Aug. 10, 2007 -- Many people with long-standing high blood pressure develop heart failure. But some don't. Daniel P. Kelly, M.D., and colleagues at Washington University School of Medicine in St. Louis and other institutions are trying to figure out what could explain that difference.
Their latest research reveals that impaired energy production in heart muscle may underlie heart failure in some hypertensive patients. The researchers assert that a molecular factor involved in maintaining the heart's energy supply could become a key to new approaches to prevent or treat heart failure.
The molecular factor, a protein called estrogen-related receptor alpha (ERR alpha), helps the heart keep up with energy-draining conditions like high blood pressure, which makes the heart work harder to pump blood. In the July issue of Cell Metabolism, Kelly and his colleagues report that mice born without any ERR alpha developed symptoms of heart failure when their hearts were forced to pump against high pressure. The hearts of normal mice took that pressure overload in stride and stayed healthy. Those contrasting outcomes suggest that heart health greatly depends on ERR alpha.
"The stress of a cardiac pressure overload asks heart muscle to manufacture more high energy compounds, and without ERR alpha, they can't do it," explains Kelly, the Tobias and Hortense Lewin Professor and Chief of the Cardiovascular Division. "You could say that in high blood pressure conditions, the heart fails because it becomes energy starved. And if you could feed the heart by using a drug that enhances ERR, for example you might enable the heart to better keep pace with its energy requirements."
Although preventions and treatments are now available for heart failure due to high blood pressure, almost all of those drugs act outside the heart by dilating blood vessels throughout the body to reduce resistance. In the future, doctors might look for diminished energy capacity in
Contact: Gwen Ericson
Washington University School of Medicine