Promising 3-year data: Saving limbs with drug-eluting stents

March 10, 2009

Attempts to treat critical limb ischemia in peripheral arterial disease (PAD) patients with below-the-knee angioplasty are still thwarted by restenosis (the re-narrowing of the artery at the site of angioplasty or stenting), the need for repeat treatments and the continued progression of atherosclerotic disease, leading to tissue death (gangrene) and amputation. Interventional radiologists have been studying a potential solution-the use of drug-eluting stents-and have found that these types of stents lessened the rate of repeat procedures to open these small arteries, according to results presented at the Society of Interventional Radiology's 34th Annual Scientific Meeting.

"This is encouraging news for PAD patients with critical limb ischemia. The smaller blood vessels below the knee are more difficult to treat due to their size (3 millimeters) and are more prone to reclog than larger vessels. The use of drug-eluting stents in the tiny infrapopliteal arteries of the leg may significantly impact their care," said Dimitris Karnabatidis, M.D., assistant professor of interventional radiology at Patras University Hospital in Rion, Greece. "Drug-eluting (or drug-coated) stents have emerged as a potential solution to the limitations of endovascular treatment of PAD patients with critical limb ischemia," he added. An interventional radiologist performs a balloon angioplasty to open a clogged blood vessel and then places a drug-eluting stent in that artery. The stent acts as scaffolding to hold the narrowed artery open. Drug-eluting stents slowly release a drug for several weeks to block cell proliferation or regrowth, thus inhibiting restenosis.

Researchers from a single center studied 103 patients in a double-arm prospective registry who had critical limb ischemia and who underwent infrapopliteal revascularization with angioplasty and placement of either a drug-eluting stent (with sirolimus, an immunosuppressant drug) or a bare-metal stent (without a drug coating). The patients had regular follow-ups up to three years, and researchers studied how they did by stent type. In the first group, 41 patients (75.6 percent diabetics) were treated with bare-metal stents, and in the second group 62 patients (87.1 percent diabetics) were treated with drug-eluting stents.

At three years, those patients with drug-eluting stents had "significantly higher patency" (length of time the blood vessels stayed open and moved blood flow efficiently); reduced restenosis of the vessels; and consequently less clinical recurrence requiring repeat angioplasty, said Karnabatidis. "In the drug-eluting stent group, an estimated 60 percent of the treated arteries remained open at three years. This is significantly longer than the bare-metal stent group, where the arteries remained open only approximately 10 percent at 3 years," said Karnabatidis. "This corresponds to a more than 5 times increased risk of vessel reclogging when bare metal stents were used," he added. "Because of the reduced vessel restenosis, repeat angioplasties were necessary in only 15 percent of the patients in the drug-eluting stent group versus almost 35 percent in the bare-metal stent group up to 3 years-this being the equivalent to an almost 2.5-fold risk of repeat procedures in the case of bare metal stents," noted Karnabatidis. "These statistical results are based on three-year adjusted survival analysis after application of a Cox model for multivariable analysis," he explained.

If a person has critical limb ischemia, it means he or she is at great risk for tissue death due to lack of blood flow, which carries oxygen and nutrients to the cells. The severely restricted blood flow results in severe pain in the feet or toes, even while resting, and sores and wounds that will not heal. Tissue death (gangrene) and amputation are imminent at this advanced stage of PAD, which is caused by atherosclerosis, the hardening and narrowing of the arteries over time due to the buildup of fatty deposits called plaque.

"Multicenter randomized trials are necessary to support these promising results and build on the level of clinical evidence supporting the integral value of infrapopliteal drug-eluting stents in critical limb ischemia treatment," he added. In the United States, drug-eluting stents are FDA-approved for the coronary arteries but not for infrapopliteal arteries. In Europe, drug-eluting stents have CE Mark approval for below-the-knee use.

Society of Interventional Radiology

Colombo's Tips & Tricks for Drug Eluting Stents
by Antonio Colombo (Author), Goran Stankovic (Author)

A trailblazer in interventional cardiology, Dr. Antonio Colombo combines his vast experience with that of Goran Stankovic and distinguished colleagues to share tips and tricks for dealing with diseased coronary arteries. Whether discussing his 'crushing and kissing' techniques or the stenting of tortuous vessels in the elderly, Dr. Colombo and his colleagues' texts and case commentaries provide the reader with succinct and simple advice based on personal experience. They provide the most comprehensive and practical guide available for those involved in coronary artery stenting. The images are all down-loadable in Powerpoint and will be of tremendous use to instructors and students alike.

Handbook of Drug-Eluting Stents
by Patrick W. Serruys (Author), Anthony H. Gershlick (Author)

Handbook of Drug-Eluting Stents, under the editorial direction of Patrick Serruys, one of the world's leading interventional cardiologists, and Tony Gershlick, a pioneer in the field of drug-eluting stents, provides the reader with up-to-date information on which stents and pharmacological agents in use or about to be launched, the kinetics of the drugs involved, and what the future may hold.

