CARDIOLOGY Cancer drug gets new task: helping stents do their job

The devices are used to keep arteries open, but reclogging frequently occurs.
LONG ISLAND NEWSDAY
In a major test, doctors have demonstrated that a widely used cancer drug works equally well in heart patients, staving off reblockage of coronary arteries when the anti-tumor medication is used to coat a stent.
The new finding, which shows that a cancer drug can play a role in the treatment of heart disease, is yet another example on the growing list of old drugs performing new tricks.
It is also another example of cardiology's reaching to other branches of medicine for innovative therapies. The first drug-coated stent, approved last year, is laced with a medication initially developed more than 30 years ago as an antibiotic.
The new device was developed by Boston Scientific in Natick, Mass. The company also sponsored the study, and seven of the research project's 12 authors have had financial ties to the company.
Work on this tiny tube -- and other coated stents in the pipeline -- represents a trend in treating arterial reblockage in a more targeted fashion.
How treatment works
Stents, tiny latticelike scaffolds capable of keeping arteries open, enable the free flow of blood in patients with coronary artery disease. The drug paclitaxel, also known as Taxol, was applied to the devices and is released slowly to prevent the processes that cause reclogging. The drug has been administered successfully for more than a decade in the treatment of breast and ovarian cancers. In its role as a heart drug, paclitaxel has been given a new trade name, Taxus.
Doctors say the cancer drug appears to work well in a wide range of coronary artery disease patients. For reasons yet to be fully explained, the drug performs particularly well in patients who also have diabetes.
"This is a tremendous advance," said Dr. Gregg Stone, referring to the overall performance of the new stent.
Dr. Stone, who directs cardiovascular research for Lenox Hill Hospital in Manhattan, also said the new stent will give doctors more treatment choices.
The new stent, like its counterpart, emits minute amounts of medication over a period of weeks to prevent reclogging. The amount is so small that it affects only the area involving the stent.
Study findings
Stone and a nationwide team of cardiologists reported the results of their analysis involving paclitaxel-coated stents in a recent issue of The New England Journal of Medicine. Stone is one of seven doctors who have worked as paid consultants or advisers to Boston Scientific.
In the study of 1,314 patients, 662 received the drug-eluting -- slow release -- stent and 652 received the bare metal variety.
The study found that reclogging was reduced by 73 percent in patients who received devices coated with paclitaxel. Reclogging occurred in only 7.9 percent of patients with the coated stent but affected more than 26 percent of those with the bare device.
Coated or uncoated, stents are implanted during a procedure known as angioplasty. A balloon catheter is guided through the vascular highway, beginning in a vessel in the groin and moving up to a blocked artery feeding the heart. When a stent is to be inserted, doctors place it on the balloon. Inflating the balloon opens the stent. The balloon and catheter are removed, but the stent stays in place.
Reclogging of arteries after implantation of bare stents is a juggernaut that has thwarted cardiologists since they started inserting the devices more than a quarter-century ago, Stone said. Up to 25 percent of patients experience reblockage with bare metal stents.