Cardiovascular Disease Overview

Also indexed as: Circulatory Disease, Heart Disease

Cardiovascular disease is the number one cause of death in the United States. This introductory article briefly discusses several diseases that have a role in the development of cardiovascular disease. Refer to the following articles for further information: angina, atherosclerosis, cardiac arrhythmia, cardiomyopathy, chronic venous insufficiency, diabetes, heart attack, high cholesterol, high homocysteine, high triglycerides, hypertension, insulin resistance syndrome, mitral valve prolapse, and stroke.

Many risk factors are associated with cardiovascular disease; most can be managed, but some cannot. The aging process and hereditary predisposition are risk factors that cannot be altered. Until age 50, men are at greater risk than women of developing heart disease, though once a woman enters menopause, her risk triples.1

Many people with cardiovascular disease have elevated or high cholesterol levels.2 Low HDL cholesterol (known as the “good” cholesterol) and high LDL cholesterol (known as the “bad” cholesterol) are more specifically linked to cardiovascular disease than is total cholesterol.3 A blood test, administered by most healthcare professionals, is used to determine cholesterol levels.

Atherosclerosis (hardening of the arteries) of the vessels that supply the heart with blood is the most common cause of heart attacks. Atherosclerosis and high cholesterol usually occur together, though cholesterol levels can change quickly and atherosclerosis generally takes decades to develop.

The link between high triglyceride levels and heart disease is not as well established as the link between high cholesterol and heart disease. According to some studies, a high triglyceride level is an independent risk factor for heart disease in some people.4

High homocysteine levels have been identified as an independent risk factor for heart disease.5 Homocysteine can be measured by a blood test that must be ordered by a healthcare professional.

Hypertension (high blood pressure) is a major risk factor for cardiovascular disease, and the risk increases as blood pressure rises.6 Glucose intolerance and diabetes constitute separate risk factors for heart disease. Smoking increases the risk of heart disease caused by hypertension.

Abdominal fat, or a “beer belly,” versus fat that accumulates on the hips, is associated with increased risk of cardiovascular disease and heart attack.7 Overweight individuals are more likely to have additional risk factors related to heart disease, specifically hypertension, high blood sugar levels, high cholesterol, high triglycerides, and diabetes.

What are the symptoms of cardiovascular disease? People with cardiovascular disease may not have any symptoms, or they may experience difficulty in breathing during exertion or when lying down, fatigue, lightheadedness, dizziness, fainting, depression, memory problems, confusion, frequent waking during sleep, chest pain, an awareness of the heartbeat, sensations of fluttering or pounding in the chest, swelling around the ankles, or a large abdomen.

How is it treated? The conventional treatment for cardiovascular disease includes specific therapy for any underlying causes and may also include ACE inhibitors (e.g., captopril, enalapril, lisinopril), beta-blockers (e.g., propranolol), blood thinners (e.g., aspirin, warfarin), the combination of hydralazine and isosorbide dinitrate, digitalis, nitroglycerin, and diuretics. In some cases, surgical treatments, such as angioplasty, bypass surgery, valve replacement, pacemaker installation, and heart transplantation, may be recommended. Doctors also commonly recommend that people with cardiovascular disease stop smoking.

Dietary changes that may be helpful: Preliminary evidence has linked high salt consumption with increased cardiovascular disease incidence and death among overweight, but not normal weight, people. Among overweight people, an increase in salt consumption of 2.3 grams per day was associated with a 32% increase in stroke incidence, an 89% increase in stroke mortality, a 44% increase in heart disease mortality, a 61% increase in cardiovascular disease mortality, and a 39% increase in death from all causes.8 Intervention trials are required to confirm these preliminary observations.

Moderate alcohol consumption appears protective against heart disease.9 However, regular, light alcohol consumption in men with established coronary heart disease is not associated with either benefit or deleterious effect.10

A high intake of carotenoids from dietary sources has been shown to be protective against heart disease in several population-based studies.11 12 A diet high in fruits and vegetables,13 fiber,14 and possibly fish15 appears protective against heart disease, while a high intake of saturated fat (found in meat and dairy fat) and trans fatty acids (in margarine and processed foods containing hydrogenated vegetable oils)16 may contribute to heart disease. In a preliminary study, the total number of deaths from cardiovascular disease was significantly lower among men with high fruit consumption17 than among those with low fruit consumption. A large study of male healthcare professionals found that those men eating mostly a “prudent” diet (high in fruits, vegetables, legumes, whole grains, fish, and poultry) had a 30% lower risk of heart attacks compared with men who ate the fewest foods in the “prudent” category.18 By contrast, men who ate the highest percentage of their foods from the “typical American diet” category (high in red meat, processed meat, refined grains, sweets, and desserts) had a 64% increased risk of heart attack, compared with men who ate the fewest foods in that category. The various risks in this study were derived after controlling for all other beneficial or harmful influencing factors.

