It is notoriously difficult to achieve and maintain the aPTT within this target range, and under-treatment is a significant problem. identification of patients with acute ST segment elevation myocardial infarction (STEMI) is vital if patients are to benefit from contemporary management strategies. Over the last 3 decades, TAPI-2 major advances in our understanding of the pathophysiological processes responsible for STEMI and its sequelae have allowed development of pharmacological therapies to target these different processes. Numerous large well designed randomized controlled trials have guided determination of ever superior management strategies and their increasing utilization has been associated with a corresponding steady decline in death from acute myocardial infarction (MI) (Goldberg et al 2004). Pathophysiology of STEMI Complex inflammatory mechanisms are now known to participate in all stages of coronary artery disease, from the initial development of the fatty streak, through progression to advanced atherosclerotic lesions causing angina pectoris, to plaque disruption and thrombus formation. Plaques vulnerable to disruption and rupture are frequently non-obstructive but have a large lipid-rich core and a high macrophage content leading to thinning of the fibrous cap (Moreno et al 1994; Davies TAPI-2 2000; Shah 2003). Plaque rupture, which typically occurs at the edge or shoulder region, exposes the lipid core, leading to platelet adhesion and aggregation, activation of the coagulation cascade, and formation of a platelet rich thrombus. A key step in this process is activation of prothrombin to thrombin (factor IIa) which promotes the formation of fibrin, the protein which acts as a scaffold in stable thrombus. The fate of the thrombus then ranges from simple incorporation into the plaque, through subtotal artery occlusion, to fully occlusive thrombus formation (Corti et al 2003), the latter typically presenting clinically as STEMI (DeWood et al 1980). Reperfusion strategies for STEMI Where possible, the immediate treatment goal in STEMI is to disperse the thrombus thereby restoring coronary blood flow to the culprit artery (Antman et al 2004) in order to limit infarct size, to preserve left ventricular function, and ultimately, to reduce mortality. Two decades on from the landmark GISSI trial with streptokinase, fibrinolytic therapy remains the most widely used reperfusion strategy (Gruppo Italiano per lo Studio della Streptochinasi nellInfarto Miocardico (GISSI) 1986). Second and third generation fibrinolytic agents interact directly with clot-bound plasminogen improving fibrin selectivity and achieve higher rates of early patency although this has translated at most into only a small further reduction in mortality. More important than the fibrinolytic agent used is the time delay from symptom onset to drug administration (Fibrinolytic Therapy Trialists (FTT) Collaborative Group 1994; Boersma et al 1996) and hence the value of third generation bolus agents which help facilitate pre-hospital use. Catheter based reperfusion with primary percutaneous coronary intervention (PCI) where available within a reasonable timeframe, may lead Rabbit polyclonal to ACADS to even better reduction in cardiovascular events, except in patients who present very rapidly after symptom onset when both strategies appear to be equivalent (Keeley et al 2003; Steg et al 2003). Primary PCI is associated with a reduced risk of bleeding complications, in particular intracranial hemorrhage (Keeley et al 2003) which typically occurs in approximately 1% of patients treated with a fibrinolytic based regimen. Trials have shown that the adjuvant anticoagulant dose may play a significant role in the risk of intracranial hemorrhage (Giugliano et al 2001). Adjuvant antiplatelet therapy The importance of adjuvant aspirin was established in ISIS-2 (ISIS-2 (Second TAPI-2 International Study of Infarct Survival) Collaborative Group 1988) and the value of concurrent clopidogrel in the more recent CLARITY and COMMIT trials TAPI-2 (Chen et al 2005; Sabatine et al 2005). It is likely that their primary benefit is to reduce reocclusion following successful reperfusion (Scirica et al 2006). Initial trials of glycoprotein TAPI-2 IIbIIIa receptor antagonists in combination with reduced dose fibrinolytic appeared promising, improving.