Late Breaking Abstract - Breathlessness post COVID-19 despite improvement in cardiopulmonary health

Background: Breathlessness is common in patients post-COVID-19, yet its association with objective measures of cardiopulmonary health is unknown. We sought to 1) describe the natural history of breathlessness and cardiopulmonary abnormalities & 2) evaluate their relationship post-COVID-19. Methods: Fifty-eight previously hospitalised COVID-19 patients & 30 controls underwent cardiopulmonary MRI (CMR), lung function testing & CPET at 2-3 & 6 months (m) from symptom-onset. Results: At 2-3m persistent breathlessness (MRC grade>1) was reported by 64% of patients, reducing to 57% by 6m, vs 10% of controls. On CMR, patients had preserved cardiac volumes & function at both 2-3m & 6m. Myocardial native T1, a marker of inflammation, was raised in 26% at 2-3m, but normalised by 6m, with no signs of active myocarditis (Fig1A). 60% of patients had lung parenchymal abnormalities at 2-3m, improving in extent by 6m. Patients had reduced FEV1 & FVC on spirometry at 2-3m. At 6m, FEV1 normalised, FVC remained slightly reduced & gas transfer was impaired in 52%. CPET revealed reduced peak VO2 & abnormal VE/VCO2 slope (marker of lung efficiency) in patients at 2-3m, which improved by 6m (Fig1B). There was no relationship between persistent breathlessness & CMR, CPET or spirometry measures at 6m (Fig1C). Conclusions: Despite improvement in objective measures of cardiopulmonary health, over half the patients post-COVID-19 continue to experience breathlessness at 6m.