Sobre martelos, pregos e nossa caixa de ferramentas, que sempre aumenta...

Abstract

Editorial This bit of folk wisdom is something that we physicians should take to heart. We have an assortment of therapeutic weaponry that we bring to bear; some of the tools we use are more favored than others, not necessarily because they are better, but frequently because they are something we have a lot of experience with, and are comfortable with. We like to use the tools (drugs, devices) that we are very familiar with, and once we have something that works well (or so we think) we tend to use it a LOT. In many ways the way we use antithrombotic therapy for coronary intervention is a perfect example of sticking with what we may be comfortable with, while we try to find ways to explore other therapeutic options and yet not straying too far from our "comfort zone".Antithrombotic therapy is currently recommended by the American College of Cardiology, the American Heart Association, and the European Society of Cardiology for use during percutaneous coronary intervention (PCI) to prevent thrombus formation at the site of arterial injury and on coronary guide wires and catheters 1,2 . Historically, unfractionated heparin (UFH) has been the mainstay of anticoagulation therapy during PCI, however due to numerous clinical and biochemical limitations, newer antithrombotic therapies (including low molecular weight heparins, direct thrombin inhibitors, and direct and indirect Xa inhibitors) are part of an ever-expanding therapeutic armamentarium.Low molecular weight heparins (LMWH), such as enoxaparin, have emerged as an attractive alternative to UFH for systemic anticoagulation due to the numerous biological and pharmacokinetic limitations of UFH. The inactivation of thrombin by UFH depends on the binding of antithrombin and thrombin in a chain length dependent fashion. However, most of the unwanted side effects of UFH are chain length (and charge) dependent, including significant protein binding (leading to inconsistent bioavailability with unreliable and variable degrees of anticoagulation), significant platelet activation, the risk of heparin-induced thrombocytopenia, and the inability to block clot bound thrombin 3-5 .Although LMWH (administered subcutaneously) is already established as an integral part in the modernday medical treatment of ACS, the use of LMWH as an alternative anticoagulant for procedural use during elective (or urgent) PCI is less well established. A number of studies have examined the use of intravenous enoxaparin as an alternative to UFH in elective PCI 6-9 . In these relatively small studies, LMWH, administered intravenously instead of subcutaneously, in the non-emergent procedural PCI setting was as efficacious as UFH, with similar bleeding risk. The STEEPLE trial 10 is the most recent large scale prospective study comparing UFH with IV enoxaparin in elective PCI.In the STEEPLE trial 10 , 3,528 patients were randomized to IV enoxaparin (0.5 mg/kg or 0.75 mg/kg) or IV UFH (50-70 U/kg or 70-100 U/kg) with or without a GP IIb IIIa antagonist. The primary endpoint, non-CABG-related major plus m...