Safety and effectiveness of direct oral anticoagulants in patients with nephrotic syndrome: a report of 21 cases

Background Nephrotic syndrome (NS) is associated with increased risk of thromboembolic events (TE) adding to the morbidity and mortality. International guidelines recommend prophylactic anticoagulation in patients with NS and high risk of TE, but no studies have identified the optimal type of anticoagulation in NS. We aimed to assess the effectiveness and safety of direct oral anticoagulant (DOAC) by analyzing the thromboembolic and bleeding events in NS patients prescribed DOAC as primary prophylaxis to prevent TE or as treatment for TE occurring in relation to NS. Methods We performed a single-center, retrospective study including patients with NS, a plasma albumin less than 25 g/L and prophylactic anticoagulation treatment with DOAC at the Department of Renal Medicine at Aarhus University Hospital, Denmark from July 2016 to June 2021. Patients treated with DOAC as thromboprophylaxis for other indications than NS were excluded. Baseline characteristics and outcomes, including TE, bleeding and other adverse effects associated with DOAC were obtained from medical records. Results We identified 268 patients treated with DOAC of which 21 patients with NS were included in the study. Nineteen patients were prescribed DOAC as thromboprophylaxis and two patients received DOAC due to previous TE, which was considered associated with the NS. The type of DOAC prescribed was apixaban (n = 10) and rivaroxaban (n = 11). No patients experienced TE during DOAC treatment, while five patients had a minor bleeding episode. Patients who experienced bleeding episodes were older (median 62 vs 51 years), more often female (80%) and had been on DOAC for a longer period (204 days vs 47 days). Neither the HAS-BLED score nor GN-risk-score predicted the risk of minor bleedings in this population. Conclusions In this case series, no new TE and only minor bleeding complications were observed among adult NS patients treated with DOAC.