Using the coronary artery calcium score to guide statin therapy: a cost-effectiveness analysis

The implications of competing risks and direct treatment disutility in cardiovascular disease and osteoporotic fracture: risk prediction and cost effectiveness analysis

Background

Clinical guidelines commonly recommend preventative treatments for people above a risk threshold. Therefore, decision-makers must have faith in risk prediction tools and model-based cost-effectiveness analyses for people at different levels of risk. Two problems that arise are inadequate handling of competing risks of death and failing to account for direct treatment disutility (i.e. the hassle of taking treatments). We explored these issues using two case studies: primary prevention of cardiovascular disease using statins and osteoporotic fracture using bisphosphonates.

Objectives

Externally validate three risk prediction tools [QRISK®3, QRISK®-Lifetime, QFracture-2012 (ClinRisk Ltd, Leeds, UK)]; derive and internally validate new risk prediction tools for cardiovascular disease [competing mortality risk model with Charlson Comorbidity Index (CRISK-CCI)] and fracture (CFracture), accounting for competing-cause death; quantify direct treatment disutility for statins and bisphosphonates; and examine the effect of competing risks and direct treatment disutility on the cost-effectiveness of preventative treatments.

Design, participants, main outcome measures, data sources

Discrimination and calibration of risk prediction models (Clinical Practice Research Datalink participants: aged 25-84 years for cardiovascular disease and aged 30-99 years for fractures); direct treatment disutility was elicited in online stated-preference surveys (people with/people without experience of statins/bisphosphonates); costs and quality-adjusted life-years were determined from decision-analytic modelling (updated models used in National Institute for Health and Care Excellence decision-making).

Results

CRISK-CCI has excellent discrimination, similar to that of QRISK3 (Harrell's c = 0.864 vs. 0.865, respectively, for women; and 0.819 vs. 0.834, respectively, for men). CRISK-CCI has systematically better calibration, although both models overpredict in high-risk subgroups. People recommended for treatment (10-year risk of ≥ 10%) are younger when using QRISK-Lifetime than when using QRISK3, and have fewer observed events in a 10-year follow-up (4.0% vs. 11.9%, respectively, for women; and 4.3% vs. 10.8%, respectively, for men). QFracture-2012 underpredicts fractures, owing to under-ascertainment of events in its derivation. However, there is major overprediction among people aged 85-99 years and/or with multiple long-term conditions. CFracture is better calibrated, although it also overpredicts among older people. In a time trade-off exercise (n = 879), statins exhibited direct treatment disutility of 0.034; for bisphosphonates, it was greater, at 0.067. Inconvenience also influenced preferences in best-worst scaling (n = 631). Updated cost-effectiveness analysis generates more quality-adjusted life-years among people with below-average cardiovascular risk and fewer among people with above-average risk. If people experience disutility when taking statins, the cardiovascular risk threshold at which benefits outweigh harms rises with age (≥ 8% 10-year risk at 40 years of age; ≥ 38% 10-year risk at 80 years of age). Assuming that everyone experiences population-average direct treatment disutility with oral bisphosphonates, treatment is net harmful at all levels of risk.

Limitations

Treating data as missing at random is a strong assumption in risk prediction model derivation. Disentangling the effect of statins from secular trends in cardiovascular disease in the previous two decades is challenging. Validating lifetime risk prediction is impossible without using very historical data. Respondents to our stated-preference survey may not be representative of the population. There is no consensus on which direct treatment disutilities should be used for cost-effectiveness analyses. Not all the inputs to the cost-effectiveness models could be updated.

Conclusions

Ignoring competing mortality in risk prediction overestimates the risk of cardiovascular events and fracture, especially among older people and those with multimorbidity. Adjustment for competing risk does not meaningfully alter cost-effectiveness of these preventative interventions, but direct treatment disutility is measurable and has the potential to alter the balance of benefits and harms. We argue that this is best addressed in individual-level shared decision-making.

Study registration

This study is registered as PROSPERO CRD42021249959.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (NIHR award ref: 15/12/22) and is published in full in Health and Social Care Delivery Research; Vol. 12, No. 4. See the NIHR Funding and Awards website for further award information.

Use of coronary artery calcium score and coronary CT angiography to guide cardiovascular prevention and treatment

Currently, cardiovascular risk stratification to guide preventive therapy relies on clinical scores based on cardiovascular risk factors. However, the discriminative power of these scores is relatively modest. The use of coronary artery calcium score (CACS) and coronary CT angiography (CCTA) has surfaced as methods for enhancing the estimation of risk and potentially providing insights for personalized treatment in individual patients. CACS improves overall cardiovascular risk prediction and may be used to improve the yield of statin therapy in primary prevention, and possibly identify patients with a favorable risk/benefit relationship for antiplatelet therapies. CCTA holds promise to guide anti-atherosclerotic therapies and to monitor individual response to these treatments by assessing individual plaque features, quantifying total plaque volume and composition, and assessing peri-coronary adipose tissue. In this review, we aim to summarize current evidence regarding the use of CACS and CCTA for guiding lipid-lowering and antiplatelet therapy and discuss the possibility of using plaque burden and plaque phenotyping to monitor response to anti-atherosclerotic therapies.

Quantifying the impact of taking medicines for primary prevention: a time-trade off study to elicit direct treatment disutility in the UK

BACKGROUND

Direct treatment disutility (DTD) represents an individual's disutility associated with the inconvenience of taking medicine over a long period of time.

OBJECTIVES

The main aim of this study was to elicit DTD values for taking a statin or a bisphosphonate for primary prevention. A secondary aim was to understand factors which influence DTD values.

METHODS

Design: We used a cross-sectional study consisting of time-trade off exercises embedded within online surveys. Respondents were asked to compare a one-off pill ('Medicine A') assumed to have no inconvenience and a daily pill ('Medicine B') over 10 years (statins) or 5 years (bisphosphonates).Setting: Individuals from National Health Service (NHS) primary care and the general population were surveyed using an online panel company.Participants: Two types of participants were recruited. First, a purposive sample of patients with experience of taking a statin (n=260) or bisphosphonate (n=100) were recruited from an NHS sampling frame. Patients needed to be aged over 30, have experience of taking the medicine of interest and have no diagnosis of dementia or of using dementia drugs. Second, a demographically balanced sample of members of the public were recruited for statins (n=376) and bisphosphonates (n=359).Primary and secondary outcome measures: Primary outcome was mean DTD. Regression analysis explored factors which could influence DTD values.

RESULTS

A total of 879 respondents were included for analysis (514 for statins and 365 for bisphosphonates). The majority of respondents reported a disutility associated with medicine use. Mean DTD for statins was 0.034 and for bisphosphonates 0.067, respectively. Respondent characteristics including age and sex did not influence DTD. Experience of bisphosphonate-use reduced reported disutilities.

CONCLUSIONS

Statins and bisphosphonates have a quantifiable DTD. The size of estimated disutilities suggest they are likely to be important for cost-effectiveness, particularly in individuals at low-risk when treated for primary prevention.

Cardiovascular Calcification Heterogeneity in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) exhibit tremendously elevated risk for cardiovascular disease, particularly ischemic heart disease, due to premature vascular and cardiac aging and accelerated ectopic calcification. The presence of cardiovascular calcification associates with increased risk in patients with CKD. Disturbed mineral homeostasis and diverse comorbidities in these patients drive increased systemic cardiovascular calcification in different manifestations with diverse clinical consequences, like plaque instability, vessel stiffening, and aortic stenosis. This review outlines the heterogeneity in calcification patterning, including mineral type and location and potential implications on clinical outcomes. The advent of therapeutics currently in clinical trials may reduce CKD-associated morbidity. Development of therapeutics for cardiovascular calcification begins with the premise that less mineral is better. While restoring diseased tissues to a noncalcified homeostasis remains the ultimate goal, in some cases, calcific mineral may play a protective role, such as in atherosclerotic plaques. Therefore, developing treatments for ectopic calcification may require a nuanced approach that considers individual patient risk factors. Here, we discuss the most common cardiac and vascular calcification pathologies observed in CKD, how mineral in these tissues affects function, and the potential outcomes and considerations for therapeutic strategies that seek to disrupt the nucleation and growth of mineral. Finally, we discuss future patient-specific considerations for treating cardiac and vascular calcification in patients with CKD-a population in need of anticalcification therapies.

