Coronary Artery Calcification and Family History of Myocardial Infarction in the Dallas Heart Study

Coronary Artery Disease, Family History, and Screening Perspectives: An Up-to-Date Review

Family history for CAD (coronary artery disease) is an established cardiovascular (CV) risk factor and it is progressively acquiring importance in patients' CV risk stratification. Numerous studies have demonstrated that individuals with a first-degree relative affected by CAD have a significantly higher risk of developing the condition themselves; in particular, when CAD occurs at an early age in relatives. Indeed, recently published CCS (chronic coronary syndrome) ESC (European Society of Cardiology) guidelines include family history (FH) as a risk factor to consider when calculating pre-test risk for CAD. ESC guidelines on preventive cardiology (2021) only suggested CV risk assessment in the presence of a positive FH for CV disease, not considering it in the actual risk scores. Evidence suggests that positive anamnesis for relatives affected by CAD correlates with ACS (acute coronary syndrome) and CAD, with slight differences in relative risk as far as the degree of kinship is concerned. Genetic factors contribute to this correlation by influencing key processes that affect heart health, such as cholesterol metabolism, blood pressure regulation, and inflammatory responses. New technologies in the genetics field are increasing the availability of genome sequencing, and new polymorphism panels are being tested as predictive for CAD, objectifying familiarity. Advances in imaging techniques allow the assessment of coronary atherosclerosis and its composition, and these are acquiring strength in evidence and recommendations in ESC guidelines as a way to define coronary disease in low and low-to-intermediate risk patients and to guide medical therapy and interventional procedures. Use of these emerging tools to guide screening is likely to be extended, beyond high CV risk patients, to individuals with FH for early CAD and/or specific genetic profiles, as recent evidence in the literature is suggesting.

Concomitant Coronary Artery Disease in Identical Twins: Case Report and Systematic Literature Review

Coronary artery disease (CAD) is multifactorial and strongly affected by genetic, epigenetic and environmental factors. Several studies have reported development of concomitant CAD in identical twins. We report a case in which a pair of Caucasian male monozygotic twins presented almost concomitantly with acute coronary syndrome (ACS) and had concordant coronary anatomy and identical site of occlusion. We performed a systematic literature review of PubMed, Web Of Science and Scopus databases from inception until 28 February 2023 of case reports/case series reporting the concomitant development of CAD in monozygotic twins. We found 25 eligible case reports with a total of 31 monozygotic twin pairs (including the case from our center) suffering from CAD and presenting (most of them simultaneously) with ACS (mean age of presentation: 45 ± 12 years, males: 81%). Coronary angiograms demonstrated lesion and anatomy concordance in 77% and 79% of the twin pairs, respectively. Screening for disease-related genetic mutations was performed in six twin pairs leading to the identification of five CAD-related genetic polymorphisms. This is the first systematic literature review of studies reporting identical twin pairs suffering from CAD. In summary, there is high concordance of coronary anatomy and clinical presentation between monozygotic twins. Future monozygotic twin studies-unbiased by age effects-can provide insights into CAD heritability being able to disentangle the traditional dyad of genetic and environmental factors and investigate the within-pair epigenetic drift.

Intracranial Arterial Calcifications: Potential Biomarkers of Stroke Risk and Outcome

Intracranial artery calcifications (IAC), a common and easily identifiable finding on computed tomorgraphy angiography (CTA), has gained recognition as a possible risk factor for ischemic stroke. While atherosclerosis of intracranial arteries is believed to be a mechanism that commonly contributes to ischemic stroke, and coronary artery calcification is well-established as a predictor of both myocardial infarction (MI) and ischemic stroke risk, IAC is not currently used as a prognostic tool for stroke risk or recurrence. This review examines the pathophysiology and prevalence of IAC, and current evidence suggesting that IAC may be a useful tool for prediction of stroke incidence, recurrence, and response to acute ischemic stroke therapy.

What should we do about Coronary Calcification on Thoracic CT?

PURPOSE

Coronary artery calcification is a frequent incidental finding on thoracic computed tomography (CT) performed for non-cardiac indications. On electrocardiogram-gated cardiac CT, it is an established marker of coronary artery disease and is associated with increased risk of subsequent cardiac events.

MATERIALS AND METHODS

This review discusses the current evidence and guidelines regarding the reporting of coronary artery calcification on non-electrocardiogram-gated thoracic CT performed for non-cardiac indications.

