Acute coronary syndrome (ACS) presents as unstable angina pectoris and non–ST-elevation acute myocardial infarction. This syndrome has high short-term morbidity and mortality rates. The American College of Cardiology/American Heart Association (ACC/AHA) revised guidelines in 2002 to diagnose and pharmacologically treat patients with ACS. The guidelines provide documentation of the levels of evidence for various treatment recommendations. Boden reviewed the most recent ACC/AHA guidelines.
The diagnosis of non–ST-segment elevation ACS is based on the usual methods of symptom history, physical examination, electrocardiographic changes at presentation, and abnormal serum cardiac markers, including troponins and creatine kinase MB isoforms. The role of other, more recently studied, markers is uncertain. Risk stratification of patients with ACS for recurrent ischemic events or death is based on conventional information or risk-stratification models such as the Thrombolysis in Myocardial Infarction risk score.
Evidence supports treatment with newer antiplatelet and antithrombotic agents for all patients with ACS. Clopidogrel in combination with aspirin is recommended for intermediate- and high-risk patients and all patients with an added glycoprotein IIb/IIIa inhibitor. High-risk patients require invasive investigation. Treatment with a loading dose of clopidogrel in addition to aspirin before percutaneous coronary intervention appears to have a beneficial effect. Fixed-dose warfarin therapy is reserved for patients with ACS who also have an established indication, such as atrial fibrillation or severe left ventricular dysfunction.
Coronary bypass surgery remains an option for patients who have left main or multivessel coronary artery disease. If this course is being considered, early treatment with antiplatelet medications before catheterization may be delayed. Platelet transfusion can be administered to patients who have received an early loading dose of anti-platelet medication and later require coronary bypass surgery.
The author concludes that the ACC/AHA guidelines can improve the outcomes of patients with ACS. Secondary prevention strategies include the use of aspirin, clopidogrel, beta blockers, statins, and angiotensin-converting enzyme inhibitors, if indicated.