Viewpoint - ED acts as a window to the heart

Erectile dysfunction (ED) is common. It affects over 50 per cent of men aged 40-70 years. As its incidence increases with age, men over 70 years are three times more likely to have ED than men in their 40s.¹

A similar age-related pattern for the development of atherosclerosis is well known and the link between vascular disease and ED is now established.

Endothelial dysfunction is recognised as the common denominator.²

ED is present in over 50 per cent of men with coronary artery disease (CAD) and shares the same risk factors (see box) but what is little recognised is that ED may predict the presence of silent CAD.³

The chicken and the egg
The artery size hypothesis explains how ED can be a marker of silent vascular disease elsewhere and especially CAD. The penile arteries are 1-2mm in diameter and can therefore potentially experience the consequences of plaque burden and/or endothelial dysfunction before the larger coronary (3-4mm), carotid (5-7mm) or iliofemoral (6-8mm) arteries.

Given that the endothelium is the same throughout the arterial tree, a malfunction in the penile arteries causing ED may be a predictor of silent sub-clinical disease elsewhere.

Because an acute coronary syndrome is usually due to rupture of a lipid-rich subclinical plaque, ED could be an early warning sign of an acute event, as well as being a manifestation of advanced obstructive coronary disease.

There is now overwhelming evidence that ED predicts the presentation of both acute and chronic coronary disease. In a study of 300 men with acute coronary syndromes, the ED prevalence was 49 per cent with, importantly, ED developing in 67 per cent an average of three years beforehand.⁴

Similar studies have reinforced the lead time between ED developing and CAD presenting symptomatically, averaging two to three years.⁵

In type-2 diabetes, ED was present in 33.8 per cent of 133 men with silent CAD and only 4.7 per cent without CAD.⁶ In this study, ED predicted CAD independently of other risk factors.

In the placebo group of the Prostate Cancer Prevention Trial, ED was associated with a significant increase in the incidence of TIAs, angina, MI and stroke with a seven-year estimated cardiovascular event risk approaching 15 per cent.⁷

In a health-screening project the presence of moderate-to-severe ED was calculated to increase the 10-year relative risk of developing CAD by 65 per cent and stroke by 43 per cent.⁸

ED is a warning sign of vascular disease in general and in the absence of an obvious cause, such as trauma, a man with ED and no cardiac symptoms should be considered a cardiac or vascular patient until proved otherwise.³

What to do next
For most men with no cardiac symptoms, we have two to three years from the onset of ED to reduce the risk of a vascular event. These patients need a detailed cardiac assessment, measurement of BP, fasting glucose and lipid profile, and lifestyle advice on physical activity and weight control. Risk factors need to be addressed as if ED is a 'cardiovascular equivalent'.

Those at highest risk should ideally undergo stress testing and referral for specialist advice.⁹

It is of little use stating that ED acts as a window to the heart unless we look through the window and do something about it. ED is an important risk factor for vascular disease, adding to and worsening conventional risk factors as well as independently increasing cardiovascular risk.

• Dr Jackson is consultant cardiologist at Guy's Hospital, London

Risk factors for CAD and ED

Coronary artery disease

• Age
• Dyslipidemia - Hypertension
• Diabetes
• Smoking
• Sedentary lifestyle
• Obesity
• Depression
• Male gender
• Family history

Erectile dysfunction

• Age
• Dyslipidemia
• Hypertension
• Diabetes
• Smoking
• Sedentary lifestyle
• Obesity
• Depression
• Coronary artery disease, peripheral vascular disease

Key points

• ED is a marker of CAD.
• CAD usually follows ED within two to three years.
• ED should be considered as a risk factor for cardiovascular disease.
• Other cardiac risk factors should be reduced in patients with ED.

References

1. Feldman HA, Goldstein I, Hatzichristou D, Krane R J, McKinlay JB. Impotence and its medical and psychological correlates: results of the Massachusetts Male Aging Study. J Urol 1994; 151: 54-61.

2. Solomon H, Man J W, Jackson G. Erectile dysfunction and the cardiovascular patient: endothelial dysfunction is the common denominator. Heart 2003; 89: 251-3.

3. Jackson G. Erectile dysfunction: a marker of silent coronary disease. Eur Heart J 2006; 27: 2,613-4.

4. Montorsi F, Briganti A, Salonia A et al. Erectile dysfunction prevalence, time of onset and association with risk factors in 300 consecutive patients with acute chest pain and angiographically documented coronary artery disease. Eur Urol 2003; 44: 360-5.

5. Montorsi P, Ravagnani P M, Gallis et al. Association between erectile dysfunction and coronary artery disease. Role of coronary clinical presentation and extent of coronary vessels involvement. The Cobra Trial. Eur Heart J 2006; 27: 2,632-9.

6. Gazzaruso C, Giordanetti S, De Amici E et al. Relationship between erectile dysfunction and silent myocardial ischemia in apparently uncomplicated type 2 diabetic patients. Circulation 2004; 110: 22-6.

7. Thompson I M, Tangen C M, Goodman P J et al. Erectile dysfunction and subsequent cardiovascular disease. JAMA 2005; 294: 2,996-3,002.

8. Ponholzer A, Temml C, Obermayr R et al. Is erectile dysfunction an indicator for increased risk of coronary heart disease and stroke? Eur Urol 2005; 48: 512-18.

9. Jackson G. Erectile dysfunction and vascular risk: let's get it right. Eur Urol 2006; 50: 660-1.