Rationale and design of the coronary artery calcium consortium: A multicenter cohort study

Detection of Coronary Artery Disease With Coronary Computed Tomography Angiography and Stress Testing in Candidates for Liver Transplant

Cardiac complications are the leading cause of morbidity and mortality in recipients of liver transplant (LT). Previous guidelines recommended stress testing to exclude coronary artery disease (CAD), although recent guidelines recommend coronary computed tomography angiography (CCTA). We aimed to assess the prevalence and predictors of CAD on CCTA and compare CCTA with stress testing in consecutive adult candidates for LT who underwent CAD noninvasive assessment between 2020 and 2023. Patients who underwent a stress test between January and December 2020 formed the stress cohort, and patients who underwent CCTA between January 2021 and September 2023 formed the CCTA cohort. There were 141 patients in the stress test cohort and 269 patients in the CCTA cohort. Stress test results were nondiagnostic or inconclusive in 18 patients (12.8%) whereas CCTA was nondiagnostic in 6 patients (2.2%). In patients evaluated with CCTA, mean coronary artery calcium (CAC) score was 332 ± 716 AU, with moderate or greater (>50%) stenosis in 33 patients (12.3%). New CAD was diagnosed in 158 patients (58.7%) using CCTA and in 5 patients (3.5%) using stress tests. Clinically actionable CAD (coronary artery calcium >100) on CCTA was present in 96 patients (35.7%). The number of CAD risk factors was associated with the presence of CAD on CCTA. In conclusion, there was a great burden of CAD, mainly nonobstructive, in a large cohort of candidates for LT who underwent CAD testing over a 4-year period. The current recommended risk-based evaluation of candidates for LT using CCTA as a first-line test was feasible and effective. Diagnosis of clinically actionable CAD on CCTA provides a vast opportunity for optimizing cardiac care in candidates for and recipients of LT.

Coronary Artery Calcium for Risk Stratification Among Persons With Very High HDL Cholesterol

Background

Compared to normal high-density lipoprotein (HDL) cholesterol values, very high HDL cholesterol is associated with a higher incidence of mortality and atherosclerotic cardiovascular disease (ASCVD). As such, clinical risk stratification among persons with very high HDL cholesterol is challenging.

Objectives

Among persons with very high HDL cholesterol, the purpose was to determine the prevalence of coronary artery calcium (CAC) and compare the association between traditional risk factors vs CAC for all-cause mortality and ASCVD.

Methods

The primary analysis was completed among 446 participants from the Cedars-Sinai Medical Center of the CAC Consortium with very high HDL cholesterol (≥77 mg/dL in men, ≥97 mg/dL in women). Cox proportional hazards regression assessed the association of CAC and traditional risk factors with all-cause mortality during a median follow-up of 10.7 years. Replication and validation analyses were performed for all-cause mortality among 119 participants from the Multi-Ethnic Study of Atherosclerosis (MESA) with very high HDL cholesterol, who also had information on incident ASCVD.

Results

The mean age was 57.9 years old, 49% were women, and the median HDL cholesterol was 98 mg/dL. One-half of participants (50%) had prevalent CAC, in whom the median CAC score was 118. Prevalent CAC conferred a 3.6-fold higher risk of all-cause mortality (HR: 3.64; 95% CI: 1.21-11.01), which appeared to be a more robust predictor than individual traditional risk factors beyond age. In the validation sample, prevalent CAC but not individual traditional risk factors were associated with all-cause mortality (HR: 2.39; 95% CI: 1.07-5.34) and a 4.0-fold higher risk of ASCVD (HR: 4.06; 95% CI: 1.11-14.84).

Conclusions

Measurement of CAC may facilitate clinical risk assessment among individuals with very high HDL cholesterol.

Coronary artery calcium and the risk of cardiovascular events and mortality in younger adults: a meta-analysis

AIMS

American College of Cardiology/American Heart Association 2019 prevention guidelines recommend utilizing coronary artery calcium (CAC) to stratify cardiovascular risk in selected cases. However, data regarding CAC and risk in younger adults are less robust due to the lower prevalence of CAC and lower incidence of events. The objective of this meta-analysis is to determine the ability of CAC to predict the risk of cardiovascular events and mortality in adults <50.

