**A groundbreaking international study, analyzing health data from millions, has unveiled that an astonishing 99% of heart attacks, strokes, and heart failures are preceded by just four major, often preventable, risk factors.** Published recently in the *Journal of the American College of Cardiology*, the research challenges the long-held notion of "out-of-nowhere" cardiovascular events, emphasizing that these catastrophic health crises rarely strike without warning signs.^[1][2][3][4] The findings underscore the critical importance of early detection and aggressive management of high blood pressure, high cholesterol, elevated blood sugar, and tobacco use.^[1][5][2][4] ### Demolishing the "Out-of-Nowhere" Myth The collaborative study, led by researchers from Northwestern University and Yonsei University in South Korea, meticulously examined health records spanning over a decade.^[4] It included data from more than 9 million adults in South Korea's National Health Insurance Service (KNHIS) and nearly 7,000 participants in the U.S.-based Multi-Ethnic Study of Atherosclerosis (MESA).^[2][3][6][4] The comprehensive analysis revealed that nearly every individual who experienced a major cardiovascular event had at least one of these four risk factors above optimal levels beforehand.^[2][7][3] This contradicts earlier suggestions that a significant portion of patients might suffer cardiovascular events without any identifiable traditional risk factors.^[2][3][6] Senior author Philip Greenland, MD, a cardiologist from Northwestern University, stated, "We think the study shows very convincingly that exposure to one or more nonoptimal risk factors before these cardiovascular outcomes is nearly 100 percent."^[1][2][3][4] The researchers propose that previous studies might have overlooked diagnoses or failed to account for risk factor levels that, while not meeting clinical diagnostic thresholds, were still "nonoptimal" and contributed to long-term risk.^[1][2][3][6] ### The Four Culprits: A Closer Look The study pinpointed four primary modifiable risk factors, which, individually or in combination, were present before almost all cardiovascular events: * **High Blood Pressure (Hypertension):** This was identified as the most prevalent risk factor. In both the U.S. and South Korean cohorts, over 93% of individuals who suffered a heart attack, stroke, or heart failure had hypertension prior to the event.^[1][2][7][4] Blood pressure levels at or above 120/80 mmHg, or being on treatment for hypertension, were considered nonoptimal.^[3][4] * **High Cholesterol:** Elevated total cholesterol levels, defined as 200 mg/dL or higher, or being on cholesterol-lowering medication, significantly increased risk.^[3][4] This factor was present in roughly 77% of KNHIS participants and 72% of MESA participants before a cardiovascular event.^[6] * **High Blood Sugar Levels:** This includes diagnosed diabetes or a fasting glucose level of 100 mg/dL or higher, or being on diabetes treatment.^[3][4] Uncontrolled blood sugar contributes significantly to cardiovascular damage over time.^[5][7] * **Tobacco Smoking:** Both current and past tobacco use were strongly linked to increased risk of heart attacks and strokes.^{[1][5][7][3][4]} Smoking is a well-established driver of cardiovascular disease globally.^[8][9] The study further highlighted that these risk factors rarely existed in isolation, with 93% to 97% of patients having a combination of two or more before experiencing cardiovascular events.^[6][4] Even in demographics traditionally considered lower risk, such as women under 60, more than 95% of heart attacks and strokes were still tied to one of these existing conditions.^[1][2][4] ### Implications for Prevention and Public Health The findings of this massive global study carry profound implications for public health strategies and individual preventative care.^[2] The researchers argue that the focus should intensify on controlling these modifiable risk factors rather than searching for elusive, untreatable causes.^[1][3][4] Key takeaways for prevention: * **Early and Consistent Monitoring:** Regular health checks are crucial to identify nonoptimal levels of blood pressure, cholesterol, and blood sugar, even if they don't yet meet full diagnostic criteria for disease.^[2] * **Aggressive Lifestyle Interventions:** Promoting healthy diets, regular physical activity, and smoking cessation are paramount.^[9] The World Health Organization (WHO) estimates that most cardiovascular diseases are preventable by addressing behavioral risk factors.^[9] * **Challenging "Borderline" Acceptance:** The study indicates that even levels considered "just a little high" or "almost fine" (e.g., blood pressure above 120/80 mm Hg or total cholesterol above 200 mg/dL) are significant enough to raise long-term risk.^[2][3][4] This suggests a need for a more proactive approach to managing these sub-clinical elevations. * **Global Burden:** Cardiovascular diseases remain the leading cause of death worldwide, accounting for an estimated 19.8 million deaths in 2022, with 85% due to heart attack and stroke.^[9] The global rates of hypertension, diabetes, and obesity continue to climb, making the study's call for prevention even more urgent.^[2][10] This definitive research reinforces that cardiovascular events are not random occurrences but are overwhelmingly linked to identifiable and manageable health metrics. By prioritizing the control of blood pressure, cholesterol, blood sugar, and tobacco use, millions of lives could be saved, and the global burden of heart attacks and strokes significantly reduced.^[2][9] The path to a healthier heart and brain, it appears, is largely within our grasp.