Adequate cavernosal arterial inflow is necessary for penile erection. Arterial morphology,28 flow,29 and diameter30 differ between diabetic and nondiabetic populations with ED. BB and STZ-induced diabetic rats exhibit impairment of endothelium-mediated vascular smooth muscle relaxation, and proposed mechanisms include changes in the expression, activity, or post-translational modification of endothelial NOS.31
Towards this direction, several sufficiently powered studies have demonstrated a higher incidence of erectile dysfunction in patients with coronary artery disease, either asymptomatic or overt. At the same time, patients with erectile dysfunction are more prone to have established coronary artery stenosis of more than 50% and consequently evident CV disease. This is in conformity with the “artery size hypothesis” according to which smaller arteries (e.g., penile arteries) are the first to undergo a vascular lesion prior to the larger ones (e.g., coronary arteries). Moreover, in such patients erectile dysfunction is connected to the number of occluded vessels and more interestingly occurs over three years before coronary artery disease becomes apparent[76-80].
While a widely held perception is that CVD drugs cause ED, data attest towards the contrary and some agents may be even beneficial.41 Only thiazide diuretics lead clearly to ED, while some older beta-blockers also do so, but the side-effect of ED was very low (∼3%) when the patient was blinded for the drug administration.42 In fact, the vasodilating nebivolol may even improve erectile function.35,43 ACE-inhibitors, angiotensin-receptor blockers, and calcium-channel blockers are reported to have neutral or even a positive effect on erectile function35,41,43 but more evidence is needed. Regarding statins, the largest body of evidence point towards a beneficial effect.44 A negative effect has been reported in high statin doses, possibly related to a potential reduction in serum testosterone levels, but this dose dependency warrants further investigation. In terms of patient management, when ED onset and therapy initiation are linked and a cause-and-effect association is presumed, a short period of drug withdrawal with monitoring for ED resolution for verification may be an option. In patients who developed ED long after the initiation of CV drug treatment, sexual dysfunction is less likely to be drug associated and PDE5 inhibition therapy may be initiated.
Myocardial ischaemia is caused by the reduction of coronary blood flow as a result of fixed or dynamic epicardial coronary artery stenosis, abnormal constriction or deficient relaxation of coronary microcirculation, or because of reduced oxygen-carrying capacity of the blood.56 Atherosclerosis is the major cause of myocardial ischaemia. Plaque that develops in atherosclerosis can rupture causing platelet aggregation and subsequent thrombus formation, which leads to MI. The other mechanisms of myocardial ischaemia are encountered far less than atherosclerosis. Endothelial dysfunction has an important role in the progression of atherosclerosis. Endothelial dysfunction enhances the intimal proliferation and malregulation that results in plaque destabilisation in the arteries.6 This process, coupled with paradoxical vasoconstriction, can result in major cardiovascular events such as MI.32
Abstract | Full Text | Full Text PDF | PubMed | Scopus (37) | Google ScholarSee all References It has been postulated that regular exercise can decrease or possibly eliminate the small risk of myocardial infarction associated with sexual intercourse in most patients.8x8Muller, JE, Mittleman, A, Maclure, M, Sherwood, JB, Tofler, GH, and Determinants of Myocardial Infarction Onset Study Investigators. Triggering myocardial infarction by sexual activity: low absolute risk and prevention by regular physical exertion. JAMA. 1996; 275: 1405–1409
Abstract | Full Text | Full Text PDF | PubMed | Scopus (25) | Google ScholarSee all References Hemodynamic stress also may cause rupture of a vulnerable atherosclerotic plaque resulting in angina, myocardial infarction, or sudden cardiac death.80x80Muller, JE. Triggering of cardiac events by sexual activity: findings from a case-crossover analysis. Am J Cardiol. 2000; 86: 14F–18F
Crossref | PubMed | Scopus (25) | Google ScholarSee all References In comparison, a randomized placebo-controlled trial of 65 patients given either placebo or 95 mg/d of sustained-release metoprolol for 4 months after percutaneous coronary angioplasty found no significant difference in sexual function between the 2 groups.44x44Franzen, D, Metha, A, Seifert, N, Braun, M, and Hopp, HW. Effects of beta-blockers on sexual performance in men with coronary heart disease: a prospective, randomized and double blinded study. Int J Impot Res. 2001; 13: 348–351
Erectile dysfunction is frequent in patients with established CAD with prevalence rates ranging between 47 and 75% in studies.2,4,14 The AssoCiatiOn Between eRectile dysfunction and coronary Artery disease (COBRA) trial tested the hypothesis that the ED rate differs in CAD patients according to the clinical presentation (acute vs. chronic coronary syndromes) and the extent of vessel involvement (one vs. two to three vessel disease)15 (Figure 3). The overall ED prevalence in CAD patients was 47%, whereas in the normal coronary angiography group the ED rate was 24%. When separately considered, the ED rate was 22% in patients with acute coronary syndromes (ACS) and one-vessel disease and 55 and 65% in patients with ACS and multi-vessel disease and with chronic coronary syndrome, respectively. The study also showed that both severity (IIEF <10) and duration (>24 months) of ED were predictive of severe coronary involvement at angiography. This study offers pathophysiological and mechanistic explanations related to the clinical setting. In patients with multi-vessel disease, regardless of the clinical presentation, the advanced coronary and systemic atherosclerosis is the reason for the high rate of ED. However, in the setting of acute myocardial infarction with one-vessel disease, ED is far less frequent because the atherosclerotic burden is modest (i.e. abrupt occlusion of a single non-obstructing plaque in the absence of extensive atherosclerosis) in both the coronary and penile circulations.15,16
Undoubtedly, heart disease is and will continue to be one of the major health problems of modern society. Approximately one death every forty seconds occurs due to cardiovascular (CV) disease in the United States alone and arterial hypertension is one of the greatest culprits for it. Considering the fact that around 25% of the global population suffer from arterial hypertension, predicted to reach 1.5 billion people in the foreseeable future, it is easily deducted that a respectful part of the general population is under major and constant CV risk[2,3].
