Proceedings of PRINCETON IV: PDE5 inhibitors and cardiac health symposium

INTRODUCTION

Prior consensus meetings have addressed the relationship between phosphodiesterase type 5 (PDE5) inhibition and cardiac health. Given significant accumulation of new data in the past decade, a fourth consensus conference on this topic was convened in Pasadena, California, on March 10 and 11, 2023.

OBJECTIVES

Our meeting aimed to update existing knowledge, assess current guidelines, and make recommendations for future research and practice in this area.

METHODS

An expert panel reviewed existing research and clinical practice guidelines.

RESULTS

Key findings and clinical recommendations are the following: First, erectile dysfunction (ED) is a risk marker and enhancer for cardiovascular (CV) disease. For men with ED and intermediate levels of CV risk, coronary artery calcium (CAC) computed tomography should be considered in addition to previous management algorithms. Second, sexual activity is generally safe for men with ED, although stress testing should still be considered for men with reduced exercise tolerance or ischemia. Third, the safety of PDE5 inhibitor use with concomitant medications was reviewed in depth, particularly concomitant use with nitrates or alpha-blockers. With rare exceptions, PDE5 inhibitors can be safely used in men being treated for hypertension, lower urinary tract symptoms and other common male disorders. Fourth, for men unresponsive to oral therapy or with absolute contraindications for PDE5 inhibitor administration, multiple treatment options can be selected. These were reviewed in depth with clinical recommendations. Fifth, evidence from retrospective studies points strongly toward cardioprotective effects of chronic PDE5-inhibitor use in men. Decreased rates of adverse cardiac outcomes in men taking PDE-5 inhibitors has been consistently reported from multiple studies. Sixth, recommendations were made regarding over-the-counter access and potential risks of dietary supplement adulteration. Seventh, although limited data exist in women, PDE5 inhibitors are generally safe and are being tested for use in multiple new indications.

CONCLUSION

Studies support the overall cardiovascular safety of the PDE5 inhibitors. New indications and applications were reviewed in depth.

The Princeton IV Consensus Recommendations for the Management of Erectile Dysfunction and Cardiovascular Disease

The Princeton Consensus (Expert Panel) Conference is a multispecialty collaborative symposium dedicated to optimizing sexual function and preserving cardiovascular health. The Fourth Princeton Consensus Conference was convened on March 10-11, 2023, at the Huntington Medical Research Institutes in Pasadena, California. Princeton panels I to III addressed the clinical management of men with erectile dysfunction (ED) who also had cardiovascular disease. Thirteen years since Princeton III, Princeton IV builds on previous foundations in several key areas. Mounting evidence supports the need for providers to treat men with ED as being at risk for cardiac events until proven otherwise. Algorithms for the diagnosis and treatment of ED are updated with new recommendations for coronary artery calcium scoring for advanced cardiovascular risk stratification. Optimization of oral phosphodiesterase type 5 inhibitors in the treatment of men with ED and cardiovascular disease is thoroughly explored, including recent evidence of potential cardioprotective effects of these drugs.

Long-term effects of phosphodiesterase-5 inhibitors on cardiovascular outcomes and death: a systematic review and meta-analysis

AIMS

Phosphodiesterase 5 inhibitors (PDE5i), which are widely used for the treatment of erectile dysfunction (ED), have been found to exhibit systemic vascular benefits by improving endothelial function. In this context, we sought to evaluate the effects of PDE5i on long-term cardiovascular outcomes and mortality.

METHODS AND RESULTS

A comprehensive search of electronic databases was conducted up to 30 May 2023. Cohort studies comparing PDE5i treatment at any dose with other ED treatment, placebo or no treatment and minimum follow-up duration of 6 months were considered eligible. The primary endpoints were: (1) major adverse cardiovascular events (MACE) and (2) all-cause mortality. Pooled risk ratios (RR) with 95% confidence intervals (CI) were calculated. Sixteen studies were included (1 257 759 subjects-10.5% treated with PDE5i). The majority of patients (99.4%) were men [median age 61.5 years (range 30-72.8)]. The median follow-up duration was 4.3 years (range 6 months-7.5 years). PDE5i use was associated with a significant reduction in the composite of MACE (RR 0.78, 95% CI 0.69-0.89). Moreover, the analysis of pooled data from 13 studies, demonstrated that the use of PDE5i was associated with a significantly lower risk of all-cause mortality (RR 0.70, 95% CI 0.56-0.87).

