RESULTS	Serum anti-Xa activity averaged 1.6 + / - 0.6 U/mL in patients receiving danaparoid and 1.9 + / - 0.8 U/mL in patients receiving heparin 30 minutes after injection of the drugs ( P = .1 ) and 0.3 + / - 0.1 and 0.04 + / - 0.08 U/mL , respectively , 12 hours after coronary artery bypass grafting ( P = .001 ) .\