AI-based opportunistic CT screening of incidental cardiovascular disease, osteoporosis, and sarcopenia: cost-effectiveness analysis

PURPOSE

To assess the cost-effectiveness and clinical efficacy of AI-assisted abdominal CT-based opportunistic screening for atherosclerotic cardiovascular (CV) disease, osteoporosis, and sarcopenia using artificial intelligence (AI) body composition algorithms.

METHODS

Markov models were constructed and 10-year simulations were performed on hypothetical age- and sex-specific cohorts of 10,000 U.S. adults (base case: 55 year olds) undergoing abdominal CT. Using expected disease prevalence, transition probabilities between health states, associated healthcare costs, and treatment effectiveness related to relevant conditions (CV disease/osteoporosis/sarcopenia) were modified by three mutually exclusive screening models: (1) usual care ("treat none"; no intervention regardless of opportunistic CT findings), (2) universal statin therapy ("treat all" for CV prevention; again, no consideration of CT findings), and (3) AI-assisted abdominal CT-based opportunistic screening for CV disease, osteoporosis, and sarcopenia using automated quantitative algorithms for abdominal aortic calcification, bone mineral density, and skeletal muscle, respectively. Model validity was assessed against published clinical cohorts.

RESULTS

For the base-case scenarios of 55-year-old men and women modeled over 10 years, AI-assisted CT-based opportunistic screening was a cost-saving and more effective clinical strategy, unlike the "treat none" and "treat all" strategies that ignored incidental CT body composition data. Over a wide range of input assumptions beyond the base case, the CT-based opportunistic strategy was dominant over the other two scenarios, as it was both more clinically efficacious and more cost-effective. Cost savings and clinical improvement for opportunistic CT remained for AI tool costs up to $227/patient in men ($65 in women) from the $10/patient base-case scenario.

CONCLUSION

AI-assisted CT-based opportunistic screening appears to be a highly cost-effective and clinically efficacious strategy across a broad array of input assumptions, and was cost saving in most scenarios.

Prediction of Coronary Artery Calcium Using Deep Learning of Echocardiograms

BACKGROUND

Coronary artery calcification (CAC), often assessed by computed tomography (CT), is a powerful marker of coronary artery disease that can guide preventive therapies. Computed tomographies, however, are not always accessible or serially obtainable. It remains unclear whether other widespread tests such as transthoracic echocardiograms (TTEs) can be used to predict CAC.

METHODS

Using a data set of 2,881 TTE videos paired with coronary calcium CTs, we trained a video-based artificial intelligence convolutional neural network to predict CAC scores from parasternal long-axis views. We evaluated the model's ability to classify patients from a held-out sample as well as an external site sample into zero CAC and high CAC (CAC ≥ 400 Agatston units) groups by receiver operating characteristic and precision-recall curves. We also investigated whether such classifications prognosticated significant differences in 1-year mortality rates by the log-rank test of Kaplan-Meier curves.

RESULTS

Transthoracic echocardiogram artificial intelligence models had high discriminatory abilities in predicting zero CAC (receiver operating characteristic area under the curve [AUC] = 0.81 [95% CI, 0.74-0.88], F1 score = 0.95) and high CAC (AUC = 0.74 [0.68-0.8], F1 score = 0.74). This performance was confirmed in an external test data set of 92 TTEs (AUC = 0.75 [0.65-0.85], F1 score = 0.77; and AUC = 0.85 [0.76-0.93], F1 score = 0.59, respectively). Risk stratification by TTE-predicted CAC performed similarly to CT CAC scores in prognosticating significant differences in 1-year survival in high-CAC patients (CT CAC ≥ 400 vs CT CAC < 400, P = .03; TTE-predicted CAC ≥ 400 vs TTE-predicted CAC < 400, P = .02).

CONCLUSIONS

A video-based deep learning model successfully used TTE videos to predict zero CAC and high CAC with high accuracy. Transthoracic echocardiography-predicted CAC prognosticated differences in 1-year survival similar to CT CAC. Deep learning of TTEs holds promise for future adjunctive coronary artery disease risk stratification to guide preventive therapies.

Imaging subclinical coronary atherosclerosis to guide lipid management, are we there yet?

Atherosclerotic cardiovascular disease risk (ASCVD) is an ongoing epidemic, and lipid abnormalities are its primordial cause. Most individuals suffering a first ASCVD event are previously asymptomatic and often do not receive preventative therapies. The cornerstone of primary prevention has been the identification of individuals at risk through risk calculators based on clinical and laboratory traditional risk factors plus risk enhancers. However, it is well accepted that a clinical risk calculator misclassifies a significant proportion of individuals leading to the prescription of a lipid-lowering medication with very little yield or a missed opportunity for lipid-lowering agents with a potentially preventable event. The development of coronary artery calcium scoring (CAC) and CT coronary angiography (CCTA) provide complementary tools to directly visualize coronary plaque and other risk-modifying imaging components that can potentially provide individualized lipid management. Understanding patient selection for CAC or potentially CCTA and the risk implications of the different parameters provided, such as CAC score, coronary stenosis, plaque characteristics and burden, epicardial adipose tissue, and pericoronary adipose tissue, have grown more complex as technologies evolve. These parameters directly affect the shared decision with patients to start or withhold lipid-lowering therapies, to adjust statin intensity or LDL cholesterol goals. Emerging lipid lowering studies with non-invasive imaging as a guide to patient selection and treatment efficacy, plus the evolution of lipid lowering therapies from statins to a diverse armament of newer high-cost agents have pushed these two fields forward with a complex interaction. This review will discuss existing risk estimators, and non-invasive imaging techniques for subclinical coronary atherosclerosis, traditionally studied using CAC and more recently CCTA with qualitative and quantitative measurements. We will also explore the current data, gaps of knowledge and future directions on the use of these techniques in the risk-stratification and guidance of lipid management.

Reporting Coronary Artery Calcium on Low-Dose Computed Tomography Impacts Statin Management in a Lung Cancer Screening Population

Background

Cigarette smoking is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD). Concomitant use of low-dose computed tomography (LDCT) for coronary artery calcium (CAC) scoring with lung cancer screening (LCS) has been proposed to further determine ASCVD risk and mortality. We aimed to determine the validity of LDCT in identifying CAC and its impact on statin management.

Methods

We conducted a retrospective review from November 2020 to May 2021 of Military Health System (MHS) beneficiaries who received LCS with LDCT and were referred for CAC scoring with electrocardiogram-gated CT. Of the 190 participants initially identified, 170 met study eligibility. The Agatston method was used to score CAC on both scan types.

Results

Participants had a mean (SD) age of 62.1 (4.6) years and were 70.6% male. CAC was seen more on ECG-gated CT compared with LDCT (88% vs 74%, P < .001). The Spearman correlation and Kendall W coefficient of concordance of CAC scores between the 2 scan types was 0.945 (P < .001) and 0.643, respectively. The κ statistic between CAC scores on the 2 different scans was 0.49 (SEκ = 0.048; 95% CI, -0.726-1.706), and the weighted κ statistic was 0.711. Bland-Altman analysis demonstrated a mean bias of 111.45 Agatston units, with limits of agreement between -268.64 and 491.54, suggesting CAC scores on electrocardiogram-gated CT were on average about 111 units higher than those on LDCT. There was a statistically significant proportion of nonstatin participants who met statin criteria based on additional CAC reporting (P < .001).

Conclusions

CAC scores are highly correlated and concordant between LDCT and electrocardiogram-gated CT. Smokers undergoing annual LDCT may benefit from concomitant CAC scoring to help stratify ASCVD risk.

Pre-screening to guide coronary artery calcium scoring for early identification of high-risk individuals in the general population

AIMS

To evaluate the ability of Systematic COronary Risk Estimation 2 (SCORE2) and other pre-screening methods to identify individuals with high coronary artery calcium score (CACS) in the general population.