CONCLUSION

The use of PDE5i primarily in men with or without known coronary artery disease was associated with a lower risk for cardiovascular events and overall mortality. This information underlines that PDE5i could provide clinical benefit beyond ED treatment and could instigate the conduction of further, large-scale randomized clinical trials.

Inflammatory proteins mediate male erectile dysfunction via plasma metabolites

Background

There are no clear conclusions as to whether inflammatory proteins and plasma metabolites influence erectile dysfunction (ED).

Aim

In this research, we used Mendelian randomization (MR) analysis to discover a causal relationship between inflammatory proteins, plasma metabolites, and ED.

Methods

Raw data with ED, inflammatory proteins, and plasma metabolites were obtained from the MRC IEU OpenGWAS and FinnGen database. After a series of screenings, the remaining single nucleotide polymorphisms were selected as instrumental variables or MR analysis to assess the relationship between genetically predicted inflammatory proteins or plasma metabolites and the pathogenesis of ED.

Outcomes

The relationship between inflammatory factors and ED was fully analyzed and elaborated.

Results

In the inverse variance-weighted method, there exists a significant causal relationship between 4 types of genetically predicted inflammatory proteins and 50 types of plasma metabolites with the incidence of ED. The primary discovery is that 3 inflammatory proteins, fibroblast growth factor 5, interleukin-22 receptor subunit alpha-1, and protein S100-A12, can impact the risk of ED through plasma metabolites.

Clinical Implications

ED metabolites and inflammatory proteins are also closely associated with cardiovascular diseases, warranting further exploration.

Strengths and Limitations

Our analysis is based on a European population, limiting its generalizability, the genome-wide association study dataset for ED has a relatively small number of cases, and we hope for larger genome-wide association study datasets for future validation.

Conclusion

This study has identified that inflammatory proteins can influence ED through plasma metabolites.

Princeton IV consensus guidelines: PDE5 inhibitors and cardiac health

BACKGROUND

In 1999, 1 year after the approval of the first oral phosphodiesterase type 5 (PDE5) inhibitor for the treatment of erectile dysfunction (ED), the first Princeton Consensus Conference was held to address the clinical management of men with ED who also had cardiovascular disease. These issues were readdressed in the second and third conferences. In the 13 years since the last Princeton Consensus Conference, the experience with PDE5 inhibitors is more robust, and recent new data have emerged regarding not only safety and drug-drug interactions, but also a potential cardioprotective effect of these drugs.

AIM

In March 2023, an interdisciplinary group of scientists and practitioners met for the fourth Princeton Consensus Guidelines at the Huntington Medical Research Institutes in Pasadena, California, to readdress the cardiovascular workup of men presenting with ED as well as the approach to treatment of ED in men with known cardiovascular disease.

METHOD

A series of lectures from experts in the field followed by Delphi-type discussions were developed to reach consensus.

OUTCOMES

Consensus was reached regarding a number of issues related to erectile dysfunction and the interaction with cardiovascular health and phosphodiesterase-5 inhibitors.

RESULTS

An algorithm based on recent recommendations of the American College of Cardiology and American Heart Association, including the use of computed tomography coronary artery calcium scoring, was integrated into the evaluation of men presenting with ED. Additionally, the issue of nitrate use was further considered in an algorithm regarding the treatment of ED patients with coronary artery disease. Other topics included the psychological effect of ED and the benefits of treating it; the mechanism of action of the PDE5 inhibitors; drug-drug interactions; optimizing use of a PDE5 inhibitors; rare adverse events; potential cardiovascular benefits observed in recent retrospective studies; adulteration of dietary supplements with PDE5 inhibitors; the pros and cons of over-the-counter PDE5 inhibitors; non-PDE5 inhibitor therapy for ED including restorative therapies such as stem cells, platelet-rich plasma, and shock therapy; other non-PDE5 inhibitor therapies, including injection therapy and penile prostheses; the issue of safety and effectiveness of PDE5 inhibitors in women; and recommendations for future studies in the field of sexual dysfunction and PDE5 inhibitor use were discussed.

