An Ounce of Prevention: New Possibilities for the Early Detection of Heart Disease
Posted: 08-01-2007 1:51 pm by Pushpa Larsen, ND, LM
Cardiovascular Disease Risk Factors:
Last year, 64% of women and 50% of men who died suddenly of a heart attack had no prior knowledge of their heart disease. 40-50% of all heart attack patients have a "normal" cholesterol profile. Perhaps you know that you have some risk factors - such as a parent or sibling who has heart disease - so you are eating a low fat diet and getting plenty of exercise. How do you know whether or not this is working or whether you, too, are developing heart disease?
Baby-boomers are starting to reach the age where cardiovascular disease, including high blood pressure, is becoming a major concern. Staying healthy takes on new importance as we consider our desire, not only to enjoy our elder years with our children and grandchildren, but also to keep health care costs down to ease the burden on the next generation. No one wants to have their children faced with shouldering the responsibility of caring for aging and ailing parents. We are looking for ways to stay healthy and vital as we age. There is a personal prevention revolution underway that is being made possible by relatively inexpensive tests that allow for ultra-early
Cardiovascular Disease Detection
The current standard for detecting cardiovascular disease is a standard lipid panel (Total Cholesterol, LDL cholesterol, HDL cholesterol, and Triglycerides), but that won't catch all those folks who end up with a heart attack despite their "normal" cholesterol. When clinical symptoms are present, such as chest pain or abnormal heart sounds, the current standard is to order a stress EKG (Electrocardiogram). The problem is that a stress EKG only detects a problem if one of the major arteries to your heart is 70% or more blocked. Yet 86% of heart attacks occur when there is less than 70% blockage. Obviously, this isn't good enough if you are trying to be proactive in treating early heart disease. Angiography -- examining the arteries that supply blood to the heart muscle - will tell you if your arteries are diseased, but it is an expensive and invasive test. It isn't useful for checking to see who might be developing heart disease.
Two kinds of relatively new tests now allow earlier detection of cardiovascular disease and identification of genetic factors that permit improved and individualized treatment. The first is ultrasound scanning of the carotid artery walls - intima media thickness scanning (IMT Scanning). The second is a battery of advanced cardiovascular blood tests that go far beyond the standard lipid panel. Early detection helps motivate patients to make beneficial lifestyle changes. Identification of genetic factors allows treatment with diet, exercise, and naturopathic treatments such as specific nutrients and botanical medicines at the point where they can make the most difference and before pharmaceuticals and surgical procedures are needed.
Ultrasound of the carotid arteries - the large arteries in the neck -- is relatively simple, non-invasive, and a fraction of the cost of a stress EKG. A particular type of carotid artery ultrasound, called Intima Media Thickness (IMT) Scanning has been used in research studies for over 16 years and has more recently become available for use in an office setting.
IMT scanning measures the thickness of the walls of your arteries and also detects the presence of plaque in the arteries. According to Dr. Bradley Bale of the Heart Attack Prevention Clinic in Spokane, WA, "The plaque data gathered in the IMT test is a huge bonus. . . Plaque is ten times more predictive of heart attack and strokes (than simply information on narrowing of the arteries); the results are even more dramtic in females. In other words, finding plaque is more important than determining how narrow the arteries have become". This information about plaque, especially that which is within the walls of the arteries themselves, cannot be detected with the duplex-type ultrasound which is used in carotid artery scans offered to the public by health screening companies.
IMT Scanning takes about 10 minutes and is done by a highly trained sonographer who has been rigorously evaluated for accuracy and consistency of results. Patients do not need to undress and are not exposed to any radiation. The sonographer takes three views of each wall of both left and right common carotid arteries. The resulting 12 ultrasound pictures are analyzed by FDA-approved software that measures a 1cm segment of each of the 12 views pixel by pixel. The number of measurements thus obtained gives a highly reproducible, and therefore reliable, result that has been correlated in many scientific studies with heart attack and stroke risk. The average thickness of the intima media is then compared with the intima media thickness of people the same age and gender to arrive at an arterial "age." For example, "you are 45 years old, and your arteries are 64 years old" (yikes!) or "you are 54 years old and your arteries are 46 years old" (yea!). Results are typically available in a week to ten days after testing.
Patients who have had IMT Scanning have reported that discovering the age of their arteries has been a great motivator for making positive changes in their lives. The American Heart Association has endorsed Carotid IMT Scanning as an independent cardiac risk diagnostic tool in people over 45 years of age. People younger than 45 should be tested if they have risk factors. Dr. Bale, however, would dispute this age recommendation. He states, "Some of the most impressive results at our clinic have been in teenagers, who appear to be in excellent health, but in reality, have arteries diseased to the age of adults in their 30's or 40's." Obviously, the earlier one learns about developing heart disease, the sooner steps can be taken to reverse it.
