Reporting in today's New England Journal of Medicine, doctors from 76 medical centers in nine countries offer evidence that supplementing angioplasty with a "stent" and a "super-aspirin" type of medication known as ReoPro significantly reduces the risk of complications that otherwise might induce a second heart attack or stroke.
But the study -- known as the CADILLAC trial -- isn't without controversy. At least one prominent heart expert calls the results "spin and hype" and questions the validity of the findings.Chief investigator Dr. Gregg W. Stone believes the study is sound and defends its findings.
"Stenting, compared to balloon angioplasty [alone], markedly improved short-term and long-term outcomes in patients undergoing mechanical interventional therapy [for a heart attack]," says Stone, an interventional cardiologist at the Lenox Hill Heart and Vascular Institute in New York City.
In balloon angioplasty, a thin wire catheter carrying a closed balloon-like device is inserted into the blocked blood vessel. Once the device reaches the blockage, the balloon is inflated, pushing against blood vessel walls and opening the narrowed space. The balloon is then removed.
While the procedure works well, sometimes complications can occur, including a re-closing of the newly opened vessel, increasing the risk of a second heart attack or stroke.
To reduce such risks, doctors developed "stenting" -- the placing of a mesh or coil-shaped wire permanently into the vessel after angioplasty, to act as a kind of "support beam," holding the vessel open. It works well, but also has its problems.
"While stenting was clearly shown to reduce restenosis [re-closing of the vessel], there was a problem with stenting increasing embolization [blood clots] ... with a trend toward increased mortality," says Stone.
What the new study shows, Stone says, is that by adding the medication ReoPro, which reduces a clot's "sticky" quality, and a new, more flexible stent design, there's a significant reduction in complications related to stenting. The results are so dramatic that stenting should almost always be the treatment of choice following a heart attack, he says.
But critics of the study, including Dr. P.K. Shah, director of cardiology at Cedars Sinai Medical Center in Los Angeles, don't agree.
"When you take into account the study's three most important outcome variables -- a [second] heart attack, death or stroke -- there is no difference in the strategies," Shah says, citing the study's results.
When it came to preventing a second heart attack, death or stroke, the study found that stenting was no more effective than angioplasty alone. And when ReoPro was used with stenting, patients in the study actually fared worse than with stenting alone, in terms of risk of death, a second heart attack or stroke, Shah says.
In addition, Shah believes the study's "population" was too selective; participants were chosen because they were extremely "low risk," which also skewed results, he says.
The study involved 2,082 heart attack patients randomly assigned to receive one of the following four procedures: angioplasty alone (512 patients); angioplasty plus ReoPro (528 patients); angioplasty plus stenting (512 patients); and angioplasty, plus stenting and ReoPro (524 patients).
The results of the procedures were tallied using the following criteria: death; a second heart attack; stroke; or "ischemia-driven target vessel revascularization" -- a re-closing of the newly opened artery.
When these four possible outcomes were totaled together, the percentage of patients who experienced them were as follows: patients undergoing angioplasty alone, 20 percent; patients receiving angioplasty plus ReoPro, 16.5 percent; stenting alone, 11.5 percent; and stenting plus ReoPro, 10.2 percent.
Based on the study results, Stone says, "Stenting should be considered the new gold standard for patients with acute myocardial infarction [a heart attack]".
Although Shah says the study researchers are among the best in their field, he disagrees with their conclusion.
"I think the authors have capitalized on the fact that the target vessel vascularization (re-closing of the artery) is normally higher in angioplasty than in the stenting. [And] I think they are using that to put a spin on these results," making the study findings look much better than they actually were, Shah says.
When the three most important outcomes are considered -- death, a second heart attack, or a stroke -- the study showed that stenting, alone or with ReoPro, did not prove more effective than angioplasty, Shah says.
What's more, Shah says, since the number of patients who experience artery-closing problems after angioplasty alone is relatively small, he also questions the need to subject all heart-attack patients to stenting.
"One could use a selective stenting approach -- only those that need it," says Shah.
But Stone stands by his study's results: "As long as the artery is in the proper configuration to accept the stent, then the stent would be the right thing to do," he says.
What to Do: To learn more about balloon angioplasty, visit this Mayo Clinic site. Or check the latest angioplasty news at the The National Library of Medicine. To read more about stenting, see The Heart Site.