Occluded Artery Trial (OAT)

The purpose of this study is to determine whether opening an occluded infarcted artery 3-28 days after an acute myocardial infarction in high-risk asymptomatic patients reduces the composite endpoint of mortality, recurrent myocardial infarction, and hospitalization for class IV congestive heart failure over an average 2.9-year follow-up with extended follow up for an average of six years. Long term follow-up of patients were completed in March 2010. Final collection of all regulatory documentation was completed June 2011.

BACKGROUND: The benefits of establishing early coronary reperfusion in acute myocardial infarction (MI) have now been unequivocally established. However, current pharmacologic strategies fail to achieve effective reperfusion in 30 percent or more of patients, and many patients with occluded infarct arteries do not meet current criteria for use of these agents. Early angioplasty, an effective reperfusion method, is available to a small proportion of potentially eligible US acute MI patients. Hence a substantial number of acute MI patients pass the time when reperfusion therapy has any documented benefit (12 - 24 hours) with a persistently closed infarct vessel. Several lines of experimental and clinical evidence suggest that late reperfusion of these patients could provide clinically significant reductions in mortality and morbidity. DESIGN NARRATIVE: Multicenter, randomized, controlled. Patients at 217 clinical sites in the United States, Canada and Internationally were randomly allocated to two treatment arms over five years. One treatment consists of conventional medical management including aspirin, beta blockers, angiotensin converting enzyme (ACE) inhibitors, and risk factor modification. The other treatment consists of conventional medical therapy plus percutaneous coronary intervention and coronary stenting. Clinical outcomes will be compared using an intention-to-treat analysis. The primary composite endpoint is mortality, recurrent myocardial infarction, and hospitalization for NYHA Class IV congestive heart failure over a three year follow-up. Individual components of the study composite primary endpoint will be compared in the two treatment arms, as will the medical costs of the two treatments and the health-related quality of life. The cost-effectiveness of percutaneous revascularization will be assessed in the study population.