Lerner
Research Institute biostatisticians and others were part of a multicenter
research project that found a combination of aspirin and a medication that
inhibits blood clots could provide a significant benefit to many people experiencing
complications from the access graft used for kidney dialysis.
People suffering from end stage renal disease require dialysis to cleanse their blood, a process that requires the blood to be drawn, filtered and returned to the patient. According to the 2008 US Renal Data System Annual Data Report, more than half a million patients have kidney failure; 70% of them are on dialysis. Costs for kidney failure are more than $30 billion annually .
But dialysis takes a heavy toll on patients' blood vessels, so functional “vascular access” is necessary. The most common type used in the United States is the arteriovenous (AV) graft in which a synthetic tube connects an artery and vein to allow easier access for dialysis.
Unfortunately, blood vessels often narrow at the point they attach to the tube, causing blood clots. This leads to costly procedures to maintain and restore access and complicates patients' care.
“In the United States, the annual cost is more than $1 billion for procedures related to vascular access,” said Gerald J. Beck, PhD, of the Institute's Department of Quantitative Health Sciences (QHS) and Principal Investigator of the Data Coordinating Center, which helped design the trial, developed the database, and coordinated the management of the trial. The project involved 649 patients from 13 U.S. centers who participated in the double blind, randomized clinical trial. The patients were split into two groups: one receiving the medication combination and the other receiving a placebo.
The trial found that the combination treatment decreased the rate of loss of primary unassisted graft patency – the useful life of a graft before it becomes blocked the first time – by 18% and the rate of developing significant narrowing of blood vessels (stenosis) by 28%, compared to placebo. Previous smaller clinical trials of anti-clotting therapies failed to show that these drugs improve AV graft patency or that they could be used safely in dialysis patients.
“More importantly, our findings can help many patients who undergo dialysis to avoid complications associated with their treatments,” Dr. Beck said. “There have been few clinical trials of drug therapies used to reduce the risk of graft dysfunction, and new preventive therapies are lacking. Our work suggests that strategies targeting narrowing of blood vessels may be an important area for future research.”
Other QHS researchers who participated in the project are Jennifer J. Gassman, PhD, Bo Hu, PhD, and Milena Radeva. The findings appeared in the New England Journal of Medicine (http://content.nejm.org/ 2009;360:2191-2201). The research was sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health.