RESULTS

For patients undergoing routine thoracic CT, coronary artery calcification is associated with an increased risk of myocardial infarction and mortality. Coronary artery calcification can be accurately assessed on non-gated thoracic CT compared to gated CT. Guidelines support the reporting of coronary artery calcification on thoracic CT. However, radiologist opinions vary. The identification of coronary artery calcification on thoracic CT may identify patients with previously unknown coronary artery disease. For asymptomatic patients this may trigger an assessment of modifiable cardiovascular risk factors and guide the appropriate use of preventative medications.

CONCLUSION

Future research will address whether changing management based on calcification on thoracic CT will improve outcomes and automated assessment of calcification using machine learning techniques.

KEY POINTS

· Coronary artery calcification is a frequent incidental finding on thoracic CT.. · The presence and severity of coronary artery calcification is associated with cardiac outcomes and mortality.. · Reporting coronary artery calcification on thoracic CT is supported by national and international guidelines..

CITATION FORMAT

· Williams MC, Llewellyn O, . What Should We Do About Coronary Calcification on Thoracic CT?. Fortschr Röntgenstr 2022; 194: 833 - 840.

Coronary Artery Calcium Scoring: Current Status and Future Directions

Coronary artery calcium (CAC) scores obtained from CT scans have been shown to be prognostic in assessment of the risk for development of cardiovascular diseases, facilitating the prediction of outcome in asymptomatic individuals. Currently, several methods to calculate the CAC score exist, and each has its own set of advantages and disadvantages. Agatston CAC scoring is the most extensively used method. CAC scoring is currently recommended for use in asymptomatic individuals to predict the risk of developing cardiovascular diseases and the disease-specific mortality. In specific subsets of patients, the CAC score has also been recommended for reclassifying cardiovascular risk and aiding in decision making when planning primary prevention interventions such as statin therapy. The progression of CAC scores on follow-up images has been shown to be linked to risk of myocardial infarction and cardiovascular mortality. While the CAC score is a validated tool used clinically, several challenges, including various pitfalls associated with the acquisition, calculation, and interpretation of the score, prevent more widespread adoption of this metric. Recent research has been focused extensively on strategies to improve existing scoring methods, including measuring calcium attenuation, detecting microcalcifications, and focusing on extracoronary calcifications, and on strategies to improve image acquisition. A better understanding of CAC scoring approaches will help radiologists and other physicians better use and interpret these scores in their workflows. An invited commentary by S. Gupta is available online. Online supplemental material is available for this article. ^©RSNA, 2022.

Impact of Adaptive Statistical Iterative Reconstruction-V on Coronary Artery Calcium Scores Obtained From Low-Tube-Voltage Computed Tomography - A Patient Study

OBJECTIVE

To evaluate the impact of adaptive statistical iterative reconstruction-V (ASIR-V) on the accuracy of ultra-low-dose coronary artery calcium (CAC) scoring.

MATERIALS AND METHOD

One-hundred-and-three patients who underwent computed tomography (CT) for CAC scoring were prospectively included. All underwent standard scanning with 120-kilovolt-peak (kVp) and with 80- and 70-kVp tube voltage. ASiR-V was applied to the 80- and 70-kVp scans at different levels. The 120-kVp scans reconstructed with filtered back projection served as the standard of reference. Recently published novel kVp-adapted thresholds were used for calculation of CAC scores from 80- and 70-kVp scans and the resulting CAC scores were compared against the standard of reference. Patients were stratified into six CAC score risk categories: 0, 1-10, 11-100, 101-400, 401-1000, and >1000.

RESULTS

Increasing levels of ASIR-V led to an increasing underestimation of CAC scores with bias ranging from -128 to -118 and from -205 to -198 for the 80- and 70-kVp scans, respectively, when compared with the standard of reference. Reconstruction with 20% and 40% ASIR-V for the 80- and 70-kVp scans, respectively, yielded noise levels comparable to the standard of reference. Nevertheless, a change in risk-class was observed in 29 (28.6%) and 46 (44.7%) patients, exclusively to a lower risk-class, when CAC scores were derived from these reconstructions.

CONCLUSION

ASIR-V leads to noise reduction in CT scans acquired with low tube-voltages. However, ASIR-V introduces substantial inaccuracies and marked underestimation of ultra-low-dose CAC scoring as compared with standard-dose CAC scoring despite normalization of noise.

Heritability of Coronary Artery Disease: Insights From a Classical Twin Study

BACKGROUND

Genetics have a strong influence on calcified atherosclerotic plaques; however, data regarding the heritability of noncalcified plaque volume are scarce. We aimed to evaluate genetic versus environmental influences on calcium (coronary artery calcification) score, noncalcified and calcified plaque volumes by coronary computed tomography angiography in adult twin pairs without known coronary artery disease.

