Chronic Thromboembolic Pulmonary Hypertension (CTEPH) after COVID-19-associated pulmonary embolism in France: a nationwide study

<bold>Background:</bold> Though long-term effects of COVID-19 such as dyspnea are frequent, the mechanisms are often poorly understood. Besides, the endothelial effects of COVID-19, such as venous or arterial thrombosis, are well documented. Thus, the incidence of CTEPH following COVID-19 is a question with many implications, particularly for screening in patients with long COVID. <bold>Methods:</bold> From the French National Hospital Discharge database, we included patients ≥18 years hospitalized for pulmonary embolism (PE) in March-December 2020. In order to study the hospital incidence of CTEPH, we excluded patients with pulmonary hypertension in the 6 years preceding the hospital stay for PE. Then, in the 2 years following the inclusion stay for PE, we compared the incidence of CTEPH between the PE patients with COVID-19 (Covid-PE) and those without COVID-19 (Non-Covid-PE). We also studied hospital mortality. <bold>Results:</bold> Among 59,841 PE patients included, 1.72% were diagnosed with CTEPH in the two following years with a significant difference between Covid-PE and Non-Covid-PE (0.91% vs 1.84%, p<0.0001). Two-year hospital mortality was significantly higher in Non-Covid-PE than in Covid PE (13.19%, vs 5.08 % p<0.0001). <bold>Conclusion</bold>: When investigating chronic dyspnea in patients hospitalized for COVID-19 associated with PE, the risk of CTEPH should not be considered as higher than for other PE. COVID-19 associated with hospitalized PE should not be considered an added harmful factor if not associated with initial mortality. To our knowledge, this is the biggest nationwide study on COVID-19-associated CTEPH following PE and the study to include Covid-PE two year mortality.