Inclusion Criteria:

• Male or female > 40 years of age.
• Pt with expected stay in hospital 6 days or >, with expectation to be bedridden for > 4 days.
• Pts admitted to the MICU, Regional Heart Units of LV-MHC

Exclusion Criteria:

• Surgical primary admission diagnosis
• Recent surgery within the past 12 weeks
• Planned surgery on the current admission
• Pregnancy
• Vent-dependent respiratory failure requiring intubation for >24 hours.
• Known current DVT or PE prior to enrollment in study.
• Creatinine clearance < 30 mL/min (calculated by the Cockcroft-Gault method) in a well-hydrated patient.
• Hx of prior or current lower upper or lower GI bleed.
• Platelet count < 100,000 per cubic millimeter
• Current or prior anticoagulation within the prior 48 hours, excluding a single dose &lor 24 hour period of prophylactic agent
• Bacterial endocarditis.
• Hemophilia
• Hypersensitivity to aspirin.
• Hypersensitivity to Arixtra or Lovenox
• Hx of hemorrhagic or ischemic stroke < 3 months prior to enrolling
• Hematocrit < 28%.
• SBP >200 mmHg or DBP >120 mmHg
• Positive for occult blood in stool.
• Admission to hospital for > 48 hours prior to randomization
• Documented congenital or acquired bleeding disorder
• Indwelling intrathecal or epidural catheter
• Life expectancy < 30 days
• Inability to have a flu assessment post-discharge from the hospital