New treatment for intractable heart failure found from compound in the blood
Researchers say they may be closer to finding a treatment for intractable heart failure using a safe compound already found in the blood. The compound, BH4, is already in FDA trials for the treatment of phenylketonuria. Scientists have discovered the compound prevented and reversed congestive heart failure in mouse studies.
When the heart muscle becomes stiff and cannot relax to completely fill with blood, the condition is known as diastolic heart failure. Sixty percent of patients with intractable heart failure die five years after being diagnosed with the disease. The other form is known as systolic heart failure that occurs when heart contractions are weak resulting in fluid buildup in the lungs and body tissues.
According to Samuel Dudley, professor of medicine and physiology at University of Illinois, at Chicago College of Medicine,” Although we have a number of treatments for systolic heart failure, there are no approved treatments at all for diastolic heart failure, a deadly disease..." Diastolic heart failure is usually caused by high blood pressure. Five and a half million Americans have congestive heart failure, and approximately half of those have diastolic heart failure.
"We know from previous studies that nitric oxide (NO) is necessary for blood vessel relaxation," said Dudley, "and that hypertension can lead to a decrease of NO in blood vessels." The researchers also know that tetrahydrobiopterin, or BH4, is essential for the tissues in the body to make nitric oxide.
The scientists discovered that by giving mice tetrahydrobiopterin, or BH4, they could prevent and even reverse heart failure. "We decided to try thinking of the heart as a huge blood vessel that might also be unable to make the NO it needed due to long-term hypertension, and see if adding BH4 could make a difference," said Dudley, who also said the researchers are "excited" about the findings.
Based on the studies, the researchers hope to find heart failure treatments based on BH4 therapy. The compound, found in the blood, reversed heart failure in the mouse studies, and could help the 670,000 new cases of congestive heart failure that are diagnosed each year.