99% of Heart Attacks and Strokes Linked to 4 Key Risk Factors

Approximately 99% of heart attacks and strokes are linked to four primary risk factors—high blood pressure, high cholesterol, high blood sugar, and smoking—according to a study of over 9 million people in the U.S. and South Korea published in the Journal of the American College of Cardiology.

The research indicates these factors are often detectable years before a major cardiovascular event occurs. This finding underscores the role of early intervention in reducing global mortality rates.

What are the four primary cardiovascular risk factors?

The study identifies high blood pressure, elevated blood cholesterol, high blood sugar levels, and current or former smoking as the dominant drivers of heart disease. These factors were present in the vast majority of patients who experienced heart attacks, strokes, or heart failure.

High blood pressure emerged as the most frequent correlation. According to the researchers, more than 93% of individuals who suffered a heart attack, stroke, or heart failure in both the U.S. and South Korea had a history of hypertension.

Did You Know? The study analyzed a massive dataset of over 9 million individuals across the United States and South Korea to determine these risk correlations.

Why do some “healthy” people suffer heart attacks?

Recent claims suggested a rise in cardiovascular events among people with no known risk factors. This study challenges that notion. Philip Greenland, a cardiologist and lead researcher from Northwestern University, stated that modifiable risk factors precede nearly all major cardiovascular events.

Researchers suggest that cases involving seemingly healthy patients may result from undiagnosed conditions. Some individuals may have risk levels that exist but haven’t yet reached the clinical thresholds required for a formal diagnosis.

Dr. Neha Pagidipati of Duke University noted in a study editorial that these results highlight the necessity of treating health risks before they evolve into life-threatening conditions.

Expert Insight: Samantha Carter notes that the gap between “sub-clinical” levels and formal diagnosis creates a dangerous blind spot. When clinicians rely solely on strict thresholds, they may miss the window for early prevention, making aggressive screening for the four primary factors a critical priority.

How do heart attack causes differ between men and women?

While the four main risk factors are universal, the mechanical causes of heart attacks vary by gender. A September 2025 Mayo Clinic study of 1,474 patients aged 65 or younger in Olmsted County, Minnesota, revealed a stark contrast in how arteries fail.

Dr. Philip Greenland talks calcium scores, risk factors and treating blood pressure.

Atherothrombosis—blockages caused by fat deposits and clots—was responsible for 75% of heart attacks in men. In women, that figure dropped to 47%.

The Mayo Clinic data showed that 34% of heart attacks in women were linked to an imbalance between oxygen supply and heart muscle demand. This can be triggered by severe infection, anemia, or various physiological stresses.

Other causes specific to women included spontaneous coronary artery dissection, where tears in the artery wall block blood flow, and blood clots traveling from other parts of the body.

What happens next for cardiovascular treatment?

Cardiologist Claire Raphael stated that misunderstanding the cause of a heart attack could lead to treatments that are less effective or potentially harmful. Identifying the exact mechanism is now viewed as being as important as the initial treatment.

Medical priorities may shift toward more effective ways to control the four primary modifiable risks. Doctors could place less emphasis on non-modifiable factors that are not direct causes of disease.

Future care is likely to focus on personalized diagnostics for women and young people to identify non-traditional causes of heart attacks, which may improve long-term recovery and prevent recurrence.

Frequently Asked Questions

What are the four main risk factors for heart attacks and strokes?

According to the Journal of the American College of Cardiology, they are high blood pressure, high cholesterol, high blood sugar, and smoking (current or former).

Do these risk factors affect women differently?

While over 95% of heart attacks or strokes in women under 60 are linked to at least one of the four factors, the physical cause often differs. Mayo Clinic research found that only 47% of women’s heart attacks were caused by artery blockages, compared to 75% of men.

What is spontaneous coronary artery dissection?

As described in the Mayo Clinic study, it is a condition where tears develop inside the artery wall, leading to blood accumulation that obstructs flow.

Do you believe your current health screenings are catching “sub-clinical” risks before they become dangerous?