Adjunctive Devices for Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

Coronary heart disease (CHD) is a leading cause of morbidity and mortality in the United States. According to the American Heart Association statistics, greater than 650,000 deaths were attributed to CHD in 2003. Moreover, treatment costs for CHD represent the largest healthcare expenditure for a single disease in the United States. Acute coronary syndromes (ACSs), which include the clinical entities of unstable angina (UA), nonST-segment elevation myocardial infarction (NSTEMI), and ST-segment elevation myocardial infarction (STEMI), account for more than 1.5 million hospital admissions annually in the United States alone. Approximately 1 million of these admissions are classified as UA/NSTEMI and approximately 500,000 are STEMI. Percutaneous coronary intervention (PCI) has revolutionized the management of angina and myocardial infarction (MI), frequently negating the need for coronary bypass surgery and permitting a more rapid return to normal activities. The clinical use of PCI is reflected in the number of patients who undergo this procedure. In the United States alone, 664,000 procedures were performed in 652,000 patients in 2003, representing a 326 percent increase from the number of procedures performed in 1987. Coronary stents and adjunctive pharmacologic agents—including glycoprotein IIb/IIIa receptor inhibitors and thienopyridines—have improved the effect of PCI establishing near normal antegrade blood flow in the vast majority of patients. However, dislodgement of atherothrombotic material from coronary lesions during PCI can result in distal embolization that leads to what is commonly referred to as the “no-reflow phenomenon.” This phenomenon, characterized by inadequate flow at the cardiac tissue level despite patent coronary vessels is often defined as (1)…