CLINICAL IMPLICATIONS

Algorithms and tables were developed to help guide the clinician in dealing with the interaction of ED and cardiovascular risk and disease.

STRENGTHS AND LIMITATIONS

Strengths include the expertise of the participants and consensus recommendations. Limitations included that participants were from the United States only for this particular meeting.

CONCLUSION

The issue of the intersection between cardiovascular health and sexual health remains an important topic with new studies suggesting the cardiovascular safety of PDE5 inhibitors.

Risk of Death in Patients With Coronary Artery Disease Taking Nitrates and Phosphodiesterase-5 Inhibitors

BACKGROUND

Phosphodiesterase-5 inhibitor (PDE5i) treatment for erectile dysfunction is associated with lower mortality compared with no treatment for erectile dysfunction after myocardial infarction (MI). There are conflicting results regarding the impact of PDE5i treatment on mortality in conjunction with nitrate medication.

OBJECTIVES

The purpose of this study was to investigate the association between PDE5i treatment and cardiovascular outcomes in men with stable coronary artery disease treated with nitrate medication.

METHODS

Using the Swedish Patient Register and the Prescribed Drug Register we included men with previous MI or revascularization in 2006-2013 who had 2 dispensed nitrate prescriptions within 6 months. Exposure was defined as at least 2 filled prescriptions of any PDE5i. We performed multivariable Cox proportional hazard regression to estimate HRs with 95% CIs for all-cause, cardiovascular, and noncardiovascular mortality, MI, heart failure, cardiac revascularization, and major cardiovascular events (MACE).

RESULTS

In total, 55,777 men were treated with nitrates and 5,710 men with nitrates and a PDE5i. The combined use of PDE5i treatment with nitrates was associated with higher mortality (HR: 1.39; 95% CI: 1.28-1.51), cardiovascular mortality (HR: 1.34; 95% CI: 1.11-1.62), noncardiovascular mortality (HR: 1.40; 95% CI: 1.27-1.54), MI (HR: 1.72; 95% CI: 1.55-1.90), heart failure (HR: 1.67; 95% CI: 1.48-1.90), cardiac revascularization (HR: 1.95; 95% CI: 1.78-2.13), and MACE (HR: 1.70; 95% CI: 1.58-1.83).

CONCLUSIONS

The use of a PDE5i in combination with nitrate medication in men with stable coronary artery disease may pose an increased hazard for cardiovascular morbidity and mortality. Careful patient-centered consideration before prescribing PDE5is to patients with cardiovascular disease using nitrate medication is warranted.

Improvement in Endothelial Function in Men Taking Phosphodiesterase Type 5 Inhibitors for Erectile Dysfunction

BACKGROUND

The purpose of this research was to explore the mechanistic protective cardiovascular effects of phosphodiesterase-5 inhibitors (PDE5-Is) in males with erectile dysfunction. Erectile dysfunction and endothelial dysfunction both precede clinical atherosclerosis. Studies have shown that treatment for erectile dysfunction with PDE5-Is decreased death, heart failure, myocardial infarction, and revascularization in males with erectile dysfunction who had previous myocardial infarction, and cardiovascular events.

METHODS

This was a pilot study that recruited 5 men with erectile dysfunction without cardiovascular disease. Endothelial function (flow-mediated percent change of the diameter of the brachial artery), erectile dysfunction grade, high-sensitivity C-reactive protein, and body mass index were measured before and 3 months after starting treatment with tadalafil, 5 mg daily. Pearson's analysis was performed to study a correlation between the change in erectile dysfunction and the change in endothelial function.

