Acute Coronary Syndromes

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Normal Lab Values

Key Points
  • Intermediate- and high-risk patients with unstable angina or non–ST-elevation myocardial infarction benefit from an early invasive approach with coronary angiography.
  • The early management of most patients with unstable angina and non–ST-elevation myocardial infarction includes aspirin, heparin, nitrates, a β-blocker, a glycoprotein IIb/IIIa receptor inhibitor, clopidogrel, and a statin.
  • The low-molecular-weight heparin enoxaparin is a suitable alternative to unfractionated heparin for patients with acute coronary syndrome or ST-elevation myocardial infarction and those undergoing early PCI.
  • The most important clinical predictors of mortality in patients presenting with an acute ST-elevation myocardial infarction are time to presentation after symptom onset, age >65 years, clinically evident heart failure, diabetes mellitus, renal failure, and previous myocardial infarction.
  • Immediate reperfusion therapy, preferably with PCI, should be performed as soon as possible after identification of ST-segment elevation.
  • Most patients with ST-elevation myocardial infarction should be started early on oral β-blocker therapy.
  • ST-elevation myocardial infarction patients with anterior infarction, pulmonary congestion, or a left ventricular ejection fraction less than 40% should be started on an ACE inhibitor.

Each year in the United States, there are more than 5 million visits to emergency departments for chest pain; approximately 1.7 million persons are hospitalized for an acute coronary syndrome and approximately 0.6 million people die from an acute myocardial infarction. Data from the Framingham Heart Study indicate that 45% of persons with myocardial infarction are younger than 65 years and 5% are younger than 40 years. Although the incidence of myocardial infarction has changed little over the past few decades, the mortality rate has dropped sharply owing to advances in diagnosis and management of acute ischemic heart disease.

The term acute coronary syndrome refers to any of the clinical syndromes caused by acute myocardial ischemia and includes unstable angina, non–ST-elevation myocardial infarction, and ST-elevation myocardial infarction. This classification scheme makes distinctions that are important in determining the appropriate acute therapeutic management of patients who present with an acute coronary syndrome. The terms Q-wave and subendocardial myocardial infarction are less specific and are now rarely used. Differences in the pharmacologic treatment of acute coronary syndromes are shown in Table 5.

31. Antman EM, Cohen M, Bernink PJ, McCabe CH, Horacek T, Papuchis G, et al. The TIMI risk score for unstable angina/non-ST elevation MI: A method for prognostication and therapeutic decision making. JAMA. 2000;284:835-42. [PMID: 10938172]
32. Sabatine MS, Antman EM. The thrombolysis in myocardial infarction risk score in unstable angina/non-ST-segment elevation myocardial infarction. J Am Coll Cardiol. 2003;41:89S-95S. [PMID: 12644346]
33. Braunwald E, Antman EM, Beasley JW, Califf RM, Cheitlin MD, Hochman JS, et al. ACC/AHA 2002 guideline update for the management of patients with unstable angina and non-ST-segment elevation myocardial infarction—summary article: a report of the American College of Cardiology/American Heart Association task force on practice guidelines (Committee on the Management of Patients With Unstable Angina). J Am Coll Cardiol. 2002;40:1366-74. [PMID: 12383588]
34. Cohen M. The role of low-molecular-weight heparin in the management of acute coronary syndromes. J Am Coll Cardiol. 2003;41:55S-61S. [PMID: 12644342]
35. Ferguson JJ, Califf RM, Antman EM, Cohen M, Grines CL, Goodman S, et al; SYNERGY Trial Investigators. Enoxaparin vs unfractionated heparin in high-risk patients with non-ST-segment elevation acute coronary syndromes managed with an intended early invasive strategy: primary results of the SYNERGY randomized trial. JAMA. 2004;292:45-54. [PMID: 15238590]
36. Kinlay S, Schwartz GG, Olsson AG, Rifai N, Sasiela WJ, Szarek M, et al. Effect of atorvastatin on risk of recurrent cardiovascular events after an acute coronary syndrome associated with high soluble CD40 ligand in the Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) Study. Circulation. 2004;110:386-91. [PMID: 15262833]
37. Okazaki S, Yokoyama T, Miyauchi K, Shimada K, Kurata T, Sato H, et al. Early statin treatment in patients with acute coronary syndrome: demonstration of the beneficial effect on atherosclerotic lesions by serial volumetric intravascular ultrasound analysis during half a year after coronary event: the ESTABLISH Study. Circulation. 2004;110:1061-8. [PMID: 15326073]
38. Antman EM, Anbe DT, Armstrong PW, et al. American College of Cardiology; American Heart Association; Canadian Cardiovascular Society. ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction–executive summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to revise the 1999 guidelines for the management of patients with acute myocardial infarction). J Am Coll Cardiol. 2004;44:671-719. PMID: 15358045
39. Antman EM, Louwerenburg HW, Baars HF, Wesdorp JC, Hamer B, Bassand JP, et al. Enoxaparin as adjunctive antithrombin therapy for ST-elevation myocardial infarction: results of the ENTIRE-Thrombolysis in Myocardial Infarction (TIMI) 23 Trial. Circulation. 2002;105:1642-9. [PMID: 11940541]
40. Scanlon PJ, Faxon DP, Audet AM, Carabello B, Dehmer GJ, Eagle KA, et al. ACC/AHA guidelines for coronary angiography. A report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on Coronary Angiography). Developed in collaboration with the Society for Cardiac Angiography and Interventions. J Am Coll Cardiol. 1999;33:1756-824. [PMID: 10334456]

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