Cardiologist Q&A: Researching a new risk factor for heart disease

Many of us are familiar with cholesterol as a lab value we want to keep under control. Today, scientists are increasingly interested in a similar blood particle we know much less about: lipoprotein(a), or Lp(a). Lp(a) is considered an important new risk factor for heart disease, and a growing body of research suggests it may be key to developing more effective preventive solutions.

The new Heart Biomarker Study now joins these efforts to better understand Lp(a), specifically focusing on people who have experienced a heart attack or stroke — a population yet to be fully explored in Lp(a) research.

We sat down with Dr. Michael McConnell, cardiologist and head of Cardiovascular Health at Verily, to get more insight into Lp(a) and learn why the scientific community believes advancing research around this little-understood protein could help improve outcomes for the 85.6 million Americans affected by heart disease.

Thanks for chatting with us, Mike! To start us off, can you tell us a little about yourself and your journey to cardiology?

Sure thing — my path to medicine was actually not a straight line, since I started as a biomedical engineer. I studied engineering as an undergraduate and graduate student at MIT, and worked summers at a pacemaker company. For an engineer, the heart is actually a really interesting organ: it's mechanical, electrical, and there are fluid dynamics at work. I wanted to explore cardiology and patient care in even more depth, and combine that with my interest in technology.

After medical school, I trained at Brigham & Women's Hospital and then spent most of my academic career at Stanford focusing on early disease detection and preventive cardiology. Mobile health devices started to emerge, and I saw an opportunity to use this technology to scale prevention.

Traditional medicine is based on clinical measurements, but so much of health happens on a daily basis and in the real world. Currently, I'm working on developing cardiovascular devices and programs to help drive Verily's mission of enabling proactive and preventive care. I also continue seeing preventive cardiology patients as a clinical professor of medicine at Stanford.

Heart health is one area where early intervention can make a huge difference. Along with my cardiology background, I also happen to have elevated Lp(a) myself, so I'm personally excited to see Project Baseline undertake this research through the Heart Biomarker Study. Having high Lp(a) isn't uncommon — it's estimated that one in five Americans has elevated levels — but more research is needed to determine whether treating Lp(a) can prevent heart disease.

Can you break that down a bit more? What is Lp(a) and why does it matter?

Lp(a) is a lipoprotein similar to LDL, the 'bad' cholesterol that promotes plaque buildup in arteries, which can lead to heart attacks and strokes. One important difference is that LDL cholesterol levels are impacted by diet and exercise. Lp(a) levels, however, are largely determined by genetics. So far, we don't have evidence that shows it can be significantly affected by lifestyle.

While both LDL and Lp(a) cause diseased arteries, Lp(a) also makes blood more prone to clotting. Generally, blood clotting is a good thing; it heals wounds to prevent blood loss. But what can happen with Lp(a) is that a plaque — the fatty substance that clogs arteries — can tear and prompt your body to form a clot to address it. Because this happens inside the artery, the clot stops blood from reaching the heart. Heart cells then start to die, which is a heart attack. A similar phenomenon can happen in arteries that go to the brain, causing strokes.

Today, the standard measurements we use to gauge heart disease risk include blood pressure and cholesterol. With patients who have a personal or family history of early heart disease, we may look for other contributors. Lp(a) is one of the factors that may be elevated in patients who have experienced heart attacks and strokes.

So to me, there is a large unmet need in identifying who should be routinely screened for Lp(a), and what we should do as a result of the Lp(a) level. Would treating Lp(a) directly reduce the risk of heart attacks and strokes the same way current cholesterol-lowering therapies do? We don't have enough data to know for sure, but potentially, this could add a critical tool to our arsenal for preventing heart disease, especially among people who are at greater risk.

Reducing risk is an important point. Can you speak to why it's important to focus on heart attack and stroke survivors as part of this research?

Previous research shows that Lp(a) is associated with a greater risk of having a heart attack or stroke. But we don't know as much about how it affects what we call secondary risk, namely the chances of experiencing a second event.

Survivors of a heart attack or stroke are typically having their blood pressure and cholesterol treated and monitored closely. To improve our treatment of these patients, and prevent worsening cardiovascular disease, we want to understand how much Lp(a) may affect health relative to the risk factors we treat today.

If you've experienced a heart attack or stroke, you may be eligible to join the Heart Biomarker Study. Learn more and consider getting involved.