"In our investigation of acute coronary syndrome (ACS) patients discharged on beta-blocker therapy, we were able to associate risk of death with the characteristics of the patients' beta-adrenergic receptor genes," says co-author Howard L. McLeod, Pharm.D., professor of medicine, of genetics and of molecular biology and pharmacology at the School of Medicine. "We identified high-, intermediate- and low-risk groups that had particular variations in these genes, which interact with beta-blocker drugs."
Patients in the high-risk group had a five times higher risk of death than those in the low-risk group according to the hazard ratio, a statistical measure of risk. If further research indicates that beta-blockers are ineffective or create a higher risk in patients with certain variations of beta-adrenergic receptor genes, physicians may modify treatment to improve survival in these patients, according to McLeod.
"These data, while provocative, should not immediately alter current practice," says lead author David E. Lanfear, M.D., formerly of the School of Medicine and now a member of the cardiology staff in the heart failure and cardiac transplant section at Henry Ford Hospital in Detroit. "Further investigation is needed to determine whether the effect seen is due to the lack of efficacy of beta-blockers in higher-risk patients or if genotype alone is responsible for a worse outcome."
Beta-adrenergic receptors in the sympathetic nervous system respond to adrenaline, but beta-blocker drugs block this interaction, slowing the heartbeat and lower
Contact: Gwen Ericson
Washington University School of Medicine