Safety of enoxaparin versus unfractionated heparin during percutaneous coronary intervention

We sought to determine the safety and efficacy of enoxaparin versus unfractionated heparin during percutaneous coronary intervention (PCI). Four hundred ninety-three consecutive patients undergoing elective or emergency PCI received unfractionated heparin (70 U/kg, intravenously) or enoxaparin (1 mg/kg, intravenously). Patients who had received subcutaneous enoxaparin in the emergency department were given a supplementary 0.3-mg/kg intravenous dose. There was no crossover of therapies. All patients received oral antiplatelet therapy and eptifibatide. Primary safety outcomes were bleeding and a postprocedural hemoglobin decrease of >or=3 g/dL. Troponin I levels were considered a marker for myocardial injury.Two hundred twenty-two patients received enoxaparin, and 271 received unfractionated heparin. There were no thrombotic events or in-hospital deaths. Multivariate logistic regression analysis showed that, compared with unfractionated heparin, enoxaparin yielded a lower risk of bleeding (odds ratio [OR]=0.47; 95% confidence interval [CI], 0.21-1.05) and significantly fewer >3-g/dL decreases in hemoglobin (OR=0.45; 95% CI, 0.22-0.94). Enoxaparin also produced less of a decrease in mean platelet count (41 +/- 34 vs 55 +/- 63 x10(9)/L; P = 0.02) and in platelets >30% from baseline (OR=0.56; 95% CI, 0.31-0.99). After elective PCI, fewer enoxaparin patients had troponin I levels >or=3 times the upper limit of normal (OR=0.40; 95% CI, 0.028-0.66).Compared with unfractionated heparin, enoxaparin entailed less bleeding during both elective and emergent PCI and less cardiac enzyme elevation in patients undergoing elective PCI. Therefore, we believe that intravenous enoxaparin is a safe alternative to unfractionated heparin in both settings.