Daniel P Andersson (Department of Medicine, Karolinska Institutet, Unit of Endocrinology, Metabolism, and Diabetes, Karolinska University Hospital, Stockholm, Sweden) and others report in Heart that treatment—specifically phos-phodiesterase (PDE5) inhibitors such as sildenafil (Viagra, Pfizer)—for erectile dysfunction in patients who have had a first myocardial infarction is associated with reduced mortality and heart failure hospitalisation. Study author Martin J Holzmann (Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden) tells Cardiovascular News why he believes a study evaluating the use of a PDE5 inhibitor in both men and women, after a first myocardial infarction, is needed.
Prior to this study, what was known about the association between erectile dysfunction and cardiovascular outcomes?
It is well-established that erectile dysfunction is related to an increased risk of cardiovascular outcomes in previously healthy men. To the best of my knowledge, no prior study has investigated the association between erectile dysfunction and cardiovascular outcomes in men after a first myocardial infarction.
What were the key findings of the study?
There was a reduction in mortality of 33% and a 40% reduction in hospitalisation for heart failure during 3.3 years of follow-up in men treated with so-called PDE5-inhibitors (eg. Viagra). No such association was found in men who were treated with alprostadil (Caverjet, Pfizer), which is a different type of medication for erectile dysfunction.
While our study does not provide an answer to the question regarding whether or not erectile dysfunction is itself related to outcomes after myocardial infarction, it does show an association between treatment for erectile dysfunction and reduction in cardiovascular outcomes.
Do you believe after a myocardial infarction, men should be asked about their sexual health (ie. to identify if they have erectile dysfunction and thus could benefit from the potential cardiovascular benefits of treatment)?
I think this is key! Our study suggests that erectile dysfunction is a seriously undertreated in men with myocardial infarction because only 7.7% of men in Sweden had a filled prescription for erectile dysfunction medication during a mean follow-up of 3.3 years after a first myocardial infarction. Many physicians still believe that we should be cautious with PDE5 inhibitors in men with a history of coronary heart disease. Both doctors and patients should dare to discuss sexual health.
Why do you think PDE5-inhibitors were associated with a reduction in outcomes but alprostadil was not?
There are numerous animal studies (and a few human studies) that suggest that PDE5 inhibitors have positive effects on endothelial function and also affects haemodynamics in a beneficial way. These are effects that are not found for alprostadil. So, from this point of view our findings were not surprising.
What further studies in this are needed?
I strongly believe that a randomised controlled trial in which both men and women with a myocardial infarction are prescribed a low daily dose of PDE5 inhibitors—for example, 5mg or 2.5mg daily dose of tadalafil (Lilly)—is needed.
The first author of the study, Daniel P Andersson, presented this study at the 2017 scientific sessions of the American College of Cardiology (ACC; 17–19 March, Washington, DC, USA).