METHODS AND RESULTS

Computed tomography-based CACS quantification was performed in 6530 individuals aged 45 years or older from the general population. Various pre-screening methods to guide referral for CACS were evaluated. Miss rates for high CACS (CACS ≥300 and ≥100) were evaluated for various pre-screening methods: moderate (≥5%) and high (≥10%) SCORE2 risk, any traditional coronary artery disease (CAD) risk factor, any Risk Or Benefit IN Screening for CArdiovascular Disease (ROBINSCA) risk factor, and moderately (>3 mg/24 h) increased urine albumin excretion (UAE). Out of 6530 participants, 643 (9.8%) had CACS ≥300 and 1236 (18.9%) had CACS ≥100. For CACS ≥300 and CACS ≥100, miss rate was 32 and 41% for pre-screening by moderate (≥5%) SCORE2 risk and 81 and 87% for high (≥10%) SCORE2 risk, respectively. For CACS ≥300 and CACS ≥100, miss rate was 8 and 11% for pre-screening by at least one CAD risk factor, 24 and 25% for at least one ROBINSCA risk factor, and 67 and 67% for moderately increased UAE, respectively.

CONCLUSION

Many individuals with high CACS in the general population are left unidentified when only performing CACS in case of at least moderate (≥5%) SCORE2, which closely resembles current clinical practice. Less stringent pre-screening by presence of at least one CAD risk factor to guide CACS identifies more individuals with high CACS and could improve CAD prevention.

Coronary Artery Calcium Score directed risk stratification of patients with Type-2 diabetes mellitus

BACKGROUND AND AIMS

This study aimed to review the available data on the role of coronary artery calcium (CAC) scoring as the preferred adjunct modality to improve risk prediction and reduce the incidence of major adverse cardiac events and mortality in T2DM patients.

METHODS

We reviewed the findings of 21 studies.

RESULTS

This study revealed that the CAC scoring system could enhance cardiovascular disease (CVD) risk stratification and positively affect the medical management of patients with T2DM.

CONCLUSION

A CAC scoring approach is necessary to reduce the incidence and prevalence of preventable CVD events in patients with type 2 diabetes.

Multi-Modality Imaging for Prevention of Coronary Artery Disease and Myocardial Infarction in the General Population: Ready for Prime Time?

Cardiovascular disease (CVD) remains a leading cause of death and disability worldwide. Acute myocardial infarction (AMI) causes irreversible myocardial damage, heart failure, life-threatening arrythmias and sudden cardiac death (SCD), and is a main driver of CVD mortality and morbidity. To control the forecasted increase in CVD burden for both the individual and society, improved strategies for the prevention of AMI and SCD are required. Current prevention of AMI and SCD is directed towards risk-modifying interventions, guided by risk assessment using clinical risk prediction scores (CRPSs) and the coronary artery calcium score (CACS). Early detection of more advanced coronary artery disease (CAD), beyond risk assessment by CRPSs or CACS, is a promising strategy to allow personalized treatment for the improved prevention of AMI and SCD in the general population. We review evidence for further testing, beyond CRPSs and CACS, and therapies focusing on promising targets, including subclinical obstructive CAD, high-risk plaques, and silent myocardial ischemia. We also evaluate the potential of multi-modality imaging to enhance the conduction of adequately powered trials to provide high-quality evidence on the impact of add-on tests and therapies in the prevention of AMI and SCD in asymptomatic individuals. To conclude, we discuss the occurrence of AMI and SCD in individuals currently estimated to be at “low-risk” by the current strategy based on CRPSs, and methods to improve prevention of AMI and SCD in this “low-risk” population.

Aortic Pulse Wave Velocity as Adjunct Risk Marker for Assessing Cardiovascular Disease Risk: Prospective Study

BACKGROUND

Aortic pulse wave velocity is a noninvasive measure of aortic stiffness and arterial aging. Its current value in cardiovascular risk estimation practice is unknown. We aimed to establish whether aortic pulse wave velocity identified individuals with higher risk of incident major adverse cardiovascular events and improved performance of the American Heart Association/American College of Cardiology atherosclerotic cardiovascular disease risk score.

METHODS

This prospective analysis included 3837 Whitehall II cohort participants screened in 2008 to 2009, and followed for 11.7 years (mean=10.3, SD=1.81), without history of stroke, myocardial infarction, or coronary heart disease.

RESULTS

Mean age of the sample was 65.0 years (SD=5.6), 2831 participants (73.8%) were male and mean atherosclerotic cardiovascular disease risk score was 13.8%. At the end of follow-up, 411 individuals (10.7%) had suffered a major cardiovascular event. Those in the highest aortic pulse wave velocity quartile were at high risk (hazard ratio, 2.99 [95% CI, 2.25-3.97]) and reached the threshold for statin medication (7.5% risk) after 5 years whereas others reached it after 10 years (difference P<0.001). The addition of aortic pulse wave velocity to the risk score improved the C statistic (0.68 versus 0.67, P=0.03) and net reclassification index (4.6%, P=0.04 and 11.3%, P=0.02).

CONCLUSIONS

Our results show that aortic stiffness predicted major adverse cardiovascular events in a cohort of elderly individuals, improving the performance of a widely used cardiovascular disease risk estimator. Aortic pulse wave velocity measurement is scalable, radiation-free, and easy to perform. Further studies on its applicability in cardiovascular disease risk assessment in primary care settings are needed.

Determinants of Incident Atherosclerotic Cardiovascular Disease Events Among Those With Absent Coronary Artery Calcium: Multi-Ethnic Study of Atherosclerosis

BACKGROUND

The 2018 American Heart Association/American College of Cardiology/Multisociety cholesterol guideline states that statin therapy may be withheld or delayed among intermediate-risk individuals in the absence of coronary artery calcium (CAC=0). We evaluated whether traditional cardiovascular risk factors are associated with incident atherosclerotic cardiovascular disease (ASCVD) events among individuals with CAC=0 over long-term follow-up.

METHODS

We included participants with CAC=0 at baseline from the MESA (Multi-Ethnic Study of Atherosclerosis), a prospective cohort study of individuals free of clinical ASCVD at baseline. We used multivariable-adjusted Cox proportional hazards models to study the association between cardiovascular risk factors (cigarette smoking, diabetes, hypertension, preventive medication use [aspirin and statin], family history of premature ASCVD, chronic kidney disease, waist circumference, lipid and inflammatory markers) and adjudicated incident ASCVD outcomes.

RESULTS

We studied 3416 individuals (mean [SD] age 58 [9] years; 63% were female, 33% White, 31% Black, 12% Chinese American, and 24% Hispanic). Over a median follow-up of 16 years, there were 189 ASCVD events (composite of coronary heart disease and stroke) of which 91 were coronary heart disease, 88 were stroke, and 10 were both coronary heart disease and stroke events. The unadjusted event rates of ASCVD were ≤5 per 1000 person-years among individuals with CAC=0 for most risk factors with the exception of current cigarette smoking (7.3), diabetes (8.9), hypertension (5.4), and chronic kidney disease (6.8). After multivariable adjustment, risk factors that were significantly associated with ASCVD included current cigarette smoking: hazard ratio, 2.12 (95% CI, 1.32-3.42); diabetes: hazard ratio, 1.68 (95% CI, 1.01-2.80); and hypertension: hazard ratio, 1.57 (95% CI, 1.06-2.33).

CONCLUSIONS

Current cigarette smoking, diabetes, and hypertension are independently associated with incident ASCVD over a 16-year follow-up among those with CAC=0.

Role of Coronary Artery Calcium Testing for Risk Assessment in Primary Prevention of Atherosclerotic Cardiovascular Disease: A Review

Importance

Current guidelines recommend a few different approaches to the use of coronary artery calcium (CAC) testing as a tool for risk assessment and decision-making regarding drug therapy for primary prevention of atherosclerotic cardiovascular disease (ASCVD).

Observations

Coronary artery calcium testing is not recommended for universal screening, particularly in patients at very low or high predicted risk for ASCVD, where its yield and utility for altering clinical decisions are limited. Use of CAC testing appears to be optimal when used in selected patients who are at intermediate or borderline risk of ASCVD as a sequential decision aid after initial quantitative risk assessment and consideration of individual patient risk-enhancing factors (eg, strong family history of premature ASCVD, chronic kidney disease). Although convincing clinical trials have not been completed, observational studies strongly suggest that, in those at intermediate risk, CAC testing can meaningfully reclassify risk and can support improved targeting of drug therapy to patients most likely to benefit.

