12. Current or recent use (within 7 days) of full-dose warfarin (except low-dose warfarin as required to maintain patency of pre-existing, permanent indwelling IV catheters). For patients receiving warfarin, International Normalization Ratio (INR) should be less than 1.5. Patients may have prophylactic use of low molecular weight heparin; however, therapeutic use of heparin or low molecular weight heparin is not acceptable;