Longitudinal follow-up of postacute COVID-19 syndrome: DL CO , quality-of-life and MRI pulmonary gas-exchange abnormalities.

129 Xe MRI red blood cell to alveolar tissue plasma ratio (RBC:TP) abnormalities have been observed in ever-hospitalised and never-hospitalised people with postacute COVID-19 syndrome (PACS). But, it is not known if such abnormalities resolve when symptoms and quality-of-life scores improve. We evaluated 21 participants with PACS, 7±4 months (baseline) and 14±4 months (follow-up) postinfection. Significantly improved diffusing capacity of the lung for carbon monoxide (DL CO , Δ=14% pred ;95%CI 7 to 21, p<0.001), postexertional dyspnoea (Δ=-0.7; 95%CI=-0.2 to -1.2, p=0.019), St George's Respiratory Questionnaire-score (SGRQ Δ=-6; 95% CI=-1 to -11, p=0.044) but not RBC:TP (Δ=0.03; 95% CI=0.01 to 0.05, p=0.051) were observed at 14 months. DL CO correlated with RBC:TP (r=0.60, 95% CI=0.22 to 0.82, p=0.004) at 7 months. While DL CO and SGRQ measurements improved, these values did not normalise 14 months post-infection. ClinicalTrials.gov NCT04584671.