FRIDAY, July 23, 2004 (HealthDay News) -- Heart specialists perform an estimated 1.2 million angioplasty procedures each year, according to the Society for Cardiovascular Angiography and Interventions.
But are they all necessary?
That depends on whom you ask, and what studies you cite.
Conventional cardiology wisdom has long held that heart attacks occur because arteries blocked by the buildup of plaque starve the organ of blood, sending it into a condition called infarction. Under that model, angioplasty, stenting (placing of a wire mesh structure in the blood vessel) and bypass surgery all make a certain amount of sense.
Angioplasty lets doctors thread a snake-like device with a balloon on the end into diseased and narrowed arteries. Inflating the balloon opens the blockage. Usually, cardiologists will leave behind one or more tiny metal scaffolds, called stents, as insurance.
Many cardiologists have long held that heart attacks result not solely from severe narrowing but also from so-called "vulnerable" plaques that shear off vessel walls, leading to clotting and infarction. That view has been gaining increasing credence lately, even among more aggressive heart doctors -- with major implications for invasive procedures to widen vessels.
While it's true that a very tight blockage causing chest pain -- or angina -- may spark a heart attack, most attacks occur at narrow spots in the blood vessel that are less serious but are considered to be vulnerable to plaque rupture.
As a result, experts say, many people who undergo angioplasty and stenting would likely do fine with a so-called "vasculo-protective cocktail" of medications that address vessel disease and its complications: statins for cholesterol, aspirin to prevent clotting, ACE inhibitors to improve heart function, beta blockers for blood pressure, relaxing vessels and correcting abnormal heart rhythms.
But changing practice patterns might take some time, said Dr. Jonathan Abrams, a cardiologist at the University of New Mexico School of Medicine.
"It's too big a boat to turn, it hasn't turned yet," Abrams said. "There clearly are people who need angioplasty. The issue is how to use these therapies and who to use them in."
Dr. Thomas Graboys, of the Lown Cardiovascular Center and Harvard Medical School, provides second opinions to patients who've been told they need angioplasty.
Although exact numbers are elusive, Graboys estimates that half of Americans who receive stents each year could do just as well on medical therapy.
"We're not against stents, they can be potentially lifesaving," Graboys said. "But that's not the population that's receiving them. Medical therapy is very good, it's outstanding now," he added. "Compared to 10 years ago, we've turned the corner in management" of coronary artery disease.
The most important question cardiologists should ask, Graboys said, is not how narrow their patients' arteries are but how well their heart works. "If it's strong, they do well despite vessel blockage. But that's not what's happening in this country."
To be sure, Graboys said, many patients are good candidates for angioplasty and stenting -- just not as many as undergo the procedures. If a person has persistent chest pain -- called unstable angina -- that doesn't improve with medication, then he'd advise more aggressive treatment.
In addition to being unnecessary in many cases, stenting isn't risk-free. Around 1 percent of patients suffer a blood clot linked to the stent procedure itself. Of those, 10 percent to 20 percent prove fatal. That means one to two of every 1,000 stent recipients dies as a direct result of the device. If Graboys and like-minded doctors are correct, that works out to between 600 and 1,200 unnecessary deaths each year.
Nor is stenting always successful in the vast majority of patients who survive the procedure. Blood vessels close up around the devices, a phenomenon called restenosis, in about 20 percent of patients.
So why is angioplasty overused? The answer is largely economic, Graboys said. Angioplasty costs roughly $15,000. Conventional stents run around $2,000 each, but new, drug-releasing stents that promise less restenosis cost about twice that much. "The market forces are incredible," he said, with "a host of non-clinical factors" driving the use of the technology.
Cardiologists, Abrams agreed, are generally overeager when it comes to angioplasty. "We're doing too much ballooning, and now that we have stents it's even worse," he said.
Abrams is an advocate of much wider use of the vasculo-protective drug regimen.
"That cocktail clearly reduces risk and may in fact stop atherosclerosis in its tracks," he said.
Doctors need to work toward ensuring that every patient discharged from the hospital with coronary artery disease leaves with a prescription for the treatment -- regardless of whether or not they've had angioplasty, Abrams said. "This is the place to put our money, and we are not doing an adequate job," he said.
The National Institutes of Health has more on angioplasty.