Conclusions and Relevance

This narrative review summarizes the evidence available about the appropriate role of CAC testing for ASCVD risk assessment. Coronary artery calcium testing should be used selectively in patients who are at intermediate risk of ASCVD, when there is persistent uncertainty after performing standard risk assessment using traditional risk factors in a risk score, and after consideration of additional individual risk-enhancing factors. In these situations, the result of the CAC test can be helpful to clarify whether the patient's true risk is high enough to justify initiation of primary prevention medications, such as statins or aspirin.

Would You Recommend Aspirin to This Patient for Primary Prevention of Atherosclerotic Cardiovascular Disease? : Grand Rounds Discussion From Beth Israel Deaconess Medical Center

Atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of death in the United States. Reducing ASCVD risk through primary prevention strategies has been shown to be effective; however, the role of aspirin in primary prevention remains unclear. The decision to recommend aspirin has been limited by the difficulty clinicians and patients face when trying to balance benefits and harms. In 2016, the U.S. Preventive Services Task Force addressed this issue by determining the risk level at which prophylactic aspirin generally becomes more favorable, recommending aspirin above a risk cut point (>10% estimated ASCVD risk). In 2019, the American College of Cardiology and the American Heart Association issued a guideline on the primary prevention of CVD that recommends low-dose aspirin might be considered for the primary prevention of ASCVD among select adults aged 40 to 70 years who are at higher ASCVD risk but not at increased risk for bleeding. Here, 2 experts discuss how to apply this guideline in general and to a patient in particular while answering the following questions: How do you assess ASCVD risk, and what is the role, if any, of the coronary artery calcium score?; At what risk threshold of benefits and harms would you recommend aspirin or not?; and How do you help a patient come to a decision about starting or stopping aspirin therapy?

Clinical Impact of Reporting Coronary Artery Calcium Scores of Non-Gated Chest Computed Tomography on Statin Management

Introduction

Coronary artery calcium (CAC) scoring is used as a screening tool for patients with intermediate 10-year arteriosclerotic cardiovascular disease (ASCVD) risk. Results obtained on non-contrast non-gated chest CT (ngCCT) correlate well to those obtained on gated CTs. This paper aims to determine how the routine reporting of CAC scores on ngCCT scans with ASCVD risk of less than 12.5% would change statin management.

Methods

Data of all patients scanned on a single CT scanner during a four-month window were reviewed. A total of 521 eligible scans were identified. After removing duplicate scans and scans from patients who were not in the age range of 40-75 years, 370 scans remained. Patients were excluded if they had documented ASCVD, type 2 diabetes mellitus, or low-density lipoprotein (LDL) > 190 mg/dL, or if they had ASCVD risk of greater than 12.5%. Ultimately, 36 scans were included in the study.

Results

Of the 36 patients who qualified, 10 were low-risk (ASCVD risk<5%), 13 were intermediate-risk (ASCVD risk 5-7.5%), and 13 were high-risk (ASCVD risk 7.5%-12.5%). A CAC score of 300 was used as a cutoff for recommending prescribing statins and 0 was used as a cutoff for recommending de-prescribing statins. In 63% of patients (23/36), CAC scoring altered statin recommendations. This included 11/13 (85%) intermediate-risk patients, 6/13 (46%) high-risk patients, and 6/10 (60%) low-risk patients.

Conclusions

Reporting CAC on ngCCTs obtained for other reasons can significantly impact statin prescribing practices. This may improve cost, patient satisfaction, and patient safety.

Coronary artery calcium scoring: an evidence-based guide for primary care physicians

Primary care physicians often must decide whether statin therapy would be appropriate (in addition to lifestyle modification) for managing asymptomatic individuals with borderline or intermediate risk for developing atherosclerotic cardiovascular disease (ASCVD), as assessed on the basis of traditional risk factors. In appropriate subjects, a simple, noninvasive measurement of coronary artery calcium can help clarify risk. Coronary atherosclerosis is a chronic inflammatory disease, with atherosclerotic plaque formation involving intimal inflammation and repeated cycles of erosion and fibrosis, healing and calcification. Atherosclerotic plaque formation represents the prognostic link between risk factors and future clinical events. The presence of coronary artery calcification is almost exclusively an indication of coronary artery disease, except in certain metabolic conditions. Coronary artery calcification can be detected and quantified in a matter of seconds by noncontrast electrocardiogram-gated low-dose X-ray computed tomography (coronary artery calcium scoring [CACS]). Since the publication of the seminal work by Dr. Arthur Agatston in 1990, a wealth of CACS-based prognostic data has been reported. In addition, recent guidelines from various professional societies conclude that CACS may be considered as a tool for reclassifying risk for atherosclerotic cardiovascular disease in patients otherwise assessed to have intermediate risk, so as to more accurately inform decisions about possible statin therapy in addition to lifestyle modification as primary preventive therapy. In this review, we provide an overview of CACS, from acquisition to interpretation, and summarize the scientific evidence for and the appropriate use of CACS as put forth in current clinical guidelines.

Cost-utility analysis of an integrated genetic/epigenetic test for assessing risk for coronary heart disease

Aim: New epigenetically based methods for assessing risk for coronary heart disease may be more sensitive but are generally more costly than current methods. To understand their potential impact on healthcare spending, we conducted a cost-utility analysis. Methods: We compared costs using the new Epi + Gen CHD™ test with those of existing tests using a cohort Markov simulation model. Results: We found that use of the new test was associated with both better survival and highly competitive negative incremental cost-effectiveness ratios ranging from -$42,000 to -$8000 per quality-adjusted life year for models with and without a secondary test. Conclusion: The new integrated genetic/epigenetic test will save money and lives under most real-world scenarios. Similar advantages may be seen for other epigenetic tests.

Optimal cholesterol treatment plans and genetic testing strategies for cardiovascular diseases

Atherosclerotic cardiovascular disease (ASCVD) is among the leading causes of death in the US. Although research has shown that ASCVD has genetic elements, the understanding of how genetic testing influences its prevention and treatment has been limited. To this end, we model the health trajectory of patients stochastically and determine treatment and testing decisions simultaneously. Since the cholesterol level of patients is one controllable risk factor for ASCVD events, we model cholesterol treatment plans as Markov decision processes. We determine whether and when patients should receive a genetic test using value of information analysis. By simulating the health trajectory of over 64 million adult patients, we find that 6.73 million patients undergo genetic testing. The optimal treatment plans informed with clinical and genetic information save 5,487 more quality-adjusted life-years while costing $1.18 billion less than the optimal treatment plans informed with clinical information only. As precision medicine becomes increasingly important, understanding the impact of genetic information becomes essential.

Cost-Effectiveness of Coronary Artery Calcium Scoring in People With a Family History of Coronary Disease

OBJECTIVES

To assess the cost effectiveness of coronary artery calcium (CAC) compared with traditional risk factor-based prediction alone in those with an family history of premature coronary artery disease (FHCAD).

BACKGROUND

The use of CAC scoring to guide primary prevention statin therapy in those with a FHCAD is inconsistently recommended in guidelines, and usually not reimbursed by insurance.

METHODS

A microsimulation model was constructed in TreeAge Healthcare Pro using data from 1,083 participants in the CAUGHT-CAD (Coronary Artery Calcium Score: Use to Guide Management of HerediTary Coronary Artery Disease) trial. Outcomes assessed were quality-adjusted life years (QALYs): cost-effectiveness was assessed over a 15-year time horizon from the perspective of the US health care sector using real-world statin prescribing, accounting for the effect of knowledge of subclinical disease on adherence to guideline-directed therapies. Costs were assessed in 2020 USD, with discounting undertaken at 3%.

RESULTS

Statins were indicated in 45% of the cohort using the CAC strategy and 27% using American College of Cardiology/American Heart Association (2019) treatment strategies. Compared with applying a statin treatment threshold of 7.5%, the CAC strategy was more costly ($145) and more effective (0.0097 QALY) with an incremental cost-effective ratio (ICER) of $15,014/QALY. CAC ICER was driven by CAC acquisition and statin prescription cost and improved with certain patient subgroups: male, age >60 years, and 10-year risk pooled cohort equation risk ≥7.5%. CAC scanning of low-risk patients (10-year risk <5%) or those 40 to 50 years of age was not cost-effective.