RESULTS

A significant correlation was found between changes in flow-mediated percent change of the diameter of the brachial artery and changes in erectile dysfunction following the administration of tadalafil (P = .010; Pearson correlation coefficient = 0.959). No change was observed in C-reactive protein or weight.

CONCLUSIONS

Erectile dysfunction and endothelial dysfunction are risk factors for cardiovascular disease. Our study showed that PDE5-Is improved endothelial function and erectile dysfunction (with a significant correlation). Improving endothelial function could be the mechanism that leads to a reduction in cardiovascular events and death in men with erectile dysfunction treated with PDE5-Is.

Cardiac Effects of Phosphodiesterase-5 Inhibitors: Efficacy and Safety

The coexistence of cardiovascular disease and erectile dysfunction is widespread, possibly owing to underlying endothelial dysfunction in both diseases. Millions of patients with cardiovascular disease are prescribed phosphodiesterase-5 (PDE5) inhibitors for the management of erectile dysfunction. Although the role of PDE5 inhibitors in erectile dysfunction therapy is well established, their effects on the cardiovascular system are unclear. Preclinical studies investigating the effect of PDE5 inhibitors on ischemia-reperfusion injury, pressure overload-induced hypertrophy, and chemotoxicity suggested a possible clinical role for each of these medications; however, attempts to translate these findings to the bedside have resulted in mixed outcomes. In this review, we explore the biologic preclinical effects of PDE5 inhibitors in mediating cardioprotection. We then examine clinical trials investigating PDE5 inhibition in patients with heart failure, coronary artery disease, and ventricular arrhythmias and discuss why the studies likely have yet to show positive results and efficacy with PDE5 inhibition despite no safety concerns.

Heterogeneity of fibroblasts is a hallmark of age-associated erectile dysfunction

BACKGROUND

The prevalence of age-associated erectile dysfunction (ED) increases pronouncedly with age. However, the cellular composition and transcriptomic changes of aging penile corpus cavernosum remain largely unclear.

METHODS

Herein, we performed single cell sequencing penile corpus cavernosum from five young with normal erectile response and five old rats with ED.

RESULTS

Clustering analysis identified 19 cell types, such as fibroblasts, myofibroblasts and immune cells. We next revealed their transcriptomic alterations and investigated novel subpopulations of major cell types. Among them, fibroblasts possessed the largest cell number and showed apparent heterogeneity. By performing single-cell entropy analysis on fibroblasts, we observed the age-associated decrease of entropy, and aged fibroblasts were found to adopt senescent secretory phenotype, as evidenced by the high expression of genes associated with the senescence-associated secretory phenotype (SASP). Finally, we constructed a comprehensive intercellular communication network and highlighted key mediators of crosstalk between fibroblasts and other cell types.

CONCLUSIONS

We plotted a cellular atlas of aging cells within penile corpus cavernosum, especially fibroblasts. Our work will deepen the understanding of the heterogeneity among certain cell types within aged penile corpus cavernosum, which will generate positive effects on the future treatment of age-associated ED.

Effect of phosphodiesterase type 5 inhibitors on major adverse cardiovascular events and overall mortality in a large nationwide cohort of men with erectile dysfunction and cardiovascular risk factors: A retrospective, observational study based on healthcare claims and national death index data

BACKGROUND

Treatment with phosphodiesterase type 5 inhibitors (PDE-5is) is effective in treating erectile dysfunction (ED).

AIM

The objective of this study was to determine the effect of PDE-5is on the incidence of major adverse cardiovascular (CV) events (MACE; composite outcome of CV death, hospitalization for myocardial infarction, coronary revascularization, stroke, heart failure, and unstable angina pectoris) and overall mortality.

METHODS

A retrospective observational cohort study was conducted in a large US claims database in men with ≥1 diagnosis of ED without prior MACE within 1 year, from January 1, 2006, to October 31, 2020. The exposed group had ≥1 claim for PDE-5i and the unexposed group had no claims for PDE-5i, and the groups were matched up to 1:4 on baseline risk variables.

