Are you one of the estimated 63 million people in the US whose Lipoprotein(a) level puts you at greater risk of heart disease? If you don’t know your Lp(a) number, or don’t know about the dangers of elevated Lipoprotein(a), it’s time to find out. Lipoprotein(a) is a low density lipoprotein cholesterol (LDL-C)-like particle that is associated with an increased risk of heart attack and aortic valve stenosis. Abnormal Lp(a) is a genetic condition that is largely unaffected by diet or exercise. According to the Lipoprotein(a) Foundation, high Lp(a) is the “strongest single inherited risk factor for early coronary artery disease and narrowing of the aorta.” www.lipoproteinafoundation.org/page/UnderstandLpa
The Foundation estimates that one in five – or one billion – people globally have high Lp(a) levels but most are unaware of it, in large part because the standard lipid panel does not include a test for Lp(a) and many doctors don’t order one when doing bloodwork. As many as 120,000 cardiovascular events a year might be prevented if the test for Lp(a) were included in the standard lipid panel, says the Lipoprotein(a) Foundation. And abnormal Lp(a) isn’t just a risk factor for a heart attack. A recent study reported in the Journal of the American College of Cardiology showed that high Lp(a) is also associated with increased risk of “ischemic stroke both observationally and causally from human genetics.” Langsted, A, Nordestgaard, BG, Kamstrup, PR, Elevated Lipoprotein(a) and Risk of Ischemic Stroke, JACC 74:1 (July 2019).
Even people who eat right, maintain a healthy weight and exercise regularly may have inherited high Lp(a) that could lead to a life-threatening cardiovascular event. That’s what happened to celebrity trainer and fitness guru Bob Harper, former host of “The Biggest Loser.” In 2017 while working out in a New York City gym he had a massive heart attack and was resuscitated by a doctor who happened to be working out at the same time. Although Mr. Harper went into full cardiac arrest, this persistent good samaritan managed to re-start his heart using the club’s AED machine and CPR and keep it going until emergency personnel arrived. As the NY Times reported in 2018, Mr. Harper and his doctors were “baffled” by his heart attack, as he had no prior symptoms and had been given a clean bill of health at his annual medical check ups. Apparently, until the heart attack gave notice that something was very, very wrong, none of Mr. Harper’s doctors had tested his Lp(a). But there were lots of reasons why they should have, including that Mr. Harper’s mother and his grandfather both died of heart attacks. After his heart attack, it was discovered that Mr. Harper has abnormally high Lp(a).
If it turns out that like Bob Harper you have the genetic material that causes elevated Lp(a) what do you do about it? In the past, some clinicians felt that treating LDL-C alone was sufficient but “recent studies have suggested..that elevated Lp(a) remains a risk factor even in patients who achieve LDL-C <70mg/dl.” Tsimikas, S, A Test in Context: Lipoprotein(a) – Diagnosis, Prognosis, Controversies, and Emerging Therapies, JACCS 69:6 (February 2017). Unfortunately there is no “cure” for high Lp(a) but there are promising developments including RNA-targeted therapies. PCSK-9 inhibitors like Repatha and Praluent can lower Lp(a) levels, but perhaps not by as much as would be ideal. However, once you know you have high Lp(a), you can aggressively target other risk factors for cardiovascular disease with lifestyle modification and drugs, and you can check the status of your cardiovascular system for blockages with a yearly stress echo and/or a CT angiogram. The point is to become aware of your personal constellation of risks and not be left in the dark about your chances of suffering a heart attack or stroke.