May 25, 2000

BIRMINGHAM, AL — Heart attack patients undergoing immediate coronary angioplasty are less likely to die at hospitals that routinely perform more of the procedures, according to lead author John Canto, M.D., a University of Alabama at Birmingham cardiologist and director of UAB's Chest Pain Center.

Angioplasty is a surgical procedure used to open narrowed or blocked arteries following a heart attack. Doctors use a fiber optic camera to guide a catheter directly to the blocked vessel and then open the vessel using one of several methods.

The study, published in the May 25 edition of the New England Journal of Medicine, used data from the National Registry of Myocardial Infarction 2, which includes hospital data on patients admitted with confirmed myocardial infarction (heart attacks) at more than 1,400 hospitals between June 1994 and March 1998.

Canto and colleagues found that patients who underwent primary angioplasty at hospitals that performed the highest volume of procedures were 28 percent less likely to die. The percentage is equivalent to 2 fewer deaths per 100 patients treated, Canto said.

Canto says there are many possible explanations for the inverse relationship between volume and mortality with angioplasty procedures. One, for example, is unlike the outcome of drug therapy, the outcome of invasive cardiac procedures such as primary angioplasty "depends on individual expertise, which in turn may depend on the volume of procedures performed," Canto said.

The study also analyzed the use of thrombolytic therapy in heart attack patients. Thrombolytics are widely used to improve blood flow to the heart after a heart attack. In this instance, no difference in survival rates was found among hospitals. "The resources and expertise required for the administration of thrombolytic therapy are minor compared with those required for angioplasty," he said.

A total of 257,602 patients with myocardial infarction were treated at a total of 450 hospitals in the primary angioplasty group and a total of 277,156 patients with myocardial infarction were treated at 516 hospitals for the thrombolytic-therapy group.

Canto has led a series of studies using national databases, several of which have been published in previous issues of the New England Journal of Medicine and the Archives of Internal Medicine. He recently received national attention with results garnered from the registry that point to racial disparities in heart treatment.