Post-Reperfusion Pulmonary Artery Pressure is a Clinical Marker of Primary Graft Dysfunction Risk Following Lung Transplant

Abstract

<h3>Purpose</h3> Primary graft dysfunction is a known risk factor of early mortality after lung transplant (LT). PGD represents ischemia-reperfusion injury in the allograft, which subsequently causes capillary leaks. Clinical models which identify patients at high risk for PGD are limited. We hypothesize high systolic pulmonary artery pressure (sPA pressure) after reperfusion in LT is a clinical marker for those at risk of developing PGD. <h3>Methods</h3> This is a retrospective review of a single site institutional lung transplant database. We included consecutive lung transplant patients from March 2020 through September 2021. Only double lung transplant patients were included, and patients with pre-transplant ECMO use were excluded as ECMO flow could impact sPA pressures. PGD was defined according to modified ISHLT criteria. Receiver operating characteristic (ROC) curve was used to find the cut off value for PGD. <h3>Results</h3> 51 patients were included in this study. PGD occurred in 43.1% (n = 22). One-year survival was reduced in recipients with PGD (p=0.005). The ROC curve of post-reperfusion sPA pressures showed 41 mmHg was the cut off for PGD (sensitivity 0.89, specificity 0.72, area under curve (AUC) 0.84), which is significantly superior to the ROC curve of pre-LT sPA pressures (sensitivity 0.44, specificity 0.68, AUC 0.54, p<0.01). The ROC curve of the difference between patient pre- and post-reperfusion sPA pressures has a sensitivity 0.86, specificity 0.68, AUC 0.71. <h3>Conclusion</h3> Patients with elevated sPA pressure after reperfusion are at increased risk of PGD after LT. Post-reperfusion sPA pressure is more indicative of PGD risk than pre-LT sPA pressure. Using post-reperfusion sPA pressure as a complementary clinical marker of PGD would allow earlier intervention in PGD, which could subsequently improve survival in these LT patients.