Researchers at the Northwestern University Feinberg School of Medicine in Chicago, Illinois, and Yonsei University College of Medicine in Seoul, South Korea, have found that 99% of people who suffer a cardiac event already have at least one cardiovascular risk factor years before, refuting the common belief that heart disease often occurs without previous warning signs.
In their study, published in The Journal of the American College of Cardiology and titled “Very High Prevalence of Nonoptimally Controlled Traditional Risk Factors at the Onset of Cardiovascular Disease,” the researchers took a closer look at how having at least one cardiovascular risk factor affects the risk of suffering a cardiovascular disease event, such as a heart attack, stroke, or heart failure.
The researchers used the definitions of ideal cardiovascular health by the American Heart Association, choosing four major cardiovascular risk factors: blood pressure should be ≥120/80 mm Hg, total cholesterol should be around ≥200 mg/dL, fasting blood sugar levels around ≥100 mg/dL, and past or current use of tobacco.
They then analyzed two population-based data sets. The first data set comprised approximately 9.34 million people in the Korean National Health Insurance Service (KNHIS), aged 20 years and above, who had regular follow-ups between 2009 and 2022. The second data set, with around 7,000 people aged 45 to 84 years, who had regular follow-ups between 2000 and 2019, was part of the Multi-Ethnic Study of Atherosclerosis (MESA) in the U.S.
Both data sets included regular health screenings, allowing the researchers to analyze the blood pressure, glucose, and cholesterol levels, and whether or not somebody used tobacco, for years before their first cardiovascular event. The team identified 601,025 cardiovascular events in the KNHIS cohort and 1,188 cardiovascular events in the MESA population.
The study showed similar results across the Korean and U.S. cohorts. Over 99% of people—across age groups and in both men and women—who developed a cardiovascular disease during the observed period had at least one cardiovascular risk factor before their diagnosis.
In detail, 99.7% in KNHIS and 99.6% in MESA with at least one risk factor developed coronary heart disease; 99.4% in KNHIS and 99.5% in MESA suffered heart failure, and 99.3% in KNHIS and 99.5% in MESA with at least one cardiovascular risk factor experienced a stroke.
More than 93% of people in both population-based data sets had two or more risk factors.
“We think the study shows very convincingly that exposure to one or more nonoptimal risk factors before these cardiovascular outcomes is nearly 100%,” said senior author Philip Greenland, PhD, professor of cardiology at Northwestern University Feinberg School of Medicine.
Cardiovascular diseases remain the leading cause of death worldwide, killing approximately 20 million people every year.
“The goal now is to work harder on finding ways to control these modifiable risk factors rather than to get off track in pursuing other factors that are not easily treatable and not causal,” Greenland concluded.
