Longitudinal follow-up of postacute COVID-19 syndrome: DLCO, quality-of-life and MRI pulmonary gas-exchange abnormalities, 2023, Matheson et al

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Longitudinal follow-up of postacute COVID-19 syndrome: DLCO, quality-of-life and MRI pulmonary gas-exchange abnormalities
Matheson AM, McIntosh MJ, Kooner HK, Abdelrazek M, Albert MS, Dhaliwal I, Nicholson JM, Ouriadov A, Svenningsen S, Parraga G

129Xe 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 (DLCO, 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. DLCOcorrelated with RBC:TP (r=0.60, 95% CI=0.22 to 0.82, p=0.004) at 7 months.

While DLCO and SGRQ measurements improved, these values did not normalise 14 months post-infection.

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Follow-up to —

https://www.s4me.info/threads/persi...lated-papers-by-grist-wild.28313/#post-426128

See also —

https://www.s4me.info/threads/lung-...ients-with-long-covid-2022-grist-et-al.27824/

 

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Hyperpolarised 129Xe MRI has also revealed alveolar gas-transfer abnormalities in PACS, including in never-hospitalised people up to 41 weeks postinfection.

The 129Xe MRI red blood cell (RBC) to alveolar tissue plasma (TP) ratio was the primary endpoint.

the RBC defects visually improved and this was coincident with clinically relevant improvements9 in SGRQ total score of 5, postexertional breath- lessness score of 1 and improved RBC:TP ratio (0.54).

Whether this snapshot in time, 14±2 months postinfection reflects a slow, ongoing recovery or permanent impairment, remains to be ascertained.

Previous work detected a significant correlation between DLCO and 129Xe RBC:TP in PACS and here, we observed that this correlation persisted over time. This suggested that 129Xe RBC:TP detected abnormal alveolar gas-exchange that remained abnormal in people with PACS, long after the infection had resolved.

Together, these data suggest gas-exchange abnormalities at least partially resolved during a period of 7 months (and 14 months postinfection). While we do not know the precise cause of abnormal RBC:TP in these participants, a recently published study that evaluated postmortem COVID-19 lungs described vasculo pathologies including vascular congestion, perivascular inflammation, thromboemboli and infarcts unique to COVID-19 that could explain ongoing pulmonary vascular abnormalities.

 

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See also Nebivolol: an effective option against long-lasting dyspnoea following COVID-19 pneumonia - a pivotal double-blind, cross-over controlled study.

 

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See also Review of Hyperpolarized Pulmonary Functional 129Xe MR for Long-COVID (2023)