Like many things we see in medicine, it just didn’t seem fair. Heart-wise, my patient seemed to have done everything right: good diet, plenty of exercise, ideal weight and no smoking. Yet, at a young age, he had hardening of the arteries, or atherosclerosis, which put him at risk of a heart attack or a stroke.
The reason was something many people haven’t heard of: elevated levels of lipoprotein(a), a type of cholesterol particle in the bloodstream that can deposit in blood vessel walls. Also known as Lp(a), it’s not a common occurrence, and for most people with cardiac problems, it’s not the issue.
The Disguise of LPA
Lp(a) is worrisome for several reasons. For starters, Lp(a) is inherited. If it’s in your genetics, you can’t avoid it, and we generally don’t screen for Lp(a) because there isn’t a clear, good treatment for it. So under the current guidelines, we don’t go looking for it (through a simple blood test) unless a patient has hardening of the arteries without a good reason.
Researchers believe Lp(a) does its damage by looking like LDL, commonly known as the “bad cholesterol.”
Researchers believe Lp(a) does its damage by looking like LDL, commonly known as the “bad cholesterol.” LDL normally is absorbed into cells in the body, which uses it to create cholesterol the body needs or flushes it out of the system. But the (a) protein on the Lp(a) prevents the cell receptors from absorbing this abnormal particle, allowing the Lp(a) to remain in the bloodstream.
Unfortunately, it’s a really bad combination to have both high LDL and high Lp(a) because you have two types of particles which can cause hardening of the arteries.
We’ve known about Lp(a) for decades. Doctors have tried to treat elevated Lp(a) with statins, niacin, and other cholesterol-lowering medicines. Estrogen has seemed to work some, but we cannot use estrogen in most patients.
Lp(a) is a risk factor for heart disease and stroke, but it’s only one risk factor. So what we can do is get real aggressive about treating all the other risk factors, such as high blood pressure, diabetes and obesity. We drop your LDL levels even more than usual. If you have high Lp(a), you simply cannot smoke.
Frontier in Treatments to Lower Cholesterol
There are new treatments on the horizon. New cholesterol-lowering drugs known as PCSK9 inhibitors work differently than statins and look like they may have an effect on Lp(a). Another potential remedy being tested is called antisense oligonucleotide, an injection of artificial RNA molecules that would block cells from producing Lp(a). But not enough studies have been done.
For now, we’ll keep looking for answers, and we still need to control the traditional risk factors for heart disease that we know how to treat.
We won’t screen the general population for Lp(a) until we have a good plan to treat it. But if you come from a family with hardening of the arteries and no clear reason for it, then you should see a cardiologist to get your Lp(a) measured.
If you’re worried you may be suffering from a genetic heart condition, learn more about Baylor Scott & White’s heart and vascular care and talk to a doctor about your family health history.
About the author
Dr. Cara East, MD, is a cardiologist, principal investigator and medical director at Baylor University Medical Center’s Soltero Cardiovascular Research Center in Dallas, Texas.