Venous Thromboembolism and Vascular Access Thrombosis in Patients on Hemodialysis: Incidence, Risk Factors, and Use of Antithrombotic Agents

Patients with end-stage kidney disease on hemodialysis (HD) have an increased risk of venous thromboembolism (VTE) and HD-specific vascular access thrombosis (VAT). We aimed to capture the incidence of VTE and VAT events and investigate risk factors for VTE and VAT occurrence, including antithrombotic agent use.Prevalent patients on maintenance HD were recruited into a prospective, population-based, observational cohort study in Vienna, Austria. During a maximum follow-up of 45 months, the occurrence of VTE, defined as deep vein thrombosis, catheter- or noncatheter-associated, and pulmonary embolism, or VAT, defined as thrombotic occlusion of an arteriovenous fistula or graft, was recorded. Risk factors for thrombotic events were analyzed by multivariable competing risk regression.VTE and VAT events occurred with an incidence rate of 1.7 (95% confidence interval [CI]: 1.2-2.6) and 7.6 per 100 person-years (95% CI: 6.3-9.3), respectively. The 30-day case fatality rates were 20.8 and 4.1% for VTE and VAT events, respectively. Prior VAT (hazard ratio [HR]: 3.07, 95% CI: 1.33-7.11, <i>p</i> = 0.009) and nephrectomy (HR: 6.53, 95% CI: 2.23-19.14, <i>p</i> = 0.001) were significantly associated with increased risk of VTE occurrence. Prior VAT was associated with a 1.8-fold (95% CI: 1.18-2.65, <i>p</i> = 0.006) and nephrectomy with a 2.8-fold increased risk of VAT occurrence (95% CI: 1.45-5.57, <i>p</i> = 0.002). Patients on vitamin K antagonists were protected from VTE (HR: 0.001, 95% CI: <0.01- < 0.01, <i>p</i> < 0.001) compared with nonusers but had no benefit with regard to VAT events.Identifying patients at high risk of thrombotic complications using risk factors, such as a history of nephrectomy and prior thrombotic events, may facilitate preventive measures.