4.5: Diseases of the Heart

Thus far we have seen that aging of the heart does not significantly alter its ability to meet the needs of the body. However, few adults have a completely normal heart, and in most individuals some degree of disease adversely affects the heart. Both the incidence and seriousness of such disease increases with age.

The reasons for these increases are the same as the reasons for those which lead to an age‑related rise in other diseases: declining resistance to adverse conditions and slower repair; more time for the development of slowly progressing diseases; and higher chances for exposure to disease‑producing factors plus increasing occasions and durations of exposure to such factors.

Heart disease has been the fourth leading chronic disease among people between the ages of 45 and 64 and ranks third among chronic disease in people over age 64 (#1 is high blood pressure, #2 is arthritis). It is a leading cause for seeking medical care among those over age 64 and a major cause of disability and altered lifestyle. Though the incidence of death from heart disease among the elderly has been declining for decades, it is still the leading cause of death for people 65 and over.

Health, United States, 2013, U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention National Center for Health, “During 2001–2002 through 2011–2012, heart disease prevalence remained stable among men and women in all age groups except among women aged 65 and over, where the prevalence declined.” https://www.cdc.gov/nchs/data/hus/hus12.pdf

Health, United States, 2017, U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention National Center for Health, “During 2006–2016, the prevalence of heart disease increased with age. The prevalence remained stable among men and women aged 45–54, and declined among men and women aged 55–64 and 65 and over. In 2016, among those aged 45–54, the prevalence was similar for men (10.5%) and women (9.9%). Among those aged 55–64, the prevalence was higher among men (16.4%) than women (12.5%). Among those aged 65 and over, about one-third of men (33.9%) and one-quarter of women (23.6%) reported a history of heart disease.” https://www.cdc.gov/nchs/data/hus/hus17.pdf

For the latest statistics and data, see:

“OlderAmericans 2016: Key Indicators of Well-Being”

FederalInteragency Forum on Aging-Related Statistics

https://agingstats.gov/data.html

CDC (Centers for Disease Control and Prevention)

National Center for Health Statistics

“Interactive Summary Health Statistics for Adults”

https://www.cdc.gov/nchs/nhis/ADULTS/www/index.htm

U.S. Department of Health & Human Services National Center for Health Statistics (https://www.cdc.gov/nchs/index.htm), including National VitalStatistics ReportsVolume 68, Number 6 June 24, 2019U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention National Center for Health Statistics National Vital Statistics System Deaths: Leading Causes for 2017 by Melonie Heron, Ph.D.

(https://www.cdc.gov/nchs/data/nvsr/nvsr68/nvsr68_06-508.pdf) and (https://www.cdc.gov/nchs/data/nvsr/nvsr68/nvsr68_06-508.pdf#tab01).

Causes of death for all ages

Rank	Cause of death	Number (thousands)	Percent of total
	All causes	2,814	100.0
1	Diseases of heart	647	23.0
2	Malignant neoplasms	599	21.3
3	Chronic lower respiratory diseases	170	6.0
4	Cerebrovascular diseases	160	5.7
5	Alzheimer disease	146	5.2
6	Diabetes mellitus	121	4.3
7	Accidents (unintentional injuries)	84	3.0
8	Influenza and pneumonia	56	2.0
9	Nephritis, nephrotic syndrome and nephrosis	51	1.8
10	Parkinson disease	47	1.7
	All others (approx.)	780	26.0

Causes of death for all ages 65 year and older

Rank	Cause of death	Number (thousands)	Percent of total
	All causes	2,067	100.0
1	Diseases of heart	519	25.1
2	Malignant neoplasms	427	20.7
3	Chronic lower respiratory diseases	136	6.6
4	Cerebrovascular diseases	125	6.1
5	Alzheimer disease	120	5.8
6	Diabetes mellitus	59	2.9
7	Accidents (unintentional injuries)	55	2.7
8	Influenza and pneumonia	46	2.3
9	Nephritis, nephrotic syndrome and nephrosis	41	2.0
10	Parkinson disease	31	1.5
	All other causes	503	24.4

