Avoiding intelligence failures in the cardiac catheterization laboratory: Strategies for the safe and rational use of dalteparin or enoxaparin during percutaneous coronary intervention.

Low-molecular-weight heparin (LMWH) has been a mainstay for the management of acute coronary syndromes (ACS) for almost a decade. However, several recent developments have seriously threatened the prominence of this drug class: (i) the adoption of an early invasive strategy, frequently leading to percutaneous coronary intervention (PCI) where the dosing and monitoring of LMWH is unfamiliar to most operators, (ii) the results of the SYNERGY trial, which not only failed to establish the superiority of enoxaparin over unfractionated heparin with respect to efficacy, but also demonstrated more bleeding with LMWH, and (iii) the results of the REPLACE-2 and ACUITY trials, which have demonstrated the advantages of an ACS and PCI treatment strategy based on direct thrombin inhibition with bivalirudin. To confront these challenges, cardiologists committed to the continued use of LMWH must develop safe and user-friendly approaches to transition patients from the noninvasive to invasive settings. This review summarizes an approach that takes advantage of the fact that LMWH can be readily monitored with the point-of-care activated clotting time (ACT) assay. This assay is inexpensive, available in virtually every catheterization laboratory, and familiar to most operators who monitor unfractionated heparin (UFH). A key concept that is presented is that the ACT is a more accurate measure of LMWH-induced anticoagulation than of UFH-induced anticoagulation. Our preliminary work suggests that during PCI operators should target an ACT of 175 seconds in the presence, and 200 seconds in the absence, of adjunctive glycoprotein IIb/IIIa inhibition. Sheath removal is recommended at an ACT < 160. These guidelines may facilitate continued use of LMWH, which has the potential to reduce cost (less expensive than bivalirudin), diminish the need for intravenous medication (can be administered subcutaneously in the noninvasive setting with minimal to no monitoring), and provide an ideal anticoagulant during PCI (easy to monitor with the ACT, at least partially reversible with protamine in the event of coronary perforation, effective antithrombin with no platelet activation, thereby potentially reducing the need for routine adjunctive IIb/IIIa inhibition).