Viagra lowers death, heart attack risk in men with CAD: Study

Sweden: Treatment with viagra lowers risk of heart attack, heart failure, and death in men with stable coronary artery disease (CAD), finds a recent study in the Journal of American College of Cardiology.

Impotence could occur as an early warning sign of cardiovascular disease (CVD) in healthy men. It can be treated either with alprostadil or with PDE5 inhibitors, such as Viagra or Cialis. Alprostadil acts by dilating the blood vessels so that the penis stiffens. PDE5 inhibitors, taken in tablet form orally before sex, acts by inhibiting the enzyme phosphodiesterase5 (PDE5) in the penis to increase the blood flow. 

PDE5 inhibitors were previously not recommended for men with coronary artery disease due to the risk of heart attack, since they decrease blood pressure. However, a 2017 study showed that men who have had a heart attack tolerate the drug well and that it even prolongs life expectancy and protects against new infarctions and heart failure.

Daniel P. Andersson, Karolinska University Hospital, Huddinge, Stockholm, Sweden, and colleagues, aimed to investigate the association between treatment with PDE5i or alprostadil and outcomes in men with stable coronary artery disease.

The study included all Swedish men with a prior MI or revascularization who received PDE5i or alprostadil during 2006 through 2013 at >6 months after the event. They were listed using the Swedish Patient Register and the Swedish Prescribed Drug Register.

The study in total included 16,548 men treated with PDE5i and 1,994 treated with alprostadil.

Cox regression was used to estimate adjusted hazard ratios with 95% confidence intervals for all-cause mortality, MI, heart failure, cardiovascular mortality, noncardiovascular mortality, cardiac revascularization, peripheral arterial disease, and stroke in men treated with PDE5i versus alprostadil.

"The risk of a new heart attack is greatest during the first six months, after which we consider the coronary artery disease to be stable," says lead author Martin Holzmann, adjunct professor at the Department of Medicine, Solna, Karolinska Institutet. 

"This suggests that there's a causal relationship, but a registry study can't answer that question," Holzmann says. "It is possible that those who received PDE5 inhibitors were healthier than those on alprostadil and therefore had a lower risk. To ascertain whether it is the drug that reduces the risk, we would need to randomly assign patients to two groups, one that takes PDE5 and one that doesn't. The results we have now give us very good reason to embark on such a study."

As PDE5 inhibitors are available by prescription only in Sweden, they cannot be bought over the counter, but Holzmann hopes that men with coronary artery disease do not shy away from addressing the matter with their doctor.

"Potency problems are common in older men and now our study also shows that PDE5 inhibitors may protect against heart attack and prolong life," he says.

Reference:

The study titled, "Association of Phosphodiesterase-5 Inhibitors Versus Alprostadil With Survival in Men With Coronary Artery Disease," is published in the Journal of American College of Cardiology.

DOI: https://www.jacc.org/doi/10.1016/j.jacc.2021.01.045