Each year, doctors snake catheters through the circulatory systems of about 600,000 Americans and open obstructed arteries in their hearts.
But a growing number of cardiologists harbor a heretical doubt about angioplasty--a procedure hailed as one of the great advances in the treatment of heart disease in the last quarter-century.
These mavericks suspect many angioplasty patients--if not most of them--would live as long and with no higher risk of heart attack if they never had the procedure. "After 25 years, we have finally begun to address the question: Are we treating too many people who receive no medical benefit?" said Dr. William E. Boden, director of the division of cardiology at Hartford Hospital in Connecticut.
Boden wants to answer that $6-billion question--the estimated annual cost of angioplasties in the United States. He is the study chairman of an ongoing trial that will compare mortality and heart attack rates of more than 3,000 patients with coronary heart disease. The $35-million trial is being conducted at 43 sites in the United States and Canada and is known by the acronym COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation). Half the patients will receive the latest drug treatments and half will receive angioplasty as well as the cutting-edge drug therapy.
If in the next few years the trial reveals that angioplasty adds little to the survival odds of patients with mild or moderate symptoms of heart disease, there could be a dramatic change in the way hundreds of thousands of people with heart disease are treated.
"This disease kills 50% of Americans, and we still don't know the optimal way of treating it," said Dr. Steven Nissen, vice chairman of the department of cardiology at the Cleveland Clinic in Ohio, one of the nation's leading centers of cardiac care and research.
"It's absolutely the most important cardiac trial under way worldwide right now," said Dr. William S. Weintraub, professor of medicine at Emory University School of Medicine and one of the trial's co-investigators.
It is also one of the more controversial. Investigators say they are having trouble enrolling patients, in part because many "interventional" cardiologists and officials at hospitals that perform angioplasties are not referring patients. Those doctors believe that even patients with mild or moderate symptoms should not participate in a trial in which they might not get an angioplasty, Weintraub said.
That's not surprising, because angioplasty has become an entrenched part of the culture and of the economics of large segments of the cardiology community, Boden said.
"Isn't it human nature to keep doing what you are being paid to do, until somebody tells you to stop?" he asked.
But some cardiologists argue that while studies such as the COURAGE trial are needed, they don't measure angioplasty's greatest benefit: improving the quality of life of heart patients.
"No one can point to a paper that says it prevents heart attacks," said Dr. Daniel Diver, chief of the section of cardiology and director of the cardiac catheterization lab at St. Francis Hospital and Medical Center in Hartford. "But angioplasty is not meant for that. It's very good at symptom relief. That's what it does."
So why is it that such a common treatment is only now being tested for efficacy 25 years after it was introduced? One reason is that its benefits seemed so self-evident, Boden said.
The procedure opens up arteries that otherwise would remain blocked, potentially killing the patient.
When Andreas Gruentzig, a German physician and pioneer of the procedure, presented pictures of a coronary angioplasty, with tiny balloons opening the arteries of animals, at a meeting of cardiologists in the mid-1970s, "Everybody went, 'Wow!"' Boden recalled.
"It spread like wildfire before it was ever subjected to a controlled, randomized trial," he said.
"The genie was out of the bottle," agreed Diver, who said the procedure was never reviewed by the U.S. Food and Drug Administration before it was approved.
Angioplasty quickly took a place alongside bypass surgery and drug treatment as chief weapons in the cardiologists' arsenal of treatments. And over the last two decades, studies have shed light on which procedure works best on certain classes of patients.
For instance, diabetics with severe heart problems are better off undergoing coronary bypass surgery rather than angioplasty, Boden said. A consensus has emerged in the last few years that angioplasty and drugs together might be better treatment than drugs alone for patients diagnosed as suffering from acute coronary syndrome, Weintraub said.
But those with more severe cases account for only about 10% to 25% of the angioplasties performed today, Weintraub and Boden estimated. There have been only a few attempts to gauge whether angioplasty saves lives and prevents heart attacks in the vast majority of heart patients who have less severe symptoms.