Effect of Low Molecular Weight Heparin vs Unfractionated Heparin on Bleeding After Cardiac Surgery

Since LMWH provide many pharmacokinetic advantages compared with UFH, and since they are a valid substitution for UFH in a number of settings, such as non-ST elevation acute coronary syndromes and prevention of venous thromboembolism, LMWH may provide a useful bridge to revascularization after aspirin discontinuation in patients undergoing CABG surgery. Obstacles to the spreading of this practice are mainly the absence of solid evidence of equivalence (or superiority) as to efficacy in this setting, and the proof of equal safety, namely the absence of excess bleeding because some studies have suggested an increased number of haemorrhagic complications after LMWH, particularly with the use of higher doses. This might here be a problem, as patients are here generally at high risk of thrombotic events and for this reason need higher doses than for prevention of venous thromboembolism.