Objectives: This study sought to determine predictors of outcome and examine the influence of baseline risk on therapeutic impact of late mechanical opening of a persistently occluded infarct related artery after myocardial infarction in stable patients.
Background: Previous studies in patients with acute coronary syndromes suggest that the impact of infarct-related artery recanalization on clinical outcome is greatest in patients at highest risk.
Methods: Of 2,201 patients (age 58.6 +/- 11.0 years) with infarct-related artery occlusion on days 3 to 28 after myocardial infarction in the OAT (Occluded Artery Trial) study, 1,101 were assigned to percutaneous coronary intervention (PCI) and 1,100 to medical therapy alone and followed for a mean of 3.2 years. The primary end point was a composite of death, reinfarction, or New York Heart Association functional class IV heart failure. Interaction of treatment effect with tertiles of predicted survival were examined using the Cox survival model.
Results: The 5-year rate for the primary end point was 18.9% versus 16.1% for patients assigned to PCI and medical treatment alone, respectively (hazard ratio [HR]: 1.14, 95% confidence interval [CI]: 0.92 to 1.43, p 0.23). Lack of benefit of PCI was consistent across the risk spectrum for both the primary end point and total mortality, including for the highest tertile (33.9% PCI vs. 27.3% medical treatment alone, HR: 1.27, 99% CI: 0.87 to 1.85 primary end point and 23.5% PCI vs. 21.7% medical treatment alone, HR: 1.16, 99% CI: 0.73 to 1.85 mortality). The independent predictors of the composite outcome were history of heart failure (HR: 2.06, p < 0.001), peripheral vascular disease (HR: 1.93, p 0.001), diabetes (HR: 1.49, p 0.002), rales (HR: 1.88, p < 0.001), decreasing ejection fraction (HR: 1.48 per 10%, p < 0.001), decreasing days from myocardial infarction to randomization (HR: 1.04 per day, p < 0.001), and decreasing glomerular filtration rate (HR: 1.11 per 10 ml/min/1.73 m(2), p < 0.001).
Conclusions: In the OAT study, there was no variation in the effect of PCI on clinical outcomes at different levels of patient risk, including the subset with very high event rates. (Occluded Artery Trial [OAT]; NCT00004562)
Keywords: myocardial infarction; revascularization; risk factors; trials.