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

March 10, 2009

SAN DIEGO, Calif. (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.
-end-
More information about PAD and interventional radiology can be found online at www.SIRweb.org.

Abstract 223: "Infrapopliteal Sirolimus-Eluting Versus Bare Metal Stents for Critical Limb Ischemia: Long-Term Angiographic and Clinical Outcome in More Than 100 Patients," K. Katsanos, Guy's and St. Thomas' Hospitals, London, United Kingdom; A. Diamantopoulos, S. Spiliopoulos, A. Karatzas, D. Karnabatidis, D. Siablis, Patras University Hospital, Rion, Greece; and G. Kagadis, School of Medicine--medical physics, Patras, Greece, SIR 34th Annual Scientific Meeting March 7-12, 2009. This abstract can be found at www.SIRmeeting.org.

About the Society of Interventional Radiology

Interventional radiologists are physicians who specialize in minimally invasive, targeted treatments. They offer the most in-depth knowledge of the least invasive treatments available coupled with diagnostic and clinical experience across all specialties. They use X-ray, MRI and other imaging to advance a catheter in the body, usually in an artery, to treat at the source of the disease internally. As the inventors of angioplasty and the catheter-delivered stent, which were first used in the legs to treat peripheral arterial disease, interventional radiologists pioneered minimally invasive modern medicine. Interventional oncology is a growing specialty area of interventional radiology.

Today many conditions that once required surgery can be treated less invasively by interventional radiologists. Interventional radiology treatments offer less risk, less pain and less recovery time compared to open surgery. Visit www.SIRweb.org.

An estimated 5,300 people are attending the Society of Interventional Radiology's 34th Annual Scientific Meeting in San Diego.

Local interviews and high-resolution images are available by contacting SIR's communications department at mverrillo@SIRweb.org.

Society of Interventional Radiology

Related Angioplasty Articles from Brightsurf:

Ticagrelor was not superior to clopidogrel to reduce heart attack risk during angioplasty
A new study found the rate of heart attack and severe complications before, during or soon after elective surgery to open a blocked artery was similar between patients treated with clopidogrel and those who received the more potent antiplatelet medication ticagrelor.

Study finds significant variability in doctors' angioplasty death rates
Some doctors have higher or lower than expected death rates from coronary angioplasty procedures, also known as percutaneous coronary intervention (PCI); however, doctors should not be judged solely on the rate of patients who die from the procedure.

Beta-blockers following angioplasty show little benefit for some older patients
Following coronary angioplasty, beta-blockers did not significantly improve mortality rates or reduce the number of future cardiovascular incidents for older patients with stable angina but no history of heart attack or heart failure, according to a study published today in the JACC: Cardiovascular Interventions.

Sleep disorders may predict heart events after angioplasty
People who have had procedures to open blocked heart arteries after acute coronary syndrome (ACS) may have a higher risk of death, heart failure, heart attack and stroke if they have sleep disorders, such as sleep apnea, compared to those who don't.

Reasons for hospital-level variations in bleeding post-angioplasty are unclear
The use of bleeding avoidance strategies has only a modest effect on the variation in bleeding rates post-angioplasty among hospitals performing this procedure, leaving about 70 percent of the causes for this variation unexplained, according to a study published today in JACC: Cardiovascular Interventions.

US prediction models for kidney injury following angioplasty hold up in Japan
Models developed by the American College of Cardiology NCDR CathPCI Registry to predict the likelihood of angioplasty patients developing acute kidney injury and acute kidney injury requiring dialysis have proven to be effective among patients in Japan.

IV beta blockers before angioplasty are safe, but offer no clinical benefit
Giving intravenous beta blockers before performing a coronary angioplasty in patients who had experienced the deadliest form of heart attack -- ST-segment elevation myocardial infarction (STEMI) -- was safe but did not reduce heart attack severity or improve blood flow from the heart's main pumping chamber, according to research presented at the American College of Cardiology's 65th Annual Scientific Session.

Life-threatening bowel ischemia can often be treated by balloon angioplasty
Acute mesenteric ischemia (AMI) can be successfully treated with endovascular therapy such as balloon angioplasty, according to research from the University of Eastern Finland.

Radial access used less than femoral approach for emergency angioplasty
Although using the radial artery as the access point for angioplasty has been linked to reduced bleeding compared to use of the femoral artery, only a small number of high-risk heart attack patients who undergo rescue angioplasty -- emergency procedures following failed therapy with clot-busting drugs -- are treated by radial access, according to a study published today in the Journal of the American College of Cardiology: Cardiovascular Interventions.

Use of rarely appropriate angioplasty procedures declined sharply
The number of angioplasty procedures classified as rarely appropriate declined sharply between 2010 and 2014, as did the number of those performed on patients with non-acute conditions, according to a study published today in the Journal of the American Medical Association and simultaneously presented at a meeting of the American Heart Association in Orlando.

Read More: Angioplasty News and Angioplasty Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.