'A Viagra-like drug could reverse heart failure'
New research in sheep shows that a drug that doctors usually prescribe for the treatment of erectile dysfunction can also treat heart failure.
In people with heart failure, the heart muscle becomes unable to pump out blood efficiently, meaning that some organs may not receive the amount of oxygen that they need to function properly.
The Centers for Disease Control and Prevention (CDC) note that 5.7 million adults in the United States have heart failure and that approximately half of the people with this condition die within about 5 years of receiving their diagnosis.
Moreover, research that Cardiac Failure Review published in 2017 argued that there is a "global pandemic" of heart failure, with this condition affecting an estimated 26 million people worldwide.
Such numbers suggest that finding new ways to treat heart failure is a priority for specialists who study this condition.
Recently, Prof. Andrew Trafford led a team of researchers from the University of Manchester in the United Kingdom who found that a drug that doctors typically use to treat erectile dysfunction could also treat systolic heart failure, in which the heart's left ventricle loses the ability to contract as normal.
The findings of the new study, which the researchers conducted in sheep, appeared today in the journal Scientific Reports.
Tadalafil brings significant improvements
Prof. Trafford and team decided to focus on tadalafil, which is available under the brand name Cialis among others. This drug falls under the same category as sildenafil, which people commonly refer to by the brand name Viagra.
"We do have limited evidence from human trials and epidemiological studies that show tadalafil can be effective in treating heart failure," Prof. Trafford says.
The researchers studied the effects of the drug in sheep, whose hearts are very similar to those of humans. The team treated the sheep with tadalafil once they had developed heart failure symptoms that were serious enough to require intervention.
Prof. Trafford and colleagues induced heart failure in the animals through the use of a pacemaker, and when they treated them with tadalafil, they gave them doses consistent with what a human patient would usually receive for erectile dysfunction.
After just 3 weeks of tadalafil treatment, the researchers began to notice improvements in the animals that received this drug.
The drug improved the heart's contraction and almost completely restored its ability to respond to epinephrine. It is a lack of response to this hormone that causes breathlessness in heart failure.
Although so far, the researchers have only tested the effects of this drug in sheep, Prof. Trafford maintains that humans are likely to experience the same benefits.
"This study provides further confirmation, adds mechanistic details, and demonstrates that tadalafil could now be a possible therapy for heart failure," the researcher notes, adding, "It's entirely possible that some patients taking it for erectile dysfunction have also unwittingly enjoyed a protective effect on their heart."
