Coronary Artery Calcium Scoring in Young Adults: Evidence and Challenges

Re-Evaluation of Cardiovascular Disease Risk and Primary Prevention Treatments with Coronary Artery Calcium Scoring in Primary Prevention Patients

Objective: The coronary artery calcium score (CACS) is used as a screening tool to identify the presence/absence of subclinical atherosclerosis in asymptomatic individuals. We evaluated the risk categories and medical therapy of asymptomatic individuals with subclinical atherosclerosis (CACS > 0) and applied the atherosclerotic cardiovascular disease (ASCVD) score and Framingham risk score (FRS) to assess those at a high risk of subclinical atherosclerosis (CACS ≥ 400). Methods: We retrospectively enrolled 218 asymptomatic individuals (65.6% women, and mean age 67.5 ± 10.3 years) who had their CACS evaluated at the cardiovascular department of our hospital between 2016 and 2020. Results: Among the 218 participants, 24.3% were classified as low-risk according to the FRS, and 19.3% had no subclinical atherosclerosis. However, only 12.8% and 27.5% of the study population were taking statins and aspirin, respectively. Furthermore, although more than half of the individuals without subclinical atherosclerosis were in the intermediate- and high-risk groups according to the risk scores, there were no considerable differences in the rates of taking aspirin and statins between the groups. When patients in the very-high-risk group according to the CACS and low-intermediate-risk patients were compared, there was no considerable difference in the rates of risk subgroups and taking statins, whereas high-risk patients took statistically significantly more aspirin. Conclusions: In primary prevention screening, CACS can be used as a reliable marker of subclinical ASCVD and help physicians optimize and improve adherence to medical therapy, including aspirin and statins, particularly for high-risk individuals.

Distribution of Coronary Artery Calcium by Age, Sex, and Race Among Patients 30-45 Years Old

BACKGROUND

Coronary artery calcium (CAC) is a measure of atherosclerotic burden and is well-validated for risk stratification in middle- to older-aged adults. Few studies have investigated CAC in younger adults, and there is no calculator for determining age-, sex-, and race-based percentiles among individuals aged <45 years.

OBJECTIVES

The purpose of this study was to determine the probability of CAC >0 and develop age-sex-race percentiles for U.S. adults aged 30-45 years.

METHODS

We harmonized 3 datasets-CARDIA (Coronary Artery Risk Development in Young Adults), the CAC Consortium, and the Walter Reed Cohort-to study CAC in 19,725 asymptomatic Black and White individuals aged 30-45 years without known atherosclerotic cardiovascular disease. After weighting each cohort equally, the probability of CAC >0 and age-sex-race percentiles of CAC distributions were estimated using nonparametric techniques.

RESULTS

The prevalence of CAC >0 was 26% among White males, 16% among Black males, 10% among White females, and 7% among Black females. CAC >0 automatically placed all females at >90th percentile. CAC >0 placed White males at the 90th percentile at age 34 years compared with Black males at age 37 years. An interactive webpage allows one to enter an age, sex, race, and CAC score to obtain the corresponding estimated percentile.

CONCLUSIONS

In a large cohort of U.S. adults aged 30-45 years without symptomatic atherosclerotic cardiovascular disease, the probability of CAC >0 varied by age, sex, and race. Estimated percentiles may help interpretation of CAC scores among young adults relative to their age-sex-race matched peers and can henceforth be included in CAC score reporting.

Predictors of Coronary Artery Calcium and Long-Term Risks of Death, Myocardial Infarction, and Stroke in Young Adults

Background Coronary artery calcium (CAC) is well-validated for cardiovascular disease risk stratification in middle to older-aged adults; however, the 2019 American College of Cardiology/American Heart Association guidelines state that more data are needed regarding the performance of CAC in low-risk younger adults. Methods and Results We measured CAC in 13 397 patients aged 30 to 49 years without known cardiovascular disease or malignancy between 1997 and 2009. Outcomes of myocardial infarction (MI), stroke, major adverse cardiovascular events (MACE; MI, stroke, or cardiovascular death), and all-cause mortality were assessed using Cox proportional hazard models, controlling for baseline risk factors (including atrial fibrillation for stroke and MACE) and the competing risk of death or noncardiac death as appropriate. The cohort (74% men, mean age 44 years, and 76% with ≤1 cardiovascular disease risk factor) had a 20.6% prevalence of any CAC. CAC was independently predicted by age, male sex, White race, and cardiovascular disease risk factors. Over a mean of 11 years of follow-up, the relative adjusted subhazard ratio of CAC >0 was 2.9 for MI and 1.6 for MACE. CAC >100 was associated with significantly increased hazards of MI (adjusted subhazard ratio, 5.2), MACE (adjusted subhazard ratio, 3.1), stroke (adjusted subhazard ratio, 1.7), and all-cause mortality (hazard ratio, 2.1). CAC significantly improved the prognostic accuracy of risk factors for MACE, MI, and all-cause mortality by the likelihood ratio test (P<0.05). Conclusions CAC was prevalent in a large sample of low-risk young adults. Those with any CAC had significantly higher long-term hazards of MACE and MI, while severe CAC increased hazards for all outcomes including death. CAC may have utility for clinical decision-making among select young adults.

