Two-Year Zilver Stent Data Shows Leg Arteries are Kept Open


October 10, 2011

January 20, 2011 – Drug-coated stents hold promise as a safe and lasting solution for the treatment of clogged leg arteries, suggest two-year results of the Zilver PTX Trial being presented at the 23rd annual International Symposium on Endovascular Therapy (ISET). Blocked leg arteries are a symptom of peripheral arterial disease (PAD), which affects 8 to 12 million Americans.

The multicenter, prospective, randomized Zilver PTX trial includes a total of 479 patients treated at 55 institutions. About half received the Cook Medical Zilver PTX (paclitaxel-coated) stent and the rest received angioplasty alone to open blocked superficial femoral arteries, which provide blood to the lower legs. Patients who received angioplasty that did not succeed in initially opening the artery were then randomized to a provisional group to receive either paclitaxel-coated or bare-metal stents.

Two-year data included 278 patients, with approximately 50 percent getting the Zilver PTX stent, 25 percent getting angioplasty alone, 12.5 percent getting angioplasty plus provisional bare metal stent and 12.5 percent getting angioplasty plus provisional Zilver PTX stent. After two years, 74.8 percent of arteries remained open in patients who received the drug-coated stents. There was no imaging of the angioplasty-only group after the first year, at which point only 32.8 percent had arteries that remained open. After two years, event-free survival was 86.6 percent for Zilver PTX patients. Events that did occur primarily involved the need to undergo another procedure to open the original blockage, worsening symptoms of PAD and one amputation. No patient deaths were related to the study device or procedure.

In the provisional stenting group at two years, 81.2 percent of arteries treated with drug-coated stents remained opened vs. 62.7 percent of those treated with bare-metal stents.

“There’s evidence of a significant drug effect even at two years, with a much higher rate of the arteries remaining open than with angioplasty alone or with bare metal stents,” said Michael Dake, M.D., lead investigator for the Zilver Trial and Thelma and Henry Doelger Professor in the department of cardiovascular surgery at the Stanford University School of Medicine, Stanford, Calif. “We have not had long-term problems with late thrombosis or aneurysm which also suggests the results are safe and durable.”

The International Symposium on Endovascular Therapy (ISET) is attended by physicians, scientists, allied professionals and industry professionals from around the world. The meeting pioneered the use of live cases to promote the multidisciplinary treatment of cardiovascular disease. ISET is presented by Baptist Cardiac and Vascular Institute, Miami. ISET 2011 is taking place Jan. 16-20 in Miami Beach, Fla.

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