Coronary Artery Disease

Though several different heart diseases become more common and more serious with age, disease of the coronary arteries stands out as the most common of these disorders. (Suggestions: Chap 04 - 76-2-2)

Functions of Coronary Arteries

When a person is at rest, the coronary arteries are normally wide enough to allow ample blood to pass through to the cardiac muscle cells. However, the demand of cardiac muscle for oxygen goes up and down as the amount of work performed by the heart rises and falls. Conditions requiring more work and higher amounts of oxygen include increases in heart rate, stroke volume, width, and thickness and in blood pressure. Such increases occur when a person becomes physically active and as part of aging. The heart normally accommodates these increases by dilating its arteries to allow more blood to flow through them.

Effects of Atherosclerosis

The coronary arteries are prevented from supplying adequate blood flow to the heart by a disease called atherosclerosis. Atherosclerosis, which is described in greater detail later in this chapter, involves the formation and enlargement of a weak scar-like material called plaque in the walls of arteries. Plaque causes coronary arteries to become narrower and thus reduces blood flow (Figure 4.7). It also stiffens the arteries, reducing their ability to dilate when more oxygen is needed by the heart muscle. Finally, plaque causes roughening of the inner lining of the arteries and exposure of the underlying collagen. Roughness and collagen cause the blood in arteries to form clots; clots clog arteries and can stop blood flow quickly and completely. (Suggestion 76.02.02)

Figure 4.7 Atherosclerosis (Copyright 2020: Augustine G. DiGiovanna, Ph.D., Salisbury University, Maryland. Used with permission.)

Whenever the amount of oxygen needed by the heart is lower than the amount supplied, the cardiac muscle cells become weak and cannot pump enough blood to body organs. In addition, the muscle cells begin to produce a waste product called lactic acid, which upsets the normal acid/base balance. This imbalance injures the muscle cells, which become even weaker, and blood flow to the body drops further. All the organs begin to perform less well. The brain, kidneys, lungs, and heart are especially in danger because these organs require high levels of blood flow. A person in this condition often feels weak and out of breath and frequently experiences chest pain as injury to the heart cells develops. In mild cases the pain will subside if the person rests because the oxygen demand of the heart drops back to the level being supplied. Such temporary pain is called angina.

If oxygen demand is brought back into balance with oxygen supply soon enough, the heart begins to function normally again. Of course, the arteries are still diseased and the problem will most likely recur. The incidents may become more severe as the degree of coronary artery disease increases.

If the oxygen supply is very low for just a few minutes, the cardiac muscle cells begin to die. This condition is a true heart attack, also called a myocardial infarction (MI) (Figure 4.8). The heart becomes much weaker, and the pumping of blood drops precipitously. Cells in the brain and other organs deteriorate, and the person is in danger of dying. In fact, first‑time heart attacks are fatal approximately 50 percent of the time. Individuals who survive the initial effects of a heart attack still face many problems. The heart attack can cause damage to the heart valves or may produce a hole between the left and right ventricles, in which case the blood will flow in the wrong direction within the heart. Incorrect blood flow tends to overwork the heart, causing more heart disease and often preventing the lungs from functioning properly. An MI can also cause blood clots to form inside the heart chambers and then be pumped to other organs. If clots travel to the brain, they can cause a stroke. Finally, the heart can become so weak that the person may require lengthy medical treatment and face long‑term disability. The person's social contacts, sense of well‑being, normal daily routines, and employment often undergo radical undesirable changes.

Figure 4.8 Coronary artery disease. (Copyright 2020: Augustine G. DiGiovanna, Ph.D., Salisbury University, Maryland. Used with permission.)

Risk Factors

All that has been said thus far about coronary atherosclerosis may seem like bad news, but there is also good news about this disease. Most of the factors contributing to the development of atherosclerosis have been identified, and many of them can be avoided or greatly reduced. This is the main reason for the dramatic decline since 1950 in the incidence of deaths from heart disease. Furthermore, reducing or eliminating one or more of the risk factors reduces the chances of being affected by this disease regardless of the age at which the decrease in risk factors occurs. Of course, the earlier the risk‑reducing steps are taken, the greater is the benefit.