While IMT Scanning is currently available through cardiology clinics, that is not really the best place for it. People don't generally see cardiologists until they have had a heart attack or stroke, or are starting to have symptoms such as chest pain. While IMT scanning may be useful in cardiology clinics to monitor response to treatment, the more appropriate and useful place for it is in a primary care setting with your family practice MD or naturopathic physician.
Most health insurance companies are covering the cost of IMT Scanning for those patients who have certain, identifiable risk factors. Typically, insurance companies want to see a diagnosis of high cholesterol, low HDL cholesterol, or high blood pressure in order to pay for the test. They may not accept a family history of heart disease, stroke, or diabetes as a justification for IMT Scanning. This is unfortunate because a family history of one or more of these conditions is one of the most important clues that a person is at risk and may already be developing heart disease. Being proactive about cardiovascular disease prevention before a person actually develops signs, such as elevated blood pressure or cholesterol, would in the long run be more cost-effective and save more lives and health-care dollars.
The cost of IMT testing for those paying out of pocket varies from $190-$356. Usually there is an additional fee for the office visit at which you review your results with the physician and discuss any further recommendations. These visits are often covered by insurance.
Advanced Cardiovascular Blood Testing
Why isn't the standard lipids panel enough to screen for incipient heart disease? Well, for one thing, there are many more factors than cholesterol that are associated with heart disease, and some of them may be even more important than cholesterol. Also, although we tend to think of heart attacks as happening to "older" people, 5% of all heart attacks occur in people younger than 40, and 45% occur in people younger than 65. Routine lipid testing can miss up to 75% these people. Panels of blood tests that look beyond cholesterol and triglycerides can catch 90% or more of people headed for cardiovascular disease. These panels look at a multitude of factors that are indicators of cardiovascular risk independent of cholesterol. This information is critical to those with a family history of heart disease, since routine tests can give patients a false sense of health.
Knowing exactly what your risk factors are is crucial to developing a strategy that will really work to prevent or reverse heart disease for you. Rather than overwhelming you with mega-doses of every supplement and herb known to be beneficial to the cardiovascular system, your physician can emphasize treatments that are specifically targeted toward your risk factors. What should be included in cardiovascular panel of tests?
You probably know that you have two kinds of cholesterol - LDL (Low-Density Lipoprotein) or "bad" cholesterol, and HDL (High-Density Lipoprotein) or "good" cholesterol. What you may not know is that LDL and HDL cholesterol come in different sizes. (LDL has seven sizes; HDL has five.) Does this matter? You bet it does! Smaller, denser LDL cholesterol particles are much more harmful to your artery walls than the larger, more buoyant ones. Remember those people with "normal" cholesterol who have heart attacks? They may have a greater percentage of the small, dense LDL and less of the large, buoyant stuff. Here is an example: A 46-year old man who is active in sports requiring a high degree of fitness runs 40-50 miles a week. He is a healthy weight and his blood pressure is within the limits of normal, perhaps even lower than would be expected for his size. His total cholesterol is well under the desirable level of 200, yet he has a heart attack. Why? He has a lot of the small, dense LDL, which couldn't be detected with a standard lipid panel. He also has very little of the larger sized HDL particles, which are the most protective. Knowing this ahead of time wouldn't have been of much use if there were nothing he could do about it. Harmful cholesterol patterns, however, are very responsive to certain changes in eating and exercise habits.
Testing for Apolipoprotein B & Lipoprotein (a)
Expanded cardiovascular panels also include testing for Apolipoprotein B (Apo B) and Lipoprotein (a) (Lp "small a"). High levels of Apo B are indicative of increased risk for heart attack and stroke even when LDL is not in the high-risk range. Elevated LP (a) is associated with a number of cardiovascular disorders throughout the body, including the heart and the brain. Apo B can be lowered with appropriate diet, certain supplements, and pharmaceutical drugs. LP (a) is not as amenable to lifestyle factors but can be affected by certain supplements and pharmaceutical drugs.
Homocysteine & Fibrinogen
A complete cardiovascular profile will also test levels of Homocysteine and Fibrinogen. Homocysteine is an amino acid that is a normal by-product of metabolism but which, in some individuals, builds up in the blood. Elevated levels of homocysteine play havoc with artery walls and are associated with heart disease. The good news is that homocysteine levels can generally be brought under control with the right combination of nutrients.
