Specialized Testing after Recent Acute Myocardial Infarction

Abstract

A wide variety of specialized laboratory tests have been used to characterize prognosis and functional capacity soon after a patient has an acute myocardial infarction. Few attempts have been made to integrate the available data on these tests into clinically relevant guidelines for the clinician. This review evaluates the use of these tests, alone and in combination, throughout the course of recovery from acute myocardial infarction. The primary objective of these tests is to quantify myocardial ischemia and left ventricular dysfunction, the pathophysiologic basis of prognosis and functional capacity. The selection of one test over another depends on whether either test provides information on myocardial ischemia and left ventricular dysfunction not available through the standard clinical evaluation, and the risk, quality, and cost associated with each test. The stepwise application of specialized testing after acute myocardial infarction enables the identification of three groups of patients: approximately 20% at very high risk, due primarily to irreversible left ventricular dysfunction; approximately 30% at moderately high risk, due primarily to myocardial ischemia; and approximately 50% at low risk who are free of significant left ventricular dysfunction or myocardial ischemia. Accurate discrimination among these three groups enables the application of aggressive medical and surgical therapy to patients at moderate to high risk and accelerated recovery for patients at low risk. Specialized testing also helps to guide subsequent management after thrombolysis and revascularization procedures.