Modeling the Recommended Age for Initiating Coronary Artery Calcium Testing Among At-Risk Young Adults

BACKGROUND

There are currently no recommendations guiding when best to perform coronary artery calcium (CAC) scanning among young adults to identify those susceptible for developing premature atherosclerosis.

OBJECTIVES

The purpose of this study was to determine the ideal age at which a first CAC scan has the highest utility according to atherosclerotic cardiovascular disease (ASCVD) risk factor profile.

METHODS

We included 22,346 CAC Consortium participants aged 30-50 years who underwent noncontrast computed tomography. Sex-specific equations were derived from multivariable logistic modeling to estimate the expected probability of CAC >0 according to age and the presence of ASCVD risk factors.

RESULTS

Participants were on average 43.5 years of age, 25% were women, and 34% had CAC >0, in whom the median CAC score was 20. Compared with individuals without risk factors, those with diabetes developed CAC 6.4 years earlier on average, whereas smoking, hypertension, dyslipidemia, and a family history of coronary heart disease were individually associated with developing CAC 3.3-4.3 years earlier. Using a testing yield of 25% for detecting CAC >0, the optimal age for a potential first scan would be at 36.8 years (95% CI: 35.5-38.4 years) in men and 50.3 years (95% CI: 48.7-52.1 years) in women with diabetes, and 42.3 years (95% CI: 41.0-43.9 years) in men and 57.6 years (95% CI: 56.0-59.5 years) in women without risk factors.

CONCLUSIONS

Our derived risk equations among health-seeking young adults enriched in ASCVD risk factors inform the expected prevalence of CAC >0 and can be used to determine an appropriate age to initiate clinical CAC testing to identify individuals most susceptible for early/premature atherosclerosis.

Can post-mortem coronary artery calcium scores aid diagnosis in young sudden death?

This study sought to explore the feasibility and utility of post-mortem coronary artery calcium (CAC) scoring in identifying patients with ischemic heart disease as cause of sudden death. 100 deceased patients aged 18-50 years underwent post-mortem examination in the setting of sudden death. At post-mortem, fifty cases were determined to have ischemic heart disease, and fifty had death attributed to trauma or unascertained causes. The CAC score was calculated in a blinded manner from post-mortem CTs performed on all cases. CAC scores were assessable in 97 non-decomposed cases (feasibility 97%). The median CAC score was 88 Agatston units [IQR 0-286] in patients deceased from ischemic heart disease vs 0 [IQR 0-0] in patients deceased from other causes (p < 0.0001). Presence of any coronary calcification differed significantly between ischemic heart disease and non-ischemic groups (adjusted odds ratio 10.7, 95% CI 3.2-35.5). All cases with a CAC score > 100 (n = 22) had ischemic heart disease as the cause of death. Fifteen cases had a CAC score of zero but severe coronary disease at post-mortem examination. Post-mortem CAC scoring is highly feasible. An elevated CAC score in cases 18-50 years old with sudden death predicts ischemic heart disease at post-mortem examination. However, a CAC score of zero does not exclude significant coronary artery disease. Post-mortem CAC score may be considered as a further assessment tool to help predict likely cause of death when there is an objection to or unavailability of post-mortem examination.

Why patients with familial hypercholesterolemia are at high cardiovascular risk? Beyond LDL-C levels

Familial hypercholesterolemia (FH) is a common genetic cause of elevated low-density lipoprotein cholesterol (LDL-C) due to defective clearance of circulating LDL particles. All FH patients are at high risk for premature cardiovascular disease (CVD) events due to their genetically determined lifelong exposure to high LDL-C levels. However, different rates of CVD events have been reported in FH patients, even among those with the same genetic mutations and comparable LDL-C levels. Hence, additional CVD risk modifiers, beyond LDL-C, may contribute to increase CVD risk in the FH population. In this review, we discuss the overall CVD risk burden of the FH population. Additionally, we revise the prognostic impact of several traditional and emerging predictors of CVD risk and we provide an overview of the role of specific tools to stratify CVD risk in FH patients in order to ensure them a more personalized treatment approach.