METHODS

In the prospective BUDAPEST-GLOBAL (Burden of Atherosclerotic Plaques Study in Twins-Genetic Loci and the Burden of Atherosclerotic Lesions) classical twin study, we analyzed twin pairs without known coronary artery disease. All twins underwent coronary computed tomography angiography to assess coronary atherosclerotic plaque volumes. Structural equation models were used to quantify the contribution of additive genetic, common environmental, and unique environmental components to plaque volumes adjusted for age, gender, or atherosclerotic cardiovascular disease risk estimate and statin use.

RESULTS

We included 196 twins (mean age±SD, 56±9 years, 63.3% females), 120 monozygotic and 76 same-gender dizygotic pairs. Using structural equation models, noncalcified plaque volume was predominantly determined by environmental factors (common environment, 63% [95% CI, 56%-67%], unique environment, 37% [95% CI, 33%-44%]), while coronary artery calcification score and calcified plaque volumes had a relatively strong genetic heritability (additive genetic, 58% [95% CI, 50%-66%]; unique environmental, 42% [95% CI, 34%-50%] and additive genetic, 78% [95% CI, 73%-80%]; unique environmental, 22% [95% CI, 20%-27%]), respectively.

CONCLUSIONS

Noncalcified plaque volume is mainly influenced by shared environmental factors, whereas coronary artery calcification score and calcified plaque volume are more determined by genetics. These findings emphasize the importance of early lifestyle interventions in preventing coronary plaque formation.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01738828.

Subclinical cardiovascular disease and utility of coronary artery calcium score

ASCVD are the leading causes of mortality and morbidity among Globe. Evaluation of patients' comprehensive and personalized risk provides risk management strategies and preventive interventions to achieve gain for patients. Framingham Risk Score (FRS) and Systemic Coronary Risk Evaluation Score (SCORE) are two well studied risk scoring models, however, can miss some (20-35%) of future cardiovascular events. To obtain more accurate risk assessment recalibrating risk models through utilizing novel risk markers have been studied in last 3 decades and both ESC and AHA recommends assessing Family History, hs-CRP, CACS, ABI, and CIMT. Subclinical Cardiovascular Disease (SCVD) has been conceptually developed for investigating gradually progressing asymptomatic development of atherosclerosis and among these novel risk markers it has been well established by literature that CACS having highest improvement in risk assessment. This review study mainly selectively discussing studies with CACS measurement. A CACS = 0 can down-stratify risk of patients otherwise treated or treatment eligible before test and can reduce unnecessary interventions and cost, whereas CACS ≥ 100 is equivalent to statin treatment threshold of ≥ 7.5% risk level otherwise statin ineligible before test. Since inflammation, insulin resistance, oxidative stress, dyslipidemia and ongoing endothelial damage due to hypertension could lead to CAC, ASCVD linked with comorbidities. Recent cohort studies have shown a CACS 100-300 as a sign of increased cancer risk. Physical activity, dietary factors, cigarette use, alcohol consumption, metabolic health, family history of CHD, aging, exposures of neighborhood environment and non-cardiovascular comorbidities can determine CACs changes.

Impact of a coronary artery calcium-guided statin treatment protocol on cardiovascular risk at 12 months: Results from a pragmatic, randomised controlled trial

BACKGROUND AND AIMS

Coronary artery calcium (CAC) may encourage patients to adhere to primary prevention recommendations. This study sought to evaluate the benefit of a CAC-guided risk-management protocol in those with a family history of premature coronary artery disease (FHCAD).

METHODS

In this Australian multi-centre, randomized controlled trial (Coronary Artery Calcium score: Use to Guide management of Hereditary Coronary Artery Disease, CAUGHT-CAD), asymptomatic, statin-native participants at low-intermediate cardiovascular risk with FHCAD underwent CAC assessment. Those with CAC between 1 and 400 were randomized (1:1) to disclosing the CAC result to both patient and physician and commencing atorvastatin (intervention) or blinding the CAC result with risk factor education only (control). The primary endpoint of this sub-study was change in Pooled Cohort Equation (PCE) at 12 months.

