October 2006 — You may know your blood pressure and cholesterol level, but do you have a broader view of the health of your heart? According to statistics gathered in the most recent Heart Disease and Stroke Update from the American Heart Association, one in three American men and women have some form of cardiovascular disease and one of every 2.7 deaths in the country are caused by this disease. That’s a powerful call to take an active role in managing and improving your cardiovascular health.

The field of heart disease prevention has advanced rapidly, but before you and your physician embark on a plan to improve your cardiovascular health, you need an accurate gauge of the current condition of your heart. Cardiac screening provides that baseline assessment.

From time-proven screening tools like stress testing and lipid panels to new technologies that look at molecular changes in the body and genes that indicate a greater risk for heart disease, there are more assessment tools available than ever before. We’ve brought together vital information to help you keep up-to-date on what’s available now and what’s currently in development.

The foundation of a comprehensive cardiac screening program “The foundation of a comprehensive approach to the detection and prevention of cardiovascular disease should begin with a good history of family cardiac disease and patient behaviors including smoking, diet and exercise,” explains Dr. Stephen C. Achuff, a cardiologist and David J. Carver Chair in Medicine and Professor of Medicine at the Johns Hopkins School of Medicine. “You should alert your doctor if anyone in your immediate family has had a stroke or heart disease before the age of 50 for male relatives or 60 for females.”

Dr. Achuff adds the assessment should also include:

blood pressure check
heart sounds to detect any murmurs
survey of arteries for bruits (sound of blood flowing through a narrowed artery) in the carotid arteries in the neck, abdominal aortic aneurysms, and peripheral pulses in legs
glucose and fasting lipid blood test
resting electrocardiogram or stress test

“Cardiac screening can be divided into two areas,” notes Dr. Gilbert H. Mudge, Director, Brigham Cardiovascular Consultants at Boston’s Brigham and Women’s Hospital. “The first is assessing for risk factors like a family history of coronary artery disease, high blood pressure and cholesterol, diabetes, and lifestyle factors. The second is assessing for existing CAD. There are three modalities for that task. A routine stress test for anyone over 50 is a time honored tool that provides valuable information and is exceedingly safe. A sestamibi exercise stress test uses a small amount of a radioactive tracer injected into the body to measure blood flow to the heart. The third modality is cardiac CT to examine the presence or absence of calcium in the coronary arteries. The presence of calcium can indicate a predisposition to the evolution of CAD.”

Who needs to look beyond traditional screening tools?
While traditional heart disease risk scoring tools are effective for many, a recent study at the Johns Hopkins School of Medicine found that an alarming one-third of women likely to develop coronary heart disease failed to be identified by those screens. The Framingham Risk Estimate (FRE) assesses a person’s likelihood to suffer a heart attack within the next ten years. The estimate is based on traditional risk factors like smoking, age, blood pressure, and cholesterol level.

Researchers used the FRE and compared its results to a cardiac CT scan seeking calcium in the arteries. Ninety-eight percent of the women in the study had a very low FRE score and only two percent showed an intermediate risk of developing heart disease. The CT scan, however, told a different story. One-third of the women classified by the FRE as low risk in fact had atherosclerosis (narrowing and hardening of the arteries) and twelve percent of the women in the study had advanced atherosclerosis.

“Our best means of preventing coronary heart disease is to identify those most likely to develop the condition, and intervene with lifestyle changes and drug treatment before symptoms start to appear,” says cardiologist Dr. Roger Blumenthal, an Associate Professor and Director of the Ciccarone Preventive Cardiology Center at The Johns Hopkins University School of Medicine and its Heart Institute. “The goal is to strongly consider therapies, such as aspirin, cholesterol-lowering medications and, possibly, blood pressure medications for individuals at higher risk, so that heart attacks will be less likely to occur in the future. We wanted to verify if the Framingham score truly captured who was most at risk, but it turns out to have underestimated a large number of those who should be considered for preventive therapies.”

A range of new screening options provide a broader base of information
Moving beyond traditional heart disease screening tools, a number of physicians suggest another use for CT. Coronary artery CT angiography performed with an ultra-fast CT scanner offers a fast, minimally invasive way to acquire clear, detailed 2-D and 3-D images of the stuctures and function of the heart. The test takes approximately a half hour to complete and only requires an IV to introduce the dye that highlights the structures of the heart on the CT scan. In most cases, there is virtually no recovery time, with patients able to return to their normal activities ten minutes after the scan is completed.

“When symptoms of heart disease occur, significant blockage of the coronary artery already exists,” notes Dr. Jonathan Goldin, Ph.D., Associate Professor of Cardiothoracic Radiology at UCLA in a recent UCLA publication. “The challenge in cardiac imaging is to acquire images of the coronary arteries when they’re not blurred by movement,” Dr. Goldin notes. “The 64-slice CT, by virtue of its speed of acquisition and high resolution, allows you to reconstruct what are effectively frozen images of the heart and provide sharper details of the coronary arteries.”

