Does Long Term Viagra Improve Heart Disease?

Dr. Andrea M. Isidori, MD, PhD Consultant - Assistant Professor of Endocrinology Department of Experimental Medicine Medical Pathophysiology Sapienza University of RomeMedicalResearch.com Interview with:
Dr. Andrea M. Isidori, MD, PhD
Consultant – Assistant Professor of Endocrinology
Department of Experimental Medicine
Medical Pathophysiology
Sapienza University of Rome

Medical Research: What is the background for this study? What are the main findings?

Dr. Isidori : Our meta-analytic research originated to clarify some controversies emerging from the available human studies. We wanted to analyze if chronic PDE5i administration was cardioprotective and safe, and, if so, where the benefits were mainly seen: cardiac muscle, peripheral vessels, or both. In the last sixteen years pre-clinical and clinical research into the extra-urological effects of PDE5i has expanded dramatically, revealing previously unsuspected indications for these drugs. Several animal studies have shown that PDE5i attenuates cardiac remodeling, with an anti-hypertrophic and anti-fibrotic effect, and protects the heart against different types of injury. Some small clinical trials have demonstrated that chronic PDE5 inhibition improves cardiac performance and geometry in various clinical conditions, including heart failure, myocardial infarction and diabetic cardiomyopathy.

We showed that continuous administration of Viagra improves cardiac performance (increase of ejection fraction and cardiac index) and has an anti-remodeling effect (decrease of left ventricular mass and increase of end diastolic volume) without a major impact on vascular parameters (blood pressure and vascular resistance) suggesting that it does indeed have a direct effect on the heart. The novelty of this meta-analysis is the identification of subgroups of patients that may benefit more from PDE5i: patients with cardiac hypertrophy and heart failure. Our study is the first to show in a large patient cohort that chronic PDE5i administration improves cardiac output and decreases heart rate. This could result in longer survival, increased exercise tolerance and a better quality of life. Surprisingly, the magnitude of effects was similar to that seen with the drugs currently used to treat these clinical conditions, and was obtained in a relatively brief period (3 to 12 months). Most strikingly, we found that PDE5is are among the very few drugs that are able to improve diastolic relaxation, thus helping the correct refilling of the ventricle after each contraction, a nearly unique feature in drugs used in cardiology, and with incredible potential for future development in the prevention of heart failure. We also demonstrated their high tolerability and safety in a population that included elderly patients with various stages of cardiac disease and numerous comorbidities who were taking multiple pharmacological treatments. This setting resembles what we normally see in real life, supporting that daily administration is safe and involves no increase in the risk of adverse events compared to on-demand use.

Medical Research: What should clinicians and patients take away from your report?

Dr. Isidori : The main message is that PDE5i are new potential drugs for heart diseases for the benefits in terms of cardiac geometry and performance, independently of changes in hemodynamic parameters. So these findings suggest a direct effect of PDE5i on heart. These arguments are sustained by the good safety profile and the great tolerability of these drugs that could increase the patients’ compliance for the treatment of diseases that need many drugs with their consequent side effects.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Isidori : Our findings provide strong evidence for future research that should consist of large multicenter trials of the effects of PDE5i on cardiac architecture, including patients affected by heart failure and/or left ventricular hypertrophy and administrating chronic PDE5i for much longer period (more than 6 months). Some earlier research suggests that drugs like Viagra might interact differently with estrogen, so the investigation of gender differences on PDE5i clinical response is another key point for further studies.

Citation:
Is chronic inhibition of phosphodiesterase type 5 cardioprotective and safe? A meta-analysis of randomized controlled trials

Giannetta E, Feola T, Gianfrilli D, Pofi R, Dall’Armi V, Badagliacca R, Barbagallo F, Lenzi A, Isidori AM1.
BMC Med. 2014 Oct 20;12(1):185. [Epub ahead of print]