Postacute COVID-19 Syndrome: (129)Xe MRI Ventilation Defects and Respiratory Outcomes 1 Year Later

BACKGROUND: In individuals with postacute COVID-19 syndrome (PACS) and normal pulmonary function, xenon 129 ((129)Xe) MRI ventilation defects, abnormal quality-of-life scores, and exercise limitation were reported 3 months after infection; the longitudinal trajectory remains unclear. PURPOSE: To measure and compare pulmonary function, exercise capacity, quality of life, and (129)Xe MRI ventilation defect percent (VDP) in individuals with PACS evaluated 3 and 15 months after COVID-19 infection. MATERIALS AND METHODS: In this prospective study, participants with PACS aged 18–80 years were enrolled between July 2020 and August 2021 from two quaternary care centers. (129)Xe MRI VDP, diffusing capacity of lung for carbon monoxide (Dlco), spirometry, oscillometry, 6-minute walk distance (6MWD), and St George Respiratory Questionnaire (SGRQ) scores were evaluated 3 months and 15 months after COVID-19 infection. Differences between time points were evaluated using the paired t test. Multivariable models were generated to explain exercise capacity and quality-of-life improvement. Odds ratios (ORs) were used to evaluate potential treatment influences. RESULTS: Overall, 53 participants (mean age, 55 years ± 18 [SD]; 27 women) attended both 3- and 15-month visits and were included in the analysis. The mean values for (129)Xe MRI VDP (5.8% and 4.2%; P = .003), forced expiratory volume in the 1st second of expiration percent predicted (84% and 90%; P = .001), Dlco percent predicted (86% and 99%; P = .002), and SGRQ score (35 and 25; P < .001) improved between the 3- and 15-month visit. VDP measured 3 months after COVID-19 infection predicted the change in 6MWD (β = −0.643, P = .006), while treatment with respiratory medication at 3 months predicted an improved quality-of-life score at 15 months (OR, 4.0; 95% CI: 1.2, 13.8; P = .03). CONCLUSION: Pulmonary function, gas exchange, exercise capacity, quality of life, and (129)Xe MRI ventilation defect percent (VDP) improved in participants with postacute COVID-19 syndrome at 15 months compared with 3 months after infection. VDP measured at 3 months after infection correlated with improved exercise capacity, while treatment with respiratory medication was associated with an improved quality-of-life score 15 months after infection. ClinicalTrials.gov registration no. NCT05014516 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Vogel-Claussen in this issue.