Test for Cardiac Risk Factors


	Test for Cardiac Risk Factors

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	If you are at increased or uncertain cardiovascular risk, there are many additional tests beyond the basic cholesterol levels and stress EKGs that can predict the likelihood of a heart attack or stroke. Post-challenge insulin, high sensitivity C-reactive protein (hs-CRP), Lp(a), iron levels, additional lipid fractions, homocysteine, fibrinogen and others can be done to provide a clearer picture of your risk. A thorough evaluation can involve as many as 20 to 30 different conditions and lab tests. Establishing your risk through laboratory testing and taking steps to reduce any abnormalities gives you more control over whether or not you experience a sudden heart attack or stroke. As an example of the value of additional testing, it is now known that persons with the greatest absolute risk of dying from a heart attack tend to have the highest ratios of apoB to apoA-I. In fact, these two cholesterol particles have turned out to be more powerful predictive markers for a future fatal heart attack than levels of "good" (HDL) cholesterol, "bad" (LDL) cholesterol, total cholesterol, or triglycerides. [Lancet 2001;358: pp.2026-2033] S-Aadenosylhomocysteine, which is the precursor of homocysteme, appears to be a more sensitive marker for differentiating cardiovascular patients from control subjects than homocysteine. [Am J Clin Nutr, 2001;74: pp.723-729] Some laboratories are offering complete profiles of your actual risk. For example, AAL Reference Laboratories offers an “Atherosclerosis Activity Evaluation” and Great Smokies Diagnostic Labs (now Genova) offers a “Comprehensive Cardiovascular Risk Profile”. A simple and inexpensive blood test for hs-CRP has proven more accurate than cholesterol screening in predicting a person's risk for a heart attack according to researchers at the Brigham and Women's Hospital in Boston [NEJM, May 23rd, 2000]. Current data suggest that the addition of hs-CRP to standard lipid screening can improve the ability to detect absolute coronary risk. This is a critical issue because one-half of all myocardial infarctions and strokes occur among individuals without overt hyperlipidemia. Recent support has been given to the concept of a bacterial infection component of heart disease. The organisms Chlamydia pneumonia and CMV (cytomegalovirus) both increase CRP and are associated with increased heart disease risk. There are treatments for these organisms. Although current guidelines for the management of high blood pressure rest almost completely on the measurement of the systolic (top) and diastolic (bottom) values, a new study has found that something known as the "pulse pressure" may actually be a better predictor of heart disease risk. The pulse pressure is the difference between the systolic and diastolic pressures. For example someone with a blood pressure of 120/80 has a pulse pressure of 40, which is considered normal. Elevated levels of serum uric acid increase the risk of heart attack. In evaluating 5,926 subjects who were between 25 and 74 years of age, after 16.4 years of follow-up, there were 1,593 deaths, of which 45.9% were attributed to cardiovascular disease. It was found that increased serum uric acid levels were independently and significantly associated with the risk of cardiovascular mortality. [JAMA, May 10, 2000;283(18): pp.2404-2410] According to the research led by Uppsala University in Sweden, high levels of two proteins in the bloodstream indicate that patients with acute coronary syndromes - chest pain caused by lack of blood to the heart - are at high risk of having potentially fatal heart attacks. Taking aggressive action to treat their blocked arteries will reduce their risk of dying within one year. On the other hand, patients with low levels of these proteins, also called biomarkers, are not at high risk for deadly heart attacks and may even be harmed by having angioplasty or bypass surgery to treat blocked arteries. The proteins - troponin-T (TnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) - are just two of the biomarkers being studied by physicians and scientists around the world in an effort to improve treatment for a wide range of illnesses. [Journal of the American College of Cardiology 9/19/2006]

Test for Cardiac Risk Factors can help with the following:

Circulation

Aneurysm / Weakened Arteries

The authors of this study concluded that a high level of lipoprotein (a) is an independent risk factor for thoracic aortic atherosclerosis and should be controlled in order to prevent aortic disease including aortic aneurysm. [American Journal of Cardiology, July 15, 1993;72: pp.227-230 ]

Total cholesterol and triglycerides have also been associated with increased risk.

Risks

Increased Risk of Coronary Disease / Heart Attack

Measuring levels of several inflammatory markers rather than a single marker can substantially improve assessment of cardiovascular disease (CVD) risk, according to a study published in the November 2005 issue of the American Heart Journal by University of Pittsburgh researchers and others.

Currently, medical guidelines recommend measuring a particular inflammatory marker, called C-reactive protein, along with cholesterol levels, for assessing CVD risk. In this study, researchers from the University of Pittsburgh Medical Center's Cardiovascular Institute and the University of Pittsburgh Graduate School of Public Health (GSPH) analyzed blood samples taken from 580 women age 31 to 85 looking for multiple inflammatory markers. The investigators also performed coronary angiographies to detect any blockage of blood vessels in the heart and then followed the women for an average of almost five years. Of interest to the researchers was whether the women experienced any heart attacks (both nonfatal and fatal), strokes, or episodes of congestive heart failure.

