Heart Disease

Cardiovascular disease is the leading cause of mortality worldwide. As cigarette smoking continues to be a status symbol in developing countries, this ranking is expected to continue well into twenty-first century. Heart disease rates increase with age, and older adults have worse outcomes and face special problems, including unusual disease presentation, increasing complications, and particular effects on daily activities and quality of life.

The heart is a muscle in the center of the chest. It is approximately the size of a fist and pumps blood throughout the body, working continuously and requiring a large blood supply. The heart can function through a large range of demands, from sleep to vigorous activity.

Ischemic heart disease

With increasing age, narrowings may develop in the coronary arteries that lead to the heart. This reduced blood supply causes ischemia (insufficient blood supply for the heart's work) and may produce chest pain or angina. Sudden blockages will result in a heart attack, also known as myocardial infarction (MI).

The incidence of heart disease begins to increase in men after the age of forty-five and in women after the age of fifty-five, but the rate for women tends to equal that of men after the age of seventy. It was once believed that hormone replacement therapy would protect women from heart disease, but more recent studies suggest this is not true. The Heart and Estrogen/Progestin Replacement Study (HERS) showed no benefit, as well as an increased risk of blood clots in the leg (deep vein thrombosis) and of gallbladder disease. Along with age, male gender, family history, and ethnicity are nonmodifiable risk factors for heart disease.

The most modifiable risk factor for heart disease is smoking, which leads to increased obstruction of the coronary arteries. Each cigarette also causes spasms in these arteries. Smokers have twice the risk of heart attacks as nonsmokers, and death rates for heavy smokers are two to three times that of nonsmokers. Quitting smoking at any age likely confers benefit. This implies that it reduces disease progression and reduces the risk of MI and stroke; it also leads to a 25 to 50 percent reduction in mortality and recurrent heart attacks (MI).

There are many aids available to help quit smoking. These include nicotine gum (although people with dentures find the gum difficult to use). A nicotine patch is also available. Success rates for quitting using nicotine replacement are 18 to 25 percent, compared to 5 to 10 percent without nicotine replacement. Patients with heart disease may be concerned that nicotine replacement is not safe (potential dangers are dream abnormalities, insomnia, and application site reaction, also known as patch-rash), but if the options are replacement therapy or continued smoking, replacement therapy is probably safer.

Other aids in quitting smoking include medication (e.g., Bupropion, cloridine, mortiptyline) that can help relieve the agitation associated with quitting. Success rates are in the range of 30 percent. Other aids include hypnosis, acupuncture, laser therapy, and relaxation therapy. It is not important which method is chosen; what is important is the need to stop smoking.

The next major modifiable risk factor is diabetes. Diabetes, like heart disease, also increases with age, and prevalence approaches 10 to 20 percent in people over the age of sixty-five. People with diabetes have a two- to four-fold increased risk of coronary artery disease. While good control of diabetes probably reduces risk for heart disease, it seems that control of blood pressure is even more important for diabetics in reducing the risk of developing heart disease.

High blood pressure has also been strongly associated with heart disease, and it also increases with aging. Treating hypertension with low-dose thiazide diuretics and long-acting dihydropyridine calcium channel blockers has been shown to reduce heart attack, stroke, and death for people over the age of sixty.

Cholesterol has also been shown to be a significant risk factor for increasing coronary artery disease (CAD). The HMG-CoA reductase inhibitors (statins) have consistently shown a 20 to 30 percent reduction in heart attacks and death. The cholesterol-lowering trials of statins excluded elderly patients over the age of seventy-five, but the medications are still considered safe. This is because there is wide experience with statins outside the elderly community, randomized trials have proven safe, and side effects have very rarely been reported. In addition, older patients have the greatest risk and suffer the greatest burden from heart attacks and strokes and therefore have the most to gain from the use of these drugs.

