129Xe lung ventilation imaging in patients with long COVID without prior respiratory disease

<bold>Aim:</bold> To evaluate lung ventilation in non-hospitalised patients with long COVID (NHLC) and dyspnoea, patients with NHLC without dyspnoea and controls. <bold>Methods:</bold> NHLC patients and control subjects (fully recovered from COVID-19) were recruited as part of the EXPLAIN study. Subjects with smoking history >10 years, previous respiratory illness or abnormal CT imaging were excluded. ¹²⁹Xe ventilation MR imaging was acquired at 1.5T. Ventilation defect percentage (VDP), low ventilation percentage, normal ventilation percentage, hyper-ventilated percentage and ventilation heterogeneity index were calculated. Groupwise statistical tests (Kruskal-Wallis or Mann-Whitney U tests) were performed using SPSS. <bold>Results:</bold> 57 patients with NHLC and dyspnoea (median 43 years old, 68% female) 17 patients with NHLC without dyspnoea (46 years, 35% female) and 21 controls (39 years, 71% female) had successful ventilation imaging. No significant differences in any ventilation metrics were found between groups (p>0.6 in all cases). 12/57 (21%) patients with long COVID and dyspnoea had abnormal VDP (VDP>2%), 1/17 (6%) subjects without dyspnoea and 1/21 (5%) control subjects had VDP>2% (Figure 1). Most patients had normal spirometry (FEV1 Z<-1.64: 2/69, FVC Z<-1.64: 1/69, FEV1/FVC Z<-1.64: 6/69). <bold>Conclusions:</bold> 20% of NHLC patients with dyspnoea had abnormal lung ventilation despite normal PFTs. <fig><object-id>erj;64/suppl_68/PA5251/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>