Cleveland Clinic Clinical Director, Center for Integrated Non-Invasive Cardiovascular Imaging Dr. Richard White adds, “I think CT’s role is increasingly being established — and will remain — as a tool to identify patients who should undergo (traditional) angiography, including those who have never undergone the procedure, but also as a tool to identify patients who have no reason to undergo angiography because it would find nothing hemodynamically significant.” Dr. White notes that worldwide, 20 to 30 percent of cardiac catheterizations result in these hemodynamically insignificant findings. CT angiography would serve as a type of triage, indicating which patients need to proceed to catheterization or other diagnostic tests.

New tools help catch heart disease before symptoms occur
New blood tests are also powerful screening tools for cardiovascular disease. These tests focus on biomarkers (chemicals in the blood) that provide information about presymptomatic processes taking place in the body.

“How do you identify people who are at heightened risk for a heart attack before they show symptoms of heart disease?” asks Dr. George Rodgers, an Austin, Texas cardiologist and co-founder of Biophysical 250, a firm that provides an innovative broad biomarker screening test. “There has been a paradigm shift in what we understand to be the cause of heart attacks. We used to believe that heart attacks were caused by arterial obstruction from plaque. We now think that it is the rupturing of these cholesterol-rich plaques that cause myocardial infarction. Atherosclerosis is a form of irritation and inflammation and the plaques form in response to that irritation. By examining a person’s biomarkers, we can identify who is more inflamed and at risk for a rupture and aggressively cool down that inflammation with anti-cholesterol medications.”

At the Mayo Clinic in Rochester, researchers are studying a simple, non-invasive test they believe may help diagnose heart disease in people who have no symptoms of the disease. The research team is using an arterial tonometer (a pencil-sized wand) placed on the skin over the carotid artery, then the femoral artery in the upper thigh. The tonometer measures how fast the pulse wave travels down the aorta. A faster wave indicates the artery is stiffer and less healthy.

Hunting for “heart attack genes”
Similar to the genetic discoveries that have lead to breakthroughs in cancer screening, researchers are seeking genomic clues to predisposition to heart disease. Dr. Eric J. Topol, Professor of Genetics at Cleveland’s Case Western Reserve University is involved in a number of studies focused on identifying genes linked to heart disease. To date his team has found a deletion mutation in the gene MEF2A that is associated with heart attacks and coronary disease and had provided validation for two other previously discovered genes linked to heart attacks.

At the Cleveland Clinic several research projects focused on the science of heart attacks recently received funding from the National Institutes of Health. One is Dr. Topol’s genetic study and another will examine genes that make people more susceptible to the development of atherosclerosis.

“In the future, we will be able to use a simple panel of genes and proteins to assess the heart-attack risk of an individual early in life,” Dr. Topol notes. “This has a great potential to radically change and improve preventive medicine.” Researchers are also investigating the use of nanoparticles to help create detailed images of tiny blood vessels that are feed plaques just as they begin to form. "These preliminary results suggest that we can manipulate nanoparticles to image plaques as they are just beginning to form," says Dr. Samuel A. Wickline, Professor of Medicine and Biomedical Engineering at Washington University in St. Louis. "Previous research of ours also suggests that this technique can distinguish between patients with stable plaques and those whose plaques are about to rupture and thereby cause a heart attack or stroke.”

PinnacleCare Members have easy access to the highest level of cardiac care
Whether you are trying to improve the health of your heart or managing an ongoing cardiac condition, the assistance and support of a PinnacleCare Advocate makes those difficult jobs easier.

The wife of one Member who had suffered a previous transient ischemic attack, often a precursor of a stroke, called her Advocate panicked because her husband had felt dizzy before bed and awoke with slurred speech, unable to walk without leaning on the wall. She called her Advocate who advised her to get her husband to the hospital immediately for evaluation and alerted PinnacleCare’s Medical Director, Dr. Denis Pauze. Dr. Pauze contacted the physician on call at the hospital to provide preliminary information and expedite the evaluation. The patient was seen as soon as he arrived at the emergency room.

While reviewing a Member’s medical records, a PinnacleCare Advocate found a physician’s note suggesting follow up on elevated cholesterol levels. The Advocate noticed that the follow up had not occurred and contacted the Member to investigate the discrepancy. Confirming that the cholesterol issue had not been revisited, the PinnacleCare Advocate immediately scheduled an appointment with the Member’s physician. Follow-up testing prompted the physician to prescribe a medication to lower the Member’s LDL levels. The Member’s cholesterol is now under control and within reasonable limits.

Take an active role to improve your health
While new technologies are valuable in the early detection of heart disease, technology is only one piece of a comprehensive approach to detection and prevention. “It is also important for patients to take an active role in improving their cardiovascular health by maintaining a healthy body weight, getting regular exercise, decreasing the amount of saturated fat in their diets and eating foods high in fiber and complex carbohydrates and not smoking,” reminds Dr. Achuff.