Another important fact regarding risk factors is that certain risk factors alter the effects of other risk factors in a given individual. Contrary to previously held beliefs, the interactions are poorly understood, quite complex, and they differ from person to person. Thus, a close approximation of an individual’s total risk for coronary artery disease can be made by simply adding the effects from each risk factor present. However, a more accurate approximation can be obtained by taking into account the known interactions among the risk factors present, which can lead to better interventions in risk management to reduce the risk of coronary artery disease. In conclusion, for a person with multiple risk factors, reducing or eliminating one risk factor may have a greater-than-expected decrease in the total risk of developing coronary artery disease.

When determining a person’s total risk for coronary artery disease using only a risk calculator, one must first decide for what specific problem the determination is being made. Examples of specific problems include having dangerously reduced heart function; having one’s first heart attack; dying from a heart attack; and having one of these problems within a specific time (e.g., the next ten years). The same is true for determining the risk of having a stroke from atherosclerosis (Chapter 6). Risk calculators used for determining a person’s total risk may be based on one of these specific problems or a combination of them, and may include stroke and other problems from atherosclerosis. Moreover, different calculators use different risk factors, assign different values to each risk factor, and use different assumptions and statistical methods to determine total risk values. Thus, each risk calculator may find different total risks for the same individual. More accurate determination of a person’s total risk would include individual consultation with a health professionals.

Thus, “Cardiovascular risk calculators weigh the same risk factors differently. For each risk factor, the relative risk increase from the calculator with the highest increase was generally three to eight times greater than the relative risk increase from the calculator with lowest increase. This likely contributes to some of the inconsistency in risk calculator estimation. It also limits the use of risk calculators in estimating the benefits of therapy.” (Quoted from “Variation among cardiovascular risk calculators in relative risk increases with identical risk factor increases”, G. Michael Allan, Faeze Nouri, Christina Korownyk, Michael R. Kolber, Ben Vandermeer, and James McCormack, BMC Res Notes. 2015; 8: 417. , PMCID: PMC4561470, PMID: 26346935, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4561470/)

A person can find their total risk of coronary artery disease using a risk calculator with any of the following.

CardioRisk Calculator ™ https://www.circl.ubc.ca/cardiorisk-calculator.html

“FRAMINGHAM RISK SCORE (FRS)Estimation of 10-year Cardio vascular Disease (CVD) Risk”

https://www.easycalculation.com/medical/framingham.php#:~:text=Framingham Risk Score is the estimation of 10-year,of heart attacks in adults older than 20.

“ASCVD Risk Estimator Plus”

American College of Cardiology http://tools.acc.org/ascvd-risk-estimator-plus/#!/calculate/estimate/

“Heart Disease Risk Calculator” Mayo Clinic Health System https://www.mayoclinichealthsystem.org/locations/cannon-falls/services-and-treatments/cardiology/heart-disease-risk-calculator

“Heart Risk Calculator” © Ahead Research Inc 2013-2020 http://www.cvriskcalculator.com/

“Omnibus Risk Calculator” http://static.heart.org/ahamah/risk/Omnibus_Risk_Estimator.xls

“Calculator: Cardiovascular risk assessment (10-year, men: Patient education)” UpToDdate EBMcalc is Copyright © 1998-2020 Foundation Internet Services, LLC https://www.uptodate.com/contents/calculator-cardiovascular-risk-assessment-10-year-men-patient-education

“Reynolds Risk Score” http://www.reynoldsriskscore.org/

“Heart Risk Calculator” Ahead Research Inc 2013-2020 http://www.cvriskcalculator.com/

References about problems from risk factor interactions and other issues in determining a person’s total risk include the following.

“Variation among cardiovascular risk calculators in relative risk increases with identical risk factor increases” G. Michael Allan, Faeze Nouri, Christina Korownyk, Michael R. Kolber, Ben Vandermeer, and James McCormack

BMC Res Notes. 2015; 8: 417.