Abstract | Full Text | Full Text PDF | PubMed | Scopus (58) | Google ScholarSee all References Avoiding sexual activity between 6 AM and noon may be recommended to higher-risk patients because this is the time of peak incidence of most arrhythmias, myocardial ischemia, sudden cardiac death, and cerebrovascular accidents.1x1Muller, JE. Sexual activity as a trigger for cardiovascular events: what is the risk?. Am J Cardiol. 1999; 84: 2N–5N
In some cases, however, these drugs may be unsuitable for patients with heart disease. If you are considering one of these drugs and you have heart disease, as many diabetics do, be sure to tell your doctor. In rare cases, the pills may create “priapism,” a prolonged and painful erection lasting six hours or more (although reversible with prompt medical attention).
Low intracavernosal nitric oxide synthase levels are found in people with diabetes, smokers, and men with testosterone deficiency. Interference with oxygen delivery or nitric oxide synthesis can prevent intracavernosal blood pressure from rising to a level sufficient to impede emissary vein outflow, leading to an inability to acquire or sustain rigid erection. Examples include decreased blood flow and inadequate intracavernosal oxygen levels when atherosclerosis involves the hypogastric artery or other feeder vessels and conditions, such as diabetes, that are associated with suboptimal nitric oxide synthase activity.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (25) | Google ScholarSee all References The Framingham Heart Study found a baseline risk of myocardial infarction in a healthy 50-year-old nonsmoking man to be approximately 1% per year, or 1 chance per million per hour.87x87Anderson, KM, Odell, PM, Wilson, PW, and Kannel, WB. Cardiovascular disease risk profiles. Am Heart J. 1991; 121: 293–298
The development of PDE5-inhibitors is a clear example of how Western medicine approached the problem of ED differently from Eastern medicine. The erectogenic effect of sildenafil (Viagra®) was discovered by accident when patients undergoing heart clinical trials reported better erections as a side effect after taking sildenafil. This observation led to further elucidation of the NO/cGMP signalling pathway and development of PDE5-inhibitors as a first-line therapy in ED (5).
In a 2005 study, three months of twice-daily sets of kegel exercises combined with biofeedback and advice on lifestyle changes, such as quitting smoking, losing weight, and limiting alcohol, worked far better than just giving the participants advice. “Wearing tight pants will affect impotence along with some other medical conditions like diabetes and heart disease,” which can also affect a man’s degree of impotence, Dr. Jennifer Burns, specializing in family practice with an emphasis on gastrointestinal health at the BienEtre Center, told Medical Daily.
"Just because there is evidence doesn't mean it's good evidence," says Andrew McCullough, MD, associate professor of clinical urology at New York University Langone Medical Center in New York City, and one of the original clinical investigators for the ED drug Viagra (sildenafil). "And before men with ED start down the naturopathic route, it's smart to make sure that there isn't some underlying medical condition that needs to be corrected." Moreover, it is estimated that 30 million American men have erectile dysfunction, and 70% of cases are a result of a potentially deadly condition like atherosclerosis, kidney disease, vascular disease, neurological disease, or diabetes. Additionally, ED can also be caused by certain medications, surgical injury, and psychological problems.
Erectile dysfunction is common in the patient with cardiovascular disease. It is an important component of the quality of life and it also confers an independent risk for future cardiovascular events. The usual 3-year time period between the onset of erectile dysfunction symptoms and a cardiovascular event offers an opportunity for risk mitigation. Thus, sexual function should be incorporated into cardiovascular disease risk assessment for all men. A comprehensive approach to cardiovascular risk reduction (comprising of both lifestyle changes and pharmacological treatment) improves overall vascular health, including sexual function. Proper sexual counselling improves the quality of life and increases adherence to medication. This review explores the critical connection between erectile dysfunction and cardiovascular disease and evaluates how this relationship may influence clinical practice. Algorithms for the management of patient with erectile dysfunction according to the risk for sexual activity and future cardiovascular events are proposed.
In many of these cases, a discussion between the physician, the man with erectile dysfunction, and possibly his partner can help to resolve the issues leading to treatment failure. For men who experience severe side effects, can’t take the drugs for other reasons (such as taking medicines such as nitroglycerin), or don’t respond in spite of further education on the correct use of the drugs, there are other treatment options that can help most men remain sexually active.