Obesity and physical inactivity are also associated with heart disease. Regular physical activity five to seven times per week for twenty to thirty minutes a day can reduce the risk of heart disease by 20 percent. This may pose problems for some older adults, as there is an increase in arthritis in the older population, which can limit their physical ability. The use of a stationary bicycle allows people to sit while exercising and takes the weight off the lower joints, as does swimming and water exercise.

The use of antioxidants such as vitamin E and beta carotene have proven to be of no benefit in reducing heart disease. Fish oil supplements, which contain polyunsaturated fatty acids, have been shown to have a small but significant benefit in those with established heart disease. A Mediterranean-style diet has also been shown to be protective for heart disease. Such a diet includes "more bread, more root vegetables and green vegetables, more fish, less meat (beef, lamb, and pork to be replaced with poultry), no day without fruit, and butter and cream to be replaced with. . . a rapeseed (canola) oil-based margarine" (de Lorgeril, 1994).

Angina is classified into four stages. Functional class I indicates symptoms only with vigorous exertion. Class II indicates symptoms with moderate exertion; such as climbing a flight of stairs, or walking more than two blocks. Functional class III occurs with less activity, and functional class IV occurs at rest or with very low levels of activity such as walking around the room. The classic symptoms of angina are central pressure or chest pain, although the full range of symptoms felt may also include burning; a feeling of heaviness, squeezing, tightness, or fullness; an ache or sharp pain; or even no chest symptoms at all. The chest pain often radiates up into the shoulder and neck and down the arm (the left more so than right). It may also present in the upper abdomen, back, and ears or jaw as well. Other typical features include shortness of breath, a cold sweat (diaphoresis), weakness, nausea and vomiting, or even a loss of consciousness. Typically, these symptoms occur with exertion and are resolved with rest. If there is a change in symptoms with less activity or if they are more severe or prolonged, then the condition is considered unstable angina. Worsening of symptoms is related to an increase in the amount of obstruction of the coronary arteries. At the extreme of this spectrum of acute ischemic syndromes or unstable angina is a myocardial infarction, or heart attack. This occurs when the circulation is insufficient to keep the heart muscle alive. Typically, it is associated with a blood clot forming on a partial obstruction in the coronary arteries.

Unfortunately, as people get older they are less likely to present with typical symptoms. They may not have pain or discomfort; problems with nausea, diaphoresis, and weakness may not be attributed to a heart problem; and, frequently, people do not seek attention. Also, diabetics and women are more prone not to have typical symptoms, resulting in misdiagnosis and undertreatment.

More alarmingly, the rates of death from heart attack increase sharply with increasing age. Mortality under the age of sixty-five is probably in the range of 4 percent. Mortality over the age of seventy-five climbs to 20 percent. Complications after an infarct are also increased in the elderly.

When presenting with a heart attack, patients are treated initially with aspirin. Provided there has been no recent surgery or problems with bleeding, they may also be treated with medication to dissolve the clot causing the heart attack. Best results occur if treated within an hour after the onset of symptoms, but benefits are still seen even six to twelve hours after the onset of pain. These thrombolytic medications (e.g., streptokinase, tissue plasminogen activator, reteplase, tenecteplase) have been shown to significantly reduce death, but they are also associated with an increased risk of bleeding. This can be controlled, however, unless there is bleeding in the head, which is almost always fatal. The benefits of the medication outweigh the risks, and, given that older patients have a much greater risk of dying, they also enjoy a much greater absolute benefit from this therapy. For two to three days following an infarct, patients are treated with intravenous medication or an injection of heparin, which keeps the blood thin.

Another possible treatment at the time of a myocardial infarction is angioplasty. Angioplasty has the greatest success for treating MIs, but requires rapid availability and experienced physicians.

Other medications given to patients to reduce mortality after a heart attack are beta blockers and ACE inhibitors. Calcium channel blockers and nitroglycerin under the tongue, in a pill or patch form, or even intravenously, help control pain with acute ischemic syndromes.