PMCID: PMC4561470

PMID: 26346935

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4561470/

“Assessing Cardiovascular Risk: Systematic Evidence Review From the Risk Assessment Work Group, 2013”

U.S. Department of Health and human Services

National Institutes of health

https://www.nhlbi.nih.gov/sites/default/files/media/docs/risk-assessment.pdf

“Variation among cardiovascular risk calculators in relative risk increases with identical risk factor increases”

G. Michael Allan, Faeze Nouri, Christina Korownyk, Michael R. Kolber, Ben Vandermeer, and James McCormack

BMC Res Notes. 2015; 8: 417.

PMCID: PMC4561470

PMID: 26346935

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4561470/

“Significant interactions between traditional risk factors affect cardiovascular risk prediction in healthy general population”, Jussi A. Hernesniemi, Juho Tynkkynen, Aki S. Havulinna, Niku Oksala, Erkki Vartiainen, Tiina Laatikainen & show all

Pages 53-60 | Received 31 May 2014, Accepted 24 Sep 2014, Published online: 18 Nov 2014

Annals of Medicine, Volume 47, 2015 - Issue 1

https://www.tandfonline.com/doi/full/10.3109/07853890.2014.970570#

Some risk factors create more problems than others do. The following six factors provide the highest levels of risk. The actual amount of increase in risk from each one depends on when the risk factor first existed; its intensity, frequency, and duration; and its interaction with other risk factors.

Smoking

Inhaling tobacco smoke increases blood pressure and adds substances to the blood that seem to promote the formation of plaque. The effect of smoking on arteries is greatly magnified in women who take birth control pills. Smoking and taking birth control pills interact. Thus, having both risk factors increases the risk of having a heart attack more than the simple sum of each individual risk factor, perhaps as much as 18‑fold. The solution is not to smoke.

High Blood Pressure

High blood pressure seems to cause repeated minor injuries to the arteries. As the arteries try to repair the damage, they form scar tissue and plaque. High blood pressure also makes the heart work harder, increasing the amount of oxygen it needs, and eventually weakens the heart.

Having blood pressure checked regularly and, if it is high, seeking professional advice on how to reduce it are especially important as people get older. Blood pressure tends to rise with age, and an abnormal increase has more of an effect on the arteries as a person ages.

High Blood LDLs

Blood contains a variety of lipoprotein molecules. The lipids in these lipoproteins are obtained from the diet and made by the body. Most of the lipid in blood lipoproteins is cholesterol and triglycerides (fats), and lipoproteins containing predominately cholesterol are called low-density lipoproteins (LDLs). When LDLs are in high concentrations, the cholesterol can accumulate in the walls of arteries and contribute to the formation of plaque. The accumulation of cholesterol is reduced by other lipoproteins called high‑density lipoproteins (HDLs). As age increases, many individuals have an increase in the concentrations of LDLs with a simultaneous decrease in HDLs.

To reduce the risk of developing high blood LDLs, the amounts of cholesterol and saturated fats in the diet should be kept low. Foods containing high amounts of these lipids include egg yolks, dairy products containing milk fat or cream, red meats such as beef and pork, solid shortening, and oils such as palm oil and coconut oil. High alcohol consumption should be avoided since it promotes the formation of LDLs. However, consuming low or moderate levels of alcohol, eating foods containing certain dietary oils (e.g., safflower oil), and exercise can reduce blood LDLs while increasing HDLs. Blood lipoprotein levels should be checked and professional guidance should be followed if the ratio of LDLs to HDLs is found to be too high.

Diabetes Mellitus

Diabetes mellitus is a disease that alters many aspects of the body, including blood glucose levels and the maintenance and repair of arterial walls. In so doing, it promotes the formation of plaque.

Individuals should be aware of the warning signs of diabetes mellitus, which include excessive hunger and thirst, fatigue, unusual weight gain or loss, excessive formation and elimination of urine, and slow healing of wounds. Suspected cases require diagnosis and treatment by a qualified professional.

Family History

Several genes increase the chances of developing coronary atherosclerosis. Progress has been made in determining mechanisms by which these genes act.

