Low Molecular Weight Heparin vs Unfractionated Heparin at Cardiac Surgery

Overview

Because the impairment of platelet function may cause excess peri-operative bleeding, pre-operative aspirin discontinuation and heparin bridging are common at cardiac surgery. We aimed to evaluate the impact of a low-molecular-weight-heparin (LMWH), enoxaparin, and unfractionated heparin (UFH) on coagulation parameters and peri-operative bleeding in patients undergoing elective coronary artery bypass grafting (CABG) surgery after aspirin discontinuation. The specific hypothesis of this study was that a 12 h interval is sufficient not to cause excess peri-operative bleeding, and is therefore an optimal compromise between antithrombotic efficacy and haemorrhagic safety.

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.

Conditions