Abstract
INTRODUCTION: Severe COVID-19 infections increase the risk of thrombotic events and Intensive Care Units reported increased extracorporeal circuit clotting (ECC) in COVID-19 patients with acute kidney injury. We wished to determine whether hemodialysis (HD) patients with COVID-19 also have increased risk of circuit clotting. METHODS: We reviewed coagulation studies and HD records, 4 weeks before and after COVID-19 polymerase chain reaction detection in HD patients between April 2020 and June 2021. FINDINGS: Sixty-eight (33.5%) of 203 HD patients with COVID-19, 65% male, mean age 64.9 ± 15.3 years, experienced some circuit clotting, and no clotting recorded prior to positive test results. In those who experienced ECC, prothrombin, activated partial thromboplastin or thrombin times were not different, whereas median factor VIII (273 [168-419] vs. 166 [139-225] IU/dl, p < 0.001), D-dimers (2654 [1381-6019] vs. 1351 [786-2334] ng/ml, p < 0.05), and fibrinogen (5.6 ± 1.4 vs. 4.9 ± 1.4 g/L, p < 0.05) were greater. Antithrombin (94 [83-112] vs. 89 [84-103] IU/dl), protein C (102 [80-130] vs. 86 [76-106] IU/dl), protein S (65 [61-75] vs. 65 [52-79] IU/dl) and platelet counts (193 [138-243] vs. 174 [138-229] × 10(9) /L) did not differ. On multivariable logistic analysis, circuit clotting was associated with log factor VIII (odds ratio [OR] 14.8 (95% confidence limits [95% CL] 1.12-19.6), p = 0.041), fibrinogen (OR 1.57 [95% CL 1.14-21.7], p = 0.006) and log D dimer (OR 4.8 [95% CL 1.16-12.5], p = 0.028). DISCUSSION: Extracorporeal circuit clotting was increased within 4 weeks of testing positive for COVID-19. Clotting was associated with increased factor VIII, fibrinogen and D-dimer, suggesting that the risk of circuit clotting was related to the inflammatory response to COVID-19.