Researchers at the University of Maryland School of Medicine in Baltimore and the University of Colorado School of Medicine in Denver have identified a common genetic variation that could help determine whether a person with heart failure would benefit from beta-blockers. The findings are significant because it often takes several months to determine if a specific beta blocker is working for a patient. The findings are published online in the Proceedings of the National Academy of Sciences .
In a study that compared an investigational beta-blocker to a placebo, researchers found a 38% reduction in the death rate among patients who took the beta-blocker and who also had two copies of a genetic variant called arginine (Arg-389). In addition, these patients had a 34% reduction in another benchmark, the combined number of hospitalizations and deaths. People with another genetic variant, glycine (Gly-389), had no response to the drug compared to the placebo.
The genetic variance occurs in the beta-1 adrenergic receptor, which is the target for beta-blockers. People either have the Arg variant or the Gly variant. The researchers” conclusions are based in part on a retrospective look at data from a placebo-controlled study of the beta- blocker drug bucindolol, during which 1,040 heart failure patients were followed for up to four years. The study volunteers also consented to participate in genotyping. The researchers looked at four parameters: whether the patients had the real drug or the placebo, and whether they had the Arg-389 receptor or the Gly-389 receptor.
“For the first time, we have a genetic test that will help guide us to the best treatment for individual patients with heart failure and provide what has been called personal medicine,” says the study’s principal investigator, Stephen B. Liggett, M.D., professor of medicine and physiology at the University of Maryland School of Medicine and director of its cardiopulmonary genomics program. “This personalized therapy, based on genes, gives us an opportunity to tailor therapy in a way that we really were never able to do before,” adds Dr. Liggett.