Enduring coagulopathy and endothelial dysfunction in post–acute COVID-19 syndrome

PACS is a chronic thromboinflammatory disorder driven by persistent endothelial injury, immune dysregulation, and coagulation imbalance. The one-year persistence of coagulation abnormalities supports future long-term surveillance strategies in PACS patients Post–acute COVID-19 syndrome (PACS), or long COVID, encompasses a range of symptoms persisting beyond the acute phase of SARS-CoV-2 infection. While 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 PACS patients, elucidating their pathological mechanisms and providing insights for patient management. This retrospective cohort study included 3,783 adult inpatients in Jinan, China, divided into COVID-19 positive and negative groups, with 363 COVID-19 patients 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 (GEE).Most inflammatory markers and some coagulation parameters showed significant recovery, including lymphocyte counts, and fibrinogen. However, several parameters remained abnormal even at 7-12 months post-infection. Notably, D-dimer ( Z = 5.692, P < .001, abnormal rate 65.79%) and ESR ( 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% CI -0.88∼ 0.69, P = .81, prolonged rate 17.29%) and platelet counts, did not normalize by 7-12 months.Our findings in survivors of severe COVID-19 pneumonia supports 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 COVID-19 survivors.