The 2009-2014 World Outlook for Drug-Eluting Stents
by Icon Group International (Author)

This econometric study covers the world outlook for drug-eluting stents across more than 200 countries. For each year reported, estimates are given for the latent demand, or potential industry earnings (P.I.E.), for the country in question (in millions of U.S. dollars), the percent share the country is of the region and of the globe. These comparative benchmarks allow the reader to quickly gauge a country vis-a-vis others. Using econometric models which project fundamental economic dynamics within each country and across countries, latent demand estimates are created. This report does not discuss the specific players in the market serving the latent demand, nor specific details at the product level. The study also does not consider short-term cyclicalities that might affect realized...

The 2009-2014 Outlook for Drug-Eluting Stents in Japan
by Icon Group International (Author)

This econometric study covers the latent demand outlook for drug-eluting stents across the prefectures and cities of Japan. Latent demand (in millions of U.S. dollars), or potential industry earnings (P.I.E.) estimates are given across some 1,000 cities in Japan. For each city in question, the percent share the city is of it's prefecture and of Japan is reported. These comparative benchmarks allow the reader to quickly gauge a city vis-a-vis others. This statistical approach can prove very useful to distribution and/or sales force strategies. Using econometric models which project fundamental economic dynamics within each prefecture and city, latent demand estimates are created for drug-eluting stents. This report does not discuss the specific players in the market serving the latent...

The 2009-2014 Outlook for Drug-Eluting Stents in India
by Icon Group International (Author)

This econometric study covers the latent demand outlook for drug-eluting stents across the states, union territories and cities of India. Latent demand (in millions of U.S. dollars), or potential industry earnings (P.I.E.) estimates are given across over 5,000 cities in India. For each city in question, the percent share the city is of it's state or union territory and of India as a whole is reported. These comparative benchmarks allow the reader to quickly gauge a city vis-a-vis others. This statistical approach can prove very useful to distribution and/or sales force strategies. Using econometric models which project fundamental economic dynamics within each state or union territory and city, latent demand estimates are created for drug-eluting stents. This report does not discuss the...

The 2009-2014 Outlook for Drug-Eluting Stents in Greater China
by Icon Group International (Author)

This econometric study covers the latent demand outlook for drug-eluting stents across the regions of Greater China, including provinces, autonomous regions (Guangxi, Nei Mongol, Ningxia, Xinjiang, Xizang - Tibet), municipalities (Beijing, Chongqing, Shanghai, and Tianjin), special administrative regions (Hong Kong and Macau), and Taiwan (all hereafter referred to as "regions"). Latent demand (in millions of U.S. dollars), or potential industry earnings (P.I.E.) estimates are given across some 1,100 cities in Greater China. For each major city in question, the percent share the city is of the region and of Greater China is reported. Each major city is defined as an area of "economic population", as opposed to the demographic population within a legal geographic boundary. For many cities,...

The 2009-2014 Outlook for Drug-Eluting Stents in the United States
by Icon Group International (Author)

This econometric study covers the latent demand outlook for drug-eluting stents across the states and cities of the United States. Latent demand (in millions of U.S. dollars), or potential industry earnings (P.I.E.) estimates are given across some 12,900 cities in the United States. For each city in question, the percent share the city is of it's state and of the United States is reported. These comparative benchmarks allow the reader to quickly gauge a city vis-a-vis others. This statistical approach can prove very useful to distribution and/or sales force strategies. Using econometric models which project fundamental economic dynamics within each state and city, latent demand estimates are created for drug-eluting stents. This report does not discuss the specific players in the market...

The 2009-2014 Outlook for Drug-Eluting Stents in The Americas & the Caribbean
by Icon Group International (Author)

This econometric study covers the outlook for drug-eluting stents in The Americas & the Caribbean. For each year reported, estimates are given for the latent demand, or potential industry earnings (P.I.E.), for the country in question (in millions of U.S. dollars), the percent share the country is of the region and of the globe. These comparative benchmarks allow the reader to quickly gauge a country vis-a-vis others. Using econometric models which project fundamental economic dynamics within each country and across countries, latent demand estimates are created. This report does not discuss the specific players in the market serving the latent demand, nor specific details at the product level. The study also does not consider short-term cyclicalities that might affect realized sales. The...

The 2009-2014 Outlook for Drug-Eluting Stents in Asia
by Icon Group International (Author)

This econometric study covers the outlook for drug-eluting stents in Asia. For each year reported, estimates are given for the latent demand, or potential industry earnings (P.I.E.), for the country in question (in millions of U.S. dollars), the percent share the country is of the region and of the globe. These comparative benchmarks allow the reader to quickly gauge a country vis-a-vis others. Using econometric models which project fundamental economic dynamics within each country and across countries, latent demand estimates are created. This report does not discuss the specific players in the market serving the latent demand, nor specific details at the product level. The study also does not consider short-term cyclicalities that might affect realized sales. The study, therefore, is...

The 2009-2014 Outlook for Drug-Eluting Stents in Africa, Europe & the Middle East
by Icon Group International (Author)

This econometric study covers the outlook for drug-eluting stents in Africa, Europe & the Middle East. For each year reported, estimates are given for the latent demand, or potential industry earnings (P.I.E.), for the country in question (in millions of U.S. dollars), the percent share the country is of the region and of the globe. These comparative benchmarks allow the reader to quickly gauge a country vis-a-vis others. Using econometric models which project fundamental economic dynamics within each country and across countries, latent demand estimates are created. This report does not discuss the specific players in the market serving the latent demand, nor specific details at the product level. The study also does not consider short-term cyclicalities that might affect realized sales....