METHODS AND RESULTS

PubMed and Cochrane CENTRAL databases were electronically searched through May 2022 for studies with a primary prevention cohort under age 55 who underwent CAC scoring. Six observational studies with a total of 45 919 individuals with an average age of 43.1 and mean follow-up of 12.1 years were included. The presence of CAC was associated with an increased risk of adverse events [pooled hazard ratio (HR) = 1.80, 95% confidence interval (CI) 1.26-2.56, P = 0.012, I2 = 65.5]. Compared with a CAC of 0, a CAC of 1-100 did carry an increased risk of cardiovascular events (pooled HR = 1.85, 95% CI 1.08-3.16, P = 0.0248, I2 = 50.3), but not mortality (pooled HR = 1.20, 95% CI 0.85-1.69, P = 0.2917), while a CAC > 100 did carry an increased risk of cardiovascular events (pooled HR = 6.57, 95% CI 3.23-13.36, P < 0.0001, I2 = 72.6) and mortality (pooled HR = 2.91, 95% CI 2.23-3.80, P < 0.0001).

CONCLUSION

In a meta-analysis of younger adults undergoing CAC scoring, a CAC of 1-100 was associated with a higher likelihood of cardiovascular events, while a CAC > 100 was associated with a higher likelihood of cardiovascular events and mortality.

Left Main Coronary Artery Calcium and Diabetes Confer Very-High-Risk Equivalence in Coronary Artery Calcium >1,000

BACKGROUND

Although a coronary artery calcium (CAC) of ≥1,000 is a subclinical atherosclerosis threshold to consider combination lipid-lowering therapy, differentiating very high from high atherosclerotic cardiovascular disease (ASCVD) risk in this patient population is not well-defined.

OBJECTIVES

Among persons with a CAC of ≥1,000, the authors sought to identify risk factors equating with very high-risk ASCVD mortality rates.

METHODS

The authors studied 2,246 asymptomatic patients with a CAC of ≥1,000 from the CAC Consortium without a prior ASCVD event. Cox proportional hazards regression modelling was performed for ASCVD mortality during a median follow-up of 11.3 years. Crude ASCVD mortality rates were compared with those reported for secondary prevention trial patients classified as very high risk, defined by ≥2 major ASCVD events or 1 major event and ≥2 high-risk conditions (1.4 per 100 person-years).

RESULTS

The mean age was 66.6 years, 14% were female, and 10% were non-White. The median CAC score was 1,592 and 6% had severe left main (LM) CAC (vessel-specific CAC ≥300). Diabetes (HR: 2.04 [95% CI: 1.47-2.83]) and severe LM CAC (HR: 2.32 [95% CI: 1.51-3.55]) were associated with ASCVD mortality. The ASCVD mortality per 100 person-years for all patients was 0.8 (95% CI: 0.7-0.9), although higher rates were observed for diabetes (1.4 [95% CI: 0.8-1.9]), severe LM CAC (1.3 [95% CI: 0.6-2.0]), and both diabetes and severe LM CAC (7.1 [95% CI: 3.4-10.8]).

CONCLUSIONS

Among asymptomatic patients with a CAC of ≥1,000 without a prior index event, diabetes, and severe LM CAC define very high risk ASCVD, identifying individuals who may benefit from more intensive prevention therapies across several domains, including low-density lipoprotein-cholesterol lowering.

Thoracic Aortic Calcium Density and Area in Long-Term Atherosclerotic Cardiovascular Disease Risk Among Men Versus Women

BACKGROUND

The development of thoracic aortic calcium (TAC) temporally precedes coronary artery calcium more often in women versus men. Whether TAC density and area confer sex-specific differences in atherosclerotic cardiovascular disease (ASCVD) risk is unknown.

METHODS

We studied 5317 primary prevention patients who underwent coronary artery calcium scoring on noncontrast cardiac gated computed tomography with TAC >0. The Agatston TAC score (Agatston units), density (Hounsfield units), and area (mm2) were compared between men and women. Cox proportional hazards regression calculated adjusted hazard ratios for TAC density-area groups with ASCVD mortality, adjusting for traditional risk factors, coronary artery calcium, and TAC. Multinomial logistic regression calculated adjusted odds ratios for the association between traditional risk factors and TAC density-area groups.