Fibrinogen is a protein made in the liver and found in the blood that contributes to the formation of blood clots. If you have too little of it you would have trouble forming clots to stop the bleeding when you are injured. On the other hand, having too much fibrinogen significantly increases your risk for heart attack or stroke. A number of lifestyle factors (such as tobacco use) affect fibrinogen levels. Diet, exercise, certain supplements and pharmaceuticals can all have an impact on lowering levels.
Keeping the Fires in Check
Inflammation is a major risk factor in heart disease and complete cardiovascular risk testing should always include tests for C-Reactive Protein and Lipo-PLA2. C-Reactive protein is a general marker for inflammation and may be elevated in anyone with an inflammatory condition or acute infection. High Sensitivity CRP is the test used for assessing cardiovascular disease risk. LP-PLA2 also tests for inflammation, but is more specific for vascular (blood vessel) inflammation. LP-PLA2, sometimes
Insulin and Blood Sugar
You probably know that having diabetes puts a person at higher risk for heart disease. Less well known is that the road to diabetes is frequently preceded for as long as 30 years by elevated insulin levels as part of a complex condition known variously as Metabolic Syndrome, Dysmetabolic Syndrome, Insulin Resistance Syndrome, or Syndrome X. High insulin levels can contribute to arterial damage and aging. Testing for insulin levels, along with looking at cholesterol fraction patterns can reveal previously unrecognized Metabolic Syndrome. Unfortunately, most people never have their insulin levels tested. The standard has been to test for blood glucose (blood sugar), which may be normal for years because it is being kept under control with very high levels of insulin. In time, the body may no longer produce enough insulin to keep blood sugar levels down. When this happens, insulin levels can drop back to the normal range but blood sugars will start to creep up. Eventually, this can result in a diagnosis of diabetes. Unfortunately, by the time this happens, a lot of damage that could have been prevented with early intervention has already occurred.
Apolipoprotein E: A Key Genetic Player
Apolipoprotein E (Apo E) is a protein found on HDL particles and other plasma lipid particles. There are three different versions of the gene that makes Apo E, and you get one copy of the gene from each of your parents. Lack of knowledge about the impact of Apo E genotype has contributed mightily to the confusion in recent years about what kind of diet is best for preventing heart disease. Low fat? High protein / High Fat / Low Carb? Knowing your Apo E genotype (what combination of genes you have) is important because it may mean that you should eat and exercise differently than you are, even if you already have healthy habits. Here are examples from two recent patients: Patient A is 57 years old, 5'7" tall and weighs 180 pounds. Patient B is 58 years old, 5'5" tall and weighs 170 pounds. They both have a body mass index (BMI) of 28 (overweight but not obese) and are both post-menopausal women. Both get regular exercise. Based on their Apo E genotypes, Patient A should eat a low fat (20% fat) diet and Patient B should eat a moderate fat (35% fat) diet. Patient B has been eating a low-fat diet in the belief that it would help her avoid heart disease, but her low fat diet has actually been making her problems worse. Patient B also requires almost twice the amount of exercise to stay healthy as Patient A, even though their BMI's
What's the Bottom Line? And Where Can I Get these Tests?
So how much does all this testing cost? Naturally, these tests can add up to quite a bit of money, especially if you have to pay for it out of pocket. Patients usually end up paying between $119.00-$463.00 for the complete panel of tests, depending on whether or not they have insurance and whether insurance will cover it. Most insurance companies cover these tests if certain risk factors are present. Many of the tests can be ordered individually through local labs. Having all the tests done together at a single lab is especially reliable with some of the less common tests. For monitoring purposes, it is a good idea to have tests repeated by the same labs where they were done initially so that differences in values reflect changes in patient status rather than possible differences in the testing procedures.
Is There Any Good News?
Yes. The good news is that knowing your specific risks and having a treatment plan tailored for you can make a measurable difference in your cardiovascular health. With the right information, you can take action to reverse heart disease and reduce your risk of having a heart attack or stroke. This is visibly demonstrated when a patient's IMT Scan is repeated after a year of treatment and she find that her arteries are "younger" than she was the year before - sometimes many years younger - and that the plaque in her arteries has diminished in size. This is clearly a case in which the old adage is proven true: an ounce of prevention is surely worth many pounds of cure.
Dr. Pushpa Larsen, ND holds professional certificates in Naturopathic Midwifery & Spirituality, Health, and Medicine. She is a former vice-president of the Washington Association of Naturopathic Physicians, has participated as a Research Clinician with the Bastyr University Research Institute, and is currently an Affiliate Clinical Faculty for Bastyr University.