Risk Factors for Incident Coronary Artery Calcium in Younger (Age 32 to 45 Years) Versus Intermediate (46 to 64 Years) Versus Older (65 to 84 Years) Persons

Beyond the Agatston calcium score: role of calcium density and other calcified plaque markers for cardiovascular disease prediction

PURPOSE OF REVIEW

To review the current evidence and highlight future strategies regarding consideration of coronary artery calcium (CAC) density in cardiovascular disease (CVD) risk stratification.

RECENT FINDINGS

Expressed as the product of plaque area and a peak calcium density weighting factor, the Agatston method is the gold-standard for measuring CAC on noncontrast cardiac computed tomography. Over the last decade, observational data have suggested that calcium density is inversely associated with CVD events and confers additional prognostic information independent of traditional risk factors and Agatston CAC scores. Specific density measures have been assessed including peak calcium density, mean CAC density, and CAC area-density discordance. Beyond calcium density, the number of affected arteries and regional distribution of CAC which may be correlated with CAC density have also improved the predictive utility of the Agatston score.

SUMMARY

Calcium density is inversely associated with CVD risk after considering plaque area and/or volume. Calcium markers including density, vessel involvement, and regional distribution confer additional prognostic information for the prediction of incident CVD among those with prevalent subclinical atherosclerosis. A future area of study includes calcium radiomics ('calcium-omics') and whether the artificial intelligence-derived automated measurement of calcium markers beyond the Agatston score may be of value in CVD risk stratification among individuals with early to advanced subclinical atherosclerosis.

Interaction Between Risk Factors, Coronary Calcium, and CCTA Plaque Characteristics in Patients Age 18-45

AIMS

The atherosclerotic profile and advanced plaque subtype burden in symptomatic patients ≤45 years old have not been established. This study aimed to assess the prevalence and predictors of coronary artery calcium (CAC), plaque subtypes, and plaque burden by coronary computed tomography angiography (CCTA) in symptomatic young patients.

METHODS AND RESULTS

We included 907 symptomatic young patients (18-45 years) from Montefiore undergoing CCTA for chest pain evaluation. Prevalence and predictors of CAC, plaque subtypes, and burden were evaluated using semi-automated software. In the overall population (55% female and 44% Hispanic), 89% had CAC = 0. The likelihood of CAC or any plaque by CCTA increased with >3 risk factors (RF, OR 7.13 [2.14-23.7] and OR 10.26 [3.36-31.2], respectively). Any plaque by CCTA was present in 137 (15%); the strongest independent predictors were age ≥35 years (OR 3.62 [2.05-6.41]) and family history of premature CAD (FHx) (OR 2.76 [1.67-4.58]). Stenosis ≥50% was rare (1.8%), with 31% of those having CAC = 0. Significant non-calcified (NCP, 37.2%) and low-attenuation (LAP, 4.24%) plaque burdens were seen, even in those with non-obstructive stenosis. Among patients with CAC = 0, 5% had plaque, and the only predictor of exclusively non-calcified plaque was FHx (OR 2.29 [1.08-4.86]).

CONCLUSIONS

In symptomatic young patients undergoing CCTA, the prevalence of CAC or any coronary atherosclerosis was not negligible, and the likelihood increased with RF burden. The presence of coronary stenosis ≥50% was rare and most often accompanied by CAC > 0 but there was a significant burden of NCP and LAP even within the non-obstructive group.

Nontraditional Risk Markers for Incident Coronary Artery Calcium Among Persons ≥65 Years of Age

Background

The initiation of coronary artery calcium (CAC) is an important physiologic milestone associated with increased cardiovascular disease risk. However, traditional risk factors (RF) do not perform well for predicting incident CAC among the 54 million older U.S. adults.

Objectives

The authors sought to assess the association between nontraditional cardiovascular disease RF and incident CAC in older persons.

Methods

There were 815 MESA (Multi-Ethnic Study of Atherosclerosis) participants ≥65 years of age who had CAC = 0 at Visit 1 and a follow-up CAC scan. Multivariable adjusted Cox hazards ratios (aHR) and C-statistics were calculated to examine the association of nontraditional RF with incident CAC.

Results

The mean age was 70.2 years and 67% were women. The median follow-up time to repeat CAC scan was 3.6 years (IQR: 2.6-9.2 years) and 45% of participants developed incident CAC. Albuminuria (aHR: 1.50, 95% CI: 1.07-2.09), carotid plaque (aHR: 1.32, 95% CI: 1.04-1.66), and thoracic aortic calcification (TAC) (aHR: 1.38, 95% CI: 1.10-1.75) were significantly associated with incident CAC, while higher levels of nontraditional RF including apolipoprotein-B, lipoprotein(a), high-sensitivity troponin T, and N-terminal pro-brain natriuretic peptide were not. When added to demographics, albuminuria, carotid plaque, and TAC provided a greater C-statistic improvement (+0.047, P = 0.004) vs all traditional RF combined (+0.033, P = 0.05).

