Atherosclerosis is a disease that causes residues of fat and cells to concentrate on the epithelium of blood vessels. This disease causes heart attacks when the residues block the coronary arteries – the blood vessels that supply blood to the heart. When not enough blood and metabolites reach the heart, a heart attack occurs.
Introducing a stent into the obstructed vessel is one of the most common ways to treat the disease. The stent, shaped as a coil pushes aside the residues and supports the vessel walls. The problem is that the implantation injures the vessel walls and causes an immune response involving monocytes. This process causes proliferation of muscle and connective tissue cells which could cause a recurring vessel blockage.
The common technique to prevent this complication is to use stents that are coated with a medication. This medication significantly reduces the recurring obstruction. Yet this solution causes a rare complication in 1% of the patients. A sudden clot may emerge, blocking the artery and causing another heart attack. To solve this problem it is common to give all stent patients blood diluting medications for a lifetime.
However a new medication developed in Israel and currently undergoing clinical trials may bring a revolution in the stent treatments field. The medication, named Liposomal Alendronate, is given to patients during or after the stent procedure. It decreases the risk of a recurring blockage and a second stent insertion by preventing the overstimulation of the immune system. Unlike the medications coating the stent, this medication’s mechanism does not increase the likelihood of blood clots, so patients receiving it do not need blood diluting medications.
This medication, which is given once by a 20 minute transfusion, is the outcome of research conducted by the BIOrest Company and the Hadassah Ein Karem hospital in Jerusalem. It is based on Alendronate, which is present in medication given to osteoporosis patients to prevent bone deterioration. The Alendronate prevents the activation of monocytes for a time period from 24 hours to a week. This prevents the inflammatory process in the vessel which had undergone the stent implantation. Contrary to what one may think, the medication does not increase the chance of infection, because it does not shut down the immune response, but only stalls it for the critical period.
So far the medication has been tested in several labs in the world in animals, healthy volunteers and patients after stent implantations. Soon a new set of clinical trials will begin in several hospitals in Israel. Half a year after the medication is given, the patients will undergo a diagnostic stent that will check the artery status. If this testing stage goes well, further trials will be conducted all over the world.
TFOT has recently covered a story on heart cells generated from skin cells at UCLA. Another story we brought you was on saliva analysis that can bring early detection and prevention of heart attacks, developed at the University of Texas at Austin.
For more information on the clinical trials for the drug, visit the clinical trials homepage.