Study finds increasing dosage of blood thinners can help cardiovascular disease patients with genetic defect

Cardiovascular disease patients who have a genetic defect that makes them less responsive to blood thinners may be helped with an increased dosage, according to results of an innovative pilot study led by a cardiologist at The University of Texas Health Science Center at Houston (UTHealth).

"Most people with cardiovascular disease are taking blood thinner medications such as Plavix but it turns out that 30 to 40 percent have a very common gene variant that reduces the effectiveness of these medications. That places them at a higher risk for developing blood clots after a procedure such as stenting," said principal investigator Colin M. Barker, M.D., assistant professor of cardiology at The University of Texas Health Science Center at Houston (UTHealth) and an attending physician at Memorial Hermann Heart & Vascular Institute.

Results of the study are published in the Oct. 18, 2010 issue of the 'Journal of the American College of Cardiology: Cardiovascular Interventions.'

Barker and researchers at the Scripps Translational Science Institute in La Jolla, Calif., enrolled 41 patients. In the 20 who had the gene variant, doubling the dose of the blood thinner clopidogrel (Plavix) resulted in a significant reduction in platelet reactivity (the process that leads to the formation of blood clots).

"This is an important study because the discovery moves the field of personalized medicine and patient-centered care a step further," Barker said. "We are now studying this in larger, randomized, controlled clinical trials."