Background
Phase 3 open-label, non-inferiority RCT (EINSTEIN-PE). 4,832 patients with acute symptomatic PE with or without DVT. Randomized to rivaroxaban (single-drug oral approach) versus standard therapy (enoxaparin bridged to VKA). PE is associated with higher mortality and recurrence risk than isolated DVT, making this a more challenging population than EINSTEIN-DVT. Rivaroxaban dose: 15 mg twice daily initial phase then 20 mg once daily.
Interventions and follow up
Arm A: Rivaroxaban 15 mg twice daily × 3 weeks, then 20 mg once daily for 3, 6, or 12 month
Arm B: Enoxaparin ≥5 days overlapping with VKA, continued for 3, 6, or 12 months (target INR 2.0–3.0)
Primary endpoint: Recurrent symptomatic VTE (fatal or non-fatal PE or symptomatic DVT) — non-inferiority margin upper CI ratio 2.0
mFollow up: 3, 6, or 12 months per arm assignment
Arm B: Enoxaparin ≥5 days overlapping with VKA, continued for 3, 6, or 12 months (target INR 2.0–3.0)
Primary endpoint: Recurrent symptomatic VTE (fatal or non-fatal PE or symptomatic DVT) — non-inferiority margin upper CI ratio 2.0
mFollow up: 3, 6, or 12 months per arm assignment
Results
Recurrent VTE: 2.1% (rivaroxaban) vs 1.8% (enoxaparin/VKA); HR 1.12, 95% CI 0.75–1.68 — non-inferior (P<.001 for non-inferiority)
Major bleeding: 1.1% vs 2.2%; HR 0.49, 95% CI 0.31–0.79 — P=.003 (superiority)
Clinically relevant non-major bleeding: 10.3% vs 11.4%
Major bleeding: 1.1% vs 2.2%; HR 0.49, 95% CI 0.31–0.79 — P=.003 (superiority)
Clinically relevant non-major bleeding: 10.3% vs 11.4%
Adverse events
Main adverse events: Major bleeding significantly lower with rivaroxaban (1.1% vs 2.2%; HR 0.49; P=.003) — driven by fewer intracranial and fatal bleeds. Fatal PE: 1.1% vs 1.3%. All-cause mortality similar. Grade ≥3 AEs not stratified by type in primary publication; net clinical benefit (VTE recurrence + major bleeding) favored rivaroxaban numerically.
Conclusions
Rivaroxaban was non-inferior to enoxaparin/VKA for acute PE treatment and caused significantly less major bleeding, supporting a simplified single-drug oral approach for most PE patients.
Key Limitations
Key Limitations: Open-label design — potential for detection bias in adjudication of both VTE recurrence and bleeding. Hemodynamically unstable PE patients and those requiring thrombolysis were excluded — results not applicable to massive PE. Non-inferiority margin for recurrence was met but the point estimate (HR 1.12) numerically favors control, warranting caution. VKA quality (TTR) not systematically reported. Treatment duration was not randomized.
Clinical Context
FDA approved rivaroxaban for PE treatment in November 2012 based on EINSTEIN-PE + EINSTEIN-DVT combined data. The superiority in major bleeding (vs non-inferiority in efficacy) is clinically important for PE, where intracranial bleeding from VKA is a real concern. DOACs are now first-line for most acute VTE including PE except in antiphospholipid syndrome, severe CKD, or pregnancy.
References