RESULTS

The mean age was 60.7 years, 38% were women, and 163 ASCVD deaths occurred over a median of 11.7-year follow-up. Women had higher median TAC scores (97 versus 84 Agatston units; P=0.004), density (223 versus 210 Hounsfield units; P<0.001), and area (37 versus 32 mm2; P=0.006) compared with men. There was a stepwise higher incidence of ASCVD deaths across increasing TAC density-area groups in men though women with low TAC density relative to TAC area (3.6 per 1000 person-years) had survival probability commensurate with the high-density-high-area group (4.8 per 1000 person-years). Compared with low TAC density-area, low TAC density/high TAC area conferred a 3.75-fold higher risk of ASCVD mortality in women (adjusted hazard ratio, 3.75 [95% CI, 1.13-12.44]) but not in men (adjusted hazard ratio, 1.16 [95% CI, 0.48-2.84]). Risk factors most strongly associated with low TAC density/high TAC area differed in women (diabetes: adjusted odds ratio, 2.61 [95% CI, 1.34-5.07]) versus men (hypertension: adjusted odds ratio, 1.45 [95% CI, 1.11-1.90]).

CONCLUSIONS

TAC density-area phenotypes do not consistently associate with ASCVD mortality though low TAC density relative to area may be a marker of increased ASCVD risk in women.

Coronary and Extra-coronary Subclinical Atherosclerosis to Guide Lipid-Lowering Therapy

PURPOSE OF REVIEW

To discuss and review the technical considerations, fundamentals, and guideline-based indications for coronary artery calcium scoring, and the use of other non-invasive imaging modalities, such as extra-coronary calcification in cardiovascular risk prediction.

RECENT FINDINGS

The most robust evidence for the use of CAC scoring is in select individuals, 40-75 years of age, at borderline to intermediate 10-year ASCVD risk. Recent US recommendations support the use of CAC scoring in varying clinical scenarios. First, in adults with very high CAC scores (CAC ≥ 1000), the use of high-intensity statin therapy and, if necessary, guideline-based add-on LDL-C lowering therapies (ezetimibe, PCSK9-inhibitors) to achieve a ≥ 50% reduction in LDL-C and optimally an LDL-C < 70 mg/dL is recommended. In patients with a CAC score ≥ 100 at low risk of bleeding, the benefits of aspirin use may outweigh the risk of bleeding. Other applications of CAC scoring include risk estimation on non-contrast CT scans of the chest, risk prediction in younger patients (< 40 years of age), its value as a gatekeeper for the decision to perform nuclear stress testing, and to aid in risk stratification in patients presenting with low-risk chest pain. There is a correlation between extra-coronary calcification (e.g., breast arterial calcification, aortic calcification, and aortic valve calcification) and incident ASCVD events. However, its role in informing lipid management remains unclear. Identification of coronary calcium in selected patients is the single best non-invasive imaging modality to identify future ASCVD risk and inform lipid-lowering therapy decision-making.

Cardiovascular risk stratification among individuals with obesity: The Coronary Artery Calcium Consortium

OBJECTIVE

The effectiveness of coronary artery calcification (CAC) for risk stratification in obesity, in which imaging is often limited because of a reduced signal to noise ratio, has not been well studied.

METHODS

Data from 9334 participants (mean age: 53.3 ± 9.7 years; 67.9% men) with BMI ≥ 30 kg/m2 from the CAC Consortium, a retrospectively assembled cohort of individuals with no prior cardiovascular diseases (CVD), were used. The predictive value of CAC for all-cause and cause-specific mortality was evaluated using multivariable-adjusted Cox proportional hazards and competing-risks regression.

RESULTS

Mean BMI was 34.5 (SD 4.4) kg/m2 (22.7% Class II and 10.8% Class III obesity), and 5461 (58.5%) had CAC. Compared with CAC = 0, those with CAC = 1-99, 100-299, and ≥300 Agatston units had higher rates (per 1000 person-years) of all-cause (1.97 vs. 3.5 vs. 5.2 vs. 11.3), CVD (0.4 vs. 1.1 vs. 1.5 vs. 4.2), and coronary heart disease (CHD) mortality (0.2 vs. 0.6 vs. 0.6 vs. 2.5), respectively, after mean follow-up of 10.8 ± 3.0 years. After adjusting for traditional cardiovascular risk factors, CAC ≥ 300 was associated with significantly higher risk of all-cause (hazard ratio [HR]: 2.05; 95% CI: 1.49-2.82), CVD (subdistribution HR: 3.48; 95% CI: 1.81-6.70), and CHD mortality (subdistribution HR: 5.44; 95% CI: 2.02-14.66), compared with CAC = 0. When restricting the sample to individuals with BMI ≥ 35 kg/m2 , CAC ≥ 300 remained significantly associated with the highest risk.

CONCLUSIONS

Among individuals with obesity, including moderate-severe obesity, CAC strongly predicts all-cause, CVD, and CHD mortality and may serve as an effective cardiovascular risk stratification tool to prioritize the allocation of therapies for weight management.

