Reperfusion via thrombolytics or PCI in patients with acute STEMI has been shown to reduce mortality and maximize myocardial salvage. It has been less clear whether patients with late presentations of MI are afforded the same benefits. Though there was no official consensus, late revascularization of the infarct vessel was frequently employed. At the AHA meeting yesterday, Dr Hochman presented the results of the The Occluded Artery Trial (OAT) and provided the medical community with a definitive answer about how to manage these patients.
OAT was designed to study patients with total occlusion of the infarct related artery on angiogram performed 3-28 days after the event. All of the patients were clinically stable and considered high risk, based on EF<50% or proximal occlusion. Extremely high risk patients with NYHA class III or IV heart failure, shock, Cr>2.5mg/dL, significant left main or triple vessel disease or ongoing ischemia were excluded. Included subjects (n=2166) were randomized to either PCI and optimal medical therapy (ASA, thienopyridine, ACE-I, BB, statin) or optimal medical therapy alone. There was no difference between the two treatment groups in the 4 yr cumulative primary event rate, which was a composite of death, nonfatal reinfarction and NYHA class IV heart failure (17.2% PCI and 15.6% med therapy, HR 1.16; 95% CI 0.92-1.45, p=0.20). There was a trend toward nonfatal reinfarction in the PCI group (6.9% PCI and 5.0% med therapy, HR 1.44, 95% CI 0.96-2.16, p=0.08) that reached clinical significance when MI was determined by the study site, as opposed to central adjudication (9.4% PCI and 7.2% med therapy, HR 1.43, 95% CI 1.02-2.00, p=0.04).
The results of this study suggest that stable, high risk patients who present 3 or more days after MI should be treated with aggressive medical management alone. The lessons learned from OAT are expected to change current practice – with the help of an early release by the NEJM and front page coverage by the New York Times, the change should be effective immediately.