Coronary Artery Calcium Density and Cardiovascular Events by Volume Level: The MESA

Coronary Artery Calcium Density and Risk of Cardiovascular Events: A Systematic Review and Meta-Analysis

BACKGROUND

There is increasing evidence that coronary artery calcium (CAC) density is inversely associated with plaque vulnerability and atherosclerotic cardiovascular disease risk.

OBJECTIVES

A systematic review and meta-analysis were performed to examine the predictive value of CAC density for future cardiovascular events in asymptomatic individuals undergoing noncontrast CAC scoring computed tomography.

METHODS

Electronic databases were searched for studies reporting CAC density and subsequent cardiovascular disease (CVD) or coronary heart disease (CHD) events. Two independent reviewers performed data extraction. Random-effects models were used to estimate pooled HRs and 95% CIs. Subgroup analyses were performed with studies stratified by CVD vs CHD events and by statin use.

RESULTS

Of 5,029 citations, 5 studies with 6 cohorts met inclusion criteria. In total, 1,309 (6.1%) cardiovascular events occurred in 21,346 participants with median follow-up ranging from 5.2 to 16.7 years. Higher CAC density was inversely associated with risk of cardiovascular events following adjustment for clinical risk factors and CAC volume (HR: 0.80 per SD of density [95% CI: 0.72-0.89]; P < 0.01; I2 = 0%). There was no significant difference in the pooled HRs for CVD vs CHD events (HR: 0.80 per SD [95% CI: 0.71-0.90] vs 0.74 per SD [95% CI: 0.59-0.94] respectively; P = 0.59). The protective association between CAC density and event risk persisted among statin-naive patients (HR: 0.79 per SD [95% CI: 0.70-0.89]; P < 0.01) but not statin-treated patients (HR: 0.97 per SD [95% CI: 0.77-1.22]; P = 0.78); the test for interaction indicated no significant between-group differences (P = 0.12).

CONCLUSIONS

Higher CAC density is associated with a lower risk of cardiovascular events when adjusted for risk factors and CAC volume. Future work may expand the contribution of CAC density in CAC scoring, and enhance its role in CVD risk assessment, treatment, and prevention.

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.

Analysis of risk factors for PCI no-reflow in coronary heart disease and construction of related prediction models

OBJECTIVE

To analyze the risk factors of percutaneous coronary intervention (PCI) no-reflow in patients with coronary heart disease (CHD) and construct a predictive nomogram model.

METHODS

This retrospective study included 260 patients with CHD who underwent PCI in the Third Affiliated Hospital of Chongqing Medical University from January 2022 to December 2023. The subjects were divided into a PCI no-reflow group (n = 86) and normal reflow group (n = 174) based on thrombolysis in myocardial infarction (TIMI) blood flow grading. General data, PCI related data and laboratory indexes of patients were collected. Logistic regression was used to analyze the risk factors of no-reflow after PCI in CHD patients. Based on the significant variables from regression analysis, a nomogram prediction model was constructed by using R language. The accuracy of the model was evaluated by receiver operating characteristic (ROC) curve and calibration curve, and the decision curve was drawn to clarify the clinical utility of the model. Model performance metrics included area under the curve (AUC), accuracy, sensitivity and specificity.

RESULTS

Multivariate logistic regression analysis showed that hypertension, cystatin C (Cys-C), hypersensitive c-reactive protein (hs-CRP) and platelet-to-lymphocyte ratio (PLR) were risk factors for no-reflow after PCI in CHD patients (OR > 1, P < 0.001), while ADAM metallopeptidase with thrombospondin type 1 motif 13 (ADAMTS-13) and lymphocyte (LYM) were protective factors (OR < 1, P < 0.001). The nomogram prediction model based on the above risk factors showed good predictive value. The AUC of the nomogram prediction model in the training set was 0.967 (95% CI: 0.946-0.989), with a specificity of 0.923 and a sensitivity of 0.908. In the validation set, the AUC was 0.894 (95% CI: 0.817-0.971), with a specificity of 0.807 and a sensitivity of 0.857. The calibration curve indicated good agreement between the predicted and actual probabilities, and the decision curve showed clinical benefit across a range of threshold probabilities in both the training and validation sets (0.0-0.99).

