HLA Sensitization in Patients Bridged to Lung Transplantation With Extracorporeal Membrane Oxygenation

Optimizing the prelung transplant candidate

PURPOSE OF REVIEW

Lung transplant outcomes are impacted by multiple modifiable risk factors. Candidate deterioration on the wait list remains problematic. Innovative technology and strategies to identify and impact pretransplant morbidity have improved short- and long-term outcomes. We focus our review on recent advances in pretransplant recipient assessment and optimization.

RECENT FINDINGS

Advancements in recipient management have focused on risk factor identification for adverse outcomes and the development of a lung transplant specific frailty assessment. Early surgical correction of gastroesophageal reflux disease (GERD), including the use of partial fundoplication in the setting of esophageal dysmotility, leads to improvements in graft function/longevity. New evidence supports expanding criteria for extracorporeal life support as a bridge to transplant.

SUMMARY

Candidate optimization requires early intervention to limit functional deterioration potentially contributing to adverse outcomes. Frailty can be identified with a transplant specific frailty assessment, and positively impacted with dedicated rehabilitation. Pretransplant frailty is reversible following transplant and should be considered in the context of overall fitness at the time of candidate selection. Invasive support modes including extracorporeal membrane oxygenation (ECMO) are appropriate to preserve strength and mobility, with awake, ambulatory ECMO preferred. The deleterious effect of GERD on graft function can be managed with early fundoplication over medical management alone.

Rejection Requiring Treatment within the First Year following Heart Transplantation: The UNOS Insight

(1) Background: Heart failure is an extremely impactful health issue from both a social and quality-of-life point of view and the rate of patients with this condition is destined to rise in the next few years. Transplantation remains the mainstay of treatment for end-stage heart failure, but a shortage of organs represents a significant problem that prolongs time spent on the waiting list. In view of this, the selection of donor and recipient must be extremely meticulous, considering all factors that could predispose to organ failure. One of the main considerations regarding heart transplants is the risk of graft rejection and the need for immunosuppression therapy to mitigate that risk. In this study, we aimed to assess the characteristics of patients who need immunosuppression treatment for rejection within one year of heart transplantation and its impact on mid-term and long-term mortality. (2) Methods: The United Network for Organ Sharing (UNOS) Registry was queried to identify patients who solely underwent a heart transplant in the US between 2000 and 2021. Patients were divided into two groups according to the need for anti-rejection treatment within one year of heart transplantation. Patients' characteristics in the two groups were assessed, and 1 year and 10 year mortality rates were compared. (3) Results: A total of 43,763 patients underwent isolated heart transplantation in the study period, and 9946 (22.7%) needed anti-rejection treatment in the first year. Patients who required treatment for rejection within one year after transplant were more frequently younger (49 ± 14 vs. 52 ± 14 years, p < 0.001), women (31% vs. 23%, p < 0.001), and had a higher CPRA value (14 ± 26 vs. 11 ± 23, p < 0.001). Also, the rate of prior cardiac surgery was more than double in this group (27% vs. 12%, p < 0.001), while prior LVAD (12% vs. 11%, p < 0.001) and IABP (10% vs. 9%, p < 0.01) were more frequent in patients who did not receive anti-rejection treatment in the first year. Finally, pre-transplantation creatinine was significantly higher in patients who did not need treatment for rejection in the first year (1.4 vs. 1.3, p < 0.01). Most patients who did not require anti-rejection treatment underwent heart transplantation during the new allocation era, while less than half of the patients who required treatment underwent transplantation after the new allocation policy implementation (65% vs. 49%, p < 0.001). Patients who needed rejection treatment in the first year had a higher risk of unadjusted 1 year (HR: 2.25; 95% CI: 1.88-2.70; p < 0.001), 5 year (HR: 1.69; 95% CI: 1.60-1.79; p < 0.001), and 10 year (HR: 1.47; 95% CI: 1.41-1.54, p < 0.001) mortality, and this was confirmed at the adjusted analysis at all three time-points. (4) Conclusions: Medical treatment of acute rejection was associated with significantly increased 1 year mortality compared to patients who did not require anti-rejection therapy. The higher risk of mortality was confirmed at a 10 year follow-up. Further studies and newer follow-up data are required to investigate the role of anti-rejection therapy in the heart transplant population.