Loss of short-term symptomatic benefit in patients with an occluded infarct artery is unrelated to non-protocol revascularization: results from the Occluded Artery Trial (OAT)

Long-term effects of percutaneous coronary intervention of the totally occluded infarct-related artery in the subacute phase after myocardial infarction

BACKGROUND

Despite observations suggesting a benefit for late opening of totally occluded infarct-related arteries after myocardial infarction, the Occluded Artery Trial (OAT) demonstrated no reduction in the composite of death, reinfarction, and class IV heart failure over a 2.9-year mean follow-up. Follow-up was extended to determine whether late trends would favor either treatment group.

METHODS AND RESULTS

OAT randomized 2201 stable patients with infarct-related artery total occlusion >24 hours (calendar days 3-28) after myocardial infarction. Patients with severe inducible ischemia, rest angina, class III-IV heart failure, and 3-vessel/left main disease were excluded. We conducted extended follow-up of enrolled patients for an additional 3 years for the primary end point and angina (6-year median survivor follow-up; longest, 9 years; 12 234 patient-years). Rates of the primary end point (hazard ratio, 1.06; 95% confidence interval, 0.88-1.28), fatal and nonfatal myocardial infarction (hazard ratio, 1.25; 95% confidence interval, 0.89-1.75), death, and class IV heart failure were similar for the percutaneous coronary intervention (PCI) and medical therapy alone groups. No interactions between baseline characteristics and treatment group on outcomes were observed. The vast majority of patients at each follow-up visit did not report angina. There was less angina in the PCI group through early in follow-up; by 3 years, the between group difference was consistently <4 patients per 100 treated and not significantly different, although there was a trend toward less angina in the PCI group at 3 and 5 years. The 7-year rate of PCI of the infarct-related artery during follow-up was 11.1% for the PCI group compared with 14.7% for the medical therapy alone group (hazard ratio, 0.79; 95% confidence interval, 0.61-1.01; P=0.06).

CONCLUSIONS

Extended follow-up of the OAT cohort provides robust evidence for no reduction of long-term rates of clinical events after routine PCI in stable patients with a totally occluded infarct-related artery and without severe inducible ischemia in the subacute phase after myocardial infarction.