Enduring coagulopathy and endothelial dysfunction in postacute COVID-19 syndrome

Postacute coronavirus disease 2019 (COVID-19) syndrome (PACS), or long COVID, encompasses a range of symptoms persisting beyond the acute phase of severe acute respiratory syndrome coronavirus 2 infection. Although acute-phase coagulation disturbances in COVID-19 are well documented, these abnormalities during recovery and their association with PACS remain inadequately explored. Our study aimed to investigate the long-term changes in coagulation function and inflammatory markers in patients with PACS, elucidating their pathological mechanisms and providing insights for patient management. This retrospective cohort study included 3783 adult inpatients in Jinan, China, divided into COVID-19-positive and -negative groups, with 363 patients with COVID-19 further diagnosed with PACS. Coagulation and inflammatory markers were collected at baseline and during 1-year follow-up, and changes over time were analyzed using generalized estimating equations. Most inflammatory markers and some coagulation parameters showed significant recovery, including lymphocyte counts and fibrinogen. However, several parameters remained abnormal even at 7 to 12 months after infection. Of note, D-dimer (Z = 5.692, P < .001, abnormal rate 65.79%) and erythrocyte sedimentation rate (Z = 2.749, P = .006, abnormal rate 57.32%) remained elevated above the normal upper limit. Additionally, certain coagulation parameters, particularly prothrombin time (β = -0.10 [95% confidence interval, -0.88 to 0.69]; P = .81, prolonged rate 17.29%) and platelet counts, did not normalize by 7 to 12 months. Our findings in survivors of severe COVID-19 pneumonia support the concept of PACS as a chronic thromboinflammatory syndrome characterized by sustained coagulation abnormalities. The prolonged elevation of D-dimer and incomplete recovery of coagulation parameters highlight the need for long-term monitoring and personalized management strategies to mitigate thrombotic risks in survivors of COVID-19.