RESULTS

Of 1088 participants who were scanned, 450 were randomised and 214 in both groups completed 1-year follow-up. At 1 year, PCE-risk decreased by 1.0% (95% CI 0.13 to 1.81) in the CAC-disclosed group and increased by 0.43% (95%CI 0.11-0.75) in the CAC-blinded group. LDL-C decreased in the CAC-disclosed group in both those who continued (1.5 mmol/L; 95% CI 1.36 to 1.74) and discontinued statins (0.62 mmol/L; 95% CI 0.32 to 0.92) but was unchanged in the CAC-blinded group.

CONCLUSION

Participants unblinded to their CAC showed reductions in LDL irrespective of statin continuation when compared to controls at 12 months. Improvements in individual risk factors and PCE risk were also noted. CAC assessment may positively influence patients and physicians to improve risk factor control.

Assessment of Coronary Artery Calcium Scoring to Guide Statin Therapy Allocation According to Risk-Enhancing Factors: The Multi-Ethnic Study of Atherosclerosis

Importance

The 2018 American Heart Association/American College of Cardiology Guideline on the Management of Blood Cholesterol recommends the use of risk-enhancing factor assessment and the selective use of coronary artery calcium (CAC) scoring to guide the allocation of statin therapy among individuals with an intermediate risk of atherosclerotic cardiovascular disease (ASCVD).

Objective

To examine the association between risk-enhancing factors and incident ASCVD by CAC burden among those at intermediate risk of ASCVD.

Design, Setting, and Participants

The Multi-Ethnic Study of Atherosclerosis is a multicenter population-based prospective cross-sectional study conducted in the US. Baseline data for the present study were collected between July 15, 2000, and July 14, 2002, and follow-up for incident ASCVD events was ascertained through August 20, 2015. Participants were aged 45 to 75 years with no clinical ASCVD or diabetes at baseline, were at intermediate risk of ASCVD (≥7.5% to <20.0%), and had a low-density lipoprotein cholesterol level of 70 to 189 mg/dL.

Exposures

Family history of premature ASCVD, premature menopause, metabolic syndrome, chronic kidney disease, lipid and inflammatory biomarkers, and low ankle-brachial index.

Main Outcomes and Measures

Incident ASCVD over a median follow-up of 12.0 years.

Results

A total of 1688 participants (mean [SD] age, 65 [6] years; 976 men [57.8%]). Of those, 648 individuals (38.4%) were White, 562 (33.3%) were Black, 305 (18.1%) were Hispanic, and 173 (10.2%) were Chinese American. A total of 722 participants (42.8%) had a CAC score of 0. Among those with 1 to 2 risk-enhancing factors vs those with 3 or more risk-enhancing factors, the prevalence of a CAC score of 0 was 45.7% vs 40.3%, respectively. Over a median follow-up of 12.0 years (interquartile range [IQR], 11.5-12.6 years), the unadjusted incidence rate of ASCVD among those with a CAC score of 0 was less than 7.5 events per 1000 person-years for all individual risk-enhancing factors (with the exception of ankle-brachial index, for which the incidence rate was 10.4 events per 1000 person-years [95% CI, 1.5-73.5]) and combinations of risk-enhancing factors, including participants with 3 or more risk-enhancing factors. Although the individual and composite addition of risk-enhancing factors to the traditional risk factors was associated with improvement in the area under the receiver operating curve, the use of CAC scoring was associated with the greatest improvement in the C statistic (0.633 vs 0.678) for ASCVD events. For incident ASCVD, the net reclassification improvement for CAC was 0.067.

Conclusions and Relevance

In this cross-sectional study, among participants with CAC scores of 0, the presence of risk-enhancing factors was generally not associated with an overall ASCVD risk that was higher than the recommended treatment threshold for the initiation of statin therapy. The use of CAC scoring was associated with significant improvements in the reclassification and discrimination of incident ASCVD. The results of this study support the utility of CAC scoring as an adjunct to risk-enhancing factor assessment to more accurately classify individuals with an intermediate risk of ASCVD who might benefit from statin therapy.

Prevention of Coronary Artery Disease-Related Heart Failure: The Role of Computed Tomography Scan

During the past decade, coronary computed tomography angiography has emerged as the primary modality to noninvasively detect and rule out coronary artery disease. Therefore, this technique could play an important role in identifying patients at high risk of heart failure, considering the high prevalence of coronary artery disease in these patients. The latest technologies have also increased diagnostic accuracy, helping to close the gap with the other functional imaging modalities.

Long-term all-cause mortality among asymptomatic individuals with 80th percentile of coronary calcium score based on age and gender in the St. Francis Heart Study

OBJECTIVES

High coronary artery calcium score (CAC) is a significant risk factor for cardiovascular morbidity and mortality. We investigated the long-term outcome of subjects with elevated CAC.