Women with significantly elevated levels of at least two of three markers (interleukin-6, serum amyloid A, and C-reactive protein) had a more than four-times greater risk of dying compared to women who had no elevated markers. According to the lead author, Kevin E. Kip, Ph.D., assistant professor of epidemiology, GSPH, this was a higher conferred risk than any single marker alone, all of which were roughly equally predictive.

KEY

Highly recommended

GLOSSARY

Acute: An illness or symptom of sudden onset, which generally has a short duration.

Atherosclerosis: Common form of arteriosclerosis associated with the formation of atheromas which are deposits of yellow plaques containing cholesterol, lipids, and lipophages within the intima and inner media of arteries. This results in a narrowing of the arteries, which reduces the blood and oxygen flow to the heart and brain as well as to other parts of the body and can lead to a heart attack, stroke, or loss of function or gangrene of other tissues.

Cardiovascular: Pertaining to the heart and blood vessels.

Chlamydia: A sexually-transmitted disease that is often without symptoms. Some females experience a white vaginal discharge that resembles cottage cheese, a burning sensation when urinating, itching, and painful intercourse. A clear watery urethral discharge in the male probably is a chlamydia infection.

Cholesterol: A waxy, fat-like substance manufactured in the liver and found in all tissues, it facilitates the transport and absorption of fatty acids. In foods, only animal products contain cholesterol. An excess of cholesterol in the bloodstream can contribute to the development of atherosclerosis.

CRP: C-reactive protein. A sensitive measure of inflammation in the body.

Cytomegalovirus: (CMV): A member of the herpes virus family which may induce the immune-deficient state or cause active illness, such as pneumonia, in a patient already immune-deficient due to chronic illness, such as cancer or organ transplantation therapy.

Diastolic: Pertaining to the relaxation phase of the heartbeat, or period when the heart muscle is resting and filling with blood. When used in blood pressure readings (for example 120/80), it refers to the second/lower number.

High-Density Lipoprotein: (HDL): Also known as "good" cholesterol, HDLs are large, dense, protein-fat particles that circulate in the blood picking up already used and unused cholesterol and taking them back to the liver as part of a recycling process. Higher levels of HDLs are associated with a lower risk of cardiovascular disease because the cholesterol is cleared more readily from the blood.

Hyperlipidemia: Increased cholesterol level.

Insulin: A hormone secreted by the pancreas in response to elevated blood glucose levels. Insulin stimulates the liver, muscles, and fat cells to remove glucose from the blood for use or storage.

Iron: An essential mineral. Prevents anemia: as a constituent of hemoglobin, transports oxygen throughout the body. Virtually all of the oxygen used by cells in the life process are brought to the cells by the hemoglobin of red blood cells. Iron is a small but most vital, component of the hemoglobin in 20,000 billion red blood cells, of which 115 million are formed every minute. Heme iron (from meat) is absorbed 10 times more readily than the ferrous or ferric form.

Lipid: Fat-soluble substances derived from animal or vegetable cells by nonpolar solvents (e.g. ether); the term can include the following types of materials: fatty acids, glycerides, phospholipids, alcohols and waxes.

Low-Density Lipoprotein: (LDL): Also known as "bad" cholesterol, LDLs are large, dense, protein-fat particles composed of a moderate proportion of protein and a high proportion of cholesterol. Higher levels of LDLs are associated with a greater risk of cardiovascular disease.

Natriuretic: Agent causing sodium to be excreted into the urine.

Protein: Compounds composed of hydrogen, oxygen, and nitrogen present in the body and in foods that form complex combinations of amino acids. Protein is essential for life and is used for growth and repair. Foods that supply the body with protein include animal products, grains, legumes, and vegetables. Proteins from animal sources contain the essential amino acids. Proteins are changed to amino acids in the body.

Serum: The cell-free fluid of the bloodstream. It appears in a test tube after the blood clots and is often used in expressions relating to the levels of certain compounds in the blood stream.

Stroke: A sudden loss of brain function caused by a blockage or rupture of a blood vessel that supplies the brain, characterized by loss of muscular control, complete or partial loss of sensation or consciousness, dizziness, slurred speech, or other symptoms that vary with the extent and severity of the damage to the brain. The most common manifestation is some degree of paralysis, but small strokes may occur without symptoms. Usually caused by arteriosclerosis, it often results in brain damage.

Systolic: Pertaining to the contraction phase of the heartbeat, or the pressure in the arterial system caused by the heart as blood is being pumped out. When used in blood pressure readings (for example 120/80), it refers to the first/upper number.

Triglyceride: The main form of fat found in foods and the human body. Containing three fatty acids and one unit of glycerol, triglycerides are stored in adipose cells in the body, which, when broken down, release fatty acids into the blood. Triglycerides are fat storage molecules and are the major lipid component of the diet.