A massive international study has found that more than 99% of people who later suffered a heart attack, stroke, or heart failure already had at least one health risk before the event.
This challenges the idea that these life-threatening conditions come without warning.
The research was led by Northwestern Medicine in the U.S. and Yonsei University in South Korea. It looked at health data from more than 9 million South Korean adults and nearly 7,000 adults in the U.S., tracking them for up to 20 years. The study will be published in The Journal of the American College of Cardiology.
Cardiovascular disease is the top cause of death in the U.S. and around the world. Dr. Philip Greenland, a senior author of the study and professor of cardiology at Northwestern University, said the findings clearly show that nearly every person who had a serious heart event had at least one warning sign.
“The goal now is to focus more on controlling the known, treatable risk factors,” said Dr. Greenland, “instead of looking into other causes that are harder to fix and may not be responsible.”
The study focused on four major risk factors: high blood pressure, high cholesterol, high blood sugar (or diabetes), and tobacco use. Researchers used the American Heart Association’s standards for what counts as a nonoptimal level:
Blood pressure of 120/80 mm Hg or higher, or taking medication for it
Total cholesterol of 200 mg/dL or higher, or on cholesterol medication
Fasting glucose of 100 mg/dL or higher, a diabetes diagnosis, or diabetes treatment
Current or past tobacco use
In a second part of the study, they also looked at more severe levels often used by doctors to diagnose illness: blood pressure of 140/90 or higher, cholesterol of 240 or more, glucose of 126 or more, and current smoking.
The results were clear in both groups of people studied. More than 99% of those who had a heart attack, stroke, or heart failure had at least one nonoptimal risk factor beforehand. Over 93% had two or more.
High blood pressure was the most common risk factor, affecting over 95% of people in South Korea and over 93% in the U.S. Even among women under 60—who are often thought to have a lower risk—more than 95% had at least one of these risk factors before getting sick.
Even when the researchers looked only at people with more severe levels, the pattern remained. At least 90% of them still had one or more of the main risk factors before they got sick.
The message from this study is strong: heart disease and strokes rarely come out of nowhere. Most people have warning signs that show up years before something serious happens. By identifying and managing these risk factors early—especially high blood pressure—we have a better chance to prevent these deadly events.
If you care about heart health, please read studies that Changing blood pressure readings is a hidden sign of heart disease and common type 2 diabetes drugs may raise heart risk.
For more about heart health, please read studies about root cause of heart rhythm disorders and Warning signal from the kidneys can predict future heart failure risk.
The study is published in the Journal of the American College of Cardiology.
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