With an uncomplicated heart attack, people can expect to be in the hospital five to seven days. After one to two days of rest, patients start to mobilize. This is done while being monitored. Medications are adjusted as tolerated, and patients generally have an assessment of their heart function by an echocardiogram (ultrasound of the heart) or a wall motion study (a nuclear X-ray). Prior to going home, most patients have an exercise stress test in which they walk on a treadmill while heart rate, blood pressure, and any changes in the electrocardiogram, as well as any recurrence of symptoms, are monitored. If these occur at low levels of activity, there is increased risk and more aggressive investigations or treatment are warranted. If not, the patient is considered low risk and should be safe for discharge.

Following discharge, patients can gradually increase their physical activity, watching for any recurrence of symptoms. Walking for five to ten minutes twice a day, and gradually increasing this up to thirty minutes twice a day, and then to forty to sixty minutes of walking or exercise once a day is recommended.

Congestive heart failure

Congestive heart failure (CHF), or cardiomyopathy, occurs when the pumping action of the heart has been weakened, causing shortness of breath, fatigue, and swelling, particularly in the legs and feet. There is decreased circulation to the major organs, and the kidneys retain more fluid to compensate. There are also neurohormonal factors that tend to stimulate or overdrive the heart. This ultimately can lead to further damage and deterioration of the heart function. Patients with functional class III to IV heart failure, where they are short of breath with low levels of activity or at rest, have a three- to four-year mortality rate of 35 to 45 percent. Mortality may be higher in older patients.

The most common cause of congestive heart failure is ischemic heart disease or prior myocardial infarctions. Older patients with congestive heart failure and coronary artery disease may benefit from revascularization, and they are at higher risk for silent ischemia or missed infarcts. While this accounts for 70 percent of the patients with congestive heart failure, there are numerous other causes, including hypertension, valvular heart disease, viral infection, and arrhythmias. Another age-related problem is chemotherapy (e.g., adriamycin, anthracycline, herceptin, taxanes, and others) for cancer.

With acute congestive heart failure, patients become suddenly short of breath, cannot lie flat, and develop edema. Patients in an emergency room will be treated with oxygen therapy as well as intravenous diuretics and nitroglycerin to help remove the fluid.

CHF can also be more insidious, with a gradual or progressive course of increasing shortness of breath over hours and days. This may be related to a change in fluid or salt intake. CHF patients require polypharmacy (the use of multiple medications, as heart patients often take anywhere from four to twelve drugs a day) to control their symptoms and improve survival. Angiotensin-converting enzyme (ACE) inhibitors have been shown to significantly reduce symptoms, hospitalizations, and mortality. For patients who are intolerant of ACE inhibitors, a reasonable next choice would probably be angiotensin receptor blockers (ARBs).

Beta blockers lower blood pressure, slow the heart rate, and decrease the heart's workload. Previously felt to worsen CHF, studies have shown that beta blockers actually improve survival, reduce symptoms, and improve heart function. Side effects may include fatigue or depression, and it is important that such side effects not be simply blamed on "old age."

Patients with severe heart failure (functional class III to IV) and an ejection fraction less than 30 percent should be treated with spironolactone. This medication is a diuretic with unique neurohormonal-blocking properties that have been shown to significantly reduce mortality. Other diuretics are also useful to help control symptoms of fluid retention.

Digoxin also reduces symptoms and decreases hospitalizations in heart failure. There are other inotropic medications available that make the heart stronger and can temporarily improve symptoms. Unfortunately, these medications decrease survival. Some patients with very severe CHF, however, may feel the benefit of fewer symptoms is worth the risk of not living as long as they would otherwise.

Certain medications are generally contraindicated in heart failure. Most calcium channel blockers worsen heart failure, though amilodipine and felodipine have been shown to be safe. Nonsteroidal anti-inflammatory drugs (NSAIDS) used to treat arthritis may also aggravate heart failure, as can alcohol, which should generally be avoided. Exercise is useful but must be individualized to a patient's physical state. Most lifestyle modifications are probably best coordinated through a heart function clinic run by nurse specialists.

