Sexual function is an important component of quality of life and subjective well being. Common disorders involve the depression of desire and arousal (female arousal disorder and male erectile dysfunction), and disorders of orgasm and ejaculation. Erectile dysfunction is the most commonly recognized and treated disorder, affecting >30% of men between 40 and 70 years of age, and a higher proportion still among those with cardiovascular disease.
Until recently, the management of sexual dysfunction was the responsibility of urologists, gynecologists, and mental health specialists. It now extends to multiple medical specialties, particularly primary care and cardiology, driven by the increased numbers of patients eligible for the oral treatment of erectile dysfunction, sildenafil citrate. Erectile dysfunction and cardiovascular disease share many risk factors and frequently coexist. Current therapies for erectile and other sexual dysfunction are safe and effective in most patients with or without cardiovascular disease, although nitrates remain a contraindication to sildenafil. Successful treatment of sexual dysfunction not only improves sexual relationships, but also overall quality of life.
The American Heart Association/American College of Cardiology Expert Consensus Document addressed the sildenafil issue in cardiovascular patients with erectile dysfunction. However, insufficient attention has been given to the assessment and management of the cardiac risk of sexual activity itself. After an international conference on sexual activity and cardiac risk convened at Princeton University on June 4 and 5,1999, a working group was formed to develop consensus recommendations for assessing the cardiac risk of sexual activity and for the office management of sexual dysfunction in patients with known cardiovascular risk factors and/or diseases.
Physiological correlates of sexual activity
Early studies indicated that the exercise aspects of sexual activity did not sufficiently account for the autonomic changes observed. Specifically, the effects of coital activity on heart rate, blood pressure, and oxygen consumption appear little greater than those associated with sexual arousal per se (noncoital activities or intercourse positions involving minimal physical exertion). More importantly, sexual arousal is associated with significant sympathetic discharge that may predispose to extrasystoles and ventricular tachyarrhythmias in susceptible individuals. Sympathetic activation appears intrinsic to sexual arousal, as evident in recent studies in women. One such study showed marked systolic and diastolic blood pressure increases during sexual arousal to orgasm in female volunteers in the laboratory, in addition to significantly increased levels of plasma epinephrine and norepinephrine.
Wide individual variability is observed in the physiological correlates of sexual activity (heart rate, blood pressure, and oxygen consumption). Further influences are situational factors such as the type of sexual stimulation and familiarity with the partner. In general, sexual activity is similar to mild-to-moderate intensity exercise for most individuals with or without coronary artery disease. Heart rate rarely exceeds 130 beats/min, and systolic blood pressure rarely exceeds 170 mm Hg.
The standard clinical measure of physical exertion is the metabolic equivalent (MET) of energy expenditure at the resting state. It is associated with a relative energy demand of oxygen consumption of approximately 3.5 mL/kg/min. MET values have been computed for a wide range of daily activities. For example, walking at 2 mph is associated with an energy expenditure of 2 METs. Some studies have associated sexual activity with an exercise workload of 2 to 3 METs in the preorgasmic phase and 3 to 4 METs during orgasm. In general, the upper range appears to be approximately 5 to 6 METs in younger individuals, and a lower range in older individuals or long-established relationships. However, excess sympathetic activation may push heart rate and blood pressure responses higher than observed during standard exercise at the same MET level. The capacity for symptom-free coitus was traditionally equated with the ability to climb two flights of stairs. However, the two activities differ in their patterns of autonomic response, not least due to the undisputed, if immeasurable, contribution of psychological and/or emotional factors.
The risk of myocardial infarction associated with sexual intercourse
Fewer than 1% of myocardial infarctions occur during sexual activity (attributable risk). A 50-year-old man in the United States has a baseline annual risk of myocardial infarction of about 1%. This annual risk increases to 1.01% as a consequence of sexual activity. In a high-risk man with a history of myocardial infarction, the annual risk increases only to 1.10%. Hence, there is a small but definite risk of a cardiac event for cardiovascular patients resuming sexual activity. Risk management takes into account the main factors involved: age, gender (male, postmenopausal female), hypertension, diabetes, obesity, smoking, dyslipidemia, and physical activity level.
Graded cardiac risk
A high-risk cardiovascular profile or established disease clearly increases the risk of sexual activity. The patient and partner are also likely to be apprehensive, especially after a recent myocardial infarction. Management is therefore guided by stratification based on graded cardiac risk. Patients can generally be placed into one of three major risk categories at initial assessment based on cardiovascular status: low, high, or intermediate/indeterminate.
