Major Study Finds 4 Risk Factors Behind 99% of Heart Attacks and Strokes

Heart attacks and strokes often feel sudden when they happen, but a major international study suggests the warning signs usually appear years earlier. The finding does not mean every event is easy to predict, but it strongly challenges the idea that most serious cardiovascular crises arrive without measurable risk.

The study, led by Northwestern Medicine and Yonsei University in South Korea and published in The Journal of the American College of Cardiology, analysed health records from more than 9.3 million South Korean adults and nearly 7,000 U.S. adults. It found that more than 99% of people who later had coronary heart disease, heart failure or stroke had at least one of four major risk factors beforehand.