A large new analysis combining Korean and U.S. data found that almost everyone who experienced a major cardiovascular event—heart attack, stroke, or heart failure—had at least one traditional risk factor outside ideal ranges before their illness, even if it did not meet diagnostic criteria. Published September 29 in the Journal of the American College of Cardiology, the study challenges the notion that heart disease commonly occurs without prior warning signs and underscores the importance of keeping blood pressure, cholesterol, blood sugar, and smoking status well within optimal levels.
Researchers analyzed two long-term cohorts. The first used South Korea’s National Health Insurance Service (KNHIS) screening records from 2009 and included 9,341,100 adults aged 20 and older who completed routine examinations measuring blood pressure, cholesterol, blood glucose, and smoking history; medication records for blood pressure, cholesterol, and glucose-lowering drugs were also reviewed. Participants were followed for a median of 13.3 years through hospital records and death registries to capture cardiovascular events.
The second dataset was the U.S.-based Multi-Ethnic Study of Atherosclerosis (MESA), which followed 6,803 adults aged 45 to 84 without known heart disease at baseline. MESA participants had repeated in-person exams to assess the same risk factors and reported smoking behavior. That cohort was tracked for about 17.7 years, with physician-led reviews of medical records to confirm heart attacks, strokes, heart failure, and cardiovascular deaths.
A key feature of the analysis was counting ‘nonoptimal’ risk factor values as well as formal diagnoses. Values above an ideal range but below diagnostic thresholds were treated as meaningful. For example, systolic blood pressure between 120 and 139 mm Hg was considered nonoptimal even when not classified as hypertension. This approach follows the American Heart Association’s ideal cardiovascular health framework, which sets stricter targets than many clinical cutoffs.
Investigators looked at five outcomes separately—coronary heart disease (including fatal and nonfatal heart attacks), heart failure, stroke, myocardial infarction specifically, and a composite total cardiovascular disease measure—and assessed how many people had at least one nonoptimal traditional risk factor, and how many had two or more, prior to their event.
Across both cohorts and all event types, roughly 99% of people had at least one nonoptimal traditional risk factor before developing cardiovascular disease. In the KNHIS population, 99.7% of those who developed coronary heart disease had at least one nonoptimal factor; 99.8% before myocardial infarction; 99.4% before heart failure; and 99.3% before stroke. MESA results were similar, with 99.5% to 99.7% having at least one nonoptimal risk factor prior to illness.
Elevated blood pressure was the most common nonoptimal factor. In Korea, 95.6% to 96.1% of people who developed cardiovascular disease had blood pressure above the ideal range; in the U.S. the range was 93.0% to 96.8%. Elevated cholesterol was the next most frequent issue, affecting 75.8% to 84.7% of affected individuals in Korea and 70.7% to 77.8% in the U.S. Elevated blood sugar—even below diabetes thresholds—was observed in 72.8% to 77.7% of Korean participants and 53.8% to 60.3% of Americans. Past or current smoking was also common, ranging from 47.9% to 68.1% in Korea and 54.1% to 63.3% in the U.S.
Multiple risk factors were the rule rather than the exception. More than 93% of participants in both studies had two or more nonoptimal risk factors before their cardiovascular event. In the KNHIS cohort, just 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 smoking history). Even when stricter cutoffs were applied, 90%–95% still had at least one risk factor above optimal. This near-universal pattern persisted across sexes and age groups.
The investigators conclude that major cardiovascular events rarely occur in people who are truly within ideal ranges for blood pressure, cholesterol, blood sugar, and smoking status. The implication is that maintaining these measures well within optimal limits is critical for prevention.
Commentators not involved in 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, noted that lifestyle changes do not have to be complicated: about 30 minutes of daily activity can help control blood pressure, cholesterol, and weight. She also highlighted stress management—mindfulness, deep breathing, and good sleep—as contributors to heart health and recommended regular checkups to monitor risk factors.
Bradley Serwer, MD, an interventional cardiologist and chief medical officer at VitalSolution, said abnormalities should be treated and then continuously managed. He advised patients to work with primary care clinicians to reach individualized targets, noting that lifestyle modification is first-line but that medications may be required when changes alone are insufficient. Serwer stressed that sustainable, long-term adjustments provide the best protection over a lifetime.
Overall, the study reinforces the importance of monitoring and managing blood pressure, cholesterol, blood sugar, and smoking status—even when values have not crossed conventional diagnostic thresholds—to reduce the risk of heart attacks, strokes, and heart failure.