CONCLUSIONS

Systematic CAC screening and treatment of those with FHCAD and subclinical disease was more cost-effective than management using statin treatment thresholds, in the US health care system.

The National Lipid Association scientific statement on coronary artery calcium scoring to guide preventive strategies for ASCVD risk reduction

An Expert Panel of the National Lipid Association reviewed the evidence related to the use of coronary artery calcium (CAC) scoring in clinical practice for adults seen for primary prevention of atherosclerotic cardiovascular disease. Recommendations for optimal use of this test in adults of various races/ethnicities, ages and multiple domains of primary prevention, including those with a 10-year ASCVD risk <20%, those with diabetes or the metabolic syndrome, and those with severe hypercholesterolemia were provided. Recommendations were also made on optimal timing for repeat calcium scoring after an initial test, use of CAC scoring in those taking statins, and its role in informing the clinician patient discussion on the benefit of aspirin and anti-hypertensive drug therapy. Finally, a vision is provided for the future of coronary calcium scoring.

Cardiac-CT and cardiac-MR cost-effectiveness: a literature review

Cardiovascular diseases are still among the first causes of death worldwide with a huge impact on healthcare systems. Within these conditions, the correct diagnosis of coronary artery disease with the most appropriate imaging-based evaluations is of utmost importance. The sustainability of the healthcare systems, considering the high economic burden of modern cardiac imaging equipments, makes cost-effective analysis an important tool, currently used for weighing different costs and health outcomes, when policy makers have to allocate funds and to prioritize interventions, getting the most out of their financial resources. This review aims at evaluating cost-effective analysis in the more recent literature, focused on the role of Calcium Score, coronary computed tomography angiography and cardiac magnetic resonance.

Cost-effectiveness of Contemporary Statin Use Guidelines With or Without Coronary Artery Calcium Assessment in African American Individuals

Importance

Clinical and economic consequences of statin treatment guidelines supplemented by targeted coronary artery calcium (CAC) assessment have not been evaluated in African American individuals, who are at increased risk for atherosclerotic cardiovascular disease and less likely than non-African American individuals to receive statin therapy.

Objective

To evaluate the cost-effectiveness of the 2013 American College of Cardiology/American Heart Association (ACC/AHA) guideline without a recommendation for CAC assessment vs the 2018 ACC/AHA guideline recommendation for use of a non-0 CAC score measured on one occasion to target generic-formulation, moderate-intensity statin treatment in African American individuals at risk for atherosclerotic cardiovascular disease.

Design, Setting, and Participants

A microsimulation model was designed to estimate life expectancy, quality of life, costs, and health outcomes over a lifetime horizon. African American-specific data from 472 participants in the Jackson Heart Study (JHS) at intermediate risk for atherosclerotic cardiovascular disease and other US population-specific data on individuals from published sources were used. Data analysis was conducted from November 11, 2018, to November 1, 2019.

Main Outcomes and Measures

Lifetime costs and quality-adjusted life-years (QALYs), discounted at 3% annually.

Results

In a model-based economic evaluation informed in part by follow-up data, the analysis was focused on 472 individuals in the JHS at intermediate risk for atherosclerotic cardiovascular disease; mean (SD) age was 63 (6.7) years. The sample included 243 women (51.5%) and 229 men (48.5%). Of these, 178 of 304 participants (58.6%) who underwent CAC assessment had a non-0 CAC score. In the base-case scenario, implementation of 2013 ACC/AHA guidelines without CAC assessment provided a greater quality-adjusted life expectancy (0.0027 QALY) at a higher cost ($428.97) compared with the 2018 ACC/AHA guideline strategy with CAC assessment, yielding an incremental cost-effectiveness ratio of $158 325/QALY, which is considered to represent low-value care by the ACC/AHA definition. The 2018 ACC/AHA guideline strategy with CAC assessment provided greater quality-adjusted life expectancy at a lower cost compared with the 2013 ACC/AHA guidelines without CAC assessment when there was a strong patient preference to avoid use of daily medication therapy. In probability sensitivity analyses, the 2018 ACC/AHA guideline strategy with CAC assessment was cost-effective compared with the 2013 ACC/AHA guidelines without CAC assessment in 76% of simulations at a willingness-to-pay value of $100 000/QALY when there was a preference to lose 2 weeks of perfect health to avoid 1 decade of daily therapy.

Conclusions and Relevance

A CAC assessment-guided strategy for statin therapy appears to be cost-effective compared with initiating statin therapy in all African American individuals at intermediate risk for atherosclerotic cardiovascular disease and may provide greater quality-adjusted life expectancy at a lower cost than a non-CAC assessment-guided strategy when there is a strong patient preference to avoid the need for daily medication. Coronary artery calcium testing may play a role in shared decision-making regarding statin use.

Computed tomography calcium scoring association and reclassification of clinical cardiovascular risk in asymptomatic Mexican patients

OBJECTIVES

To establish tailored preventive treatment, we studied the ability of coronary artery calcium scoring to reclassify patients with intermediate cardiovascular risk and its association with additional risk factors in our Mexican preventive care center.

MATERIALS AND METHODS

In this retrospective cohort study, we analyzed 520 asymptomatic patients from a Mexican primary prevention population between 2014 and 2018. Coronary artery calcium scoring, laboratory results, and anthropometric measurements (abdominal circumference and body mass index) were assessed. The Framingham risk score and American Heart Association/American College of Cardiology (AHA/ACC) atherosclerotic cardiovascular disease risk algorithm were calculated. Correlations between coronary artery calcium scoring, anthropometric measurements, and clinical cardiovascular risk scores were assessed. We assessed the ability of coronary artery calcium scoring to reclassify patients recommended for statin therapy compared with the cardiovascular risk scores.

RESULTS

Patients had a mean age of 67.5 years (SD ± 9.8) and 294 subjects (56.5%) were male. Coronary artery calcium scoring has a positive correlation with age, AHA/ACC atherosclerotic cardiovascular disease risk algorithm, and Framingham risk score (p < 0.001 for all). Coronary artery calcium scoring was prevalent, occurring in 63.2% of patients with a median Agatston score of 22 with and interquartile range of 178. Male gender, older age, smoking habit, diabetes, and abdominal circumference were independent predictors of coronary artery calcium scoring (p < 0.001). Coronary artery calcium scoring downwardly reclassified 44.9% of patients in intermediate cardiovascular risk categories by the AHA/ACC atherosclerotic cardiovascular disease risk algorithm and 43.9% by the Framingham risk score. Coronary artery calcium scoring upwardly reclassified 46.8% of patients in intermediate risk categories by the AHA/ACC atherosclerotic cardiovascular disease risk algorithm and 56% by the Framingham risk score.

CONCLUSION

Coronary artery calcium scoring is prevalent in this Mexican primary prevention cohort and has the ability to reclassify a significant percentage of intermediate cardiovascular risk patients.

Comparison of Transatlantic Approaches to Lipid Management: The AHA/ACC/Multisociety Guidelines vs the ESC/EAS Guidelines

The 2018 American Heart Association/American College of Cardiology/Multisociety (AHA/ACC) guidelines and the 2019 European Society of Cardiology/European Atherosclerosis Society (ESC/EAS) guidelines on lipid management were published less than a year apart. Both guidelines focus on reducing cardiovascular risk, but they follow different approaches in terms of methods of risk estimation, definitions of at-risk groups, and treatment goals to achieve this common underlying objective. Both recommend achieving risk-based percentage reductions of low-density lipoprotein cholesterol (LDL-C) levels with statin therapy. The ESC/EAS guidelines additionally recommend target LDL-C levels and are more liberal in supporting the use of both statin and nonstatin therapies across broader patient groups. The AHA/ACC guidelines may be considered more conservative, reserving the addition of nonstatins to maximally tolerated statins for only select patient groups based on specific LDL-C thresholds. One of the main reasons for these differences is incorporation of cost value considerations by the AHA/ACC guidelines, whereas the ESC/EAS guidelines consider an ideal setting with unlimited resources while making recommendations. In this review, we discuss similarities and differences between the 2 lipid guidelines to help clinicians become more cognizant of these recommendations and provide the best individualized patient care.