OUTCOME

The primary outcome was MACE and the secondary outcomes were overall mortality and individual components of MACE, determined by multivariable Cox proportional hazard modeling.

RESULTS

Matched plus multivariable analyses showed that MACE was lower by 13% in men exposed (n = 23 816) to PDE-5is (hazard ratio [HR] 0.87; 95% CI 0.79-0.95; P = .001) vs nonexposure (n = 48 682) over mean follow-up periods of 37 and 29 months, respectively, with lower incidence of coronary revascularization (HR 0.85; 95% CI 0.73-0.98; P = .029), heart failure (HR 0.83; 95% CI 0.72-0.97; P = .016), unstable angina (HR 0.78; 95% CI 0.64-0.96; P = .021), and CV death (HR 0.61; 95% CI 0.41-0.90; P = .014) with PDE-5i exposure. Phosphodiesterase type 5 inhibitor-exposed men had a 25% lower incidence of overall mortality (HR 0.75; 95% CI 0.65-0.87; P < .001). Men without coronary artery disease (CAD) but with CV risk factors at baseline showed a similar pattern. In the main study cohort, men in the highest quartile of PDE-5i exposure had the lowest incidence of MACE (HR 0.45; 95% CI 0.37-0.54; P < .001) and overall mortality (HR 0.51; 95% CI 0.37-0.71; P < .001) vs the lowest exposure quartile. In a subgroup with baseline type 2 diabetes (n = 6503), PDE-5i exposure was associated with a lower MACE risk (HR 0.79; 95% CI 0.64-0.97; P = .022).

CLINICAL IMPLICATIONS

PDE-5is may have cardioprotective effects.

STRENGTHS AND LIMITATIONS

Strengths are the large numbers of participants and consistency of the data; limitations include the retrospective nature of the study and unknown confounders.

CONCLUSIONS

In a large population of US men with ED, PDE-5i exposure was associated with lower incidence of MACE, CV death, and overall mortality risk compared to non-exposure. Risk reduction correlated with PDE-5i exposure level.

Endothelial Dysfunction, Erectile Deficit and Cardiovascular Disease: An Overview of the Pathogenetic Links

Erectile dysfunction (ED) is a condition with multifactorial pathogenesis, quite common among men, especially those above 60 years old. A vascular etiology is the most common cause. The interaction between chronic inflammation, androgens, and cardiovascular risk factors determines macroscopically invisible alterations such as endothelial dysfunction and subsequent atherosclerosis and flow-limiting stenosis that affects both penile and coronary arteries. Thus, ED and cardiovascular disease (CVD) should be considered two different manifestations of the same systemic disorder, with a shared aetiological factor being endothelial dysfunction. Moreover, the penile arteries have a smaller size compared with coronary arteries; thus, for the same level of arteriopathy, a more significant blood flow reduction will occur in erectile tissue compared with coronary circulation. As a result, ED often precedes CVD by 2–5 years, and its diagnosis offers a time window for cardiovascular risk mitigation. Growing evidence suggests, in fact, that patients presenting with ED should be investigated for CVD even if they have no symptoms. Early detection could facilitate prompt intervention and a reduction in long-term complications. In this review, we provide an overview of the pathogenetic mechanisms behind arteriogenic ED and CVD, focusing on the role of endothelial dysfunction as the common denominator of the two disorders. Developed algorithms that may help identify those patients complaining of ED who should undergo detailed cardiologic assessment and receive intensive treatment for risk factors are also analyzed.

Cardiovascular Outcome Risks in Patients With Erectile Dysfunction Co-Prescribed a Phosphodiesterase Type 5 Inhibitor (PDE5i) and a Nitrate: A Retrospective Observational Study Using Electronic Health Record Data in the United States

BACKGROUND

Phosphodiesterase type 5 inhibitors (PDE5i) are first-line therapy for erectile dysfunction (ED). Approximately 1-4% of PDE5i recipients co-possess nitrates, despite this combination potentially producing clinically significant hypotension. Real-world data in these patients and insights into prescriber rationales for co-prescription are limited.

