A large-scale health study has revealed that heart attacks and strokes rarely occur suddenly or without warning. The vast majority of these events are linked to known and detectable risk factors.
Based on health data from more than 9 million adults in both South Korea and the United States, researchers found that all individuals who experienced a major cardiovascular event had at least one of four major risk factors prior to the event.
These factors are high blood pressure, high cholesterol, high blood sugar, and current or past smoking.
The results of the long-term study, published in 2025, showed that these factors collectively preceded approximately 99% of all cardiovascular events observed during the follow-up period.
High blood pressure was the most common risk factor associated with cardiovascular disease. Data from both the United States and South Korea showed that more than 93% of people who suffered a heart attack or stroke had high blood pressure before the event.
This suggests that controlling blood pressure may be the cornerstone of preventing serious cardiovascular disease in the future.
In this context, the study's lead author, cardiologist Philip Greenland of Northwestern University, said the findings "clearly demonstrate that exposure to one or more risk factors before these cardiovascular events occur is almost inevitable."
He emphasized that the focus should be on improving control of modifiable risk factors, rather than being preoccupied with other factors that are difficult to treat or are not a direct cause of the disease.