METHODS

We studied 1005 participants of The St. Francis Heart Study who were asymptomatic and apparently healthy and had CAC scores at 80th percentile or higher for age and gender. They were randomized to receive atorvastatin 20 mg daily or placebo for up to 5 years. We used an as-treated study design accounting for cross-overs at the end of the original trial. All-cause mortality risk was assessed using adjusted hazard ratios.

RESULTS

Mean age was 59 ± 6 years and 26% (N = 263) were female. After 17 ± 3 years follow-up 176 subjects died. High CAC at baseline was associated with increased mortality risk with adjusted hazard ratio for logarithmic transformed CAC at 1.33 and 95% confidence interval 1.06-1.68. The mortality risk associated with CAC was similar between the group with high-sensitivity CRP ≥2 and <2 mg/dL. Those with a family history of premature coronary artery disease exhibited a higher mortality risk in association with high CAC with an adjusted hazard ratio 1.51 (1.09, 2.09).

CONCLUSION

Elevated CAC is an independent risk for long-term all-cause mortality. The screening of CAC score in addition to identifying conventional risk factors can differentiate asymptomatic individuals with and without increased long-term mortality risk.

Coronary artery calcium scoring and cardiovascular risk reclassification in patients undergoing coronary computed tomography angiography

INTRODUCTION

Coronary artery calcium (CAC) scoring is used for both cardiovascular risk reclassification and as a gatekeeper for coronary computed tomography angiography (CCTA). The aims of this study were to assess to what extent CAC score results can reclassify the cardiovascular risk of patients without obstructive coronary artery disease (CAD) on CCTA, and to measure the proportion of these patients whose primary prevention medication is changed after the exam.

METHODS

In a retrospective analysis of a multicenter registry of individuals who underwent CCTA for suspected CAD during a two-year period, the Systematic COronary Risk Evaluation (SCORE) and Multi-Ethnic Study of Atherosclerosis (MESA) risk scores were calculated for each individual. In a subset of 184 patients, we also assessed the prescription of statins and antiplatelet agents before and after the test.

RESULTS

A total of 467 patients (248 women, mean age 60±9.10 years) were included. Median CAC score was 0 (interquartile range 0-40). Overall, 249 patients (53%) and 159 (34%) were classified as being of moderate/intermediate risk according to the SCORE and MESA risk scores, respectively. Among these, 29 (12%) and 30 (19%) patients had CAC score >100 AU, making them eligible for statin therapy. The inclusion of CAC scoring in the MESA score resulted in the reclassification of 215 patients (46%). The proportion of patients who were prescribed statins or antiplatelet agents did not change significantly after the test.

CONCLUSION

CAC scoring can reclassify cardiovascular risk in a significant proportion of patients undergoing CCTA. Despite this, little change was seen in the prescription of statins and antiplatelet agents.

Astronaut Cardiovascular Health and Risk Modification (Astro-CHARM) Coronary Calcium Atherosclerotic Cardiovascular Disease Risk Calculator

BACKGROUND

Coronary artery calcium (CAC) is a powerful novel risk indicator for atherosclerotic cardiovascular disease (ASCVD). Currently, there is no available ASCVD risk prediction tool that integrates traditional risk factors and CAC.

METHODS

To develop a CAC ASCVD risk tool for younger individuals in the general population, subjects aged 40 to 65 without prior cardiovascular disease from 3 population-based cohorts were included. Cox proportional hazards models were developed incorporating age, sex, systolic blood pressure, total and high-density lipoprotein cholesterol, smoking, diabetes mellitus, hypertension treatment, family history of myocardial infarction, high-sensitivity C-reactive protein, and CAC scores (Astro-CHARM model [Astronaut Cardiovascular Health and Risk Modification]) as dependent variables and ASCVD (nonfatal/fatal myocardial infarction or stroke) as the outcome. Model performance was assessed internally, and validated externally in a fourth cohort.

RESULTS

The derivation study comprised 7382 individuals with a mean age 51 years, 45% women, and 55% nonwhite. The median CAC was 0 (25th, 75th [0,9]), and 304 ASCVD events occurred in a median 10.9 years of follow-up. The c-statistic was 0.784 for the risk factor model, and 0.817 for Astro-CHARM ( P<0.0001). In comparison with the risk factor model, the Astro-CHARM model resulted in integrated discrimination improvement (0.0252), and net reclassification improvement (0.121; P<0.0001), as well. The Astro-CHARM model demonstrated good discrimination (c=0.78) and calibration (Nam-D'Agostino χ², 13.2; P=0.16) in the validation cohort (n=2057; 55 events). A mobile application and web-based tool were developed to facilitate clinical application of this tool ( www.AstroCHARM.org ).

