129Xe MRI ventilation defects in ever-hospitalised and never-hospitalised people with post-acute COVID-19 syndrome

Abstract

BackgroundPatients often report persistent symptoms beyond the acute infectious phase of COVID-19. Hyperpolarised129Xe MRI provides a way to directly measure airway functional abnormalities; the clinical relevance of129Xe MRI ventilation defects in ever-hospitalised and never-hospitalised patients who had COVID-19 has not been ascertained. It remains unclear if persistent symptoms beyond the infectious phase are related to small airways disease and ventilation heterogeneity. Hence, we measured129Xe MRI ventilation defects, pulmonary function and symptoms in ever-hospitalised and never-hospitalised patients who had COVID-19 with persistent symptoms consistent with post-acute COVID-19 syndrome (PACS).MethodsConsenting participants with a confirmed diagnosis of PACS completed129Xe MRI, CT, spirometry, multi-breath inert-gas washout, 6-minute walk test, St. George’s Respiratory Questionnaire (SGRQ), modified Medical Research Council (mMRC) dyspnoea scale, modified Borg scale and International Physical Activity Questionnaire. Consenting ever-COVID volunteers completed129Xe MRI and pulmonary function tests only.ResultsSeventy-six post-COVID and nine never-COVID participants were evaluated. Ventilation defect per cent (VDP) was abnormal and significantly greater in ever-COVID as compared with never-COVID participants (p<0.001) and significantly greater in ever-hospitalised compared with never-hospitalised participants who had COVID-19 (p=0.048), in whom diffusing capacity of the lung for carbon-monoxide (p=0.009) and 6-minute walk distance (6MWD) (p=0.005) were also significantly different.129Xe MRI VDP was also related to the 6MWD (p=0.02) and post-exertional SpO2(p=0.002). Participants with abnormal VDP (≥4.3%) had significantly worse 6MWD (p=0.003) and post-exertional SpO2(p=0.03).Conclusion129Xe MRI VDP was significantly worse in ever-hospitalised as compared with never-hospitalised participants and was related to 6MWD and exertional SpO2but not SGRQ or mMRC scores.Trial registration numberNCT05014516.