Through a prospective, single-center, randomized controlled trial, we aim to determine the thromboprophylactic efficacy of rivaroxaban in patients with idiopathic membranous nephropathy (IMN). IMN patients at high risk of thrombosis and low risk of bleeding will be enrolled and randomly assigned to a rivaroxaban group or a control group (receiving warfarin). Prophylactic anticoagulation will be administered with rivaroxaban or warfarin accordingly. Over the 6 months following initiation of prophylactic anticoagulation, the incidence of the primary efficacy endpoint (a composite of pulmonary embolism, deep vein thrombosis, and lower-extremity deep vein thrombosis) and the safety endpoint (bleeding events) will be compared between the two groups.

Inclusion Criteria:

Age 18-80 years, either sex. Kidney biopsy findings on both light microscopy and electron microscopy consistent with idiopathic membranous nephropathy (IMN).

IMN patients at high risk of thrombosis: meeting the diagnostic criteria for nephrotic syndrome and having serum albumin <25 g/L. Normal renal function (normal creatinine clearance).

Exclusion Criteria:

Prior thrombotic events, such as pulmonary embolism, renal vein thrombosis, or lower-extremity deep vein thrombosis.

Pulmonary diseases that may affect the accuracy of ventilation-perfusion (V/Q) scanning for diagnosing pulmonary embolism, such as pulmonary infection/inflammation, lung tumors, or chronic obstructive pulmonary disease.

Inability to undergo V/Q scanning, e.g., right-to-left congenital cardiac shunt, prior allergy to radiopharmaceuticals, or inability to cooperate with the examination.

Clinically significant active bleeding. Pregnant or breastfeeding women. Acute myocardial infarction and/or acute stroke, or atrial fibrillation. Active infection or active malignancy. Coagulation abnormalities; hepatic dysfunction (aminotransferases ≥3× the upper limit of normal); or thrombocytopenia (platelet count <100×10^9/L).