A parallel study of female healthcare professionals showed a 15% reduction in cardiovascular risk for those women eating a diet high in fruits and vegetables—compared with those eating a diet low in fruits and vegetables.19

Lifestyle changes that may be helpful: Both smoking20 and exposure to secondhand smoke21 increase cardiovascular disease risk.

Moderate exercise protects both lean and obese individuals from cardiovascular disease.22

References:

1. Kannel WB. Hazards, risks, and threats of heart disease from the early stages to symptomatic coronary heart disease and cardiac failure. Cardiovasc Drugs Ther 1997;11 Suppl:199–212 [review].

2. Kinosian B, Glick H, Garland G. Cholesterol and coronary heart disease: predicting risks by levels and ratios. Ann Intern Med 1994;121:641–7.

3. Kwiterovich PO Jr. The antiatherogenic role of high-density lipoprotein cholesterol. Am J Cardiol 1998;82:Q13–21 [review].

4. Gotto AM Jr. Triglyceride as a risk factor for coronary artery disease. Am J Cardiol 1998;1998;82:Q22–5 [review].

5. Seman LJ, McNamara JR, Schaefer EJ. Lipoprotein(a), homocysteine, and remnantlike particles: emerging risk factors. Curr Opin Cardiol 1999;14:186–91.

6. Kannel WB. Office assessment of coronary candidates and risk factor insights from the Framingham study. J Hypertens Suppl 1991;9:S13–9.

7. Megnien JL, Denarie N, Cocaul M, et al. Predictive value of waist-to-hip ratio on cardiovascular risk events. Int J Obes Relat Metab Disord 1999;23:90–7.

8. He J, Ogden LG, Vupputuri S, et al. Dietary sodium intake and subsequent risk of cardiovascular disease in overweight adults. JAMA 1999;282:2027–34.

9. Schaefer FJ, Lamon-Fava S, Ordovas JM, et al. Factors associated with low and elevated plasma high density lipoprotein cholesterol and apolipoprotein A-1 levels in the Framingham Offspring Study. J Lipid Res 1994;35:871–82.

10. Shaper AG, Wannamethee SG. Alcohol intake and mortality in middle aged men with diagnosed coronary heart disease. Heart 2000;83:394–9.

11. Kritchevsky SB. Beta-carotene, carotenoids and the prevention of coronary heart disease. J Nutr 1999;129:5–8 [review].

12. Palace VP, Khaper N, Qin Q, Singal PK. Antioxidant potentials of vitamin A and carotenoids and their relevance to heart disease. Free Radic Biol Med 1999;26:746–61.

13. Law MR, Morris JK. By how much does fruit and vegetable consumption reduce the risk of ischaemic heart disease? Eur J Clin Nutr 1998;52:549–56.

14. Pietinen P, Rimm EB, Korhonen P, et al. Intake of dietary fiber and risk of coronary heart disease in a cohort of Finnish men. The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. Circulation 1996;94:2720–7.

15. Albert CM, Hennekens CH, O’Donnell CJ, et al. Fish consumption and risk of sudden cardiac death. JAMA 1998;279:23–8.

16. Hu FB, Stampfer MJ, Rimm E, et al. Dietary fat and coronary heart disease: a comparison of approaches for adjusting for total energy intake and modeling repeated dietary measurements. Am J Epidemiol 1999;149:531–40.

17. Strandhagen E, Hansson PO, Bosaeus I, et al. High fruit intake may reduce mortality among middle-aged and elderly men. The Study of Men Born in 1913. Eur J Clin Nutr 2000;54:337–41.

18. Kinosian B, Glick H, Garland G. Cholesterol and coronary heart disease: predicting risks by levels and ratios. Ann Intern Med 1994;121:641–7.

19. Kannel WB. Hazards, risks, and threats of heart disease from the early stages to symptomatic coronary heart disease and cardiac failure. Cardiovasc Drugs Ther 1997;11 Suppl:199–212 [review].

20. Freund KM, Belanger AJ, D’Agostino RB, Kannel WB. The health risks of smoking. The Framingham Study: 34 years of follow-up. Ann Epidemiol 1993;3:417–24.

21. Law MR, Morris JK, Wald NJ. Environmental tobacco smoke exposure and ischaemic heart disease: an evaluation of the evidence. BMJ 1997;315:973–80.

22. Lee CD, Blair SN, Jackson AS. Cardiorespiratory fitness, body composition, and all-cause and cardiovascular disease mortality in men. Am J Clin Nutr 1999;69:373–80.