CONCLUSION

The Astro-CHARM tool is the first integrated ASCVD risk calculator to incorporate risk factors, including high-sensitivity C-reactive protein and family history, and CAC data. It improves risk prediction in comparison with traditional risk factor equations and could be useful in risk-based decision making for cardiovascular disease prevention in the middle-aged general population.

Use of coronary artery calcium testing to improve coronary heart disease risk assessment in a lung cancer screening population: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Assessment of coronary artery calcium (CAC) during lung cancer screening chest computed tomography (CT) represents an opportunity to identify asymptomatic individuals at increased coronary heart disease (CHD) risk. We determined the improvement in CHD risk prediction associated with the addition of CAC testing in a population recommended for lung cancer screening.

METHODS

We included 484 out of 6814 Multi-Ethnic Study of Atherosclerosis (MESA) participants without baseline cardiovascular disease who met U.S. Preventive Service Task Force CT lung cancer screening criteria and underwent gated CAC testing. 10 year-predicted CHD risks with and without CAC were calculated using a validated MESA-based risk model and categorized into low (<5%), intermediate (5%-10%), and high (≥10%). The net reclassification improvement (NRI) and change in Harrell's C-statistic by adding CAC to the risk model were subsequently determined.

RESULTS

Of 484 included participants (mean age = 65; 39% women; 32% black), 72 (15%) experienced CHD events over the course of follow-up (median = 12.5 years). Adding CAC to the MESA CHD risk model resulted in 17% more participants classified into the highest or lowest risk categories and a NRI of 0.26 (p = 0.001). The C-statistic improved from 0.538 to 0.611 (p = 0.01).

CONCLUSIONS

CHD event rates were high in this lung cancer screening eligible population. These individuals represent a high-risk population who merit consideration for CHD prevention measures regardless of CAC score. Although overall discrimination remained poor with inclusion of CAC scores, determining whether those reclassified to an even higher risk would benefit from more aggressive preventive measures may be important.

Beyond Coronary Calcification, Family History, and C-Reactive Protein: Cholesterol Efflux Capacity and Cardiovascular Risk Prediction

BACKGROUND

Cholesterol efflux capacity (CEC), which is a key step in the reverse cholesterol transport pathway, is independently associated with atherosclerotic cardiovascular disease (ASCVD). However, whether it predicts ASCVD beyond validated novel risk markers is unknown.

OBJECTIVES

This study assessed if CEC improved ACSVD risk prediction beyond using coronary artery calcium (CAC), family history (FH), and high-sensitivity C-reactive protein (hs-CRP).

METHODS

CEC, CAC, self-reported FH, and hs-CRP were assessed among participants without baseline ASCVD who were enrolled in the Dallas Heart Study (DHS). ASCVD was defined as a first nonfatal myocardial infarction (MI) or stroke, coronary revascularization, or cardiovascular death, assessed over a median 9.4 years. Risk prediction was assessed using various modeling techniques and improvements in the c-statistic, the integrated discrimination index (IDI), and the net reclassification index (NRI).

RESULTS

The mean age of the population (N = 1,972) was 45 years, 52% had CAC (>0), 31% had FH, and 58% had elevated hs-CRP (≥2 mg/l). CEC greater than the median was associated with a 50% reduced incidence of ASCVD in those with CAC (5.4% vs. 10.5%; p = 0.003), FH (5.8% vs. 10%; p = 0.05), and elevated hs-CRP (3.8% vs. 7.9%; p = 0.004). CEC improved all metrics of discrimination and reclassification when added to CAC (c-statistic, p = 0.004; IDI, p = 0.02; NRI: 0.38; 95% confidence interval [CI]: 0.13 to 0.53), FH (c-statistic, p = 0.006; IDI, p = 0.008; NRI: 0.38; 95% CI: 0.13 to 0.55), or elevated hs-CRP (c-statistic p = 0.008; IDI p = 0.02; NRI: 0.36; 95% CI 0.12 to 0.52).

CONCLUSIONS

CEC improves ASCVD risk prediction beyond using CAC, FH, and hs-CRP and warrants consideration as a novel ASCVD risk marker.

