After fitness expert Bob Harper suffered a heart attack in 2017, he went in search of the answers behind his health scare. A trainer on The Biggest Loser, Harper was vigilant about maintaining an active lifestyle and did not appear to have traditional risk factors for heart disease.

It turned out that Harper did have high levels of a little-understood biomarker called lipoprotein(a). Elevated lipoprotein(a), or Lp(a) (pronounced "L-P-little A") is a genetic risk factor for heart disease that, like cholesterol, can increase the risk of blockages in the arteries. These plaques can in turn lead to heart attacks and strokes.

What is Lp(a) and why does it matter?

For most of us, "cholesterol" is a value on a lab chart: we know high levels can negatively impact heart health. However, "cholesterol" is often used as a blanket term to cover two fatty particles in the blood: healthy high-density lipoprotein (HDL) -- which is actually good for you -- and low-density lipoprotein, also known as "bad cholesterol." Within normal ranges, cholesterol is essential to creating hormones, vitamin D, and other substances our bodies need. Scientists are still learning about what job Lp(a) performs in the body, but a growing body of research suggests that it plays an important role in heart health.

In fact, Lp(a) is considered the strongest genetic risk factor for coronary heart disease, or the arterial blockages that cause cardiac events. High levels are also shown to triple the risk of experiencing a heart attack or stroke at a young age.

While Lp(a) is not included in standard cholesterol blood tests, it's estimated that one in five Americans has high levels. More research is needed to improve the scientific understanding of Lp(a) -- especially among heart patients.

Advancing the science of heart health

To enable better health solutions, Project Baseline's Heart Biomarker Study is exploring the link between Lp(a) and heart disease. Because this research is observational, researchers will study Lp(a) by collecting the health records of participants who have experienced a heart attack or stroke. Participants will also complete a blood test to measure their Lp(a) level and receive their results. While Lp(a) is rarely included in standard tests, as a genetic factor, it can be inherited and passed on. Particularly for heart attack and stroke survivors, knowing their Lp(a) level can help inform whether Lp(a)-specific testing makes sense for their families.

"Heart disease is America's greatest health threat, causing one in four deaths in the United States annually," said Dr. Svati Shah, director of Duke University School of Medicine's Adult Cardiovascular Genetics Clinic. "We need better preventive treatments, especially for those with a greater genetic risk profile. The Heart Biomarker Study was created to accelerate research around a genetic risk factor that we simply don't know enough about today. Advancing scientific knowledge of Lp(a) could dramatically improve outcomes, and help us provide better care for heart patients."

Previous Lp(a) research has not focused specifically on how the biomarker affects the health of heart attack and stroke survivors. One of the leading research experts on Lp(a), Shah helped design the Heart Biomarker Study to identify how the biomarker impacts this population. "There were many different paths we could have taken for this research," Shah noted. "By focusing on how Lp(a) impacts those who have experienced a cardiac event, we hope to improve knowledge around reducing the risk of subsequent heart attacks and strokes."

Mapping human health together

The Heart Biomarker Study is part of Verily's Project Baseline. Born out of Google X, Verily is Alphabet's healthcare and life sciences arm focused on making health data useful and actionable so people can enjoy healthier lives. Project Baseline is an initiative to map human health, launched in 2017 to address one of the most fundamental challenges of clinical research: accessibility. Less than 10% of Americans participate in research today, due to challenges including the historical difficulty of participation and lack of transparency around the research process. Project Baseline is focused on approaching clinical research in new ways, from the breadth and complexity of data collected to fostering greater partnership with participants.