Balloons coated with a drug used to open blocked stents in heart arteries restore blood flow and also reduce bleeding in some high-risk patients, recent research shows.
Background
Bare-metal stents, implanted to keep a blood vessel in the heart open during angioplasty, can narrow over time as scar tissue develops, which restricts blood flow and requires another procedure to widen the vessel, the researchers say.
In the new balloon procedure, a catheter with a drug-coated balloon is passed through the narrowed stent to restore blood flow. The procedure leaves behind the drug, which acts to prevent the stent from renarrowing.
Gregg Fonarow, MD, a professor of cardiology at the University of California, Los Angeles, and a spokesman for the American Heart Association, said, "drug-eluting stents significantly attenuate scar formation and the need for repeat procedures." However, dependency on prolonged therapy with two anti-clotting drugs and late-stent thrombosis have led to investigations of alternative treatments, he added.
In recent years, drug-eluting balloons have emerged as an alternative to drug-eluting stents to address blocking of arteries and avoid the need for prolonged dual anti-clotting therapy. The drug paclitaxel (Taxol) is used to coat the balloons and minimize cell growth, he said.
Study #1
Mariusz Zadura, MD, a senior cardiologist at the Heart and Diabetes Center of MecklenburgVorpommern in Karlsburg, Germany, and his team studied the responses of 84 patients who had narrowed bare metal stents reopened. The balloons used in the procedure were coated with paclitaxel, a cancer drug also used to prevent blocking of arteries.
In all, 91 stented arteries were treated. After six to nine months, the procedure kept 85 of the arteries open.
New blockages occurred in six stented arteries, but only three patients needed an additional procedure, the researchers noted.
Study #2
The research team followed 63 patients who were at high risk of bleeding. These patients were being treated with anti-clotting drugs for other medical problems, such as mechanical heart valves, atrial fibrillation and pulmonary embolism.
These patients also had narrowed stented arteries. Over six to nine months, drug-coated balloon procedures were effective in keeping 69 of 73 narrowed arteries open.
Although narrowing occurred in four stents, only two patients needed another procedure, the researchers reported.
The study findings were presented at the American Heart Association's annual meeting in Orlando, Florida.
Conclusion
Using the drug-eluting balloon is better than using drug-eluting stents, according to the researchers.
"Drug-eluting (emitting] balloons are, in my opinion, the therapy of choice in case of bare-metal stent restenosis," said Dr. Zadura, the lead researcher of both studies.
Also, patients treated with drug-eluting metal stents need daily aspirin and other anti-clotting drugs for at least one year, which can increase the risk of bleeding, the researchers said.
However, they said, patients treated with a drug-coated balloon only need to take dual anti-clotting therapy for one month.
"Drug-eluting balloon technology has been demonstrated to be safe and potentially efficacious in small studies," Dr. Fonarow said.
Both of these studies on patients showed very good efficacy and safety. These promising findings should be further evaluated in prospective randomized clinical trials, he said.
