ST-Elevation Myocardial Infarction STEMI

ST-Elevation Myocardial Infarction (STEMI) is a life-threatening event, thus prehospital treatment is expected to be available by establishing a sophisticated system for this purpose. In this condition a fibrinolysis protocol is advised. 

The acute coronary syndromes (ACS) are now classified on the basis of the ECG and plasma troponin measurements into (1) patients with ST elevation myocardial infarction (STEMI), (2) non-ST elevation myocardial infarction (non-STEMI, by ECG and a positive troponin test) and (3) unstable angina (by ECG and negative troponin test). The present account recognises that this is a rapidly evolving field, but therapeutic strategies are likely to evolve according to these forms of ACS. 

Results from the Thrombolysis in Myocardial Infarction (TIMI) I study confirmed that prompt myocardial reperfusion decreased mortality (1). Results of several large-scale trials before and after TIMI I were consistent in establishing that treatment with intravenously administered thrombolytic agents to recanalize infarct-related arteries decreased mortality in patients with ST elevation myocardial infarction (STEMI) (2,3). However, despite the obvious benefits of thrombolysis, 30-day mortality in the GISSI-2 and ISIS-3 trials was as high as 8-10% (4,5). Because early restoration of myocardial blood flow was shown to... 

Timely reperfusion of jeopardized myocardium is the most effective means of restoring the balance between myocardial oxygen supply and demand in patients with ST elevation myocardial infarction (STEMI) (1,2). Two distinct approaches to reperfusion, pharmacologic and catheter-based, have been intensively studied and are widely utilized worldwide. However, such a dichotomous approach has a number of deficiencies (3). In addition to oversimplifying a complex science, it fails to emphasize adequately the role of ancillary treatments critical to the success or failure of a reperfusion strategy and limits the development of creative approaches that combine the two reperfusion strategies. 

Although the therapeutic benefit of coronary reperfusion—fibrinolytic therapy and primary percutaneous coronary intervention (PCI)—for the treatment of acute ST elevation myocardial infarction (STEMI) in younger patients is well established, there remains considerable debate over the appropriate choice of a reperfusion strategy for elderly patients. 

This book was written to develop a perspective, referred to as pharma-coinvasive therapy, and to present nomenclature designed to explicitly and logically define an overall approach for the treatment of patients with acute ST elevation myocardial infarction (STEMI). Previous terminology such as facilitated angioplasty has, we believe, obfuscated key concepts rather than articulated them in a fashion consistent with their value (1). 

Antman EM, Anbe DT, Armstrong PW, et al. ACC/AHA 2004 Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction. A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Available atwww.acc.org/clinical/guidelines/stemi/ index.pdf. Accessed July 7, 2006. 

In English literature, it is usually named STEMI (ST elevation myocardial infarction), but we consider the name STE-ACS better because currently with quick reperfusion treatment some of these cases present aborted MI. 

FIGURE 2.1 Algorithm for risk stratification and treatment of patients with acute coronary syndromes. (STEMI, ST-elevation myocardial infarction NSTEMI, non-STEMI.)... 

A compelling question confronting clinicians is how to optimally treat acute ST segment elevation myocardial infarction (STEMI). Over the past several decades, it has become clear that early recanalization of the infarct-related artery (IRA) is pivotal. How to best achieve this objective remains hotly debated. Some argue that thrombolysis is the preferred modality. Others promulgate primary percutaneous coronary intervention (PCI). Some advocate a combination, conventionally denoted as facilitated PCI. However, thrombolysis does not literally facilitate PCI. It may, in fact, render it more difficult. Furthermore, the combination deserves to be denoted as a specific entity with attributes that may be synergistic. Thus, we shall refer to the combination as pharmacoinvasive therapy. To better understand the potential synergies of thrombolysis and acute infarct PCI, it is instructive to carefully consider the evolution of recanalization therapy itself. 

CPMP (2003) Points to Consider on the Clinical Development of Fibrinolytic Medicinal Products in the Treatment of Patients wdth ST Segment Elevation Acute Myocardial Infarction (STEMI) ... 

Abbreviations D, death MI, myocardial infarction NNH, numbers needed to harm NNT, numbers needed to treat PCI, percutaneous coronary inteivention STEMI, ST-elevation myocardial infraction UR, urgent reintervention. 

Abbreviations ACS, acute coronary syndrome ACT, activated clotting time BP, blood pressure CTO, chronic total occlusion i.v., intravenous MI, myocardial infarction NSTEMI, non-ST-segment elevation myocardial infarction PCI, percutaneous coronary intervention RCA, right coronaiy artery STEMI, ST-segment elevation myocardial ... 

Figure 1.8 A hypothetical cumulative frequency distribution of time to Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow in patients treated for ST segment elevation myocardial infarction. Although as many as 50% of patients can be expected to exhibit TIMI 3 flow induced with thrombolysis in the first 60 minutes after hospital presentation, achievement of TIMI grade 3 flow in 90% of patients with STEMI requires a pharmacoinvasive recanaUza-tion strategy and a broadening of the window during which benefit can be conferred. (From Ref. 30.)...

CABG coronary bypass surgery, PCI percutaneous intervention, STEMI ST-segment elevation myocardial infarction. 

ACS can be classified into UA, myocardial infarction (Ml) without ST-segment elevation [non-ST-elevation Ml (NSTEMI)], or STEMI. The presence of cardiac troponin in ACS indicates worse prognosis than the absence of troponin (9). 

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