WASHINGTON, Dec. 13 /PRNewswire/ -- Patients treated with drug-eluting stents must take a combination of aspirin and the clot-reducing drug clopidogrel for at least one year, and possibly longer, after stent implantation. This is a crucial message in a guideline update published online today in the journals of the Society for Cardiovascular Angiography and Interventions (SCAI), American College of Cardiology (ACC), and American Heart Association (AHA). To access the "2007 Focused Update of the ACC/AHA/SCAI 2005 Guideline Update for Percutaneous Coronary Intervention," visit SCAI's official journal, Catheterization and Cardiovascular Interventions, via http://www.scai.org.
Every year, thousands of patients experiencing a heart attack or chest pain (known as angina) undergo percutaneous coronary intervention (PCI), or angioplasty. The procedure is a proven therapy for stopping heart attack and relieving painful symptoms of heart disease that result from arteries narrowed or blocked by the build-up of fatty deposits. The guideline update incorporates findings from research published relatively recently on the role of PCI in the spectrum of care for heart disease patients.
During angioplasty, an interventional cardiologist guides a thin tube (catheter), usually through the groin, to the arteries to reach the blockage. The interventionalist then threads a tiny wire over which a tube carrying a deflated balloon on its tip is advanced to the narrowed segment of the artery. As the tiny balloon is inflated, it compresses the blockage against the inside wall of the artery. This re-opens the artery so blood may again flow freely. To keep the artery open, doctors also may insert an expandable mesh stent - a tiny "scaffold" made of metal -- at the site of the blockage. Drug-eluting stents release medication over time to help keep new tissues from growing and re-blocking the artery.
"For most patients suffering a heart attack, angioplasty and implantation of a stent is a life-saving procedure," says SCAI President Dr. Bonnie Weiner. "However, both patients and the medical community need to understand how essential dual anticoagulant therapy is after receiving a drug-eluting stent. That's the purpose of this update -- to stress this and other evidence published relatively recently."
The update specifically addresses findings from studies published through late 2006. One of the concerns that arose during this period was about a slightly higher risk of blood clots forming inside drug-eluting stents. These clots are a rare but serious complication of drug-eluting stents and must be prevented with a strict regimen of aspirin plus the clot-reducing drug clopidogrel for at least one year after the artery is opened with a stent. "By emitting tiny amounts of medication, drug-eluting stents reduce the regrowth of scar tissue and other build-up that could renarrow the artery, creating a need for a repeat angioplasty," explains Dr. Weiner. "While we don't want to understate the precautions that should be taken to prevent clots, we also want to factor in the benefits of these newer devices.
"If there are doubts about whether the patient can stay on the dual-antiplatelet therapy for at least one year, then a bare metal stent is probably the better choice," stresses Dr. Weiner. "We want to encourage physicians to think about the patient's history with compliance to drug therapy as well as other potential obstacles, such as planned surgeries, that might lead them to not take their aspirin and clopidogrel. In those cases, the update calls for a bare metal stent or balloon angioplasty with provisional stent implantation."
The guideline update also considers OAT (Open Artery Trial) and the earlier ICTUS (Invasive versus Conservative Treatment in Unstable coronary Syndromes) study, two randomized clinical trials that looked at whether to open totally blocked arteries in patients who had suffered a heart attack between 3 and 28 days earlier. "OAT looked at patients with a completely blocked artery who had suffered a heart attack between 72 hours and 28 days earlier but had neither serious chest pain nor evidence of ischemia," says Dr. Weiner. "Considering the findings of ICTUS, the writing committee suggests that in patients with unstable angina or the milder form of heart attack known as non-ST-segment elevation myocardial infarction (NSTEMI), risk stratification is critical to determining the optimal approach to patient care and that coronary angiography and PCI improve outcomes in high-risk patients."
"The OAT findings might rule out a small subset of patients who might have otherwise been candidates for angioplasty," says Dr. Douglass Morrison, a writing committee member and an OAT investigator, "but it also points to a very important issue: time. The real emphasis needs to be on educating patients to call 9-1-1 if they are having heart attack symptoms so they can get to the emergency department in time to have PCI when it will do the most good."
The update also strengthens the earlier guideline's recommendations about smoking cessation, exposure to second-hand smoke, medical management of high cholesterol and high blood pressure, coordinated care of diabetic patients, and getting a flu shot. The update does not address in detail when PCI should be used for patients with chronic stable angina. The more recent studies addressing this issue are still being tested in ongoing studies and debated in the medical literature.
"This is a valuable document for interventional cardiologists and all physicians who treat patients with heart disease, but we need to keep it in perspective because we are continually learning more about the best ways to treat cardiovascular disease," says Dr. Weiner. "Guidelines and updates like these offer us a snapshot of our knowledge at a given point in time. Between the time that the updates are written and then published, new information may become available that would further clarify daily clinical practice."
Headquartered in Washington, DC, the Society for Cardiovascular Angiography and Interventions is a 4,000-member professional organization representing invasive and interventional cardiologists in 70 nations. SCAI's mission is to promote excellence in invasive and interventional cardiovascular medicine through physician education and representation, and advancement of quality standards to enhance patient care. SCAI's annual meeting has become the leading venue for education, discussion, and debate about the latest developments in this dynamic medical specialty.
|SOURCE Society for Cardiovascular Angiography and Interventions|
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