Heart transplantation is an option only if patients have failed all other medical treatments and still have severe heart failure. It is also restricted to patients under sixty-five, as older patients do not do as well with the burden of aggressive immunosuppressive therapy.

Valvular heart disease

The heart consists of four chambers. The two upper chambers, or atria, pump blood into the lower chambers, or ventricles. The right ventricle pumps blood through the lungs, and the blood then returns with oxygen to the left ventricle. The left ventricle pumps blood to the rest of the body and the veins return blood to the right atria. The valves between the atria and ventricle are the tricuspid valve (right) and the mitral valve (left). The valves out of the heart are the pulmonary valve (right) and the aortic valve (left). These prevent blood from going backwards, optimizing pumping efficiency. There are two possible malfunctions with any valve. The valves can become stenotic, or tight, and cause a flow obstruction, or the valves can become loose or floppy and allow backward flow, or insufficiency. Most valve disease in adults involves the mitral valve or the aortic valve. Rheumatic fever is probably the most common cause of valvular heart disease worldwide. Caused by untreated streptococcal infections, rheumatic fever can cause either stenosis or insufficiency. This is much less common where antibiotics are widely available. The aortic and the mitral valve are also prone to calcification, or thickening, and stenosis with aging.

Mild-to-moderate mitral insufficiency does not require any surgical intervention, but if the insufficiency becomes severe, or if there are signs of worsening heart failure, then repair or replacement of the mitral valve may be necessary. If the mitral valve is too tight, it can cause CHF. This is diagnosed by an echocardiogram. Mitral stenosis can be repaired either by surgery or with a balloon (valvuloplasty). The balloon prevents the need for invasive surgery but may result in some mitral insufficiency. If a patient is not a good candidate for open heart surgery, a valvuloplasty is an attractive option.

Artificial valves are either tissue or metal. Tissue valves are frequently used on older patients because they do not require anticoagulation and cause less risk of stroke, but they tend to wear out within ten to fifteen years. Metal or mechanical valves require special blood thinners (e.g., warfarin) to prevent the valve from clotting up and blocking, and to prevent strokes. These blood thinners do increase the risk of bleeding and require regular monitoring.

The aortic valve occasionally shows significant leaking. If this is mild or moderate, it can be treated with medication. Nifedipine has been shown to reduce the progression and the need for surgery. If regurgitation is severe, valve replacement may be necessary. Aortic stenosis causes an increased strain on the pumping action of the heart. This can lead to angina, CHF, or loss of consciousness (syncope). Surgery is the only definitive treatment with severe aortic stenosis.

The risks of valvular surgery is increased in elderly patients, including an increased rate of perioperative mortality, increased postoperative infection, stroke and renal failure, prolonged hospital stay, and postoperative disability. Operative risks also depend on other comorbidities. Surgical consideration must be individualized for each patient and a balanced discussion of all reasonable risks and benefits is necessary for making the right decision.

Patients with valvular heart disease or artificial heart valves are at increased risk for developing endocarditis—an infection on the heart valve. Antibiotics are needed to prevent such infections when undergoing surgery and dental work.

Arrhythmias

The sinus node is the pacemaker of the heart. It sits high in the atria and sends out a regular signal for the heart to beat. This signal is controlled by neurological and hormonal triggers that make the heart speed up and slow down as needed. There is a delay switch between the atria and ventricle that is called the AV node. Arrhythmias occur when the heart is either beating too fast (tachycardia) or too slow (bradycardia). The most common arrhythmias consist of isolated and premature atrial contractions (PACs), and extra beats, called premature ventricular contractions (PVCs). These are normal. Some people are quite sensitive and can feel the heart skip or flip in their chest, followed by a brief pause before the heart returns to its normal rhythm. Most people notice this when sitting quietly or lying in bed. Triggers include smoking, alcohol, coffee, tea, chocolate, or other stimulants. These are not life threatening and do not require treatment.