Low-risk patients can initiate sexual activity without requiring further cardiovascular evaluation or treatment. High-risk patients have cardiovascular disease requiring specialized cardiac consultation, evaluation, and priority cardiovascular management. Sexual activity and the management of sexual dysfunction should be deferred until full evaluation, treatment and stabilization of the cardiac condition. Patients at intermediate/indeterminate risk should be counseled to resume sexual activity or be treated for sexual dysfunction only after cardiac evaluation has restratified them as high- or low-risk.
Asymptomatic, cardiovascular risk factors (excluding gender).
Mild, stable (documented and/or treated) angina.
Post-successful coronary revascularization.
Uncomplicated past myocardial infarction.
Mild valvular disease.
Congestive heart failure (left ventricular dysfunction and/or New York Heart Association [NYHA] class I).
These patients have no significant cardiac risk associated with sexual activity. Based upon current knowledge of the exercise demands or emotional stress involved, no special cardiac testing or evaluation is indicated before initiating or resuming sexual activity or undergoing therapy for sexual dysfunction.
Asymptomatic, cardiovascular risk factors (excluding gender)
These patients are generally good candidates for erectile or other dysfunction therapies, although routine monitoring of cardiovascular risk status remains important.
Regardless of the number or class of antihypertensive medications, such patients can be readily and safely managed with currendy approved medical therapies for sexual dysfunction. However, some antihypertensive medications, notably (3-blockers and thiazide diuretics, may compound erectile dysfunction. Calcium channel blockers and angiotensin-converting enzyme (ACE) inhibitors are less commonly responsible, and a-blockers more rarely still. Although there may be rational grounds for changing a patient’s drug class or dosage, there is little objective evidence that this actually reverses sexual dysfunction. Most of these patients will require direct therapy. Antihypertensive therapy has also been associated with depressed sexual response in women, although the specific mechanisms are uncertain.
Mild stable angina
Patients with documented treated angina typically have a functional reserve exceeding that required by sexual activity. Even in a borderline patient, medical management of the angina (after an exercise stress test) may prevent symptoms during sexual activity. The relative risk of acute nonfatal myocardial infarction during sexual activity does not significantly exceed that in subjects without documented cardiac disease. Antianginal therapy may need to be modified depending on the medication selected for the sexual dysfunction. Nitrates are an absolute contraindication to sildenafil.
The risk of sexual activity after revascularization, by either coronary artery bypass grafting (CABG) or percutaneous transluminal coronary angioplasty (PTCA), clearly depends on the adequacy of the procedure. Exercise stress testing helps to assess the extent and severity of residual ischemia. Adequate revascularization with no significant residual ischemia signifies low risk.
Recent myocardial infarction
The risk of coital recurrence, cardiac rupture, or perhaps more commonly, coitus-induced arrhythmia appears maximal in the first 2 weeks after infarction. After 6 to 8 weeks, however, asymptomatic patients are at low risk provided they have no ongoing ischemia and the postinfarction stress test is negative. In selected patients, this may even be reduced to 3 to 4 weeks. Completion of a successful exercise stress test to 4 to 5 METs or greater is useful in assessing risk and providing reassurance. Postinfarction exercise training also improves cardiovascular efficiency and reduces myocardial oxygen consumption during sexual activity. Cardiac rehabilitation programs are associated with fewer reported coital symptoms and lower coital heart rates.
Mild valvular disease
The patient with mild mitral valvular disease is not at appreciably increased risk of coital cardiac events. This may also be true of selected cases of aortic stenosis. Male patients may safely employ oral, intraurethral, or injectable medications for erectile dysfunction without the need for antibiotic prophylaxis.
Mild congestive heart failure (NYHA class I)
Most patients capable of performing activities of daily living without symptoms, especially if receiving appropriate treatment, have no increased risk of coital cardiac events.
Other cardiovascular conditions
Conditions such as atrial fibrillation with controlled ventricular response, mitral valve prolapse, and pericarditis should be managed on an individualized basis. Information on the risk associated with such conditions is scarce. Individual factors may prompt further cardiological assessment as appropriate.
Unstable or refractory angina.
Congestive heart failure (NYHA class III/IV).
Recent myocardial infarction (<2 weeks).
Hypertrophic obstructive and other cardiomyopathies.
Moderate-to-severe valvular disease.
A more or less restrictive approach to initiating or resuming sexual activity is advised in patients in this category until certain conditions are met.
Unstable refractory angina
Patients with severe, accelerated, refractory, new-onset, or rest angina are at higher risk of coital infarction. Their functional cardiac reserve is exceeded by the mild physical activity typically involved in coitus.
