Use of coronary revascularization in patients with unstable and non-ST- segment elevation acute myocardial infarction

Abstract

Percutaneous coronary intervention can be safely performed in patients with acute coronary syndromes (ACS), including those with non-ST-segment elevation myocardial infarction (MI), and unstable angina. Although there remains debate about whether an aggressive strategy involving early coronary arteriography and revascularization should be routinely performed in patients who present with non-ST-segment elevation MI and unstable angina, recent clinical trials suggest that an aggressive approach should be taken in both intermediate- and high-risk patients with ACS. There have been 4 clinical trials that have compared the outcomes of patients presenting with non-ST-segment elevation MI or unstable angina who were assigned to invasive or conservative strategies. The Thrombolysis in Myocardial Infarction (TIMI) IIIB trial and the Veterans Affairs Non-Q-Wave Infarction Strategies in Hospital (VANQWISH) trial failed to demonstrate a reduction in death or MI in patients assigned to an invasive approach, but it did demonstrate an important reduction in the frequency of rehospitalization. However, these studies were performed before the availability of coronary stents or the use of glycoprotein IIb/IIIa inhibitors. In contrast, the Fragmin and Fast Revascularisation During Instability in Coronary Artery Disease (FRISC) II and the Treat Angina with Aggrastat and Determine Cost of Therapy with an Invasive or Conservative Strategy (TACTICS) trials demonstrated significant improvements in the rates of death or MI in patients with non-ST-segment elevation MI or unstable angina assigned to an invasive strategy. Event reductions were greatest in patients with non-ST-segment elevation MI or unstable angina at intermediate or high risk for an adverse outcome. Understanding that these subgroups comprise approximately 75% of patients presenting with non-ST-segment elevation MI or unstable angina, we believe that an invasive approach is indicated in most patients who develop non-ST-segment elevation MI or unstable angina. Regardless of the strategy used in ACS patients, lipid-lowering therapy is necessary to reduce recurrent ischemia events at the site of plaque instability and in atherosclerotic disease remote to the target lesion.