CONCLUSION

The risk factors affecting the occurrence of no-reflow after PCI in patients with CHD include hypertension, serum Cys-C, hs-CRP, PLR, ADAMTS-13 and LYM levels. The nomogram risk prediction model based on the above factors is valuable for identifying patients with high risk of no-reflow after PCI.

Recent advances in cardiovascular risk assessment: The added value of non-invasive anatomic imaging

In 2022, multiple original research studies were conducted highlighting the utility of coronary artery calcium (CAC) imaging in young individuals and provided further evidence for the role of CAC to improve atherosclerotic cardiovascular disease (ASCVD) risk assessment. Mean calcium density was shown to be a more reliable predictor than peak density in risk assessment. Additionally, in light of the ACC/AHA/Multispecialty Chest Pain Guideline's recent elevation of coronary computed tomography angiography (CCTA) to a Class I (level of evidence A) recommendation as an index diagnostic test for acute or stable chest pain, several studies support the utility of CCTA and guided future directions. This review summarizes recent studies that highlight the role of non-invasive imaging in enhancing ASCVD risk assessment across different populations.

Assessment of Subclinical Atherosclerosis in Asymptomatic People In Vivo: Measurements Suitable for Biomarker and Mendelian Randomization Studies

BACKGROUND

One strategy to reduce the burden of cardiovascular disease is the early detection and treatment of atherosclerosis. This has led to significant interest in studies of subclinical atherosclerosis, using different phenotypes, not all of which are accurate reflections of the presence of asymptomatic atherosclerotic plaques. The aim of part 2 of this series is to provide a review of the existing literature on purported measures of subclinical disease and recommendations concerning which tests may be appropriate in the prevention of incident cardiovascular disease.

METHODS

We conducted a critical review of measurements used to infer the presence of subclinical atherosclerosis in the major conduit arteries and focused on the predictive value of these tests for future cardiovascular events, independent of conventional cardiovascular risk factors, in asymptomatic people. The emphasis was on studies with >10 000 person-years of follow-up, with meta-analysis of results reporting adjusted hazard ratios (HRs) with 95% CIs. The arterial territories were limited to carotid, coronary, aorta, and lower limb arteries.

RESULTS

In the carotid arteries, the presence of plaque (8 studies) was independently associated with future stroke (pooled HR, 1.89 [1.04-3.44]) and cardiac events (7 studies), with a pooled HR, 1.77 (1.19-2.62). Increased coronary artery calcium (5 studies) was associated with the risk of coronary heart disease events, pooled HR, 1.54 (1.07-2.07) and increasing severity of calcification (by Agaston score) was associated with escalation of risk (13 studies). An ankle/brachial index (ABI) of <0.9, the pooled HR for cardiovascular death from 7 studies was 2.01 (1.43-2.81). There were insufficient studies of either, thoracic or aortic calcium, aortic diameter, or femoral plaque to synthesize the data based on consistent reporting of these measures.

CONCLUSIONS

The presence of carotid plaque, coronary artery calcium, or abnormal ankle pressures seems to be a valid indicator of the presence of subclinical atherosclerosis and may be considered for use in biomarker, Mendelian randomization and similar studies.

CT-derived coronary artery calcium density is affected by regional lesion distribution and image reconstruction parameters

PURPOSE

The prognostic relevance of coronary artery calcium (CAC) density, assessed from cardiac CT scans, is established. However, the influence of CAC distribution, volume, image reconstruction, and clinical factors on CAC density warrants further examination.

METHODS

In this study, 120 patients underwent non-contrast ECG-gated cardiac CT scans using a prospectively defined CAC scoring protocol with 1-, 3-, and 5-mm thick image reconstructions, both with and without a 20% image overlap. We segmented CAC in all reconstructions and assessed the relationship between CAC density, volume, and number of detected calcifications/patient.