Cost-Effectiveness of Multigene Pharmacogenetic Testing in Patients With Acute Coronary Syndrome After Percutaneous Coronary Intervention

OBJECTIVE

To evaluate the cost-effectiveness of multigene testing (CYP2C19, SLCO1B1, CYP2C9, VKORC1) compared with single-gene testing (CYP2C19) and standard of care (no genotyping) in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) from Medicare's perspective.

METHODS

A hybrid decision tree/Markov model was developed to simulate patients post-PCI for ACS requiring antiplatelet therapy (CYP2C19 to guide antiplatelet selection), statin therapy (SLCO1B1 to guide statin selection), and anticoagulant therapy in those that develop atrial fibrillation (CYP2C9/VKORC1 to guide warfarin dose) over 12 months, 24 months, and lifetime. The primary outcome was cost (2016 US dollar) per quality-adjusted life years (QALYs) gained. Costs and QALYs were discounted at 3% per year. Probabilistic sensitivity analysis (PSA) varied input parameters (event probabilities, prescription costs, event costs, health-state utilities) to estimate changes in the cost per QALY gained.

RESULTS

Base-case-discounted results indicated that the cost per QALY gained was $59 876, $33 512, and $3780 at 12 months, 24 months, and lifetime, respectively, for multigene testing compared with standard of care. Single-gene testing was dominated by multigene testing at all time horizons. PSA-discounted results indicated that, at the $50 000/QALY gained willingness-to-pay threshold, multigene testing had the highest probability of cost-effectiveness in the majority of simulations at 24 months (61%) and over the lifetime (81%).

CONCLUSIONS

On the basis of projected simulations, multigene testing for Medicare patients post-PCI for ACS has a higher probability of being cost-effective over 24 months and the lifetime compared with single-gene testing and standard of care and could help optimize medication prescribing to improve patient outcomes.

Role of Coronary Calcium Score to Identify Candidates for ASCVD Prevention

PURPOSE OF REVIEW

In this review, we describe the mechanism behind coronary artery calcification formation and detection, as well as its implication in cardiovascular disease (CVD) risk stratification, intervention, and prognosis in asymptomatic individuals.

RECENT FINDINGS

Multiple cohort and population studies have shown that coronary artery calcium scoring is effective and reproducible in predicting the risk for cardiovascular disease. The updated 2018 ACC/AHA guideline has incorporated consideration of coronary artery calcification testing into cardiovascular disease risk stratification and therapy guidance. Coronary artery calcification's evidence-based role in detection, risk stratification, and ultimately its unique influence on therapeutic intervention and prognosis of cardiovascular disease in asymptomatic population is increasingly being recognized..

Evaluation of an AI-based, automatic coronary artery calcium scoring software

Objectives

To evaluate an artificial intelligence (AI)–based, automatic coronary artery calcium (CAC) scoring software, using a semi-automatic software as a reference.

Methods

This observational study included 315 consecutive, non-contrast-enhanced calcium scoring computed tomography (CSCT) scans. A semi-automatic and an automatic software obtained the Agatston score (AS), the volume score (VS), the mass score (MS), and the number of calcified coronary lesions. Semi-automatic and automatic analysis time were registered, including a manual double-check of the automatic results. Statistical analyses were Spearman’s rank correlation coefficient (⍴), intra-class correlation (ICC), Bland Altman plots, weighted kappa analysis (κ), and Wilcoxon signed-rank test.

Results

The correlation and agreement for the AS, VS, and MS were ⍴ = 0.935, 0.932, 0.934 (p < 0.001), and ICC = 0.996, 0.996, 0.991, respectively (p < 0.001). The correlation and agreement for the number of calcified lesions were ⍴ = 0.903 and ICC = 0.977 (p < 0.001), respectively. The Bland Altman mean difference and 1.96 SD upper and lower limits of agreements for the AS, VS, and MS were − 8.2 (− 115.1 to 98.2), − 7.4 (− 93.9 to 79.1), and − 3.8 (− 33.6 to 25.9), respectively. Agreement in risk category assignment was 89.5% and κ = 0.919 (p < 0.001). The median time for the semi-automatic and automatic method was 59 s (IQR 35–100) and 36 s (IQR 29–49), respectively (p < 0.001).

Conclusions

There was an excellent correlation and agreement between the automatic software and the semi-automatic software for three CAC scores and the number of calcified lesions. Risk category classification was accurate but showing an overestimation bias tendency. Also, the automatic method was less time-demanding.

Key Points

• Coronary artery calcium (CAC) scoring is an excellent candidate for artificial intelligence (AI) development in a clinical setting.

• An AI-based, automatic software obtained CAC scores with excellent correlation and agreement compared with a conventional method but was less time-consuming.

Coronary artery calcium data and reporting system: Strengths and limitations

Coronary artery calcium data and reporting system (CAC-DRS) is a recently introduced standardized reporting system for calcium scoring on computed tomography. CAC-DRS provides four risk categories (0, 1, 2 and 3) along with treatment recommendations for each category. As with any other new reporting platform, CAC-DRS has both advantages and disadvantages. Improved communication, better clarity of details, organized management recommendations and utility in future research and education are the major strengths of CAC-DRS. It has many limitations such as questionable need for a new system, few missing components, use of a less accurate visual method and treatment suggestions based on expert opinion instead of clinical trials. In this contemporary review, we discuss the new reporting system CAC-DRS, its application, strengths and limitations and conclude with some remarks for the future.

Optimizing Dyslipidemia Management for the Prevention of Cardiovascular Disease: a Focus on Risk Assessment and Therapeutic Options

Primary prevention of incident atherosclerotic cardiovascular disease (ASCVD) as well as decreasing the risk of future events in those with established atherosclerosis is critical from a public health perspective. Management of dyslipidemias constitutes a key target in decreasing the risk of developing ASCVD events. While there have been great strides in the treatment of dyslipidemia over the last three decades, there are important recent developments and ongoing research that will expand the available therapeutic options and enable further cardiovascular risk reduction. PURPOSE OF REVIEW: The purpose of this paper is to review new developments relating to the primary prevention and management of ASCVD with a specific focus on optimizing the treatment of dyslipidemias. RECENT FINDINGS: In the realm of ASCVD risk prediction, mounting evidence over the last decade has demonstrated that coronary artery calcium testing is superior to any serum biomarker in the prediction of future ASCVD events and in discriminating future cardiovascular risk. As such, it has been incorporated into the most recent ACC/AHA primary prevention guideline to help guide management decisions in select patients. In terms of the management of dyslipidemias, PCSK9 inhibitors lower LDL-C by 50-70% and provide an additional 15% reduction in key cardiovascular events in high-risk patients with known ASCVD, as demonstrated in the ODYSSEY and FOURIER trials. Cholesteryl ester transfer protein (CETP) inhibitors, which significantly increase HDL-C levels, demonstrated mixed results in large clinical trials and have helped reframe HDL-C as a risk marker rather than a modifiable risk factor. In regard to the management of triglycerides, the REDUCE-IT trial demonstrated a nearly 5% absolute reduction in key cardiovascular events with a highly purified fish-oil derivative named icosapent ethyl in high-risk patients already on statin therapy. Finally, in regard to lipoprotein(a)-which is a strong risk factor for ASCVD-there are exciting developments in the therapeutic pipeline which reduce circulating lipoprotein(a) levels by nearly 90%. The management of dyslipidemias continues to be an exciting field with several ongoing cardiovascular outcomes trials, improvement in risk prediction models, and new therapeutic agents in the pipeline that will further mitigate residual cardiovascular risk in both primary and secondary prevention patients.

Is the coronary artery calcium score the first-line tool for investigating patients with severe hypercholesterolemia?

Background

Coronary artery calcium (CAC) is known as a reliable tool for estimating risk of myocardial infarction, coronary death, all-cause mortality and is even used to evaluate suitable asymptomatic patients. We therefore aimed to evaluate whether CAC scoring can be applied in the algorithm for clinical examination of patients with severe hypercholesterolemia (SH).

Methods

During the period of 2016–2017 a total of 213 asymptomatic adults, underwent computed tomography angiography to evaluate their CAC scoring. The sample consisted of 110 patients with SH and 103 age and sex matched controls without dyslipidemia and established cardiovascular disease.

