A hidden genetic risk factor lurks in the bloodstreams of roughly one in five people—many of them completely unaware—putting them at significantly higher risk for stroke and sudden cardiac death even when their standard cholesterol numbers look normal. Researchers analyzing data from more than 20,000 adults enrolled in three major National Institutes of Health trials have now quantified exactly how much danger very high levels of Lipoprotein(a), or Lp(a), pose to cardiovascular health.
Lp(a) is a cholesterol-carrying particle that resembles LDL, the "bad" cholesterol, but carries an extra protein that makes it potentially more harmful to the heart and blood vessels. Unlike standard cholesterol, Lp(a) levels are largely determined by genetics—you inherit them from your parents—which means lifestyle changes alone cannot lower them. Yet because Lp(a) causes no symptoms, most people who carry elevated levels have no idea they're at risk.
The new analysis, presented at the Society for Cardiovascular Angiography & Interventions Scientific Sessions in Montreal, focused on 20,070 adults with an average age of 65 years who had their Lp(a) levels measured from stored blood samples collected during the ACCORD, PEACE, and SPRINT clinical trials. Over a median follow-up period of nearly four years, researchers tracked major adverse cardiovascular events, including heart attacks, strokes, procedures to open blocked arteries, and cardiac deaths. They found that 1,461 participants—7.3% of the group—experienced such events.
The breakthrough came in identifying a specific threshold that dramatically shifts risk. Patients with Lp(a) levels of 175 nmo/L or higher faced a 31% higher risk of major cardiovascular events overall, a 49% higher risk of dying from cardiovascular causes, and a striking 64% higher risk of stroke compared to those with lower levels. The risk was especially pronounced among people who already had established heart disease.
"For the first time, we can quantify the specific level of Lp(a) that puts patients at a significantly higher risk of major cardiovascular events, especially stroke and death," said Dr. Subhash Banerjee, an interventional cardiologist at Baylor Scott & White in Dallas, who presented the findings. What makes this discovery particularly actionable is its simplicity: identifying elevated Lp(a) requires only a straightforward, low-cost blood test available to virtually anyone.
The implications are profound. Millions of people at heightened cardiovascular risk could be identified through routine screening, allowing them to work with healthcare providers to aggressively manage other modifiable risk factors like LDL cholesterol, blood pressure, and lifestyle habits. While drugs specifically targeting Lp(a) are still in development, knowing about elevated levels gives patients and doctors crucial information for tailoring prevention strategies.
Researchers emphasized that this study represents just the beginning of what stored biospecimens from completed trials can reveal. Future analyses are expected to examine how Lp(a) affects other high-risk populations, including people with chronic kidney disease and peripheral artery disease, potentially uncovering even more opportunities to identify and protect vulnerable patients before cardiovascular events strike.