2016 SCCT/STR guidelines for coronary artery calcium scoring of noncontrast noncardiac chest CT scans: A report of the Society of Cardiovascular Computed Tomography and Society of Thoracic Radiology

The Society of Cardiovascular Computed Tomography (SCCT) and the Society of Thoracic Radiology (STR) have jointly produced this document. Experts in this subject have been selected from both organizations to examine subject-specific data and write this guideline in partnership. A formal literature review, weighing the strength of evidence has been performed. When available, information from studies on cost was considered. Computed tomography (CT) acquisition, CAC scoring methodologies and clinical outcomes are the primary basis for the recommendations in this guideline. This guideline is intended to assist healthcare providers in clinical decision making. The recommendations reflect a consensus after a thorough review of the best available current scientific evidence and practice patterns of experts in the field and are intended to improve patient care while acknowledging that situations arise where additional information may be needed to better inform patient care.

CT calcium scoring. History, current status and outlook

Cardiovascular risk assessment has assumed a prominent role in the course of preventive care of all adults. Traditionally cardiovascular risk assessment has been performed using risk factors including gender, age, smoking history, lipid status, diabetes status, and family history. Increasingly, imaging has been deployed to directly detect coronary atherosclerotic disease. Quantification of coronary calcium (e.g., Agatston method, calcium mass and volume) is readily detected using helical CT scanners. Large multicenter cohort studies have enabled a better understanding of the relevance of coronary calcium detection. The purpose of this review is to review the methods for quantification of coronary artery calcium, as well as to present current and future perspectives on calcium scoring for cardiovascular risk stratification.

Coronary artery calcium scanning: past, present, and future

Coronary artery calcium scanning (CAC) has emerged as the most robust predictor of coronary events in the asymptomatic primary prevention population, particularly in the intermediate-risk cohort. Every study has demonstrated its superiority to risk factor-based paradigms, e.g., the Framingham Risk Score, with outcome-based net reclassification indexes ranging from 52.0% to 65.6% in the intermediate-risk, 34.0% to 35.8% in the high-risk, and 11.6% to 15.0% in the low-risk cohorts. CAC improves medication and lifestyle adherence and is cost-effective in specified populations, with the ability to effectively stratify the number needed to treat and scan for different therapeutic strategies and patient cohorts. Data have emerged clearly demonstrating the worse prognosis associated with increasing CAC on serial scans, suggesting a potential role for evaluating residual risk and treatment success or failure. CAC is also strongly associated with the development of stroke and congestive heart failure.

10-Year Coronary Heart Disease Risk Prediction Using Coronary Artery Calcium and Traditional Risk Factors: Derivation in the MESA (Multi-Ethnic Study of Atherosclerosis) With Validation in the HNR (Heinz Nixdorf Recall) Study and the DHS (Dallas Heart Study)

BACKGROUND

Several studies have demonstrated the tremendous potential of using coronary artery calcium (CAC) in addition to traditional risk factors for coronary heart disease (CHD) risk prediction. However, to date, no risk score incorporating CAC has been developed.

OBJECTIVES

The goal of this study was to derive and validate a novel risk score to estimate 10-year CHD risk using CAC and traditional risk factors.

METHODS

Algorithm development was conducted in the MESA (Multi-Ethnic Study of Atherosclerosis), a prospective community-based cohort study of 6,814 participants age 45 to 84 years, who were free of clinical heart disease at baseline and followed for 10 years. MESA is sex balanced and included 39% non-Hispanic whites, 12% Chinese Americans, 28% African Americans, and 22% Hispanic Americans. External validation was conducted in the HNR (Heinz Nixdorf Recall Study) and the DHS (Dallas Heart Study).

RESULTS

Inclusion of CAC in the MESA risk score offered significant improvements in risk prediction (C-statistic 0.80 vs. 0.75; p < 0.0001). External validation in both the HNR and DHS studies provided evidence of very good discrimination and calibration. Harrell's C-statistic was 0.779 in HNR and 0.816 in DHS. Additionally, the difference in estimated 10-year risk between events and nonevents was approximately 8% to 9%, indicating excellent discrimination. Mean calibration, or calibration-in-the-large, was excellent for both studies, with average predicted 10-year risk within one-half of a percent of the observed event rate.

CONCLUSIONS

An accurate estimate of 10-year CHD risk can be obtained using traditional risk factors and CAC. The MESA risk score, which is available online on the MESA web site for easy use, can be used to aid clinicians when communicating risk to patients and when determining risk-based treatment strategies.

Coronary Artery Calcium Improves Risk Assessment in Adults With a Family History of Premature Coronary Heart Disease: Results From Multiethnic Study of Atherosclerosis

BACKGROUND

The prognostic value of coronary artery calcium (CAC) or carotid intima-media thickness (CIMT) among asymptomatic adults with a family history (FH) of premature coronary heart disease is unclear.

