Clinical & Industry News: Zommax, Type 2 Diabetes

Abbott Vascular Devices Enrolls First Patient in Clinical Trial of the ZoMaxx Drug-Eluting Coronary Stent Abbott Vascular Devices, a division of Abbott Laboratories, announced the enrollment of the first patient in the ZOMAXX I drug-eluting coronary stent clinical trial. ZOMAXX I is a 400-patient prospective randomized clinical trial that will be conducted in more than 30 centers in Europe, Australia and New Zealand. The study compares Abbott’s ZoMaxx drug-eluting coronary stent to Boston Scientific’s Taxus Express2 drug-eluting stent with a primary endpoint of 9-month in-segment late loss. Enrollment is expected to continue through the first quarter of 2005. Robert Whitbourn, MD, of St. Vincent’s Hospital in Melbourne, Australia, enrolled the first patient in the ZOMAXX I trial. I am looking forward to enrolling additional patients. Based on in vitro studies, the ZoMaxx stent design demonstrated excellent flexibility, contributing to a high level of deliverability. I am eager to test the device clinically, said Dr. Whitbourn. The ZoMaxx stent used in this study consists of three key components: the drug, the stent platform and the polymer carrier. The drug, ABT-578, is a patent-protected immunosuppressant discovered and synthesized by Abbott scientists. It inhibits inflammation and proliferation of smooth muscle cells, both key targets in treating restenosis. In animal testing, when compared to similar compounds, ABT-578 has been shown to be highly lipophilic (allowing a greater concentration of drug to penetrate the tissue). The second key component for ZoMaxx is the underlying stent platform the TriMaxx Coronary Stent, which is currently under CE Mark review as a non-drug eluting stent. The TriMaxx stent is anticipated to be the next evolution in metallic stents with its tri-layer composite of stainless steel and tantalum, and its ultra-low crossing profile. This tri-layer composite material allows for extremely thin struts while maintaining optimal visibility via angiography. The TriMaxx stent also utilizes a novel stent pattern with Apex Ring Control (A.R.C), which is designed to maximize flexibility and deliverability while maintaining ideal scaffolding and vessel wall coverage for uniform drug delivery. Alexandre Abizaid, MD, of Dante Pazzanese Hospital in Sao Paulo, Brazil, conducted the first clinical implants of the TriMaxx Coronary Stent in May 2004. I was impressed with the very low profile and exceptional deliverability of the TriMaxx stent, said Dr. Abizaid. Even with such thin struts, it was still clearly visible via angiography during the procedure, allowing me to place the stent with precision. The third key component of the ZoMaxx stent is Pharmacoat, a formulation of phosphorylcholine polymer coating licensed to Abbott from Biocompatibles International plc. Phosphorylcholine is a polymeric replica of the outer surface of a red blood cell that acts as a biologically inert coating that resists clot formation in vitro. Pharmacoat is a specific formulation of phosphorylcholine that contains an extra cap-coat an additional layer of coating that enables the drug to elute over time. In vitro studies show that Pharmacoat acts as a versatile drug-eluting vehicle that provides a stable foundation for the slow, controlled release of ABT-578. Since 1996, 150,000 non-drug eluting phosphorylcholine-coated stents have been implanted worldwide. The principal investigator of ZOMAXX I, Bernard Chevalier, MD, of Centre Cardiologique Nord, near Paris, France, said, The drug, ABT-578, is a promising compound in the battle against restenosis, and the phosphorylcholine polymer, Pharmacoat, is formulated to provide a slow, controlled release of the drug. By randomizing against Taxus, the ZOMAXX I trial will demonstrate the performance of the ZoMaxx stent. Medtronic Announces Market Availability of theDriver Coronary Stent on the Next Generation Multi-Exchange MX2 Coronary Stent Delivery System Medtronic, Inc. announced approval by the Food and Drug Administration (FDA) and full U.S. market availability of the Driver Coronary Stent System on the Multi-Exchange (MX2) Coronary Stent Delivery System. By pairing the new MX2 Delivery System with the Driver cobalt-alloy stent, physicians will now have a short-wire delivery system to deploy the Driver stent. The new MX2 Delivery System features a low profile, flexible shaft that is compatible with short (190 cm) guide wires. The system facilitates wire exchange during an angioplasty or stenting procedure and does not require an assistant to operate. The system allows the operator to exchange wires during the procedure, while maintaining the wire position at the lesion site and without removing the entire system. The MX2 platform is only available in the United States for use with the Driver Coronary Stent System. Medtronic intends to expand the use of MX2 platform to other leading products, including the Sprinter® and NC Stormer® balloons. The Driver Coronary Stent is composed of a cobalt chromium alloy. This alloy permits the Driver stent to feature ultra-thin struts. The stent has cells which each measure around 1 millimeter squared. Since its cobalt-based alloy is denser than stainless steel, the Driver stent maintains optimal radiopacity. Heart Remodels Itself After Coronary Treatment Swiss researchers report that after successful angioplasty or stenting to clear coronary blockages, cardiac dimension do become more normal. Dr. Michael J. Zellweger and colleagues from University Hospital in Basel measured various parameters related to heart function in 28 patients before and after they underwent angioplasty and/or stenting. The team found that, overall, the efficiency of cardiac pumping had not changed significantly six months after the procedure, but there was a clear trend to improvement in patients who had not suffered a prior heart attack. The researchers noted a reduction in the volume of the left ventricle indicating improvement. This was mainly among patients who had a procedure performed on the left anterior descending artery. The investigators conclude that angioplasty/stenting not only has a beneficial effect on symptoms but also has a positive effect ... on left ventricular remodeling. New Blood Test Advised for Diabetes Patients A relatively new blood test for people with diabetes can predict their risk of developing heart disease, U.S. researchers reported. Two separate studies suggest that people with both type 1 and type 2 diabetes should regularly take the hemoglobin A1c test, on top of their regular checks of blood sugar. The HA1c test looks for glycated hemoglobin, also called glycosylated hemoglobin, and is a measure of how well blood sugar is controlled. In one study, Dr. Sherita Golden and colleagues at Johns Hopkins University in Baltimore reanalyzed the data from 13 studies involving nearly 10,000 people from North America and Europe and found those with higher levels had much higher risks of heart and artery disease. The researchers said a 1 percentage point increase in HA1c predicted an 18 percent increase in risk for total cardiovascular disease and a 28 percent risk for peripheral vascular disease. Although diabetes is known to double the risk of heart disease death, Golden said the specific relationship was unclear. As a result, many people living with diabetes monitor their health for well-known risk factors for heart disease, such as central obesity, cholesterol levels and blood pressure, but the big unknown has been the role of blood sugar levels in managing their risk of developing cardiovascular disease, she said. A second study found similar results. Dr. Kay-Tee Khaw of Cambridge University and colleagues at Britain’s Medical Research Council studied 10,030 people aged 45 to 79 for six years. They found a 21 percent increase in cardiovascular events such as heart attack, for every 1 percentage point increase in hemoglobin A1c above 5%. Persons with HA1c concentrations less than 5 percent had the lowest rates of cardiovascular disease and mortality, they noted. This was true even when patients were older and fatter, and regardless of blood pressure or cholesterol levels. The two studies clearly prove that the glycosylated hemoglobin level is an independent progressive risk factor for incident cardiovascular events, regardless of diabetes status, Dr. Hertzel Gerstein of McMaster University in Ontario, Canada noted. Glycosylated hemoglobin level can now be added to the list of other clearly established indicators of cardiovascular risk, such as blood pressure and cholesterol level, added Gerstein, a diabetes expert.

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