“Genetic Markers for Coronary Artery Disease” Nevena Veljkovic,¹ Bozidarka Zaric,² Ilona Djuric,³ Milan Obradovic,² Emina Sudar-Milovanovic,² Djordje Radak,^4,5,6 and Esma R. Isenovic^2,*

Medicina (Kaunas). 2018 Jul; 54(3): 36.

Published online 2018 May 28. doi: 10.3390/medicina54030036

PMCID: PMC6122104

PMID: 30344267

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6122104/

“Network analysis of coronary artery disease risk genes elucidates disease mechanisms and druggable targets”

Nature

Scientific Reports volume 8, Article number: 3434 (2018)

Published: 21 February 2018

https://www.nature.com/articles/s41598-018-20721-6

Individuals from families with a history of atherosclerosis may have inherited the genes that predispose them to this disease. Though these individuals cannot alter their genes, they should try to reduce or eliminate as many other risk factors as possible. They should also inform their health care providers of their family history so that problems can be detected and necessary treatments can be initiated early.

Advancing Age

Advancing age increases the risk of problems from coronary artery disease in several ways. First, aging causes arterial stiffening. Second, there is an increase in the heart's oxygen demand because the heart becomes less efficient. Third, aging is associated with higher blood pressure, elevated blood cholesterol and LDLs, lowered blood HDLs, an increased incidence of diabetes, and decreased physical activity. Fourth, increasing age provides more time for other risk factors to take effect and for the slow process of plaque formation to progress significantly.

Though nothing can be done to alter the passage of time, people of advanced age should reduce other risk factors as much as possible. Other risk factors are of moderate importance compared with the six just discussed. They include the following.

High Blood Homocysteine

Homocysteine (Hcy) is produced and released into the blood when the body breaks down an amino acid called methionine. Having high blood levels of Hcy increases the risk of developing atherosclerosis. Blood levels of Hcy rise with increasing age and when women pass through menopause. High blood levels of Hcy also develop in people with deficiencies in vitamin B6 or the vitamin B12 (cobalamin). These vitamins are essential for adequate disposal of Hcy. Finally, some people are born with a metabolic abnormality that causes them to produce excess Hcy.

Usually blood levels of Hcy can be kept low by eating a diet with adequate vitamin B6 and vitamin B12. Since there is little vitamin B12 in plants, vegetarians are at risk for vitamin B12 deficiency. People with abnormalities of the stomach may be unable to absorb adequate vitamin B12. Vitamin supplements can help people who do not get adequate vitamin B6 or vitamin B12 from foods.

Physical Inactivity

The cells of people who are physically inactive require less blood flow, and the heart therefore gets less exercise because it does not have to work hard. Like every other muscle, heart muscle that gets little exercise becomes weaker and less efficient and loses some of its blood vessels. Such a heart is unprepared to increase the pumping of blood when a person suddenly begins strenuous activity. When such activity begins, an imbalance in the oxygen demand and supply of the heart occurs. In addition, lack of exercise promotes increases in blood pressure and in the ratio of LDLs to HDLs; both changes promote the development of atherosclerosis.

Engaging in a regular program of vigorous physical activity or in an occupation or hobby that includes such activity greatly reduces or eliminates this risk factor. This occurs because the heart is strengthened and develops more blood vessels, blood pressure is kept low, blood levels of HDLs are increased, body weight is less likely to become excessive, and psychological stress is minimized. All these effects reduce the risk of coronary artery disease. Planning involvement in physical activity is especially important for persons of advanced age because of the tendency toward age‑related reductions in physical activity.

Obesity

Being very overweight weakens the heart and makes it less efficient because the heart is being overworked and tends to become invaded with fat. Obesity also promotes high blood pressure, high levels of blood cholesterol and LDLs, diabetes mellitus, and low levels of physical activity. Obesity can be prevented or reduced by participation in a planned program of diet modification and regular exercise.

Stress

A sustained high level of emotional tension or stress promotes atherosclerosis by causing prolonged periods of high blood pressure.