Results

In total there were 79 (37.2%) subjects with elevated (≥25th) CAC percentiles. Out of them 47 (59.5%) had SH and 32 (40.5%) did not. CAC score did not differ between groups (SH (+) 140.30 ± 185.72 vs SH (−) 87.84 ± 140.65, p = 0.146), however there was a comparable difference in how the participants of these groups distributed among different percentile groups (p = 0.044). Gender, blood pressure, tabaco use, physical activity, family history of coronary artery disease and diabetes mellitus were not associated with CAC score (p > 0.05). There were no significant correlations between biochemical parameters and CAC percentiles except for increase in lipoprotein(a) (p = 0.038). Achilles tendon pathology, visceral obesity, body mass index and increased waist-hip ratio were not associated with CAC percentiles either (p > 0.05).

Conclusions

CAC score is not associated with presence of SH. CAC score is not an appropriate diagnostic tool in the algorithm for clinical examination of patients with SH. Further larger studies are needed to support our findings.

Association of Coronary Artery Calcium in Adults Aged 32 to 46 Years With Incident Coronary Heart Disease and Death

Importance

Coronary artery calcium (CAC) is associated with coronary heart disease (CHD) and cardiovascular disease (CVD); however, prognostic data on CAC are limited in younger adults.

Objective

To determine if CAC in adults aged 32 to 46 years is associated with incident clinical CHD, CVD, and all-cause mortality during 12.5 years of follow-up.

Design, Setting, and Participants

The Coronary Artery Risk Development in Young Adults (CARDIA) Study is a prospective community-based study that recruited 5115 black and white participants aged 18 to 30 years from March 25, 1985, to June 7, 1986. The cohort has been under surveillance for 30 years, with CAC measured 15 (n = 3043), 20 (n = 3141), and 25 (n = 3189) years after recruitment. The mean follow-up period for incident events was 12.5 years, from the year 15 computed tomographic scan through August 31, 2014.

Main Outcomes and Measures

Incident CHD included fatal or nonfatal myocardial infarction, acute coronary syndrome without myocardial infarction, coronary revascularization, or CHD death. Incident CVD included CHD, stroke, heart failure, and peripheral arterial disease. Death included all causes. The probability of developing CAC by age 32 to 56 years was estimated using clinical risk factors measured 7 years apart between ages 18 and 38 years.

Results

At year 15 of the study among 3043 participants (mean [SD] age, 40.3 [3.6] years; 1383 men and 1660 women), 309 individuals (10.2%) had CAC, with a geometric mean Agatston score of 21.6 (interquartile range, 17.3-26.8). Participants were followed up for 12.5 years, with 57 incident CHD events and 108 incident CVD events observed. After adjusting for demographics, risk factors, and treatments, those with any CAC experienced a 5-fold increase in CHD events (hazard ratio [HR], 5.0; 95% CI, 2.8-8.7) and 3-fold increase in CVD events (HR, 3.0; 95% CI, 1.9-4.7). Within CAC score strata of 1-19, 20-99, and 100 or more, the HRs for CHD were 2.6 (95% CI, 1.0-5.7), 5.8 (95% CI, 2.6-12.1), and 9.8 (95% CI, 4.5-20.5), respectively. A CAC score of 100 or more had an incidence of 22.4 deaths per 100 participants (HR, 3.7; 95% CI, 1.5-10.0); of the 13 deaths in participants with a CAC score of 100 or more, 10 were adjudicated as CHD events. Risk factors for CVD in early adult life identified those above the median risk for developing CAC and, if applied, in a selective CAC screening strategy could reduce the number of people screened for CAC by 50% and the number imaged needed to find 1 person with CAC from 3.5 to 2.2.

Conclusions and Relevance

The presence of CAC among individuals aged between 32 and 46 years was associated with increased risk of fatal and nonfatal CHD during 12.5 years of follow-up. A CAC score of 100 or more was associated with early death. Adults younger than 50 years with any CAC, even with very low scores, identified on a computed tomographic scan are at elevated risk of clinical CHD, CVD, and death. Selective use of screening for CAC might be considered in individuals with risk factors in early adulthood to inform discussions about primary prevention.

Cost-effectiveness of Financial Incentives for Patients and Physicians to Manage Low-Density Lipoprotein Cholesterol Levels

IMPORTANCE

Financial incentives shared between physicians and patients were shown to significantly reduce low-density lipoprotein cholesterol (LDL-C) levels in a randomized clinical trial, but it is not known whether these health benefits are worth the added incentive and utilization costs required to achieve them.

OBJECTIVE

To evaluate the long-term cost-effectiveness of financial incentives on LDL-C level control.

DESIGN, SETTING, AND PARTICIPANTS

In this economic evaluation, a previously validated microsimulation computer model was parameterized using individual-level data from the randomized clinical trial on financial incentives, National Health and Nutrition Examination Surveys for model population inputs, and other published sources. The study was conducted from April 15, 2016, to March 29, 2018.

INTERVENTIONS

The following interventions were used: (1) usual care, (2) trial control strategy (increased cholesterol level monitoring and use of electronic pill bottles), (3) financial incentives for physicians, (4) financial incentives for patients, and (5) incentives shared between physicians and patients.

MAIN OUTCOMES AND MEASURES

Discounted costs (2017 US dollars), lifetime cardiovascular disease risk, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs).

RESULTS

The model population (n = 1 000 000 [30.7% women]) had similar mean (SD) age (61.5 [11.9] years) and LDL-C level (153.9 mg/dL) as the observed trial population (n = 1503 [42.7% women]; age, 62.0 [8.7] years; and LDL-C level, 160.6 mg/dL). Using base-case assumptions (including a 10-year waning period of LDL-C level reductions), the usual-care strategy was dominated (higher costs and lower QALYs) by all other strategies. Strategies for physician- or patient-only incentives were dominated by the shared-incentives strategy, which had an ICER of $60 000/QALY compared with the trial control strategy. In a sensitivity analysis regarding the duration of LDL-C level reductions, the shared-incentives strategy remained cost-effective (ICERs <$100 000/QALY and <$150 000/QALY) for scenarios with LDL-C level reductions lasting, with linear waning, at least 7 and 5 years, respectively. In the 1-way sensitivity analysis for the time horizon of the analysis, the ICER of the shared-incentives strategy exceeded $100 000/QALY at 11 years and $150 000/QALY at 8 years. In probabilistic sensitivity analysis, the shared-incentives intervention was cost-effective in 69% to 77% of iterations using cost-effectiveness thresholds of $100 000 to $150 000/QALY. Cost-effectiveness results were also sensitive to the duration of intervention costs.

CONCLUSIONS AND RELEVANCE

This study suggests that the financial incentives shared between patients and physicians for LDL-C level control meet conventional standards of cost-effectiveness, but these results appeared to be sensitive to assumptions about the durations of LDL-C level reductions and years of intervention costs included, as well as to the choice of time horizon.

Coronary Calcium Score and Cardiovascular Risk

Coronary artery calcium (CAC) is a highly specific feature of coronary atherosclerosis. On the basis of single-center and multicenter clinical and population-based studies with short-term and long-term outcomes data (up to 15-year follow-up), CAC scoring has emerged as a widely available, consistent, and reproducible means of assessing risk for major cardiovascular outcomes, especially useful in asymptomatic people for planning primary prevention interventions such as statins and aspirin. CAC testing in asymptomatic populations is cost effective across a broad range of baseline risk. This review summarizes evidence concerning CAC, including its pathobiology, modalities for detection, predictive role, use in prediction scoring algorithms, CAC progression, evidence that CAC changes the clinical approach to the patient and patient behavior, novel applications of CAC, future directions in scoring CAC scans, and new CAC guidelines.

Implications of Coronary Artery Calcium Testing for Treatment Decisions Among Statin Candidates According to the ACC/AHA Cholesterol Management Guidelines: A Cost-Effectiveness Analysis

This review evaluates the cost-effectiveness of using coronary artery calcium (CAC) to guide long-term statin therapy compared with treating all patients eligible for statins according to 2013 American College of Cardiology/American Heart Association cholesterol management guidelines for atherosclerotic cardiovascular disease. The authors used a microsimulation model to compare costs and effectiveness from a societal perspective over a lifetime horizon. Both strategies resulted in similar costs and quality-adjusted life years (QALYs). CAC resulted in increased costs (+$81) and near-equal QALY (+0.01) for an incremental cost-effectiveness ratio of $8,100/QALY compared with the treat-all strategy. For 10,000 patients, the treat-all strategy would theoretically avert 21 atherosclerotic cardiovascular disease events, but would add 47,294 person-years of statins. With CAC costs <$100, and higher cost and/or disutility associated with statin therapy, CAC strategy was favored. These findings suggest the economic value of both approaches were similar. Clinicians should account for individual preferences in context of shared decision making when choosing the most appropriate strategy to guide statin decisions.

