Fall 2004
Fall 2004
  • Why New, Small Plaques Can Be More Dangerous than Bigger, Older Ones

    Why New, Small Plaques Can Be More Dangerous than Bigger, Older Ones

    "I can't understand why I had a heart attack. I'm only 50, my cholesterol levels are pretty good, and the cardiologist told me that none of my arteries was blocked by more than 40%. So why did it happen to me?"

    Suzanne Pollard-Quintner, cardiac rehabilitation manager in the Heart Institute at Bridgeport Hospital, has heard that question many times. "Half of all heart attacks occur in people with normal cholesterol levels," she explains. “Smaller, younger plaques in coronary arteries cause more than half of all heart attacks. The most dangerous plaques in coronary arteries are not the oldest or the largest.”

    To understand why, it helps to understand how a plaque is born and lives inside the artery.

    The beginning of a plaque

    An injury to the inner lining of an artery starts an inflammatory process in the artery. First, Low Density Lipoproteins (LDL cholesterol—the bad kind) accumulate at the site of the injury. Next, the site is bombarded by oxygen free radicals—"hungry" molecules that can damage living tissue. The body uses these molecules to fight infection, but too many of them can lead to oxidation—like causing a pipe to rust. This oxidation process changes the LDL to dangerous oxidized LDL. Unless it is neutralized by antioxidants this inflammation process will keep on happening, and a cholesterol plaque will form.

    The Formation of a Cap over the Plaque

    When a plaque forms, a scab or cap grows over it. Over time, even as the plaque grows bigger and blocks more of the artery, the cap on the plaque becomes thick and fibrous, making it harder to rupture.

    The Rupture of a Cap

    Plaque caps rupture for a variety of reasons, in a number of ways. They can crack, develop a fissure, be a victim of slow erosion, or be torn or sheered off. Rupture can be prompted by the chemical reaction that can happen as a result of an intense emotional or physical outburst. Diabetes, advancing age, tobacco smoke, hypertension, sedentary activity patterns, and a poor diet all contribute to the likelihood that plaques will rupture.

    Then the cholesterol oozes out like lava from a volcano. Its presence in the artery starts a chain-reaction clotting mechanism. That's because the body responds to an internal injury just as it does to an external cut: It tries to clot the injury to heal the surface of the cut. On your knee, that clotting is fine. Unfortunately, in the coronary artery, clots can restrict the flow of blood to the heart, causing a heart attack.

    The Bottom Line

    The newer, smaller plaques may only narrow the artery by 40–60%, but their caps rupture more easily, causing blood clots, and so are more likely to cause a heart attack.

    What You Can Do to Reduce Plaque Formation and Rupture

    • Control or prevent diabetes.
    • Exercise 3 – 5 times per week.
    • Keep your total cholesterol under 200, your LDL under 100 and your HDL (high-density lipoprotein, or “good” cholesterol) over 40.
    • Eat plenty of fruits and leafy green vegetables—excellent sources of antioxidants; consider taking a multivitamin supplement.
    • Keep your waist measurement under 35 inches if you are a woman and under 40 if you are a man.
    • Maintain an appropriate weight based on your body type.
    • Watch for hypertension and if you have it, keep it controlled.
    • Don't smoke.