RESULTS

Overall, 75/120 (63%) patients (66% men, mean age 63 ± 11 years) presented CAC across 342 segments. CAC density, CAC volume, and the number of detected calcifications decreased with increasing slice thickness (p < 0.001 for all); these effects were slightly reduced by image overlap (p < 0.001 for all). Higher CAC density correlated with greater CAC volume (ρ = 0.62; p < 0.001) and more calcified segments per person (ρ = 0.32; p = 0.006). Higher CAC density was also associated with lower patient weight (beta: -0.6, 95%CI: -1.1--0.1, p = 0.022) and increased high-density lipoprotein (HDL) levels (beta: 0.7, 95%CI: 0.0-1.4, p = 0.046). In a multivariable analysis adjusted for clinical covariates, lower CAC density was associated with broader CAC distribution (i.e., a higher number of calcified segments at a given CAC volume; beta-coefficient: -58.9; 95%CI: -84.7 to -33.1; p < 0.001).

CONCLUSION

CAC density is significantly impacted by regional CAC distribution and image reconstruction, potentially confounding its prognostic value. Accounting for these factors may improve patient risk assessment, management, and cardiovascular health outcomes.

Coronary Artery Calcium Scoring in Asymptomatic Patients

Coronary artery calcium (CAC) scoring is an important prognostic tool for personalized cardiovascular preventive care and has recently been incorporated into American College of Cardiology/American Heart Association guidelines. CAC provides direct visualization and quantification of CAC burden for risk stratification and primary prevention of cardiovascular events in an asymptomatic population. CAC scoring is recommended for individuals with intermediate 10-year atherosclerotic cardiovascular disease (ASCVD) risk and selective populations with borderline ASCVD risk. In this review, we outline the interpretation of CAC scores for predicting the risk of cardiovascular events, and we highlight the guidelines for starting statin and potentially starting aspirin therapy. A CAC score of 0 is the strongest negative predictive factor for cardiovascular disease (CVD), and a 0 score can successfully de-risk a patient. On the contrary, higher CAC scores correlate with worse cardiovascular prognostic outcomes. The CAC scan is a widely available and reproducible means for an early look at the atherosclerotic burden, and it can help strategize early interventions. The CAC interpretation and the decision to start treatment need to be personalized based on individual risk factors. We believe the emerging literature supports our contention that the CAC score can be used more broadly to improve the prophylaxis and treatment of a wider range of apparently healthy patients.

Association of apolipoproteins C-I and C-II truncations with coronary heart disease and progression of coronary artery calcium: Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

Higher truncated-to-native proteoform ratios of apolipoproteins (apo) C-I (C-I'/C-I) and C-II (C-II'/C-II) are associated with less atherogenic lipid profiles. We examined prospective relationships of C-I'/C-II and C-II'/C-II with coronary heart disease (CHD) and coronary artery calcium (CAC).

METHODS

ApoC-I and apoC-II proteoforms were measured by mass spectrometry immunoassay in 5790 MESA baseline plasma samples. CHD events (myocardial infarction, resuscitated cardiac arrest, fatal CHD, n = 434) were evaluated for up to 17 years. CAC was measured 1-4 times over 10 years for incident CAC (if baseline CAC = 0), and changes (follow-up adjusted for baseline) in CAC score and density (if baseline CAC>0).

RESULTS

C-II'/C-II was inversely associated with CHD (n = 434 events) after adjusting for non-lipid cardiovascular risk factors (Hazard ratio: 0.89 [95% CI: 0.81-0.98] per SD), however, the association was attenuated after further adjustment for HDL levels (0.93 [0.83-1.03]). There was no association between C-I'/C-I and CHD (0.98 [0.88-1.08]). C-II'/C-II was positively associated with changes in CAC score (3.4% [95%CI: 0.6, 6.3]) and density (6.3% [0.3, 4.2]), while C-I'/C-I was inversely associated with incident CAC (Risk ratio: 0.89 [95% CI: 0.81, 0.98]) in fully adjusted models that included plasma lipids. Total apoC-I and apoC-II concentrations were not associated with CHD, incident CAC or change in CAC score.

CONCLUSIONS

Increased apoC-II truncation was associated with reduced CHD, possibly explained by differences in lipid metabolism. Increased apoC-I and apoC-II truncations were also associated with less CAC progression and/or development of denser coronary plaques.