METHODS AND RESULTS

Multiethnic Study of Atherosclerosis enrolled 6814 adults without known atherosclerotic cardiovascular disease (ASCVD). Hard ASCVD events were ascertained over a median follow-up of 10.2 years. We estimated adjusted-hazard ratios for CAC and CIMT categories using Cox regression, both within and across FH status groups. Improvement in discrimination with CAC or CIMT added to variables from the ASCVD pooled cohort equation was also evaluated using receiver-operating characteristic curve and likelihood ratio analysis. Of 6125 individuals (62±10 years; 47% men) who reported information on FH, 1262 (21%) had an FH of premature coronary heart disease. Among these, 104 hard ASCVD events occurred. Crude incidence rates (per 1000 person-years) for hard ASCVD were 4.4 for CAC, 0 (n=574; 46% of the sample); 8.8 for CAC, 1 to 99 (n=368); 14.9 for CAC, 100 to 399 (n=178); and 20.8 for CAC, ≥400 (n=142). Relative to CAC=0, adjusted hard ASCVD hazard ratios for each CAC category among persons with an FH were 1.64 (95% confidence interval, 0.94-2.87), 2.45 (1.31-4.58), and 2.80 (1.44-5.43), respectively. However, there was no increased adjusted hazard for hard ASCVD in high versus low CIMT categories. In participants with an FH of premature coronary heart disease, CAC improved discrimination of hard ASCVD events (P<0.001). However, CIMT did not discriminate ASCVD (P=0.70).

CONCLUSIONS

Nearly half of individuals reporting FH have zero CAC and may receive less net benefit from aspirin or statin therapy. Among persons with an FH, CAC is a robust marker of absolute and relative risk of ASCVD, whereas CIMT is not.

Low cardiorespiratory fitness and coronary artery calcification: Complementary cardiovascular risk predictors in asymptomatic type 2 diabetics

BACKGROUND

Despite its well-established prognostic value, cardiorespiratory fitness (CRF) is not incorporated routinely in risk assessment tools. Whether low CRF provides additional predictive information in asymptomatic type 2 diabetics beyond conventional risk scores and coronary artery calcification (CAC) is unclear.

METHODS

We studied 600 type 2 diabetics aged 55-74 years without known coronary heart disease. CRF was quantified in metabolic equivalents (METs) by maximal treadmill testing and categorized as tertiles of percent predicted METs (ppMETs) achieved. CAC was calculated by non-enhanced computed tomography scans. The individual and joint association of both measures with an outcome event of all-cause mortality, myocardial infarction or stroke, was determined over a mean follow-up period of 80 ± 16 months.

RESULTS

There were 72 (12%) events during follow-up. Low CRF was independently associated with event risk after adjustment for traditional risk factors and CAC (HR 2.25, 95% CI 1.41-3.57, p = 0.001). CRF (unfit/fit) allowed further outcome discrimination both amongst diabetics with low CAC scores (9.5% versus 2.0% event rate), and amongst diabetics with high CAC scores (23.5% versus 12.4% event rate), p < 0.001. The addition of CRF to a model comprising UKPDS and CAC scores improved the area under the curve for event prediction from 0.66 to 0.71, p = 0.03, with a positive continuous net reclassification improvement (NRI) of 0.451, p = 0.002.

CONCLUSIONS

CRF, quantified by ppMETs, provided independent prognostic information which was additive to CAC. Low CRF may identify asymptomatic diabetic subjects at higher risk for all-cause mortality, myocardial infarction or stroke, despite low CAC.

Ischemic heart disease in women: a focus on risk factors

Heart disease remains a major contributor to morbidity and mortality in women in the United States and worldwide. This review highlights known and emerging risk factors for ischemic heart disease (IHD) in women. Traditional Framingham risk factors such as hypertension, hyperlipidemia, diabetes, smoking, as well as lifestyle habits such as unhealthy diet and sedentary lifestyle are all modifiable. Health care providers should be aware of emerging cardiac risk factors in women such as adverse pregnancy outcomes, systemic autoimmune disorders, obstructive sleep apnea, and radiation-induced heart disease; psychosocial factors such as mental stress, depression, anxiety, low socioeconomic status, and work and marital stress play an important role in IHD in women. Appropriate recognition and management of an array of risk factors is imperative given the growing burden of IHD and need to deliver cost-effective, quality care for women.