Untreated, uncontrolled, accelerated, or malignant hypertension is a clear risk factor for both acute cardiac and vascular events, including stroke.
Congestive heart failure (NYHA class III or IV)
Coitus can trigger cardiac decompensation in patients who are breathless at rest (NYHA class IV) or when walking on the flat (class III).
Recent myocardial infarction
Coitus should be avoided in the first 2 weeks.
Malignant arrhythmia is an uncommon cause of sudden death during sexual activity. However, exercise or coitus can induce high-risk, frequently ventricular, arrhythmias. Holter monitoring during sexual activity may help in selected cases. However, patients with an implanted defibrillator or pacemaker do not appear to be at any greater risk
Hypertrophic obstructive cardiomyopathy/idiopathic hypertrophic subaortic stenosis
Either condition is associated with syncope and sudden death during or after exercise. Little is known about the specific risk of sexual activity or sexual dysfunction therapy in such cases. Vasodilators may increase the intra-ventricular gradient and must be avoided. Management of effort-induced symptoms or arrhythmias should be guided by cardiological evaluation, including exercise stress testing and echocardiography. Specific recommendations on sexual activity can be made accordingly.
Moderate-to-severe valvular disease
Significant aortic stenosis is associated with sudden death. Little is known about the impact of sexual activity in this condition, except that vasoactive drugs must be used with caution: systemic vasodilation in such patients risks depressing coronary and cerebrovascular perfusion pressures.
3 cardiovascular risk factors (excluding gender).
Moderate stable angina.
Recent myocardial dysfunction (>2 weeks, <6 weeks).
Left ventricular dysfunction and/or congestive heart failure (NYHA class II).
Noncardiac signs of atherosclerosis (stroke, peripheral vascular disease).
In these cases, referral to a cardiologist can help the primary care physician to assess the relative safety of sexual activity in the individual patient.
Asymptomatic, 3 risk factors (excluding gender)
Exercise stress testing should be considered, given the increase in risk profile. A sedentary lifestyle is an important risk factor that justifies an exercise test in this setting.
Moderate stable angina
Myocardial ischemia in patients with stable angina is usually reproducible at a given exercise-induced heart rate and increase in systolic blood pressure. Exercise testing will increase the accuracy of risk assessment.
Recent myocardial infarction (>2 weeks, <6 weeks)
Exercise testing is indicated by the slighdy higher risk of coital ischemia, reinfarction, and malignant arrhythmia.
Left ventricular dysfunction/congestive heart failure (NYHA class II)
Class II heart failure and asymptomatic left ventricular dysfunction (ejection fraction <40%) are moderate risk factors for exacerbation during sexual activity. Cardiovascular assessment and rehabilitation will facilitate restratification into a lower risk category.
Noncardiac signs of atherosclerosis
Atherosclerosis is a diffuse condition affecting multiple vascular beds. Clinically evident peripheral arterial disease and a history of stroke or transient ischemic attack are risk factors for myocardial infarction. Most such patients require cardiological referral.
Risk stratification and patient management algorithm
Assessment of the risk associated with sexual activity forms a 2-step process with the treatment of sexual dysfunction and can be represented in a cardiovascular risk stratification and patient management algorithm (Figure).
Assessment of sexual function should be routinely included in the initial evaluation of all patients. Further clinical evaluation based upon a thorough medical history, physical examination, and relevant laboratory testing enables stratification of patients into high, low, or intermediate levels of cardiac risk. Specialized cardiovascular testing is recommended to reclassify patients at intermediate (or indeterminate) levels of risk into the low- or high-risk category.
The majority of patients at low risk may be safely encouraged to engage in or resume sexual activity or to receive treatment for sexual dysfunction as needed. Patients at high risk should be stabilized by cardiological treatment for their specific condition(s) before resumption of sexual activity is considered or treatment of sexual dysfunction is recommended. Additional clinical considerations, such as the patient's age, overall health status, and motivational state may need to be taken into account in making this determination. Patient follow-up and reassessment at regular intervals (for example every 6 months) is recommended in all cases.
Sexual activity Therapy for sexual dysfunction
Sexual activity deferred until stabilization of cardiac condition
Figure. Cardiovascular risk stratification and patient management.
Reproduced from: De Busk R, Drory Y, Goldstein I, et al. Management of sexual dysfunction in patients with cardiovascular disease: recommendations of The Princeton Consensus Panel. Am J Cardiol. 2000;86:175-181; Copyright Â© 2000 Elsevier Science, Ltd.
management; sexual dysfunction; physiology; risk; myocardial infarction; cardiovascular risk stratification