Questions
How to detect a Heart Attack: Symptoms and Warning Signs You Should Never Ignore
Learn how to detect the warning signs of a heart attack, understand how it differs from angina, and know when to seek emergency medical care
10 min read
Tool
Heart risk test
Find out your risk of cardiovascular disease.
After a heart attack, a stroke, or living with risk factors, the same question keeps coming back: where do I actually stand?
This tool is here to inform you. It applies published risk scores to your answers and nothing else: it makes no diagnosis and recommends no treatment.
Understanding your result
What is 10-year cardiovascular risk?
It is the probability of a heart attack or stroke in the next ten years, estimated from a handful of measurements: age, sex, smoking, blood pressure and cholesterol. A risk of 10% means that out of a hundred people with a comparable profile, about ten will have such an event in that period.
How does this test calculate risk?
It applies published equations validated on large cohorts, with nothing added. The coefficients come from the original papers, which are cited at the foot of this page.
Which score applies to me?
Two, chosen by what you tell us. PREVENT, the American Heart Association's equations, if you have never had a cardiovascular event: it was built on United States cohorts, covers ages 30 to 79 in a single model, and carries no race term. SMART2 between 40 and 80, if you have already had a heart attack, a stroke, peripheral artery disease or an aortic aneurysm. A model built for one population says little about another.
What does a risk of 10% mean?
It describes a group, not a person. Out of a hundred people with your characteristics, about ten will have an event within ten years and ninety will not. The test cannot say which group you will be in, and no score can.
Is there a threshold for high risk?
Not by a number here. American guidelines do band risk for people who have never had an event, but those thresholds are tied to treatment decisions, and they moved when PREVENT replaced the older Pooled Cohort Equations. Whether a percentage puts you on a statin is a conversation with a clinician, not a colour on a web page. If you have already had an event the question does not arise: established cardiovascular disease is itself the highest category, whatever the percentage says. The figure here is most useful compared with your own, after a change in treatment.
Is risk different after a heart attack?
Yes, and the question itself changes. For someone with no history, the estimate is for a first event. After a heart attack, a stroke or peripheral artery disease, the question is the risk of another event, which is what SMART2 was built for. It accounts for how many arterial beds are affected, how long ago the diagnosis was made, kidney function, inflammation and whether you take an antithrombotic. It also accounts for the chance of dying of something else, which its predecessor did not, and it is calibrated for the United States rather than borrowed from Europe.
Which factors can I actually change?
Age and history do not move. Blood pressure, cholesterol and smoking do. That is why the result also shows your risk with those three at target: the gap between the two numbers is the part that treatment can work on.
What does the optimal value mean?
It is your risk calculated as if you did not smoke, did not have diabetes, and had blood pressure and cholesterol at target. It is a reference point, not a forecast, and depending on your situation it may not be reachable.
Why does my result differ from another calculator?
Because different calculators run different equations. Many American ones still use the 2013 Pooled Cohort Equations, which PREVENT was published to replace and which overestimate risk in people measured today. This test uses PREVENT for a first event and SMART2 for a further one, both calibrated on United States data rather than European constants.
Day-to-day support
Noctua Care works with people living with cardiovascular disease, between appointments.
See the programmeWhat if I don't know my values?
Answer "I don't know". The test substitutes a documented mid-range value and names it under the result, so you can see what came from you and what came from us. Run it again once you know your own.
How often should I retake the test?
It is only worth retaking once something has changed: after a blood test, a change in medication, stopping smoking. Taken again the next day with the same answers, it returns the same number.
What happens to my answers?
Nothing. The calculation runs in your browser, your answers are never sent to us and nothing is stored. Close the page and they are gone.
Does this test replace seeing a doctor?
No. It does not diagnose anything and does not set a target value for you. It is an estimate built on a few variables, where your doctor sees many more and knows your history.
How Noctua Care changed their lives
What our participants say, in their own words.
“I learned to listen to my body instead of being afraid of it.”
Evelyne G.Heart attack, 2023 
“I had the app when I left the hospital. I wasn't alone with my questions anymore.”
Jean-LouisAcute coronary syndrome 
“115 pounds down over two years, and I quit smoking. I started with a ten-minute walk.”
Franck G.Patient since 2022
Also worth reading
Sources
- Hageman SHJ, McKay AJ, Ueda P, et al. Estimation of recurrent atherosclerotic cardiovascular event risk in patients with established cardiovascular disease: the updated SMART2 algorithm. European Heart Journal, 2022.
- Khan SS, Matsushita K, Sang Y, et al. Development and Validation of the American Heart Association's PREVENT Equations. Circulation, 2024.