Half of heart attacks strike people told they’re low risk

The team evaluated the accuracy of the widely used atherosclerotic cardiovascular disease (ASCVD) risk score and a newer tool known as PREVENT. PREVENT incorporates additional variables and is designed to offer a broader picture of cardiovascular risk alongside screening for symptoms.

Risk Scores Often Underestimate Individual Danger

"Our research shows that population-based risk tools often fail to reflect the true risk for many individual patients," says corresponding author Amir Ahmadi, MD, Clinical Associate Professor of Medicine (Cardiology) at the Icahn School of Medicine at Mount Sinai. "If we had seen these patients just two days before their heart attack, nearly half would NOT have been recommended for further testing or preventive therapy guided by current risk estimate scores and guidelines."

Dr. Ahmadi adds that relying heavily on risk assessments and symptom reports may not be the best strategy for prevention. "This study suggests that the current approach of relying on risk scores and symptoms as primary gatekeepers for prevention is not optimal," he says. "It may be time to fundamentally reconsider this model and move toward atherosclerosis imaging to identify the silent plaque -- early atherosclerosis- before it has a chance to rupture."

How ASCVD and PREVENT Are Used in Routine Care

In everyday practice, physicians calculate a person's ASCVD risk score during routine primary care visits, typically for adults aged 40 through 75 who do not have known heart disease. The score estimates the likelihood of a heart attack or stroke within 10 years by factoring in age, sex, race, blood pressure, cholesterol, diabetes, and smoking. Results from the ASCVD or PREVENT calculators guide decisions about preventive therapy, including whether to start statins.

Cardiologists also use these scores to help determine treatment. Patients with intermediate or high scores are usually offered cholesterol-lowering medication and sometimes additional diagnostic testing. Individuals with low or borderline scores, particularly if they report no chest pain or shortness of breath, are frequently reassured and discharged without further evaluation. The study found, however, that if patients who ultimately had their first heart attack had been assessed two days before the event, nearly half would have been classified as low or borderline risk by ASCVD, and more than half would have been categorized that way by PREVENT.

Study Examined Nearly 500 Patients With First Heart Attacks

To examine how well current tools perform, the researchers conducted a retrospective review of 474 patients younger than 66 who had no known coronary artery disease. All were treated for their first heart attack at Mount Sinai Morningside or The Mount Sinai Hospital between January 2020 and July 2025. Investigators collected demographic information, medical history, cholesterol levels, blood pressure readings, and the timing of symptoms such as chest pain or shortness of breath. Each patient's 10-year ASCVD risk score was calculated, and the team simulated how the patient would have been evaluated two days before their heart attack. Patients were sorted into four categories: low (under 5 percent), borderline (5-7.5 percent), intermediate (7.5-20 percent), and high (more than 20 percent).

Symptoms Appear Too Late for Effective Prevention

The analysis focused on two areas: which patients would have qualified for preventive measures based on their score, and when symptoms began. Overall, 45 percent of patients would not have been recommended for preventive therapy or further diagnostic testing under ASCVD-based guidelines. This proportion rose to 61 percent when PREVENT was used. In addition, most patients (60 percent) noticed symptoms fewer than two days before their heart attack. This pattern shows how often symptoms emerge only when the disease has already advanced. The combined findings reveal a serious gap in prevention: people who appear healthy according to standard assessments may already have significant and silent atherosclerosis. Because of this, depending solely on symptoms and risk calculators can delay detection until meaningful prevention is no longer possible.

Researchers Call for Earlier Detection of Silent Plaque

"When we look at heart attacks and trace them backwards, most heart attacks occur in patients in the low or intermediate risk groups. This study highlights that a lower risk score, along with not having classic heart attack symptoms like chest pain or shortness of breath, which is common, is no guarantee of safety on an individual level," says first author Anna Mueller, MD, an internal medicine resident at the Icahn School of Medicine at Mount Sinai. "Our study exposes a major flaw where tools effective for tracking large populations fall short when guiding individualized care. Instead, doctors should shift their focus from detecting symptomatic heart disease to detecting the plaque itself for earlier treatment, which could save lives."

The researchers note that more work is needed to refine these methods, and future studies should explore ways to improve early identification and prevention approaches, including the use of cardiovascular imaging.