High Grade Primary Graft Dysfunction after Lung Transplantation is Associated with Acute Rejection but Not Chronic Allograft Dysfunction

Purpose Evidence suggests that high grade primary graft dysfunction after lung transplantation (LTx) is a major threat for early and late outcomes. Herein, we aim to examine the risk factors and clinical impact of PGD in a contemporary cohort at a single center. Methods From 1/2008 to 7/2018, 1147 LTx procedures were performed at our institution. Clinical data was prospectively collected and PGD defined according to ISHLT criteria. Median follow up was 3.3 years (interquartile range 1.2 - 7.4). Multi-variable analysis utilizing recipient, donor, and LTx procedure variables was performed to assess risk factors for PGD, acute rejection, chronic lung allograft dysfunction (CLAD), early mortality, and late survival. Results Out of 1147 LTx procedures, 61% were bilateral. The incidence of PGD (grade II & III) was 13% & 15% at 24 hr , 12% & 14% at 48 hr , and 12% & 14% at 72 hr, respectively. Multi-variable analysis identified cardiopulmonary bypass usage/duration, single LTx, recipient pulmonary arterial hypertension, longer ischemic time, earlier year of LTx, older donor, higher Lung Allocation Score, and higher ratio of recipient/donor weight as risk factors for high grade PGD (grade II or III at 48-72 hr). Notably, recipient body mass index, donor smoking history, and diabetes were not significant risk factors for high grade PGD. Further analysis demonstrated that PGD II or III at 48-72 hr were independent significant risk factors for early mortality and higher acute rejection grades, while not significantly associated with CLAD or late survival. PGD grade II or III at 24 hr were not significant risk factors for early mortality, acute rejection, CLAD, or late survival. Conclusion This single-center data analysis of > 1000 contemporary lung transplants identified risk factors for high grade PGD. While high grade PGD at 48-72 hr was associated with higher risk of early mortality and acute rejection, in contrast to previous studies, it was not associated with a higher risk of CLAD or late survival, perhaps due to evolving management strategies.