Genes Affect Response to Heart Failure Drugs

WEDNESDAY, Jan. 3 (HealthDay News) -- A person's genes may determine how he or she responds to heart failure drugs, say researchers in Germany.

Beta blockers are drugs used to treat people who have chronic heart failure. They slow nerve impulses traveling through the heart to reduce the heart's workload. They work on beta-adrenergic receptors, which are present in cardiac cells.

In a study that appears in the January issue of the Journal of Clinical Investigation, researchers from the University of Wurzburg, Germany, explained why some heart failure patients respond better to others to certain beta blockers.

The researchers examined variations in the genes that code for beta-adrenergic receptors in rat cardiac cells. They looked at how the receptors responded to three different beta blockers -- bisoprolol, metoprolol, and carvedilol.

While each drug caused a conformational change in the receptors, the effect of bisoprolol and metoprolol was minor in certain variations of the genes. Carvedilol, on the other hand, induced a 2.5-fold response in one of the variants.

It seems that beta-adrenergic receptors may vary from person to person, which alters the receptor's conformation, subsequently altering the receptor's response to a given beta blocker.

The authors of a commentary that accompanied the study proposed that these findings may help researchers figure out why there are ethnic differences in the response to beta blockers, since some receptor variations are more common in certain ethnicities.

Future studies are needed to determine if genetic testing could help doctors decide which heart failure medication would work best on a given patient.