Lung Transplantation in COVID-19 patients: What we have learned so far

A Multi-Center International Analysis of Lung Transplantation Outcomes in Patients With COVID-19

INTRODUCTION

Lung transplantation has become increasingly utilized in patients with COVID-19. While several single-center and UNOS database studies have been published on lung transplants (LTs) for end-stage lung disease (ESLD) from Coronavirus disease 2019 (COVID-19), there is a lack of multi-center and international data.

METHODS

This is a multicenter analysis from 11 high-volume lung transplant centers in the United States and Europe. Data were collected through the Multi-Institutional ECLS Registry and stratified by ESLD due to COVID-19 versus other etiologies. Demographics and clinical variables were compared using Chi-square test and Fisher's exact test. Survival was assessed by Kaplan-Meier curves and compared by log-rank test with propensity score matching.

RESULTS

Of 1606 lung transplant recipients, 46 (2.9%) were transplanted for ESLD from COVID-19 compared to 1560 (97.1%) without a history of COVID-19. Among COVID-19 patients, 30 (65.2%) had COVID-19-associated ARDS and 16 (34.8%) had post-COVID-19 fibrosis. COVID-19 patients had higher lung allocation scores (78.0 vs. 44.4, p < 0.0001), had severely limited functional status (37.0% vs. 2.9%, p < 0.0001), had higher preoperative ECMO usage (65.2% vs. 5.4%, p < 0.0001), and spent less time on the waitlist (32 vs. 137 days, p < 0.0001). A 30-day survival was comparable between COVID-19 and non-COVID-19 patients before (100% vs. 98.7%, p = 0.39) and after propensity matching (p = 0.15).

CONCLUSIONS

Patients who received LTs due to COVID-19 had short-term survival comparable to that of patients without COVID-19. Our findings support the idea that lung transplantation should be considered for select patients with ESLD due to COVID-19.

Chronic Lung Injury after COVID-19 Pneumonia: Clinical, Radiologic, and Histopathologic Perspectives

With the COVID-19 pandemic having lasted more than 3 years, concerns are growing about prolonged symptoms and respiratory complications in COVID-19 survivors, collectively termed post-COVID-19 condition (PCC). Up to 50% of patients have residual symptoms and physiologic impairment, particularly dyspnea and reduced diffusion capacity. Studies have also shown that 24%-54% of patients hospitalized during the 1st year of the pandemic exhibit radiologic abnormalities, such as ground-glass opacity, reticular opacity, bronchial dilatation, and air trapping, when imaged more than 1 year after infection. In patients with persistent respiratory symptoms but normal results at chest CT, dual-energy contrast-enhanced CT, xenon 129 MRI, and low-field-strength MRI were reported to show abnormal ventilation and/or perfusion, suggesting that some lung injury may not be detectable with standard CT. Histologic patterns in post-COVID-19 lung disease include fibrosis, organizing pneumonia, and vascular abnormality, indicating that different pathologic mechanisms may contribute to PCC. Therefore, a comprehensive imaging approach is necessary to evaluate and diagnose patients with persistent post-COVID-19 symptoms. This review will focus on the long-term findings of clinical and radiologic abnormalities and describe histopathologic perspectives. It also addresses advanced imaging techniques and deep learning approaches that can be applied to COVID-19 survivors. This field remains an active area of research, and further follow-up studies are warranted for a better understanding of the chronic stage of the disease and developing a multidisciplinary approach for patient management.

Single-Center Experience With Lung Transplant Evaluation Referrals of Acute Respiratory Distress Syndrome Patients During the COVID-19 Pandemic: How Do You Make Up For Lost Time?

Transfer of select, medically refractory acute respiratory distress syndrome patients to lung transplant centers requires extensive resources. Here, we report 270 consecutive lung transplant patient referrals to our center for medically refractory ARDS from June 2021 to April 2022, following the implementation of clinical care pathways for intake of these patients. Eighty-seven of 270 patients (32.2%) met screening criteria and were evaluated for transfer within a median of 12 days, during which 38 of 87 patients (43.7%) died and 12 of 87 patients (13.8%) transferred elsewhere. Thirty-seven of 87 patients (42.5%) were accepted for transfer of which 16 of 37 patients (43.2%) successfully transferred to our center with a median transfer waiting period of 12 days. Because of resource constraints, 21 of 37 accepted patients (56.8%) could not be transferred of which 9 of 21 patients (42.9%) died while waiting. Nine of 16 transferred patients (56.2%) eventually underwent lung transplantation with over 80% 6-month survival. ARDS patients referred for transplantation have high risk of mortality and, therefore, require well-described pathways for evaluation and transfer.