Emotional stress can be reduced in many ways. One way is to avoid stress‑inducing situations. When this is not possible, taking breaks or vacations from such situations helps. Exercise, hobbies, and other diversions can also provide relief. Talking with a trusted confident can help, and some individuals can benefit from professional counseling.

Menopause

The decline in estrogen and progesterone that occurs at menopause ends the protective effect those hormones have on the arteries. Surgical removal of the ovaries has the same effect.

Some women can benefit from hormone replacement therapy. Such therapy should be conducted only on the advice and under the continued direction of a physician knowledgeable in this area.

Male Gender

Coronary artery disease occurs more frequently in men than in women, probably because the lifestyle of men generally includes more and higher levels of the risk factors associated with this disease. The incidence rate for women has been approaching that for men as women have become more involved in the same activities. Furthermore, the incidence among women approaches that of men as the age of a population increases because of losing the protective effects of female hormones after menopause.

Personality

Individuals with certain personality characteristics seem to be at higher risk for developing coronary atherosclerosis. These characteristics include being highly competitive, striving for perfection, and feeling that there is never enough time to accomplish one's goals. These characteristics indicate a high level of stress. Recent evidence suggests that stress is the key feature and that personality contributes little if any risk.

High Blood Iron Levels

Another possible risk factor, which some scientists think provides a risk exceeded only by that from smoking, is having higher than average levels of iron in the blood. The iron may promote atherosclerosis by increasing the accumulation of LDLs in arteries and causing cell damage by promoting the formation of free radicals. If having relatively high blood levels of iron is shown conclusively to be a significant risk factor, steps to lower the levels might include reducing the consumption of foods high in iron (e.g., red meat, liver, spinach, iron‑fortified foods); not drinking water with a high iron content; taking iron supplements only when absolutely necessary; and giving blood regularly.

Periodontal disease

Periodontal disease is associated with increased risk of atherosclerosis, heart attack, and stroke. The mechanisms by which periodontal disease contributes to atherosclerosis are not known. They may involve a genetic predisposition to both periodontal disease and atherosclerosis; toxins and chemical signals produced at the teeth; and effects from bacteria spreading from the teeth throughout the body. Some of these mechanisms may affect endothelial function.

Congestive Heart Failure

Congestive heart failure (CHF) is another disease that becomes more common and serious with age. Approximately three million people in the U.S. have CHF, and there are approximately 400,000 new cases each year. More than 75 percent of cases are in people age 65 and over. Incidence rates double for each decade over age 45, and approximately 10 percent of elders over age 80 have CHF. Congestive heart failure is the leading cause of hospital admissions for people 65 and over, and it is a major cause of disability, reduced independence, and death. The number of cases is expected to double by the year 2040.

Main causes of CHF are factors that weaken the heart. The most frequent causes are coronary artery disease, high blood pressure, disease of the heart valves, obesity, and kidney disease. The underlying problem is years of overworking the heart. An overworked heart tends to strengthen itself by dilating and thickening. At first these changes increase heart strength, but if the heart continues to be overworked, it continues to dilate and thicken. Excessive amounts of these changes weaken the heart. Then the heart chambers contain a great deal of blood but cannot pump it effectively. The flow of blood diminishes and organs begin to malfunction.

In addition, fluid accumulates in the lungs (pulmonary edema). Affected individuals have difficulty breathing and may feel out of breath after the slightest exertion or even when resting. Poor circulation in other areas, especially the legs, causes swelling and discomfort and promotes the formation of varicose veins. Many ordinary activities become difficult or impossible.

The heart tends to solve these problems by dilating and thickening even more, but this exacerbates the situation. Unless steps are taken to strengthen the heart and reduce its workload, the heart gradually becomes so weak that it fails completely and the individual dies.

Valvular Heart Disease

Untreated serious valvular heart disease causes detrimental changes similar to those resulting from congestive heart failure. This disease usually develops after coronary artery disease or rheumatic fever, which can prevent the valves from closing properly. Then some of the blood in the heart flows backward during each beat. Rheumatic fever can also prevent the valves from opening properly, and so blood does not flow forward as easily as it should. In either case the heart is overworked.