According to this study:

* Angioplasty and stent placement performed more than 12 hours after myocardial infarction might not be beneficial.

The preferred treatment for patients with acute myocardial infarction with coronary artery occlusion and ST-segment elevation is angioplasty or thrombolytic therapy within 12 hours. Approximately one-third of these patients get neither treatment within that interval, but many still undergo late angioplasty with possible stent placement. This treatment has been thought to reduce the rates of heart failure, reinfarction, and death, but a recently published study strongly challenges that assumption.

Researchers in the Occluded Artery Trial evaluated outcomes at a mean of three years in 2,166 patients in whom coronary angiography showed total occlusion of the artery and poor or absent antegrade blood flow or who had an ejection fraction of less than 50% or an additional occluded coronary artery three to 28 days after myocardial infarction. Patients were randomly assigned to receive either percutaneous coronary intervention (angioplasty) with stent placement and pharmacologic therapy consisting of aspirin, anticoagulants if necessary, angiotensin-converting enzyme inhibitors, [beta]-blockers, lipid-lowering agents, and thienopyridines, or the drug regimen only. The study's primary end point was the "composite of death" from any cause, reinfarction, or New York Heart Association class IV heart failure requiring hospitalization or admission to a short-stay unit.

Stable patients who received angioplasty with stent placement and drug therapy (n = 1,082) fared no better than did those treated with medication alone (n = 1,084). There was no significant statistical difference between the two groups in the rates of death, reinfarction, and heart failure after a mean of three years. Among patients who had undergone angioplasty with stent placement there was "a trend toward an excess risk of reinfarction," and more patients in the group receiving only drug therapy had signs of coronary revascularization.

The researchers hypothesize that small collateral blood vessels that develop to compensate for blocked arteries shut down after angioplasty, when blood takes the easier route of flow through the newly opened artery, and when spontaneous reocclusion occurs, reinfarction results.

In a press release announcing the study's findings, researcher Judith Hochman, MD, stated, "Our findings indicate that routine late opening of the heart attack-related coronary artery is not appropriate and should be reserved only for certain patients, such as those who are unstable or continue to have chest pain following a heart attack." --LE