7 Management of Acute Coronary Syndrome in the Light of Recent Trials

Abstract: The spectrum of acute coronary syndrome (ACS) constitutes unstable angina, non-ST segment elevation myocardial infarction (NSTEMI) and ST segment elevation myocardial infarction (STEMI). Disruption of plaque is now considered to be the common pathophysiological substrate of ACS. Patients with NSTEMI, defined as those with an elevated biomarker of necrosis, CB-MB or troponin, have a worse long-term prognosis than those with unstable angina. Beyond just a positive versus negative test results, there is a linear relationship between the level of troponin T or I in the blood and subsequent risk of death—the higher the troponin, higher the mortality risk. Patient presenting with persistent ST segment elevation are candidates for reperfusion therapy (either pharmacological if in the first two hours or catheter based) to restore flow in the occluded epicardial infarct-related artery. ACS patients presenting without ST segment elevation are not candidates for pharmacological reperfusion but should receive anti ischemic therapy, often followed by PCI. Meta analysis of recent randomized trials in over 8,000 NSTE–ACS patients treated in the era of potent antiplatelets therapy and coronary stents shows that early invasive therapy decreases mortality by 25 % at a mean of 2 years of follow-up, compared with a more conservative approach. Early invasive therapy also decreases nonfatal myocardial infarction by 17 % and recurrent unstable angina requiring rehospitalization by 31%