- INR no greater than 1.3 and aPTT no greater than upper limits of normal (ULN) within 28 days prior to enrollment for subjects not on low molecular weight heparin or fondaparinux. Subjects on low molecular weight heparin or fondaparinux are not required to meet INR or aPTT limits. Chronic full-dose anticoagulation with warfarin is not permitted.