What is the strongest inherited risk factor for heart disease and stroke? You probably haven’t heard of it just yet – lipoprotein(a), also known as Lp(a). It is a lipoprotein that at high levels can increase the risk of cardiovascular events. Currently there are no treatments that directly target Lp(a) levels, however, Baylor College of Medicine researchers are beginning trials to test two new drugs that could change that.
“The vast majority of doctors don’t measure Lp(a) but when we do make the diagnosis, the only treatment we have is to focus on lowering LDL cholesterol and to lower overall risk factors,” said Dr. Christie Ballantyne, professor of medicine and chief of the sections of cardiology and cardiovascular research at Baylor.
As high levels of Lp(a) travel through the bloodstream, it collects in the arteries, leading to plaque build-up and blockages of the artery that can limit blood supply to the heart and brain, causing heart attacks and strokes. In the United States, 5 to 10 percent of the population have very high levels of Lp(a), which includes millions of Americans.
The test to measure Lp(a) levels is a blood test. There also is the option of genetic testing, since it is inherited, but a blood test is usually easier to obtain and widely available, Ballantyne said.
“We usually prescribe a statin or in some severe cases a PCSK9 inhibitor as well as suggesting lifestyle changes, such as losing weight, quitting smoking, changing diet and exercising, but past studies show that these new therapies could have more effective, promising results,” Ballantyne said.
The current clinical trials use injectable drugs designed with gene-silencing technologies to target the process that produces Lp(a). So the drug stops production of the protein before it affects cardiovascular health.
Earlier studies showed that these treatments have long-lasting effects, so rather than a daily dosage like some statins, a person might only need a dose every 1 to 6 months depending on the therapy. One of the trials is determining if using this drug will lower the risk of cardiovascular events, such as heart attack and stroke, in patients who have elevated Lp(a) and cardiovascular disease. The other trial will focus on optimal dosage and how often a dosage should be taken.