WASHINGTON (AP) - An experimental device that acts like a miniature drill and vacuum cleaner partially broke up clogs inside diseased heart arteries and sucked out the debris, letting doctors conduct angioplasties that were a little safer for their patients, researchers announced Tuesday.
Angioplasties restore blood flow through clogged arteries with a balloon-tipped catheter threaded inside the blood vessel and inflated to push back blockages. More than 1 million angioplasties are performed each year in this country alone.
They carry a risk: Clogs usually are a mix of soft and hard plaque, and while balloons push aside the hard stuff, they can break up the softer plaque so that it floats downstream and lodges in another blood vessel to cause a heart attack.
Doctors have long explored different ways to filter out that debris, a technique called thrombectomy.
The latest attempt: an experimental device called the X-Sizer, a hollow tube filled with a spinning blade and suction device. Thread it over any standard catheter wire and push it to the blockage. The blade cuts up the soft clog and the X-Sizer vacuums up the pieces, clearing the way for standard angioplasty to push aside the remaining hardened plaque.
Scientists randomly assigned nearly 800 patients to get X-Sizer treatment before angioplasty, or a regular angioplasty. Some 9.6 percent of people getting regular angioplasty had large heart attacks within 30 days, compared with 5.5 percent who got the thrombectomy first, said Dr. Gregg Stone of New York's Lenox Hill Hospital, who presented the study at a cardiology meeting here Tuesday.
There were no differences in deaths or small heart attacks.
Still, large heart attacks that damage significant amounts of heart muscle are a troubling angioplasty risk, and "there's really no drawback" to using the X-Sizer to lower that risk, Stone said.
Downstream heart attacks are "one of the unresolved problems" of angioplasty, and thrombectomy looks promising, said Dr. Sidney Smith of the American Heart Association. But which device performs a thrombectomy best is far from clear, he cautioned: Devices already sold try suctioning out blood clots before angioplasties or trapping debris and pulling it out once the angioplasty is done. The X-Sizer wasn't compared to such alternatives.
Manufacturer ev3 Inc. financed the study and is seeking Food and Drug Administration approval of the experimental device.
