OC 01.4 - Prevalence of chronic thromboembolic pulmonary hypertension and evaluation of thrombus resolution in COVID-19-associated pulmonary embolism survivors

Background: Considering the high incidence of acute pulmonary embolism (PE) in coronavirus disease (COVID-19) and its potentially unique pathophysiology, it may be hypothesised that thrombus resolution after COVID-19-associated PE is less than after non-COVID-19-associated PE, and that the prevalence of chronic thromboembolic pulmonary hypertension (CTEPH) and rate of recurrent venous thromboembolism (VTE) are higher.

Aims: To assess the prevalence of CTEPH, rate of recurrent VTE, and thrombus resolution in adult COVID-19-associated PE survivors.

Methods: A multicentre cross-sectional study of adult hospitalised patients diagnosed with and treated for acute COVID-19-associated PE during or after hospital admission was performed. All patients were treated with anticoagulants for at least three months and subjected to structured follow-up procedures, aimed at detection of long-term complications after COVID-19-associated PE. CTEPH was defined in accordance with the ESC/ERS guidelines.

Results: Of the 299 included patients (mean age 60 years; 71% male), no patient developed CTEPH or had recurrent VTE during a median follow-up of 19 months after PE diagnosis (both 0%, upper limit of 95% confidence interval 1.3%). Few small residual clots, with morphology comparable to residual non-COVID-19-associated PE, were observed on follow-up computed tomography pulmonary angiography (CTPA) scans (quantification of residual thromboembolic obstruction and details regarding clot morphology in Table 1). The estimated resolution of PE over time is shown in Figure 1. After six months, an estimated 4.4% (95% CI 1.2-15) of patients had residual thrombotic obstruction.

Conclusion(s): No cases of CTEPH and recurrent VTE were observed in this population of COVID-19-associated PE survivors. The results suggest that CTEPH is at least not a more common long-term complication after COVID-19-associated PE than after PE in non-COVID-19 patients. The observed thrombus resolution was comparable to that observed in non-COVID-19-associated PE. These findings add important knowledge to the evolving field focused on aftercare of COVID-19 survivors.