A large new study from Korea and the United States found that nearly everyone who suffers a major cardiovascular event—such as a heart attack, stroke, or heart failure—had at least one traditional risk factor at a suboptimal level beforehand, even if it didn’t meet criteria for a formal diagnosis.
Published September 29 in the Journal of the American College of Cardiology, the research challenges the idea that heart disease often strikes people who have no warning signs. Instead, researchers report that over 99% of people who developed cardiovascular disease had at least one of the key risk factors—blood pressure, cholesterol, blood sugar, or smoking status—outside ideal ranges before their illness. The authors say this underscores the value of keeping these measures well within optimal limits.
Two long-term datasets were analyzed. The first was South Korea’s National Health Insurance Service (KNHIS), which included 9,341,100 adults aged 20 and older who completed routine government health screenings in 2009. Those examinations measured blood pressure, cholesterol, blood sugar, and smoking history; researchers also reviewed prescription records for medications that lower blood pressure, cholesterol, or glucose. Participants were followed for a median of 13.3 years using hospital records and death registries to identify cardiovascular events.
The second source was the U.S.-based Multi-Ethnic Study of Atherosclerosis (MESA), which followed 6,803 adults aged 45 to 84 who had no known heart disease at baseline. MESA participants underwent repeated in-person exams to measure the same risk factors and reported smoking. The MESA cohort was tracked for about 17.7 years, with physician-led medical record reviews confirming heart attacks, strokes, heart failure, and related deaths.
Importantly, the investigators did not restrict their analysis to formal diagnoses of hypertension, high cholesterol, or diabetes. They also counted “nonoptimal” values: levels above the ideal range but short of diagnostic thresholds. For example, systolic blood pressure of 120–139 mm Hg was considered nonoptimal even if not labeled hypertension. This approach follows the “ideal cardiovascular health” framework from the American Heart Association, which sets stricter targets than many clinical guidelines.
Researchers examined five outcomes separately—coronary heart disease (including fatal and nonfatal heart attacks), heart failure, stroke, myocardial infarction specifically, and composite “total cardiovascular disease.” They calculated the percentage of people who had at least one nonoptimal risk factor before their event and how many had two or more.
Across both datasets and all event types, roughly 99% of people had at least one nonoptimal traditional risk factor prior to developing cardiovascular disease. In the KNHIS cohort, 99.7% of people who developed coronary heart disease had at least one nonoptimal factor; rates were 99.8% for myocardial infarction, 99.4% for heart failure, and 99.3% for stroke. The MESA findings were nearly identical, with 99.5% to 99.7% having at least one nonoptimal risk factor before illness.
Elevated blood pressure was the most prevalent nonoptimal factor. In Korea, 95.6% to 96.1% of people with cardiovascular disease had blood pressure above the ideal range; U.S. rates were 93.0% to 96.8%. Elevated cholesterol followed, affecting 75.8% to 84.7% in Korea and 70.7% to 77.8% in the U.S. Elevated blood sugar—even below diabetes thresholds—was seen in 72.8% to 77.7% of Korean participants and 53.8% to 60.3% of Americans. Past or current smoking also appeared frequently, ranging from 47.9% to 68.1% in Korea and 54.1% to 63.3% in the U.S.
Multiple risk factors were common: over 93% of participants in both studies had two or more nonoptimal risk factors before their event. In the KNHIS cohort, only 0.3% of people with coronary heart disease had none of the four measured risk factors, while 42.8% had all four (elevated blood pressure, elevated cholesterol, elevated blood sugar, and a history of smoking). Even when investigators applied stricter cutoffs, 90%–95% still had at least one risk factor above optimal. The near-universal pattern held across sexes and age groups.
The findings suggest that major cardiovascular events rarely occur in people who are truly within ideal ranges for blood pressure, cholesterol, blood sugar, and smoking status. Keeping these measures well within optimal limits may therefore be critical for prevention.
Clinicians quoted about the study emphasized practical prevention strategies. Yanting Wang, MD, director of the Women’s Heart Program and Cardio-Obstetrics Program at Robert Wood Johnson University Hospital (not involved in the study), noted that lifestyle changes need not be complicated: staying active (even about 30 minutes a day) can help control blood pressure, cholesterol, and weight. She highlighted stress management—mindfulness, deep breathing, and good sleep—as contributors to heart health and advised regular checkups with a physician to monitor key risk factors.
Bradley Serwer, MD, an interventional cardiologist and chief medical officer at VitalSolution (also not involved in the research), said abnormalities should be treated and then continuously managed. He urged patients to work with primary care providers to reach individualized treatment goals. Lifestyle modification is first-line therapy, Serwer said, but medications may be needed if changes don’t sufficiently control risk factors. He emphasized that sustainable, long-term adjustments—not short-term efforts—are essential for lifelong cardiovascular protection.
Overall, the study reinforces that monitoring and managing blood pressure, cholesterol, blood sugar, and smoking status—even when values haven’t crossed diagnostic thresholds—are important for preventing heart attacks, strokes, and heart failure.
