When a doctor wants to get a picture of a patient's risk of having a heart attack or stroke, they usually calculate their atherosclerotic cardiovascular disease risk score (ASCVD) during a primary care visit.

The ASCVD score is determined for patients between the ages of 40 and 75 years old. The score uses a patient's age, sex, race, blood pressure and cholesterol levels and their diabetes and smoking status to arrive at a number indicating their likelihood of having a cardiovascular event within the next 10 years.

There's also a newer risk calculator, PREVENT, or Predicting Risk of cardiovascular disease EVENTs, that includes factors such as hemoglobin A1C levels and estimates cardiovascular event risk in patients as young as 30 years old.

Patients who appear healthy by standard measures may already have significant, silent heart disease. Relying solely on risk scores can mean a doctor may delay diagnosis until it is too late for prevention.

Both ASCVD and PREVENT are designed to help doctors and their patients decide if preventive treatment, such as a taking a statin, is necessary.

These calculators are useful for predicting risk on a population level, but they may fall short when it comes to predicting an individual patient's risk of a heart attack, according to a recent study.

Most heart attacks occur in patients considered to be at low- or intermediate-risk, but, “A lower risk score, along with not having classic heart attack symptoms, which is common, does not guarantee safety on an individual level,” Anna Mueller, first author on the study, told TheDoctor.

Researchers from Mount Sinai Hospital in New York City and the Icahn School of Medicine at Mount Sinai came to this conclusion when they analyzed data from 465 patients who were younger than 66 years old, had no known cardiovascular disease, and had been treated for their first heart attack at two hospitals in New York City.

The researchers reviewed the patients' medical histories and checked their cholesterol levels and blood pressure. They also asked patients when their symptoms, defined as shortness of breath or chest pain, began.

Then they calculated the ASCVD risk score for each patient and divided them into four risk groups: low (less than five percent); borderline (five percent to seven-and-a-half percent); intermediate (seven-and-a-half percent to 20 percent); and high (more than 20 percent).

They also simulated what the risk scores would be if the patients' health had been evaluated two days before their heart attack and found that most patients (60 percent) did not develop symptoms such as chest pain or shortness of breath until less than two days before their cardiac event.

Medicine is moving towards regular imaging to screen for heart disease, much like regular screening for breast cancer or colon cancer, even in patients who don't have symptoms.

The results make it clear that acute symptoms tend to appear too late for doctors to help with changing the course of disease. Relying solely on risk scores and symptoms can mean a doctor may delay diagnosis until it is too late for prevention.

Cardiovascular imaging to detect atherosclerosis is a better predictor of heart attack and stroke risk in individual patients, studies have shown. Patients who have atherosclerosis would be treated with medication in advance to hopefully prevent a heart attack or other cardiovascular event. Ongoing studies are trying out this strategy, said Mueller.

Medicine is moving towards regular imaging to screen for heart disease, she added, much like regular screening for breast cancer or colon cancer, even in patients who don't have symptoms. “It is hard to say at what age you should start imaging or how often you should repeat it,” she said. Current and future studies can help researchers answer these questions.

In the meantime, Mueller, chief resident at Mount Sinai West/Mount Sinai Morningside, recommends that people focus on living a heart-healthy lifestyle — eating well, exercising, not smoking or drinking to excess, and checking their blood pressure and cholesterol levels regularly. If you are concerned about signs you think might signal heart problems, mention it to your provider. They may agree that an imaging study is the right decision.

The study is published in the Journal of the American College of Cardiology: Advances.