Interpretation of new treatment guidelines for non-ST-segment elevation acute coronary syndromes: "ischemia-guided" versus "early invasive" strategies.

The American College of Cardiology/American Heart Association Task Force on Practice Guidelines has recently published recommendations regarding the diagnosis and management of patients with non-ST-segment elevation (NSTE) acute coronary syndromes (ACS). Conventional therapy for non-ST-segment elevation acute coronary syndrome (NSTE ACS) has traditionally employed an "ischemia-guided" approach in which diagnostic cardiac catheterization and revascularization are only used in patients with objective-evidence of residual myocardial ischemia as identified by recurrent symptoms or provocative stress testing. More recent studies, however, have demonstrated improved clinical outcomes with the use of an "early invasive" approach, employing routine coronary angiography early in the patient's hospital course, followed by percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery where appropriate. Improved clinical outcomes associated with an "early invasive" strategy may have evolved as a consequence of recent advances in both adjunctive pharmacotherapy and revascularization technique. For example, use of GP IIb/IIIa inhibitors and/or low-molecular-weight heparin prior to catheterization have been shown to reduce clinical events in NSTE ACS patients, and may reduce the risk of an invasive approach by plaque passivation prior to interventional therapy. Perhaps more importantly, the combined use of GP IIb/IIIa inhibitors and intracoronary stenting may reduce the potential early hazard of an invasive approach by specifically decreasing the incidence of death and non-fatal myocardial infarction associated with percutaneous intervention. In spite of the benefits of this synergistic combination of pharmacology and mechanical revascularization, risk stratification remains important in identifying high-risk individuals most likely to benefit from an "early invasive" approach.