This trial is a prospective, single-center Phase II randomized study to demonstrate the superior efficacy of Fondaparinux Sodium subcutaneous injections in patients undergoing CABG surgery (isolated and redo isolated) versus treatment with placebo. All consecutive patients scheduled for CABG surgery that meet the general inclusion and none of the exclusion criteria will be considered for enrollment in the study.

Consecutive patients will be randomized on the day of admission prior to their CABG surgery into one of two groups. One group will be randomized to the placebo while the second group will receive 2.5 mg Fondaparinux Sodium injections. Both groups will receive routine mechanical prophylaxis as determined by the treating physicians. Group randomized to receive Fondaparinux Sodium will receive a 2.5 mg SQ daily drug dose starting 12 +/- 2 hours post-wound closure or the following day in the morning (at the discretion of the cardiothoracic surgeon). The second dose would be administered 24 hours later and the dosing will then be once a day. The group randomized to placebo will receive subcutaneous equivolume isotonic saline at the same time points described above.

Patients randomized will receive a 2.5 mg dose of Fondaparinux Sodium or placebo subcutaneously for a total of 3-9 days post CABG with day 1 being the day of surgery. The drug will be discontinued if the patient is discharged before day 9. If the patient stays for more than 9 days inside hospital, a duplex would be obtained per protocol and further DVT prevention measures would be instituted per the discretion of treating physician.

Patients will be assessed daily while hospitalized for any symptoms and adverse reactions and will undergo laboratory testing (CBC, PT/INR, PTT and UA) as specified in the protocol. Post-op day 3-9(no later than 2 days after the last preventive drug dose) patients will undergo the protocol specific lower limb venous duplex scan and earlier if symptomatic. Patients will also be contacted (phone/office visit) for follow-up 25-35 days post CABG to assess for signs or symptoms of deep venous thrombosis or thromboembolism and for any potential complications.