Thrombotic events after COVID-19 infection in hemodialysis patients∗

ABSTRACT

BACKGROUND AND AIMS: 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. METHOD: 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. RESULTS: 185 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. Stroke incidence was 38.9 episodes/1000 patient-years in patients infected with SARS-CoV-2, compared to an incidence of 2.8 episodes/1000 patient-years in non-infected patients during the follow-up period. The median time from diagnosis of SARS-CoV-2 to the first thrombotic event was 62 days (interquartile range 5-118 days). Survival analysis with Kaplan-Meier curves revealed an increase in the rate of thrombotic events after SARSCoV- 2 compared to non-infected patients (see Figure 1). Mean survival from thrombotic event was 6.160.4 months in the COVID-infected group, compared to 6.97±0.04 months in the non-infected group (p<0.001). 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 (OR 26.4, 95% CI 2.5-280.6, p=0.01). Clinical and laboratory markers did not predict thrombotic events. CONCLUSION: 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. (Table Presented).