Vytorin Study Shows Little Change In Artery Thickness
The study looked at whether Vytorin, which is combination of Under pressure from Congress and some doctors over the long-delayed study
results The study will be presented Sunday at the American College of Cardiology's annual meeting here, and were also published online in the New England Journal of Medicine. The study will then undergo a review by an expert panel of cardiologists at the meeting. The study, which involved 720 patients with a family history of unusually high cholesterol, showed various measurements of the carotid, or neck artery, and the femoral artery, which runs from the lower abdomen and goes through the thigh, were essentially the same at baseline, or when the study started and after patients had been treated for two years. There was also little change in the difference of new plaque formation in the arteries between the two patient groups. Vytorin works to target LDL cholesterol, or so-called "bad cholesterol" in two ways through the combination of Zocor and Zetia. Zocor, like other statins, blocks LDL production in the liver, while Zetia prevents its absorption from food in the gut. It was thought that decreases in LDL cholesterol would translate into a reduction in artery thickness, which was measured by ultrasound, and that the additional cut in LDL by adding Zetia to Zocor would have resulted in a greater reduction in artery thickness than patients on Zocor alone. Other studies involving statins have shown that lowering LDL also stops or cuts the rate of artery thickening, which in turn cuts the risk of heart attacks and strokes. Indeed, the study showed both patient groups had significant drops in LDL cholesterol over the two-year study period and that adding Zetia to Zocor, or patients on Vytorin, had a 27% greater reduction in LDL than patients on Zocor alone. However, the lead researcher, Dr. John J.P. Kastelein, of the Academic Medical
Center in "If you are near normal, it's very hard to show an effect of the drug," he said in an interview. Patients, who averaged age 46, in the Enhance trial started with an average .70 millimeter in the thickness of their carotid artery walls, according to measure that looked at six sections of the carotid artery and ended with about the same average thickness. In strict terms, however, the study showed carotid artery walls slightly increased in both groups with thickening progressing by 0.0111 millimeter in those taking Vytorin, compared with an increase of 0.0058 millimeter for those on Zocor alone over the two-year study period. Kastelein explained that most people are born with an average artery-wall thickness of about .5 millimeter and in people without cardiovascular disease such as high cholesterol, arteries slowly thicken to .8 millimeter over an average life span. Indeed, an editorial about the Enhance study also being published in the New England Journal of Medicine, said the average carotid artery thickness among patients in the study was much thinner than expected, and thinner than other trials involving statins and looks at artery thickness. "This seemingly rigorous and well-executed study of a combination therapy that
has been approved by the Food and Drug Administration dramatically contradictors
our expectations," the editorial said. It was written by The study has become a lightening rod for controversy because of a delays in getting results out and proposals by the companies - which were later dropped - to change the main study goal. The last patient scans were completed in 2006 and it took more than a year for the some 40,000 images to be interpreted. Some congressional lawmakers accused the companies of delaying the results because the firms knew the results would be negative and wanted to protect the brisk sales growth for Vytorin and Zetia. Both drugs cost more than Zocor, which is now available as a generic drug. The companies have denied the accusations. Kastelein said he would personally keep using Zetia in patients whose cholesterol isn't adequately lowered by high doses of statins such as Zocor. He said doctors need to wait for the results of a much larger study looking at the impact of adding Zetia to a statin drug and whether it cuts the number of heart attacks and strokes. Late Friday researchers of that study, known as Improve It, led by Brigham and
Women's Hospital in -By (END) Dow Jones Newswires |
|