Longer-Term ASCVD Risk Assessment Best for Younger Patients

Taking the long view can help identify younger patients at higher near-term risk for atherosclerotic cardiovascular disease (ASCVD) who would benefit from aggressive lifestyle changes and possible interventions, a new study suggests.

Investigators say that when dealing with young patients, risk prediction tools that focus on the next 30 years, or even a lifetime, as opposed to the next decade alone, may be best for capturing those at risk for MI, stroke, or coronary heart disease.  

“With cardiovascular events, such as MI or stroke, there is an increasing trend in young adults,” lead investigator Jaejin An, PhD (Kaiser Permanente Southern California, Pasadena), told TCTMD. While researchers aren’t entirely sure why these events are occurring in younger patients, An said there is a push to find those who would benefit from earlier modification of ASCVD risk factors, such as lowering LDL cholesterol and blood pressure and improving glycemic control, through lifestyle changes or medication.  

“There has been more of an emphasis on earlier assessment and earlier treatment that may be more helpful,” said An. “The field is emphasizing that we need to maintain the best health as much as we can at a much younger age.”   

The 2018 American College of Cardiology/American Heart Association (ACC/AHA) cholesterol guidelines recommend the pooled cohort equations to estimate the 10-year risk of ASCVD, but the risk calculator is recommended only for adults ages 40 to 75 years, which is a somewhat arbitrary cutoff, said An. This leaves physicians in the lurch when it comes to assessing risk in younger patients, she added.

For those younger than 40 years, the ACC/AHA still recommends physicians check on the cardiovascular health of patients using an estimation of lifetime or 30-year ASCVD risk. The existing lifetime and 30-year ASCVD risk calculators were derived from a cohort of non-Hispanic white patients in 2006 and 2009, respectively, but it’s unclear how well these tools perform in the near term when compared against the pooled cohort equations, according to the researchers.

With this in mind, the researchers wanted to determine if the longer-term risk assessment calculators could discriminate high versus low ASCVD risk in a cohort of Black and non-Black patients ages 18 to 39 years who received care within a large integrated US healthcare system.

Longer-Term Risk Assessment

The study, published online ahead of the February 21, 2023, issue of the Journal of the American College of Cardiology, included data on 414,260 young adults (mean age 29.8 years; 60.6% women) from the Kaiser Permanente Southern California healthcare system. Using the ACC/AHA pooled cohort equation, the 10-year risk of ASCVD was 0.6%. The 30-year risk of hard ASCVD events, based on a risk calculator developed using the Framingham Offspring Study, was 3.1%. Over a median follow-up of 4.0 years, 813 adults had incident ASCVD events.

Compared with the 10-year predicted risk, 30-year predicted risk improved the reclassification of patients (net reclassification index 16%).

Of the entire cohort, 1% of the young adults had an elevated 10-year risk of ASCVD (defined as 7.5% or higher) while 2.2% had an elevated 30-year predicted risk of ASCVD (defined as 20% or greater). In total, 1.6% of the cohort had a low 10-year risk of ASCVD but an increased projected risk at 30 years. In terms of ASCVD, the incidence rates per 1,000 person-years were 2.60 for those with an elevated 10-year risk, 1.87 for those with a low 10-year but elevated 30-year risk, and 0.32 for those with a low 10-year and 30-year predicted risk of ASCVD.

Overall, those with a low 10-year but elevated 30-year predicted risk had a threefold higher incidence of ASCVD compared with those with a low 10- and 30-year predicted risk (incidence rate ratio 3.04; 95% CI 2.25-4.10).

“The 10-year risk prediction tool identified a very small number of people at elevated risk,” said An. When using the 30-year risk prediction calculator, they identified an additional 6,425 patients who had a low 10-year but high 30-year predicted risk of ASCVD. “We think this might be a helpful to further discriminate a subset of young adults who may be at high risk for cardiovascular events,” said An. “I hope our study findings provide more information to general physicians that assessing longer-term risk prediction may be important.”

In an editorial, Donald Lloyd-Jones, MD, ScM, and John Wilkins, MD, MS (both Northwestern University Feinberg School of Medicine, Chicago, IL), said that predicting near-term ASCVD risk in a young population is challenging. While there is a long way to go to optimize risk assessment in young patients, they believe the findings support the current guideline recommendations of 30-year or lifetime risk assessment in this young group. The hope, they add, is to identify those who might benefit from aggressive lifestyle or drug therapies.

The editorialists lay out the current status of risk assessment approaches across the life span, noting that during the period of young adulthood (age 20 to 39 years), the focus is on identifying causal determinants of ASCVD.

“Specifically, we could identify the overwhelming majority of those destined to have near-term and longer-term ASCVD events if we routinely evaluated, fully understood, and acted on levels of non–high-density-lipoprotein cholesterol, apolipoprotein B, blood pressure, tobacco exposure, and blood glucose,” write Lloyd-Jones and Wilkins. “Exposures to causal risk factors during this life stage, even at levels below clinical thresholds for diagnosing dyslipidemia, hypertension, or dysglycemia, clearly lead to vascular damage and can lead to a ‘point of no return’ from which eventual ASCVD cannot be avoided despite later effective preventive drug therapy.”