Little known cardiovascular risks that can have a big impact

Most people can name a few, if not all, of the traditional risk factors for heart disease, such as high cholesterol, obesity, family history or smoking. But there are two risk factors that are not discussed as frequently, and a Baylor College of Medicine cardiologist says it is time to talk about lipoprotein(a) and triglycerides. Both can have a big impact on your risk for cardiovascular disease.

Lipoprotein (a)

“Lipoprotein(a), also known as Lp(a), is one of the strongest inherited risk factors for heart disease and stroke, and most doctors are not testing for it,” said Dr. Christie Ballantyne, professor of medicine and chief of the section of cardiology at Baylor.

Lp(a) is a lipoprotein that travels through the bloodstream, collecting in arteries, leading to gradual narrowing of the artery that can limit blood supply to parts of the body, including the heart and lungs. It can increase the risk of blood clots, heart attack or stroke. This affects 5 to 10% of the population, which includes millions of Americans.

There is a blood test to measure Lp(a) levels as well as genetic testing, since it is inherited. However, once a diagnosis is made there isn’t an effective approved treatment available. Ballantyne says treating other risk factors using statins, a PCSK9 inhibitor or lifestyle changes can lessen the overall cholesterol burden.  

Studies that target the production of Lp(a) currently are ongoing, and so far the results are promising. These new therapies target messenger RNA, the genetic material that contains instructions for making proteins. The drug therapies target and block the production of Lp(a) before it can affect cardiovascular health.

“Our studies have shown a drop in Lp(a) levels by 80 to 90%, and we are finding that smaller dosages have a longer lasting effect, with injections needed every 1 to 3 months,” Ballantyne said. “This will help with medication adherence; it is much easier to get a shot once a month or every few months vs. daily medications.”

More information on these trials can be found here.

Triglycerides

When there is talk of cholesterol and cardiovascular disease risk, the focus is usually on LDL or HDL levels. Since LDL is known as the bad type of cholesterol, the focus is on lowering those levels. And since HDL is considered the good type of cholesterol, it was thought that raising those levels would help reduce the risk of heart disease.

“It turns out raising HDL levels really doesn’t have a significant benefit. What we found affects heart health more is triglyceride levels,” said Ballantyne. “Higher levels increase the risk for heart attack and stroke.”

Triglyceride levels over 500 mg/dL are considered very high and levels over 1,000 mg/dL are considered severe. Those numbers are not common but are difficult to control and can contribute to an increased risk of coronary heart disease and stroke. In some cases when levels are considered severe, there is an increased risk of pancreatitis, a painful and life-threatening disorder.

For some, including those with an inherited condition with severe hypertriglyceridemia known as familial chylomicronemia syndrome, common treatments don’t work.

A study using a therapy targeting messenger RNA that blocks the production of a protein known as APOC3 resulted in dramatic lowering of triglyceride levels and the injections can be given monthly.

“Exercise and a healthy lifestyle and diet are important, but if those combined with other common treatments are not working, there are new therapies and approaches to treatment,” Ballantyne said.

For more information on current clinical trial call 713-798-3330 or email ccdpclinic@bcm.edu