All blood thinners aren’t equal. And neither is their effect on patients with atrial fibrillation, the most common type of abnormal heart rhythm.
To determine how clinical and genetic factors predict a patient’s response to therapy, a multidisciplinary team led by School of Medicine researchers has received a four-year, $2.7 million grant from the National Heart, Lung, and Blood Institute.
Two main concerns for patients with atrial fibrillation are stroke and bleeding. People with this type of abnormal heart rhythm are five times more likely to develop a stroke than normal, according to Brian F. Gage, M.D.
But the use of potent blood thinners to prevent complications such as strokes could be dangerous for patients at risk for excessive bleeding.
“Right now, everyone with this condition is treated generically, regardless of genetic or clinical factors that might increase the risk for stroke or bleeding,” said Gage, associate professor of medicine and principal investigator for this study. “We’d like to be able to predict the right dose of the right drug for the right patient. To do that, we need to determine in advance who is likely to develop a stroke, heart attack or hemorrhage.”
In a pilot study with 400 patients, which recently appeared in the journal Thrombosis and Haemostasis, Gage’s team found variations in response to treatment were attributable to genetic factors about 10 percent of the time and clinical and demographic factors about 30 percent of the time.
“These preliminary results tell us there are a lot of different factors influencing the risk for stroke and bleeding,” Gage said. “We need a comprehensive, interdisciplinary approach to study this issue.”
To that end, Gage is collaborating with a multidisciplinary team at the University, including Charles S. Eby, M.D., associate professor of medicine and of pathology and immunology; Howard L. McLeod, Pharm.D., associate professor of genetics, of medicine and of molecular biology and pharmacology; Thomas G. Cole, Ph.D., research professor of medicine; Robert C. Culverhouse, Ph.D., instructor in medicine; Deepak Voora, M.D., internal medicine resident; and Paul E. Milligan, Pharm.D., clinical pharmacist.
The team is also working with investigators at Duke University, Boston University, Brigham and Women’s Hospital, Stanford University and the St. Louis Veterans Affairs Medical Center.