One Year Into the Pandemic: Evolving COVID-19 Outcomes in Lung Transplant Recipients, a Single-center Experience

A Single-center Experience With >200 Lung Transplant Recipients With COVID-19 Infection

Background

Although COVID-19 is no longer a declared global health emergency, data remain limited on the impact of COVID-19 in lung transplant recipients.

Methods

We identified lung transplant recipients who were diagnosed with COVID-19 from March 2020 through August 2022 in our institutional database and investigated clinical outcomes. We then analyzed outcomes based on date of COVID-19 diagnosis (first wave March 2020-October 2020; second wave November 2020-2021; third wave December 2021-September 2022) and compared these results.

Results

Of the 210 lung transplant recipients (median age 67; 67% men) enrolled, 140 (67%) required hospital admission. Among admitted recipients, 35 (25%) were intubated and 7 (5%) were placed on extracorporeal membrane oxygenation. Overall survival was 67.1% at 1 y and 59.0% at 2 y post-COVID-19 diagnosis. COVID-19 led to mortality in all 5 patients diagnosed during their index admission for lung transplantation. Although overall survival was significantly better in recipients with COVID-19 during the third wave, in-hospital mortality remained high (first wave 28%, second wave 38%, and 28% third wave). Vaccination (partially vaccinated versus none and fully vaccinated versus none) was the only significant protective factor for hospital admission, and age 70 y and older and partially vaccinated (versus none or fully vaccinated) were independent risk factors for in-hospital mortality.

Conclusions

Overall survival after COVID-19 infection in lung transplant recipients continues to improve; however, in-hospital mortality remains remarkably high. Vaccination appears to have been impactful in preventing hospital admission, but its impact on in-hospital mortality is still unclear. Further research is needed to better identify lung transplant recipients at high risk for mortality from COVID-19.

Current and Emerging Therapies for COVID-19 in Lung Transplantation

Purpose of Review

The landscape of the coronavirus disease 2019 (COVID-19) pandemic has rapidly changed over the past 3 years. Paralleling this evolution, the scientific and medical communities have reported many novel findings relating to the infection's epidemiology, transmission, diagnosis, and treatment. We review pertinent studies of COVID-19 therapeutics with an emphasis on their application to lung transplant recipients.

Recent Findings

Agents that have been well-studied for treating COVID-19 include antivirals (remdesivir, nirmatrelvir/ritonavir, molnupiravir), monoclonal antibodies, and immunomodulators (for example, corticosteroids and tocilizumab).

Summary

Remdesivir remains an essential therapy for managing mild-moderate COVID-19. Though highly efficacious for mild-moderate COVID-19 for outpatient therapy, ritonavir-boosted nirmatrelvir has limited use in lung transplant recipients due to significant drug-drug interactions. Monoclonal antibodies, though useful, are the most affected by the emergence of new viral variants.

CT imaging findings in lung transplant recipients with COVID-19

OBJECTIVES

Our goal was to compare the chest computed tomography (CT) imaging findings of COVID-19 in lung transplant recipients (LTR) and a group of non-transplanted controls (NTC).

METHODS

This retrospective study included 51 consecutive LTR hospitalized with COVID-19 from two centers. A total of 75 NTC were included for comparison. Images were classified regarding the standardized RSNA category, main pattern of lung attenuation, and longitudinal and axial distribution. Quantitative CT (QCT) analysis was performed to evaluate percentage of high attenuation areas (%HAA, threshold -250 to -700 HU). CT scoring was used to measure severity of parenchymal abnormalities.

RESULTS

The imaging findings of COVID-19 in LTR were significantly different from controls regarding the RSNA classification and pattern of lung attenuation. LTR had a significantly higher proportion of patients with an indeterminate pattern on CT (0.31 vs. 0.11, p = 0.014). The most frequent pattern of attenuation in LTR was predominantly consolidation (0.39 vs. 0.22, p = 0.144) followed by a mixed pattern of ground-glass opacities (GGO) and consolidation (0.37 vs. 0.20, adjusted p = 0.102). On the other hand, the most common pattern in NTC was GGO predominant (0.58 vs. 0.24 of LTR, p = 0.001). LTR had significantly more severe parenchymal disease measured by CT score and %HAA by QCT (0.372 ± 0.08 vs. 0.148 ± 0.06, p < 0.001).

CONCLUSION

The most frequent finding of COVID-19 in LTR is a predominant pattern of consolidation. Compared to NTC, LTR more frequently demonstrated an indeterminate pattern according to the RSNA classification and more extensive lung abnormalities on QCT and semi-quantitative scoring.

KEY POINTS

• The most common CT finding of COVID-19 in LTR is a predominant pattern of consolidation followed by a mixed pattern of GGO and consolidation, while controls more often have a predominant pattern of GGO. • LTR more often presents with an indeterminate pattern of COVID-19 by RSNA classification than controls; therefore, molecular testing for COVID-19 is essential for LTR presenting with lower airway infection independently of imaging findings. • LTR had more extensive disease by semi-quantitative CT score and increased percentage areas of high attenuation on QCT.