When compared with intensive drug therapy, percutaneous coronary intervention (PCI, angioplasty) was more beneficial in reducing the long-term risk of major cardiac events among heart attack survivors with "silent ischemia", according to a study in the May 9 issue of Journal of the American Medical Association.
Cardiac ischemia is caused by insufficient blood flow to the heart muscle tissue. Silent ischemia can occur without accompanying signs or symptoms of angina (chest pain due to inadequate supply of oxygen to the heart muscle), but can be detected by electrocardiogram (ECG) and other techniques. Silent ischemia has been shown to predict adverse prognosis in patients after myocardial infarction (MI, heart attack), coronary artery bypass graft surgery, and PCI, with or without stenting, according to background information in the article. However, the effect of PCI on the long-term prognosis of patients with silent ischemia after a heart attack is not known.
Paul Erne, M.D., of the Division of Cardiology, Kantonsspital Luzern, Luzern, Switzerland, and colleagues conducted a randomized, unblinded, controlled trial from May 2, 1991, to February 25, 1997, to determine whether PCI compared with drug therapy improves long-term outcome of asymptomatic patients with silent ischemia after a heart attack. A total of 201 patients with a recent heart attack, silent myocardial ischemia verified by stress imaging, and one- or two-vessel coronary artery disease took part in the study. Ninety-six patients underwent PCI, and 105 patients received intensive anti-ischemic drug therapy. All patients received 100 mg. per day of aspirin and a statin (cholesterol-lowering) drug. Follow-up ended on May 23, 2006.