Apixaban Reduces Hospitalizations in Patients With Venous Thromboembolism: An Analysis of the Apixaban for the Initial Management of Pulmonary Embolism and Deep-Vein Thrombosis as First-Line Therapy (AMPLIFY) Trial

J Am Heart Assoc. 2015 Dec 1;4(12):e002340. doi: 10.1161/JAHA.115.002340.


Background: In the Apixaban for the Initial Management of Pulmonary Embolism and Deep-Vein Thrombosis as First-Line Therapy (AMPLIFY) trial, apixaban was noninferior to enoxaparin/warfarin in preventing recurrent symptomatic venous thromboembolism (VTE) or venous thromboembolism-related death, with significantly less bleeding. This analysis evaluated the effects of apixaban versus enoxaparin/warfarin on all-cause hospitalizations during AMPLIFY.

Methods and results: Of the 5365 patients included, 2676 received apixaban and 2689 received enoxaparin/warfarin. All-cause hospitalizations during the treatment period after the index event were captured using dedicated case report forms. Outcomes included all-cause hospitalizations and time from randomization to first hospitalization. Patients were censored at death, loss to follow-up, or end of study, whichever came first. Treatment effects were assessed using Cox proportional hazards regression models. During the treatment period after the index event, 343 patients were hospitalized at least once: 153 (5.72%) in the apixaban group and 190 (7.07%) in the enoxaparin/warfarin group. Compared with enoxaparin/warfarin, apixaban significantly reduced all-cause hospitalizations (hazard ratio 0.804, 95% CI=0.650-0.995, P=0.045). All-cause hospitalization rates within the first 30 days after the index event were 2.28% and 3.35% in the apixaban and enoxaparin/warfarin groups, respectively (hazard ratio 0.676, 95% CI=0.488-0.935, P=0.018). For all patients, the average per-patient estimated mean length of hospital stay was also shorter with apixaban than enoxaparin/warfarin (0.57 days versus 1.01 days, P<0.0001).

Conclusions: Apixaban significantly reduced all-cause hospitalizations versus enoxaparin/warfarin, and shortened the length of hospital stay in patients with acute venous thromboembolism.

Clinical trial registration: URL: https://Clinicaltrials.Gov/. Unique identifier: NCT00643201.

Keywords: anticoagulants; hemorrhage; mortality; prevention; thrombosis.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Anticoagulants / administration & dosage
  • Anticoagulants / therapeutic use
  • Double-Blind Method
  • Drug Therapy, Combination
  • Enoxaparin / administration & dosage
  • Enoxaparin / therapeutic use
  • Factor Xa Inhibitors / therapeutic use*
  • Female
  • Hospitalization / statistics & numerical data
  • Humans
  • Length of Stay / statistics & numerical data
  • Male
  • Middle Aged
  • Proportional Hazards Models
  • Pulmonary Embolism / drug therapy*
  • Pyrazoles / therapeutic use*
  • Pyridones / therapeutic use*
  • Treatment Outcome
  • Venous Thromboembolism / drug therapy*
  • Venous Thrombosis / drug therapy*
  • Warfarin / administration & dosage
  • Warfarin / therapeutic use


  • Anticoagulants
  • Enoxaparin
  • Factor Xa Inhibitors
  • Pyrazoles
  • Pyridones
  • apixaban
  • Warfarin

Associated data

  • ClinicalTrials.gov/NCT00643201