PVCs are also associated with CHF. While frequent PVCs may be a sign of increased risk in patients with ischemic heart disease and congestive heart failure, treating these with antiarrhythmic medication has been proven to increase mortality. Treatment is therefore reserved only for symptomatic and sustained ventricular tachycardia (VT), which causes symptoms of weakness, lightheadedness, or syncope. Sustained VT can cause sudden death and requires defibrillation with electrical paddles. This is commonly depicted in television and movies, with survival rates on television of approximately 75 percent. In reality, survival rates are generally less than 20 percent.

Unfortunately, medications that have been used to treat ventricular tachycardia have had modest success at best. Newer automatic implantable cardiac defibrillators (AICD) are special pacemakers, and they can be programmed to give a shock to restore normal rhythm when VT is detected. These devices are very expensive, but very effective.

Other common arrhythmias in the upper chamber of the heart include supraventricular (SVT) or atrial tachycardias. If prolonged, these can cause palpitations, shortness of breath, fatigue, weak spells, and even syncope.

Atrial fibrillation is an irregular SVT that can occur intermittently or continuously. Increasing age is a major risk factor for atrial fibrillation, which occurs in 5 percent of people over sixty-five and as many as 10 percent of people over the age of eighty. Patients who have infrequent atrial fibrillation lasting only a few minutes may not require any antiarrhythmic medication. If atrial fibrillation causes weakness, shortness of breath, angina, or heart failure, treatment with medication is warranted.

If patients do not convert (from abnormal to normal rhythm) with medication or are unstable, they may require electrical cardioversion, in which patients are sedated ,or asleep, and then shocked with external paddles to restore normal rhythm.

Frequently, patients are not symptomatic with atrial fibrillation, and it may be picked up incidentally. This can happen when a patient undergoes an electrocardiogram (ECG) as part of a routine or presurgical check-up and atrial fibrillation is discovered as a result. In this situation, there is no clear benefit to trying to restore sinus rhythm, as many antiarrhythmic medications carry significant side effects. Beta blockers or calcium channel blockers may be used to control heart rates with atrial fibrillation. The other important risk is stroke. Patients who have atrial fibrillation and no valvular disease, as well as no other risk factors, have a risk of stroke of 1 percent per year. Risk factors include age greater than seventy-five, prior stroke or transient ischemic attack (TIA), diabetes, and hypertension. These risks increase the annual stroke rate to 4 to 5 percent per year. Anticoagulation using warfarin reduces the risk of stroke by 70 to 80 percent. The major risk associated with using this medication is an increased risk of bleeding. If warfarin is deemed unsafe, aspirin reduces the risk by 35 percent.

Bradycardia, or slow heart rate, is caused by sinus node disease, AV node disease, or heart block (which means the electrical impulse fails to reach the ventricle; heart block is caused by AV node disease). It also increases in frequency with increasing age. Symptoms include weakness or lightheadedness, fatigue, shortness of breath, or syncope. Bradyarrhythmias can be diagnosed by an ECG at the time of symptoms. Additionally, a holter monitor (a small device worn for twenty-four to forty-eight hours to record all heart beats) can detect and record arrhythmias.

Several cardiac medications, such as beta blockers, calcium channel blockers, and digoxin, can cause bradyarrhythmias and may need to be stopped. A pacemaker is used to treat bradycardia, and is generally inserted in the operating room or in a cardiac care unit. Pacemakers have a single wire in the ventricle and sometimes a second one in the atria. Modern pacemakers are no longer affected by interference caused by micro-waves, metal detectors, or store security systems, though there has been some interactions noted with cellular phones. As the world becomes more electronically busy, the potential for interference with pacemakers changes, and pacemaker manufacturers must continue to strive to keep ahead of new potential hazards.

