3 simple tests that can predict and prevent a heart attack

Your doctor can order a host of complex tests to gauge the health of your heart, but Prevention’s resident cardiologist, Arthur Agatston, MD, shared three new methods of predicting heart disease that are surprisingly simple and effective. One can be done with your eyes closed—literally. Another can be ordered the next time you have a blood test, and the third involves taking the temperature of your finger. Here's a rundown of how each one works:

1. The Sleep Test

Answer this question: Do you feel drowsy during the day? If so, you may be harming your heart. Every extra hour of sleep middle-aged adults can add to their nightly average reduces their risk of coronary artery calcification by 33%, according to a study reported in the Journal of the American Medical Association. When you're even a little sleep deprived, your body releases stress hormones that constrict arteries and cause inflammation. If you routinely wake up feeling tired or need an afternoon nap, then you're probably sleep deprived. Try either changing your sleep habits (darker room, TV off, earplugs) or going to bed 30 minutes earlier until symptoms disappear. If your spouse complains about your snoring or you often wake up with a headache, get checked for sleep apnea disorder.

2. The Vitamin D Test

Low levels of vitamin D, found in nearly 80% of US adults, can cause a rise in blood pressure and increased arterial inflammation. Fortunately, it's easy to test for and remedy any deficiency. Ask your doctor to order a vitamin-D analysis as part of your next blood test. Optimal levels are 30 to 40 ng/mL, but some doctors contend 50-plus ng/mL is even better. If yours is low, get 10 to 15 more minutes of sunlight per day (without sunblock), eat more vitamin D–rich foods (salmon, tuna, fortified orange juice), or take a D supplement (as recommended by your doctor). It's one of the simplest things you can do to protect your heart.

3. The Finger Test

Lining all your blood vessels—even those in your index finger—is a single layer of cells, called the endothelium, that produce chemicals that affect the vessels' function, causing dilation, constriction, clotting, etc. Negative changes in the endothelium occur years before any other measurable signs of heart trouble appear, so researchers have believed that if the health of the endothelium could be tested, we just might lick heart disease and stroke.

Now that test exists. The one Dr. Agatston uses, called Vendys, involves attaching a fingertip-temperature detector to your index finger and wrapping a blood-pressure cuff around your arm. As the cuff is inflated, blood flow to the hand decreases and finger temperature drops. After 5 minutes, the cuff is deflated and blood flow returns. The faster and more completely finger temperature rebounds, the healthier the endothelium.

The great thing about this test is that your doctor can not only assess your vascular health but also partially monitor how well treatment is working. If a patient loses weight, lowers her blood pressure, or begins taking medication, positive changes in her endothelial function can be detected almost instantaneously. With other methods—calcium scoring, for instance—it would take years. Eventually, this finger test could be an invaluable aid for monitoring heart health.