Late thrombotic complications after SARS‐CoV‐2 infection in hemodialysis patients

INTRODUCTION: There is an increased risk of thrombotic complications in patients with COVID‐19. Hemodialysis patients are already at an increased risk for thromboembolic events such as stroke and pulmonary embolism. The aim of our study was to determine the incidence of late thrombotic complications (deep vein thrombosis, pulmonary embolism, stroke, new‐onset vascular access thrombosis) in maintenance hemodialysis patients after recovery from COVID‐19. METHODS: We performed a retrospective cohort study of 200 prevalent hemodialysis patients in our center at the start of the pandemic. We excluded incident patients after the cohort entry date and those who required hemodialysis for acute kidney injury, and excluded patients with less than 1 month follow‐up due to kidney transplantation or death from non‐thrombotic causes. FINDINGS: One‐hundred and eighty five prevalent hemodialysis patients finally met the inclusion criteria; 37 patients (17.6%) had SARS‐CoV‐2 infection, out of which 10 (27%) died during the acute phase of disease without evidence of thrombotic events. There was an increased risk of thrombotic events in COVID‐19 survivors compared to the non‐infected cohort (18.5% vs. 1.9%, p = 0.002) after a median follow‐up of 7 months. Multivariate regression analysis showed that COVID‐19 infection increased risk for late thrombotic events adjusted for age, sex, hypertension, diabetes, antithrombotic treatment, and previous thrombotic events (Odds Ratio (OR) 26.4, 95% confidence interval 2.5–280.6, p = 0.01). Clinical and laboratory markers did not predict thrombotic events. CONCLUSIONS: There is an increased risk of late thrombotic complications in hemodialysis patients after infection with COVID‐19. Further studies should evaluate the benefit of prolonged prophylactic anticoagulation in hemodialysis patients after recovery from COVID‐19.