Microvascular Injury and Distal Thrombosis in COVID-19

Investigators plan to consecutively enrol 25 patients without clinical or biological evidence for superinfection, without left ventricular dysfunction and for whom a pulmonary embolism was discarded by computed tomography pulmonary angiography. Investigators will investigate lung ventilation and perfusion (LVP) by LVP scintigraphy, and, 24 hours later, left and right ventricular function by 99mTc-labelled albumin gated-blood-pool scintigraphy with late (60 mn) tomographic albumin images on the lungs to evaluate lung albumin retention that could indicate microvascular injuries with secondary edema

Inclusion criteria

• Non-critically ill patients hospitalized in the COVID-19 Unit of the Centre Hospitalier Princesse Grace of Monaco
• Presenting with a sudden clinical deterioration defined by a respiratory rate impairment and/or a rise of oxygen flow to reach a peripheral capillary oxygen saturation (SpO2) of more than 95% during at least 48 hours
• a diagnosis of pulmonary embolism was discarded by CT pulmonary angiography
• no clinical or biological (procalcitonin levels) evidence of lung superinfection
• without clinical evidence for LV dysfunction

Exclusion criteria

• Non confirmed COVID-19 pneumonia according to the WHO guidance by a positive result of RT-PCR assay of nasal and pharyngeal swabs,
• Patients without peripheral pulmonary ground-glass opacities or air-space consolidation on their chest CT scan at admission and common laboratory findings including lymphocytopenia, eosinopenia, significantly elevated markers of organ inflammation such as fibrinogen and C-reactive protein.
• Patients could not be included if their medical condition was unstable or precluded a safe transfer to the nuclear medicine department, if they were under mechanical ventilation (either non-invasive or invasive), if they required critical care unit, or in case of a pregnancy.