Nearly one in 10 heart attacks and strokes in England and Wales could have been better if they were check-ups.
Currently, people aged 40 and over are entitled to their health every five years.
But UCL scientists at low risk are checked too often while those considered at high risk are not checked often enough.
They say a personalized approach could save lives without costing any more.
Chances of a heart attack or stroke may be ascribed to risk factors such as blood pressure, cholesterol and blood-sugar levels, age and family history.
High-risk patients are told to change their lifestyle and reduce their cholesterol or drugs to lower blood pressure.
The researchers followed 7,000 people to see how they spent in different risk categories.
The study, in the Lancet Public Health, showed:
- "Low-risk" patients took an average of nine years to reach "intermediate-low-risk"
- "Intermediate-low-risk" patients spent an average of seven years in this category; 90% went on to become "intermediate-high-risk"
- But within four years, 70% of "intermediate-high-risk" patients became "high-risk" and needed treatment
The researchers then simulated different ways of screening people depending on their heart-risk category.
For example, screening low-risk patients every seven years, intermediate-low every four years and intermediate-high every year.
How big an impact?
8% of heart attacks and strokes, say the researchers.
That would prevent 5,000 people a year in England and Wales having a life-threatening heart attack or stroke.
Prof Mika Kivimaki, one of the researchers, said, "The key message is individualized screening, not one-size-fits-all.
"I believe this will change because there is a tendency towards precision medicine and individualized treatment and prevention.
"I think this is going to happen in the future and I hope it will happen sooner rather than later."
The next stage of the research would be to make a clinical trial to see if screening would actually make a difference.
Prof Sir Nilesh Samani, medical director of the British Heart Foundation, said: "While the heart-health check-ups based on a person's individual risk could potentially save lives and costs, it's easier said than done.
"An issue that is even more important to address is why so many people who could not receive them in the first place.
"If you know you are at the higher risk of developing heart and circulatory disease, it is very important to take care of it."
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