Cardiovascular Genetic Risk Testing for Targeting Statin Therapy in the Primary Prevention of Atherosclerotic Cardiovascular Disease: A Cost-Effectiveness Analysis

BACKGROUND

It is unclear whether testing for novel risk factors, such as a cardiovascular genetic risk score (cGRS), improves clinical decision making or health outcomes when used for targeting statin initiation in the primary prevention of atherosclerotic cardiovascular disease (ASCVD). Our objective was to estimate the cost-effectiveness of cGRS testing to inform clinical decision making about statin initiation in individuals with low-to-intermediate (2.5%-7.5%) 10-year predicted risk of ASCVD.

METHODS AND RESULTS

We evaluated the cost-effectiveness of testing for a 27-single-nucleotide polymorphism cGRS comparing 4 test/treat strategies: treat all, treat none, test/treat if cGRS is high, and test/treat if cGRS is intermediate or high. We tested a set of clinical scenarios of men and women, aged 45 to 65 years, with 10-year ASCVD risks between 2.5% and 7.5%. Our primary outcome measure was cost per quality-adjusted life-year gained. Under base case assumptions for statin disutility and cost, the preferred strategy is to treat all patients with ASCVD risk >2.5% without cGRS testing. For certain clinical scenarios, such as a 57-year-old man with a 10-year ASCVD risk of 7.5%, cGRS testing can be cost-effective under a limited set of assumptions; for example, when statins cost $15 per month and statin disutility is 0.013 (ie, willing to trade 3 months of life in perfect health to avoid 20 years of statin therapy), the preferred strategy (using a willingness-to-pay threshold of $50 000 per quality-adjusted life-year gained) is to test and treat if cGRS is intermediate or high. Overall, the results were not sensitive to assumptions about statin efficacy and harms.

CONCLUSIONS

Testing for a 27-single-nucleotide polymorphism cGRS is generally not a cost-effective approach for targeting statin therapy in the primary prevention of ASCVD for low- to intermediate-risk patients.

CAC-DRS: Coronary Artery Calcium Data and Reporting System. An expert consensus document of the Society of Cardiovascular Computed Tomography (SCCT)

The goal of CAC-DRS: Coronary Artery Calcium Data and Reporting System is to create a standardized method to communicate findings of CAC scanning on all noncontrast CT scans, irrespective of the indication, in order to facilitate clinical decision-making, with recommendations for subsequent patient management. The CAC-DRS classification is applied on a per-patient basis and represents the total calcium score and the number of involved arteries. General recommendations are provided for further management of patients with different degrees of calcified plaque burden based on CAC-DRS classification. In addition, CAC-DRS will provide a framework of standardization that may benefit quality assurance and tracking patient outcomes with the potential to ultimately result in improved quality of care.

Statin Trials, Cardiovascular Events, and Coronary Artery Calcification: Implications for a Trial-Based Approach to Statin Therapy in MESA

OBJECTIVES

This study sought to determine whether coronary artery calcium (CAC) could be used to optimize statin allocation among individuals for whom trial-based evidence supports efficacy of statin therapy.

BACKGROUND

Recently, allocation of statins was proposed for primary prevention of atherosclerotic cardiovascular disease (ASCVD) based on proven efficacy from randomized controlled trials (RCTs) of statin therapy, a so-called trial-based approach.

METHODS

The study used data from MESA (Multi-Ethnic Study of Atherosclerosis) with 5,600 men and women, 45 to 84 years of age, and free of clinical ASCVD, lipid-lowering therapy, or missing information for risk factors at baseline examination.

RESULTS

During 10 years' follow-up, 354 ASCVD and 219 hard coronary heart disease (CHD) events occurred. Based on enrollment criteria for 7 RCTs of statin therapy in primary prevention, 73% of MESA participants (91% of those >55 years of age) were eligible for statin therapy according to a trial-based approach. Among those individuals, CAC = 0 was common (44%) and was associated with low rates of ASCVD and CHD (3.9 and 1.7, respectively, per 1,000 person-years). There was a graded increase in event rates with increasing CAC score, and in individuals with CAC >100 (27% of participants) the rates of ASCVD and CHD were 18.9 and 12.7, respectively. Consequently, the estimated number needed to treat (NNT) in 10 years to prevent 1 event varied greatly according to CAC score. For ASCVD events, the NNT was 87 for CAC = 0 and 19 for CAC >100. For CHD events, the NNT was 197 for CAC = 0 and 28 for CAC >100.

CONCLUSIONS

Most MESA participants qualified for trial-based primary prevention with statins. Among the individuals for whom trial-based evidence supports efficacy of statin therapy, CAC = 0 and CAC >100 were common and associated with low and high cardiovascular risks, respectively. This information may guide shared decision making aimed at targeting evidence-based statins to those who are likely to benefit the most.

Use of the Coronary Artery Calcium Score in Discussion of Initiation of Statin Therapy in Primary Prevention

Clinical guidelines for instituting pharmacotherapy for the primary prevention of atherosclerotic cardiovascular disease (ASCVD), specifically lipid management and aspirin, have long been based on absolute risk. However, lipid management in the current era remains challenging to both patients and clinicians in the setting of somewhat discordant recommendations from various organizations. All guidelines endorse the use of statins for primary prevention for those at sufficient absolute risk, and treatment recommendations are generally "risk-based" rather than exclusively targeting specific low-density lipoprotein cholesterol levels. Nonetheless, guidelines differ in relation to the risk threshold for initiation and the intensity of statin treatment. The key concept of the clinician-patient risk discussion introduced in the 2013 American College of Cardiology/American Heart Association cholesterol guidelines is a process that addresses the potential for ASCVD risk reduction with statin treatment, potential for adverse treatment effects, patient preferences, encouragement of heart-healthy lifestyle, and management of other risk factors. However, operationalizing the clinician-patient risk discussion requires effective communication of the most accurate and personalized risk information. In this article, we review our treatment approach for the appropriate use of coronary artery calcium testing in the intermediate-risk patient to guide shared decision making. The decision to initiate or intensify statin therapy may be uncertain across a broad range of estimated 10-year ASCVD risk of 5% to 20%, and coronary artery calcium testing can reclassify risk upward or downward in approximately 50% of this group to inform the risk discussion. We conclude with 2 case-based examples of uncertain risk and uncertain statin therapeutic benefit to illustrate execution of the clinician-patient risk discussion.

Coronary Artery Calcium Scoring in Current Clinical Practice: How to Define Its Value?

OPINION STATEMENT

Detecting subclinical atherosclerosis with coronary artery calcium (CAC) is promising for identifying individuals at risk for cardiovascular events and appears to be a robust tool for guiding initiation of appropriate and timely primary prevention strategies. However, how do we best determine its clinical value? It is clear that traditional risk prediction models based primarily on age, gender, and risk factors are insufficient for ideal personalization of risk estimation. It is now well established from epidemiologic studies that CAC adds to traditional risk scores for a more accurate risk prediction. However, such traditional epidemiology studies have limitations in establishing "clinical value," and they must be supplemented by additional data before being translated into strong recommendations in clinical practice guidelines. Fortunately, over the last few years, the research around CAC has matured to include data supporting enhanced clinician-patient risk discussions, shared decision-making, flexible risk factor treatment goals, specific clinical decision algorithms, as well as favorable cost-effectiveness analyses. We had moved from a time when we asked "if CAC adds to the risk score" to a time when we are asking "does CAC facilitate a shared decision-making model matching risk, treatment, and patient preferences?" A new risk calculator incorporating CAC into global risk scoring, and 2017 guidelines on the use of CAC published by the Society of Cardiovascular Computed Tomography (SCCT), reflect this new approach. In this article, we review the recent transition to this more clinically relevant CAC research that may support a stronger recommendation for its use in future prevention guidelines.