Dissolvable Heart Stents

Richard Melpignano

Coronary Heart DiseaseCoronary Heart Disease (CHD) is, as of 2012, the

leading cause of death worldwide.

Plaque in blood accumulates against the walls of the Coronary Artery, which returns oxygen rich blood from lungs to heart

If left untreated, will lead to blood clots/heart attacks

Traditional TreatmentsCoronary Artery Bypass Surgery (High Risk)

Cholesterol Lowering Medication, Nitroglycerin, Beta-Blockers etc. (Less Effective)

Angioplasty

AngioplastyMinimally invasive

Involves the insertion of a mesh stent which expands to fit the coronary artery, forcing plaque against the artery wall, allowing significantly increased blow flow to the heart

Stents have traditionally been made of various metals, and may or may not be drug eluting

ProblemsEffective, but often delay natural healing

process of the arteries

If metal mesh is not inserted properly, plaque may actually build up on the stent, called stent thrombosis (kills 1 in 200 patients in procedure)

To improve upon these conditions, Abbott Laboratories in IL have been working on a biodegradable polymer drug eluding stent

Polymer (DES) StentMade of biodegradable material called

polylactide

Inserted into Coronary Artery through similar method as metal stents

Designed to completely dissolve into the bloodstream within 2-3 years after procedure

ProcedureA dye that can be seen on X-rays is released into the

blood in order to pinpoint the location and severity of the blockage

Catheter is inserted into the patients body, usually into the groin, but may be inserted into the arm or thigh as well

Catheter is lead along the artery until it reaches the blockage, where the mesh is forced against the artery wall through the inflation of a balloon, compressing the plaque blockage

The balloon is deflated and the catheter is removed from the body

ResultsIn comparing metal stents with metal DES

stents, the DES stents have shown more instances of heart complications than ones without supporting drugs

But, biodegradable DES stents were found to be safer than both of the metal stents

The risk of stent thrombosis, lesion revascularization, and myocardial infarction were significantly reduced

ABSORB III Clinical TrialsEarly in September, these trials enrolled 2,250

patients across the country to test the effectiveness of dissolvable heart stents

Some facilities participating include Mount Sinai Medical Center and the Stony Brook University Heart Institute

FutureMany physicians believe that these dissolvable

heart stents will someday replace metal stents (which have been used in over 6 million procedures)

It was approved for testing in Europe in 2011 and has been successful in trials

If trials are successful, it is expected to be available in the United States by 2015

The cost is estimated to be between $1500-$2000

Work Cited [1] Cutlip, Donald, MD, and J. Dawn Abbott, FACC. "Coronary Artery Stent Thrombosis: Incidence and Risk Factors."

Coronary Artery Stent Thrombosis: Incidence and Risk Factors. Up To Date, 13 May 2013. Web. 26 Sept. 2013. <http://www.uptodate.com/contents/coronary-artery-stent-thrombosis- incidence-and-risk-factors>.

[2] "European Heart Journal." Biodegradable Polymer Drug-eluting Stents Reduce the Risk of Stent Thrombosis at 4 Years in Patients Undergoing Percutaneous Coronary Intervention: A Pooled Analysis of Individual Patient Data from the ISAR-TEST 3, ISAR-TEST 4, and LEADERS Randomized Trials. N.p., 21 Jan. 2012. Web. 26 Sept. 2013. <http://eurheartj.oxfordjournals.org/content/early/2012/03/22/eurheartj.ehs086.abstract>.

[3] "How Are Stents Used?" - NHLBI, NIH. National Heart, Lung, and Blood Institute, n.d. Web. 26 Sept. 2013. <http://www.nhlbi.nih.gov/health/health-topics/topics/stents/used.html>.

[4] Jaspen, Bruce. "Abbott's Dissolvable Heart Stent Gets OK for Use in Europe." Chicago Tribune. N.p., 10 Jan. 2011. Web. 26 Sept. 2013. <http://articles.chicagotribune.com/2011-01-10/health/ct-biz-0111- abbott-stent-20110110_1_drug-coated-metal-dissolvable-heart-stent-absorbable-stent>.

[5] Luscher, Thomas, MD, Jan Steffel, MD, Franz R. Eberli, MD, Michael Joner, MD, Gaku Nakazawa, MD, Felix C. Tanner, MD, and Renu Virmani, MD. "Drug-Eluting Stent and Coronary Thrombosis." Biological Mechanisms and Clinical Implications (2007): n. pag. American Heart Association- Circulation. Web. 26 Sept. 2013. <http://circ.ahajournals.org/content/115/8/1051.full>.

[6] "Stony Brook Heart Institute Evaluates First Dissolvable Stent." Stony Brook Heart Institute Evaluates First Dissolvable Stent. Stony Brook University, 20 Sept. 2013. Web. 26 Sept. 2013. <http://commcgi.cc.stonybrook.edu/am2/publish/Medical_Center_Health_Care_4/Stony_Brook_Heart_I nstitute_Evaluates_First_Dissolvable_Stent.shtml>.

[7] Woods, Lauren. "Fully Dissolvable, Temporary Stent for Opening Heart Artery Blockages." Fully Dissolvable, Temporary Stent for Opening Heart Artery Blockages. The Mount Sinai Hospital, 17 Sept. 2013. Web. 26 Sept. 2013. <http://www.eurekalert.org/pub_releases/2013-09/tmsh-fdt091713.php>.