Driving and heart disease

Regulations regarding driving and heart disease vary in different locations. Patients who are functional class IV should not drive, while those who are functional class III or better may drive, provided their doctor agrees. Following unstable angina or a heart attack, patients should be stabilized one month before driving. Patients should also wait one month after bypass surgery or insertion of a pacemaker before driving. Patients with AICD and documented episodes of VT should probably not drive if spells or shocks are frequent.

Sex and heart disease

Sexual activity is an important part of people's lives, including both older adults and patients with heart disease. Many of the problems that give rise to heart disease, such as diabetes, hypertension, and various medications, can also give rise to sexual dysfunction. More commonly, patients and their partners may be afraid to engage in sexual intercourse for fear it may trigger a heart attack, though the risk of precipitating a heart attack or heart disease during intercourse is quite low.

The first question to be asked is whether the heart can cope with the physical exertion involved. A middle-aged person uses approximately four to five METS (metabolic equivalent units) during intercourse. This is the equivalent of a brisk walk or of climbing two to three flights of stairs. An exercise stress test is measured in METS, and this is an easy way to determine if the work of intercourse will bring on angina. In general, it is safe to resume sexual activity two to three weeks after a heart attack. While elderly patients likely exert less energy than younger individuals during sexual intercourse, if symptoms such as angina or excessive shortness of breath develop, then the activity should be stopped and, if necessary, nitroglycerin may be used to relieve angina.

The question of patients with heart disease using Viagra raises some serious concerns. While Viagra is a highly effective and popular medication to treat erectile dysfunction, it is contraindicated in patients who are using nitroglycerin. This includes patients who are using nitroglycerin pills or patches, or people who need to use nitroglycerin by spray or pills under the tongue to relieve angina. Viagra and nitroglycerin taken together may cause significant and severe drops in blood pressure. This effect may occur up to twenty-four hours after using Viagra, and the potential exists for these effects occurring even later in elderly patients.

Glossary of cardiac medication

Angiotensin-converting enzyme (ACE) inhibitors improve survival with congestive heart failure and ischemic heart disease, reduce complications and incidence of diabetes, and lower blood pressure. They may decrease kidney function, increase potassium levels, and cause a dry cough. Also present the rare risk of angioedema. Angiotensin receptor blockers are useful to lower blood pressure and for congestive heart failure with no cough. However, they may cause renal failure or elevated potassium levels.

Aspirin is a blood thinner that reduces death from heart attacks and angina and reduces the chance of strokes. It does present a very small increased risk of bleeding and ulcer irritation may occur.

Beta blockers improve survival following heart attacks with congestive heart failure and with hypertension, lower blood pressure, have antiarrhythmic benefits, and also improve heart function. Side effects include possible fatigue, depression, erectile dysfunction, and bradycardia. Beta blockers are contraindicated in asthmatics. Calcium channel blockers are used to reduce blood pressure and help with angina. May be associated with constipation or reflux. Constipation may be a bigger problem with older patients, especially if immobility is present. Edema is another possible problem associated with these drugs.

Clopedigrol is a blood thinner used to reduce heart attack or stroke and may be used with or instead of aspirin.

Digoxin is used in the treatment of heart failure and reduces symptoms and hospitalizations. Adverse effects include nausea, GI upset, and bradycardia.

Diuretics are useful for lowering blood pressure and treating symptoms of congestive heart failure. May be associated with postural hypotension. Also can cause electrolyte abnormalities, including low potassium. May increase uric acid and precipitate gouty attacks.

Nitroglycerin is used to treat symptoms of angina. It may cause headaches, but tolerance develops.

Spironolactone is used to treat severe congestive heart failure, but may increase potassium and decrease renal function. It also may cause gynecomastia and increased hair growth.

Statins (HMG-CoA reductase inhibitors) are useful in reducing cholesterol and decreasing the risk of heart attacks and strokes. Very rare problems with liver abnormalities or muscle pain sometimes occur.

Warfarin is used to prevent strokes with valvular heart disease and with atrial fibrillation. Negative effects include the increased risk of bleeding.