According to University of Manchester research Tadalafil/Cialis may help to halt progression of heart failure, by helping to reverse some adverse biological and molecular effects of heart failure, and prevent development of HF symptoms in treated animals.
When the heart is too weak to pump enough blood around the body heart failure can occur; heart failure can also cause build-up of fluids that back up into the lungs, and fluid retention leading to swelling in various body parts. Currently treatments for heart failure are largely ineffective, and survival rates are worse than many common cancers.
HF is accompanied by changes to enzyme activity and molecular signalling pathways that inhibit heart responsiveness to key catecholamine hormones; and HF is associated with cellular structural remodeling, including loss of transverse tubule networks playing important roles in calcium ion transport and control heart cell contractility.
Tadalafil/Cialis blocks PDE5 which regulates tissue responses to adrenaline, studies suggest such inhibition can also protect the heart that animal studies support but most have started therapy before or alongside development of heart disease. Whether this inhibition has benefits when heart failure has already progressed to symptomatic disease, and whether or not it can improve survival was less unclear. But “we do have limited evidence from human trials and epidemiological studies that show tadalafil can be effective in treating heart failure.” says Andrew Trafford, PhD.
To test whether PDE5 inhibition would be beneficial in cases of heart failure with reduced ejection fraction a series of tests were carried out in sheep that were fitted with pacemakers to induce heart failure, which were treated using human equivalent doses of Tadalafil when HF progressed enough to need therapy. Within a few weeks treatment was found to have halted heart failure progression and some detrimental biochemical and signalling effects were reversed, as wells as transverse tubule network density and heart ability to respond to adrenaline were restored. Most control animals developed subjective symptoms of heart failure, while all of the treated animals remained free from signs of heart failure for the duration of the study providing insights to possible mechanisms by which PDE5 inhibition can protect against worsening heart failure.
“Importantly, in this study we demonstrate that PDE5 inhibition reverses rather than prevents the HF-dependent changes in cellular structure and catecholamine responsiveness as both the reduction in TT density and loss of catecholamine responsiveness are already present before PDE5 inhibition is commenced. Thus, this study adds to a growing weight of evidence on the effectiveness of PDE5 inhibition in treating systolic HF and demonstrates reversal of key elements of the disease process that are evident when cardiac dysfunction is at an advanced stage prior to initiation of PDE5 inhibition.”
“While tadalafil is a widely used and very safe drug with minimal side effects, it’s not known whether the treatment may have off-target effects in heart failure. The benefits also only relate to cases of systolic heart failure. Tadalafil is only suitable as a treatment for systolic heart failure, when the drug is not able to pump properly, and there may be interactions with other drugs patients are taking…… we would not advise the public to treat themselves with the drug and should always speak to their doctor if they have any concerns or questions.”
“Viagra-type drugs were initially developed as potential treatments for heart disease before they were found to have unexpected benefits in the treatment of erectile dysfunction. We seem to have gone full-circle, with findings from recent studies suggesting that they may be effective in the treatment of some forms of heart disease—in this case, heart failure … The evidence from this study—that a Viagra-like drug could reverse heart failure—should encourage further research in humans to determine if such drugs may help to save and improve lives.” says Metin Avkiran, MD of the British Heart Foundation.
