Occluded Artery Trial (OAT)

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Accession Number

Study Type
Clinical Trial

Collection Type
Open BioLINCC Study See bottom of this webpage for request information

Study Period
September 1999 – May 2011

NHLBI Division

Dataset(s) Last Updated
January 3, 2018


Commercial Use Data Restrictions No

Data Restrictions Based On Area Of Research No


To test the hypothesis that opening an occluded infarct artery 3-28 days after an acute MI (day 1= date of index MI) in stable patients who are at increased long-term risk (ejection fraction <50% or proximal occlusion of a large coronary artery) will reduce the composite endpoint of mortality, recurrent MI, and New York Heart Association (NYHA) Class IV congestive heart failure (CHF) over an average three-year follow-up.


The benefits of establishing early coronary perfusion in acute myocardial infarction (MI) have been unequivocally established. However, often due to late presentation, a substantial number of acute MI patients are ineligible for reperfusion therapy by exceeding the time for which acute reperfusion therapy provides a documented benefit. The best strategy of care for those with persistent total occlusion of the infarct-related artery, identified after the currently accepted period for administration of reperfusion, was therefore unclear. Late PCI may improve outcomes over medical management alone, by reducing left ventricular remodeling with preservation of left ventricular function, improving electrical stability, potentially decreasing ventricular arrhythmia, or providing collateral blood flow to coronary territories at risk of future occlusion.


2166 stable patients who had total occlusion of the infarct-related artery 3 to 28 days after myocardial infarction and who met a high-risk criterion (an ejection fraction of <50% or proximal occlusion). Of these patients, 1082 were assigned to routine PCI and stenting with optimal medical therapy, and 1084 were assigned to optimal medical therapy alone. An additional 35 patients were enrolled in 2006 as part of the OAT-NUC (nuclear ancillary study).


Patients at approximately 320 clinical sites in the United States and Canada were randomly allocated to two treatment arms over two years. One treatment consisted of conventional medical management including aspirin, beta blockers, angiotensin converting enzyme (ACE) inhibitors, and risk factor modification. The other treatment consisted of conventional medical therapy plus percutaneous coronary intervention and coronary stenting. Clinical outcomes were compared using an intention-to-treat analysis. The primary composite endpoint was mortality, recurrent myocardial infarction, and hospitalization for NYHA Class IV congestive heart failure over a three year follow-up. An additional 3 years of follow-up was conducted extending the follow-up to a maximum of 9 years (average approximately 5.5 years). Individual components of the study composite endpoint were compared in the two treatment arms, as were the medical costs of the two treatments and the health-related quality of life. The cost-effectiveness of percutaneous revascularization was assessed in the study population.


PCI did not reduce the occurrence of death, reinfarction, or heart failure, and there was a trend toward excess reinfarction during 4 years of follow-up. Extended follow-up continued to show no reduction in clinical events after PCI (NEJM, 2006; 355(23):2395-407, Circulation, 2011; 124(21):2320-8)

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