Conclusions

Among nontraditional RF and measures of subclinical atherosclerosis, only albuminuria, carotid plaque, and TAC were significantly associated with incident CAC in persons ≥65 years of age. Identification of albuminuria or extracoronary atherosclerosis may help guide the timing of repeat CAC scoring in older persons with baseline CAC = 0.

Coronary artery calcium: from risk prediction to treatment allocation and clinical trials

Coronary artery calcium (CAC) is a direct measure of an individual's coronary atherosclerotic burden. Higher levels of CAC are strongly associated with an increased risk of cardiovascular disease (CVD) events and individuals with very high CAC levels have a CVD risk similar to stable persons with a prior CVD event. Conversely, the absence of CAC (CAC=0) is associated with a low long-term risk of CVD, even among groups classified as high risk based on traditional risk factors. Accordingly, the guideline-based role of CAC in allocation of CVD prevention therapies has expanded to include both statin and non-statin medications. Beyond prevention therapies, it is now widely recognised that the total burden of atherosclerosis is a stronger risk factor for CVD than a sole focus on coronary stenosis. Furthermore, evidence is accruing to support expanding the value of CAC=0 among low-risk symptomatic patients given its very high negative predictive value for ruling out obstructive coronary artery disease. There is now an appreciation of the value of routine assessment of CAC on all non-gated chest CTs and with the advent of artificial intelligence, automated interpretation is now possible. Additionally, CAC is now firmly established in randomised trials as a tool to identify high-risk patients most likely to benefit from pharmacotherapies. Future studies incorporating measures of atherosclerosis beyond the Agatston score will lead to continued refinement of CAC scoring, further improvements in personalisation of CVD risk prediction and more individualised allocation of prevention therapies to the patients at highest CVD risk.

HDL-cholesterol concentration and its association with coronary artery calcification: a systematic review and meta-analysis

BACKGROUND

Coronary artery calcification (CAC) is a potential risk marker of coronary atherosclerosis that has high specificity and sensitivity. However, the association between high-density lipoprotein cholesterol (HDL-C) concentration and CAC incidence and progression is controversial.

METHODS

PubMed, Embase, Web of Science, and Scopus were systematically searched to identify relevant observational studies up to March 2023 and assessed the methodological quality using Newcastle-Ottawa Scale (NOS) scale. Random-effects meta-analysis was used to estimate pooled odds ratios (OR) and 95% confidence interval considering heterogeneity across studies.

RESULTS

Of the 2,411 records, 25 cross-sectional (n = 71,190) and 13 cohort (n = 25,442) studies were included in the systematic review. Ten cross-sectional and eight cohort studies were not eligible and were omitted from the meta-analysis. A total of 15 eligible cross-sectional studies (n = 33,913) were included in the meta-analysis and pooled results revealed no significant association between HDL-C and CAC > 0, CAC > 10, or CAC > 100 [pooled OR: 0.99 (0.97, 1.01)]. Meta-analysis of the 5 eligible prospective cohort studies (n = 10,721) revealed no significant protective effect of high HDL-C against CAC > 0 [pooled OR: 1.02 (0.93, 1.13)].

CONCLUSIONS

According to this analysis of observational studies, high HDL-C levels were not found to predict protection against CAC. These results suggest HDL quality rather than HDL quantity is important for certain aspects of atherogenesis and CAC.

REGISTRATION NUMBER

CRD42021292077.

The context-dependent role of transforming growth factor-β/miR-378a-3p/connective tissue growth factor in vascular calcification: a translational study

BACKGROUND

Vascular calcification (VC) constitutes an important vascular pathology with prognostic importance. The pathogenic role of transforming growth factor-β (TGF-β) in VC remains unclear, with heterogeneous findings that we aimed to evaluate using experimental models and clinical specimens.

METHODS

Two approaches, exogenous administration and endogenous expression upon osteogenic media (OM) exposure, were adopted. Aortic smooth muscle cells (ASMCs) were subjected to TGF-β1 alone, OM alone, or both, with calcification severity determined. We evaluated miR-378a-3p and TGF-β1 effectors (connective tissue growth factor; CTGF) at different periods of calcification. Results were validated in an ex vivo model and further in sera from older adults without or with severe aortic arch calcification.

RESULTS

TGF-β1 treatment induced a significant dose-responsive increase in ASMC calcification without or with OM at the mature but not early or mid-term VC period. On the other hand, OM alone induced VC accompanied by suppressed TGF-β1 expressions over time; this phenomenon paralleled the declining miR-378a-3p and CTGF expressions since early VC. TGF-β1 treatment led to an upregulation of CTGF since early VC but not miR-378a-3p until mid-term VC, while miR-378a-3p overexpression suppressed CTGF expressions without altering TGF-β1 levels. The OM-induced down-regulation of TGF-β1 and CTGF was also observed in the ex vivo models, with compatible results identified from human sera.

CONCLUSIONS

We showed that TGF-β1 played a context-dependent role in VC, involving a time-dependent self-regulatory loop of TGF-β1/miR-378a-3p/CTGF signaling. Our findings may assist subsequent studies in devising potential therapeutics against VC.