AIM

This study investigated whether PDE5i and nitrate co-possession is associated with increased rates of cardiovascular (CV) outcomes.

METHODS

Adult males with ED and PDE5i prescription and males with nitrate prescription were identified from a U.S. electronic health record database (2012-2016). Quantitative comparisons were made between patients with ED and co-possession (ED + PDE5i + nitrate), only nitrate possession (ED + nitrate and nitrate only [without ED]), and only PDE5i possession (ED + PDE5i).

OUTCOMES

We quantified incidence of CV outcomes in co-possession and comparator periods, calculating incidence rate ratios after propensity score matching. Prescriber rationales were derived by reviewing virtual patient records.

RESULTS

Over 168,000 patients had ≥1 PDE5i prescription (∼241,000 possession periods); >480,000 patients had ≥1 nitrate prescription (∼486,000 possession periods); and 3,167 patients had 3,668 co-possession periods. Non-significantly different or lower rates of CV outcomes were observed for co-possession periods vs ED + nitrate and nitrate only periods. Most CV outcome rates were non-significantly different between co-possession and ED + PDE5i periods (myocardial infarction, hospitalized unstable angina and fainting were higher with co-possession). From qualitative assessment of patient records with co-possession, 131 of 252 (52%) documented discussion with a physician regarding co-possession; 69 of 131 (53%) warned or instructed on safely managing these contraindicated medications.

CLINICAL IMPLICATIONS

Findings from this real-world study indicate that co-possession of nitrate and PDE5i prescriptions is not associated with increased rates of CV outcomes, relative to possession of nitrates alone. Physicians should and often do discuss the risks of using both medications together with their patients.

STRENGTHS & LIMITATIONS

Strengths of this study are the large size of the U.S. real-world patient cohort with data available for analysis, and our ability to utilize natural language processing to explore co-prescription rationales and patient-physician interactions. Limitations are the retrospective nature of the analysis and inability to establish whether recorded prescriptions were filled or the medication was consumed.

CONCLUSION

Co-exposure of PDE5i and nitrates should continue to be avoided; however, co-possession of PDE5i and nitrate prescriptions is not necessarily associated with increased CV risk. Co-possession can be successfully managed in suitable circumstances. Nunes AP, Seeger JD, Stewart A, et al. Cardiovascular Outcome Risks in Patients With Erectile Dysfunction Co-Prescribed a Phosphodiesterase Type 5 Inhibitor (PDE5i) and a Nitrate: A Retrospective Observational Study Using Electronic Health Record Data in the United States. J Sex Med 2021;18:1511-1523.

Association of Phosphodiesterase-5 Inhibitors Versus Alprostadil With Survival in Men With Coronary Artery Disease

BACKGROUND

Phosphodiesterase 5 inhibitor (PDE5i) treatment is associated with reduced mortality compared with no treatment for erectile dysfunction after myocardial infarction (MI).

OBJECTIVES

This study sought to investigate the association between treatment with PDE5i or alprostadil and outcomes in men with stable coronary artery disease.

METHODS

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

RESULTS

This study included 16,548 men treated with PDE5i and 1,994 treated with alprostadil. The mean follow-up was 5.8 years, with 2,261 deaths (14%) in the PDE5i group and 521 (26%) in the alprostadil group. PDE5i compared with alprostadil treatment was associated with lower mortality (hazard ratio: 0.88; 95% confidence interval: 0.79 to 0.98) and with similar associations for MI, heart failure, cardiovascular mortality, and revascularization. When quintiles (q) of filled PDE5i prescriptions were compared using q1 as reference, patients in q3, q4, and q5 had lower all-cause mortality. Among alprostadil users, those in q5 had a lower all-cause mortality compared to q1.

CONCLUSIONS

In men with stable coronary artery disease, treatment with PDE5i is associated with lower risks of death, MI, heart failure, and revascularization compared with alprostadil treatment. Although the decrease in all-cause mortality was PDE5i dose dependent, the data do not permit the inference of causality or any clinical benefits of PDE5i because of the observational study design.