Warfarin Genetic Testing Decreases Hospitalization Rate, Study Finds

• Date: March 18, 2010
• Source: Admin

A recent study, done by Medco Research Institute and Mayo Clinic, shows that by using warfarin genetic hospitalization rates have been dropped by almost 30%. At the American College of Cardiology's 59th annual scientific session, results of the first nationwide prospective study examining end products of incorporating genetic testing into the management of warfarin as part of the usual care of patients were presented today.

Warfarin and Its Challenging Aspects

Warfarin, marketed under the brand names Coumadin® and Jantoven®, may prove to be challenging given variable drug response between individuals. Additionally, because of its narrow therapeutic range: doses that are too high or too low can lead to bleeding or clotting complications, respectively. It is anticipated that up to 20 percent or more of patients can be hospitalized for bleeding within six months of starting warfarin. Finding its association with severe health hazards, the US Food and Drug Administration issued a black box warning on warfarin labels outlining such risks and recommending close patient monitoring. The new the labeling now refers to a table outlining recommended doses for individuals depending on their CYP2C9 and VKORC1 genotype information.

What Medco and Mayo Found

Medco and Mayo initiated this study in July, 2007 with patients from 49 states. Patients even got insured by dozens of health plan sponsors managed by Medco.

In a study of comparison 896 individuals who received genetic testing for CYP2C9 and VKORC1 genes early in their warfarin treatment were compared with 2,688 control individuals, selected from the same group of health insurance sponsors the previous year, who had received treatment without genetic testing.

Patients participated in the study ranged from 40 to 75 years old, with an average age of 65 years, of them around 60% were men. Genetic testing for the study was performed at the Mayo Clinic, which also gave doctors guidelines for applying genetic information to drug dosing and management. The researchers found that those in the genetic testing group were 28 percent less likely to be hospitalized for bleeding or thromboembolism — and 31 percent less likely to be hospitalized for any reason — than individuals in the control group, based on medical claim data.

Impact of the Study

Conducted in national "real world" settings, this comparative effectiveness study validates that testing for an individual's unique genetic predisposition can significantly improve warfarin's safety and effectiveness by providing information about the patient's sensitivity to the drug.  

According to the lead author Robert Epstein, Medco's chief medical officer and president of the Medco Research Institute "These results show that we can greatly reduce hospitalizations, and their significant costs, by making genetic testing routine early in a patient's therapy with warfarin, If it costs a few hundred dollars for the genetic test but avoids the $13,500 hospital bill, it very quickly pays for itself."

What Others Say

However, Mandeep Mehra, chief of cardiology at the University of Maryland Medical Center, presented his own view at the ACC meeting that the study of the Medco/Mayo study could provide a better result if physicians followed those patients more closely instead of making them genotyped.

Source:

http://newsblog.mayoclinic.org/...warfarin-genetic-test-cuts-hospital-admissions
http://medco.mediaroom.com/index.php?s=43&item=428
http://www.genomeweb.com/...warfarin-genetic-testing-decreases-hospitalization