Venous Thromboembolism in Severe Renal Insufficiency: 20 Years of Contemporary Management and Clinical Outcomes.

BACKGROUND: Patients with severe renal insufficiency have been systematically excluded from randomized trials of anticoagulation for venous thromboembolism (VTE), leaving uncertainty regarding their management in clinical practice. OBJECTIVES: The purpose of this study was to describe the clinical profile, temporal trends in management, and phase-specific outcomes of patients with acute VTE and severe renal insufficiency. METHODS: We analyzed 5,763 patients with acute VTE and creatinine clearance < 30 mL/min enrolled in Registro Informatizado de Enfermedad TromboEmbólica (2005-2024). Baseline characteristics, anticoagulant strategies, and 90-day outcomes were evaluated across 4 calendar periods and during the early (days 0-10) and late (days 11-90) treatment phases. RESULTS: Mean age was 81 years; 69% were women, 56% presented with pulmonary embolism (PE), 16% had creatinine clearance <15 mL/min, and 3.6% were receiving hemodialysis. Over time, severe renal dysfunction and hemodialysis became more frequent. Initial treatment remained predominantly low-molecular-weight heparin, whereas vitamin K antagonist use declined and direct oral anticoagulant use increased. At 90 days, recurrent VTE occurred in 1.3% of patients, major bleeding in 5.1%, and 20% died. During the first 10 days, fatal PE exceeded fatal bleeding (2.0% vs 0.3%), whereas during days 11 to 90 fatal bleeding exceeded fatal PE (0.7% vs 0.3%). CONCLUSIONS: Patients with VTE and severe renal insufficiency are elderly, medically complex, and experience high short-term mortality. The relative balance between fatal PE and fatal bleeding changes over time, with fatal PE predominating early and fatal bleeding thereafter, while real-world management frequently differs from product labels and guideline recommendations.