardiopulmonary features (p < 0.050). Oversized donor allografts estimated using CT analysis were significantly associated with PGD (p < 0.050). The MLP model achieved a maximum AUROC of 0.85 (95% CI: 0.81-0.88) in predicting PGD with four features: Preop FEV1, heart-chest cavity volume ratio, waitlist time, and donor to recipient chest cavity volume ratio.

CT-derived features are significantly associated with PGD, and models incorporating these features can predict PGD in SSc recipients.