A Guide to Heart Screenings
Regular checkups are critical, but unneeded procedures may do more harm than good
The heart pumps away day after day in the warm embrace of your rib cage, sending blood, nutrients, and oxygen from your brain to your toes and back again. This is a tough job, and so critical for life that a person can’t do without that constant heartbeat.
Cardiovascular disease—which includes a cluster of conditions involving the heart and blood vessels—is something everyone needs to be aware of, particularly people with diabetes. While studies from the past decade suggest but don’t prove that diabetes leads to heart disease, says Frans Wackers, MD, PhD, a cardiologist at the Yale School of Medicine, “it is still true that patients with diabetes who have proven clinical cardiovascular disease do very poorly compared to patients who do not have diabetes.”
It’s critical to identify cardiovascular disease and take steps to combat it. But it’s also important to balance the need to check the heart for signs of damage with avoiding unnecessary procedures that may do more harm than good. Here is what experts have to say about the sometimes controversial topic of heart disease screening tests for people with diabetes.
The following tests are used routinely by physicians to screen for cardiovascular disease risk factors in “asymptomatic” people with diabetes—those without apparent evidence of heart problems such as shortness of breath, chest pain, fatigue, or other symptoms associated with cardiovascular disease.
These tests are inexpensive and noninvasive. They can give your doctor insight into whether you are at an elevated risk for heart disease and may benefit from lifestyle changes and medications that aim to prevent heart attacks, strokes, and other cardiovascular conditions.
Blood Pressure Checks. High blood pressure (hypertension) increases the risk for heart attacks and strokes. Experts recommend that people with diabetes have their blood pressure checked at every routine visit to the doctor’s office. Be sure you’ve been seated and resting for 15 minutes and your arm is supported at heart level at your side before an arm cuff blood pressure measurement is taken. In general, a blood pressure of less than 140/80 mmHg is recommended by the American Diabetes Association (ADA) for people with diabetes. Your specific target may vary depending on factors such as your age and any health problems.
Cholesterol Measurements. Diabetes can contribute to an imbalance of blood fats that promotes atherosclerosis, the buildup of plaque that narrows arteries and makes the heart have to work harder. Experts recommend that most adults with diabetes get a blood test of cholesterol and triglyceride levels at least once a year (though certain people at lower risk may be tested every other year). See “Blood-Fat Targets” (below) for recommended goals.
For asymptomatic patients with diabetes, the ADA does not recommend routine screening with procedures such as stress tests (more on those later) for coronary artery disease, the most common type of cardiovascular disease. This recommendation is based on studies that show that while screening can identify who is at high or low risk for heart attacks and strokes, the tests do not actually lead to improvements in long-term health. What does lead to better outcomes is treatment of risk factors such as high blood pressure and high LDL cholesterol levels.
There is considerable debate within the medical community about using diagnostic heart tests for asymptomatic patients with diabetes. Everyone with diabetes, including those with risk factors for heart disease, should be followed closely for the development of symptoms of cardiovascular disease, says Wackers. “Then they need diagnostic tests.” These basically consist of several types of “stress tests.” Such tests put the heart under stress with exercise (typically on a treadmill) or medications that raise the heart rate (to mimic the effect of exercise) while the heart is monitored for changes in function that signal coronary artery disease.
Stress Electrocardiogram. The stress electrocardiogram (ECG or EKG) is a noninvasive test that measures the electrical activity of the heart at rest and during stress. Certain changes during stress can indicate a lack of blood flow through one or more coronary arteries, which supply blood to your heart muscle.
Stress Echocardiogram. This ultrasound test of the heart provides information about the heart’s structure and pumping ability. Certain changes during stress can indicate lack of blood flow through the coronary arteries.
Myocardial Perfusion Imaging. For myocardial perfusion imaging (MPI), a patient is injected with a radioactive “tracer” that is visible on a scan both at rest and during cardiac stress. Areas the tracer can’t penetrate are places where blood flow is lacking, which may be because of blocked coronary arteries.
Two additional screening tests for coronary artery disease are available, but their value in screening asymptomatic people with diabetes remains unproven.
Coronary Calcium Scan. This test uses radiation to quickly scan the coronary arteries for calcium buildup, an indication of atherosclerosis. The results come as a calcium score. “The nice thing about a calcium score is that it’s easy, reproducible, and generally low cost,” says Leslee Shaw, PhD, FACC, FASNC, FAHA, a cardiologist at the Emory University School of Medicine. A score of less than 100 indicates a person is at a low risk for a heart attack, while those with scores of 400 and above are at high risk.
Computed Tomography Angiogram. For people with high calcium scores or other indicators of a serious heart problem, a computed tomography (CT) angiogram can generate an image of the heart. The tests are controversial because of the hefty amounts of radiation needed to create the images. According to Shaw, “there is no evidence to support that asymptomatic adults should have a full-blown CT angiogram.”
Symptoms of heart disease can be sneaky, so stay watchful. Routine screenings can go a long way to help you and your doctor keep your heart pumping.
People with diabetes can reduce their risk for heart attack and stroke by keeping their blood fats at target levels through a combination of lifestyle changes—such as quitting smoking, losing weight, and exercising—and medication, as necessary.
Less than 100 mg/dl; targets are lower for people with cardiovascular disease
Higher than 40 mg/dl for men and 50 mg/dl for women is good; an HDL of 50 mg/dl or higher is associated with a lower risk of heart disease.
Less than 150 mg/dl