What Does High Cardiovascular Risk Mean? A Plain-Language Guide
Your doctor mentions your "cardiovascular risk" and moves on to the next topic. It is a phrase that sounds important but rarely gets explained. In simple terms, it is your estimated chance of having a heart attack, stroke or other serious heart or blood vessel problem in the coming years.
Key takeaways
Established cardiovascular disease means a heart or blood vessel problem has already been diagnosed, such as a heart attack, stent, bypass or stroke.
High cardiovascular risk means no major event yet, but a combination of factors makes one more likely.
Doctors estimate risk with tools such as the AHA PREVENT calculator, and sometimes with a coronary calcium scan.
High blood pressure is one of the biggest risk factors you can change, which is why it is a major focus of research.
Two terms that sound alike but mean different things
Established cardiovascular disease
A heart or blood vessel condition has already been diagnosed. Examples include a heart attack, coronary artery disease, a coronary stent or balloon angioplasty, bypass surgery, a stroke, narrowed neck (carotid) arteries and peripheral artery disease in the legs. Here, the main goal is preventing a second event.
High cardiovascular risk
No major event has happened yet, but a combination of factors makes one more likely. These can include older age, diabetes, chronic kidney disease, smoking, high cholesterol or a very high coronary calcium score. Here, the main goal is preventing a first event.
How doctors estimate your risk
Risk calculators
The 2025 AHA and ACC blood pressure guideline uses the PREVENT calculator, which estimates your 10-year chance of cardiovascular disease from factors like age, blood pressure, cholesterol, diabetes, smoking and kidney function. For adults with readings of 130/80 or higher, a 10-year risk of 7.5% or more is one of the reasons the guideline recommends starting medicine promptly rather than waiting.
Coronary artery calcium (CAC) score
This quick CT scan measures calcium buildup in the heart arteries. A score of zero is reassuring. A score above 400 signals extensive buildup and a much higher chance of future heart problems, even in someone who feels well.
Your history
Past procedures, hospital stays and diagnoses all count. Many people forget to mention a stent placed years ago or a "mini-stroke" (TIA). If you are unsure, your records or your cardiologist can confirm.
Try this at your next visit
Ask: “What is my estimated 10-year cardiovascular risk, and which of my risk factors would make the biggest difference if we improved it?” A specific number is easier to act on than a general warning.
Where high blood pressure fits in
High blood pressure multiplies the effect of other risk factors. Someone with diabetes and uncontrolled blood pressure faces more risk than either condition alone would suggest. The upside is that blood pressure is one of the factors you and your doctor can change. For more on what the numbers mean for your organs, see high blood pressure is more than a number.
High blood pressure plus a heart, stroke or artery history? ZENITH may be worth checking.
Why the ZENITH study focuses on cardiovascular risk
ZENITH (NCT07181109) is testing whether zilebesiran, an investigational injection given every six months, reduces heart attacks, strokes, heart failure events and cardiovascular deaths when added to usual blood pressure treatment. Studying people who already face higher risk makes it possible to answer that question. Participants need uncontrolled blood pressure despite two or more medicines and one of the following profiles:
Heart: a past heart attack, coronary artery disease, a coronary stent or angioplasty, bypass surgery, or a CAC score above 400
Brain and neck arteries: a past stroke, narrowed carotid arteries, or a carotid stent or surgery
Circulation: peripheral artery disease, a leg artery stent or bypass, or an amputation due to poor circulation
Or a combination of factors that places a person at high cardiovascular risk, as assessed by the study team
Study snapshot: ZENITH (NCT07181109)
What is being studied
Zilebesiran, an investigational medicine given as an injection under the skin every six months, added to a person's usual blood pressure medicines.
Compared with
Placebo (an injection with no active medicine). Participants keep taking their regular blood pressure medicines either way.
Main question
Whether zilebesiran lowers the risk of serious heart and blood vessel events, such as heart attack, stroke, heart failure events or death from cardiovascular causes.
Size and scope
A global Phase 3 study planned to include about 11,000 adults in 35 countries.
Who may be a fit
Adults whose blood pressure stays high despite two or more blood pressure medicines, and who have established cardiovascular disease or high cardiovascular risk.
Local study sites
Research sites working with HEKMA include Birmingham, AL; Evansville, IN; Phoenix, AZ; and San Antonio, TX.
Having one of these conditions does not by itself mean someone qualifies. There are other criteria, and people with a very recent heart attack or stroke (within 60 days) are not eligible at that time. See who the study is looking for for the full overview.
Frequently asked questions
What is the difference between cardiovascular disease and cardiovascular risk?
Cardiovascular disease means a heart or blood vessel condition has already been diagnosed, such as a heart attack or stroke. Cardiovascular risk is the estimated chance of developing such a problem in the future.
What does a coronary calcium score over 400 mean?
It indicates extensive calcium buildup in the heart arteries and a substantially higher chance of future heart problems. Your healthcare professional can explain what your own score means for you.
What is the PREVENT calculator?
PREVENT is an American Heart Association tool that estimates 10-year cardiovascular risk using factors such as age, blood pressure, cholesterol, diabetes, smoking and kidney function. The 2025 blood pressure guideline uses it to guide treatment decisions.
Can I join ZENITH if I had a heart attack last month?
People who had a heart attack, stroke or artery procedure within the past 60 days are not eligible at that time. The study team can explain whether you might be considered later.