The use of coronary artery calcium scoring in young adults

Although overall atherosclerotic cardiovascular disease (ASCVD) incidence has been declining in the United States, there is evidence that the incidence of ASCVD events in young adults is increasing. The early initiation of preventive therapies could result in a greater number of life-years saved, and therefore determining the appropriate way to identify high-risk young adults is becoming increasingly important. The coronary artery calcium (CAC) score, an established marker of coronary artery atherosclerosis, can improve discrimination for ASCVD risk beyond established risk prediction tools. Based on abundant evidence, the American College of Cardiology/American Heart Association (ACC/AHA) guidelines currently recommend an approach of using CAC scores as a tool for risk assessment and decision-making regarding drug therapy for primary prevention in middle-aged individuals. However, CAC scoring is not recommended for universal screening in young adults, where its yield and utility for altering clinical decisions are limited. Recent studies have demonstrated the nonnegligible prevalence of CAC and its strong association with ASCVD in young adults, suggesting its potential to reclassify risk and improve selection of young adults most likely to benefit from early preventive therapies. Although convincing clinical trials have not been performed in this population yet, CAC scores should be used selectively in young adults whose ASCVD risk may be sufficiently high to warrant a CAC score assessment. This review summarizes the evidence available regarding CAC scoring in young adults, and discusses an appropriate future role of CAC scores in preventing ASCVD in this population.

Coronary Artery Calcium Dispersion and Cause-Specific Mortality

Coronary artery calcium (CAC) measures subclinical atherosclerosis and improves risk stratification. CAC characteristics-including vessel(s) involved, number of vessels, volume, and density-have been shown to differentially impact risk. We assessed how dispersion-either the number of calcified vessels or CAC phenotype (diffuse, normal, and concentrated)-impacted cause-specific mortality. The CAC Consortium is a retrospective cohort of 66,636 participants without coronary heart disease (CHD) who underwent CAC scoring. This study included patients with CAC >0 (n = 28,147). CAC area, CAC density, and CAC phenotypes (derived from the index of diffusion = 1 - [CAC in most concentrated vessel/total Agatston score]) were calculated. The associations between CAC characteristics and cause-specific mortality were assessed. The participant details included (n = 28,147): mean age 58.3 years, 25% female, 89.6% White, and 66% had 2+ calcified vessels. Diabetes, hypertension, and hyperlipidemia were predictors of multivessel involvement (p <0.001). After controlling for the overall CAC score, those with 4-vessel CAC involvement had more CAC area and less dense calcifications than those with 1-vessel. There was a graded increase in all-cause and cardiovascular disease (CVD)- and CHD-specific mortality as the number of calcified vessels increased. Among those with ≥2 vessels involved (n = 18,516), a diffuse phenotype was associated with a higher CVD-specific mortality and had a trend toward higher all-cause and CHD-specific mortality than a concentrated CAC phenotype. Diffuse CAC involvement was characterized by less dense calcification, more CAC area, multiple coronary vessel involvement, and presence of certain traditional risk factors. There is a graded increase in all-cause and CVD- and CHD-specific mortality with increasing CAC dispersion.

Mortality impact of low CAC density predominantly occurs in early atherosclerosis: explainable ML in the CAC consortium

BACKGROUND

Machine learning (ML) models of risk prediction with coronary artery calcium (CAC) and CAC characteristics exhibit high performance, but are not inherently interpretable.

OBJECTIVES

To determine the direction and magnitude of impact of CAC characteristics on 10-year all-cause mortality (ACM) with explainable ML.

METHODS

We analyzed asymptomatic subjects in the CAC consortium. We trained ML models on 80% and tested on 20% of the data with XGBoost, using clinical characteristics ​+ ​CAC (ML 1) and additional CAC characteristics of CAC density and number of calcified vessels (ML 2). We applied SHAP, an explainable ML tool, to explore the relationship of CAC and CAC characteristics with 10-year all-cause and CV mortality.

RESULTS

2376 deaths occurred among 63,215 patients [68% male, median age 54 (IQR 47-61), CAC 3 (IQR 0-94.3)]. ML2 was similar to ML1 to predict all-cause mortality (Area Under the Curve (AUC) 0.819 vs 0.821, p ​= ​0.23), but superior for CV mortality (0.847 vs 0.845, p ​= ​0.03). Low CAC density increased mortality impact, particularly ≤0.75. Very low CAC density ≤0.75 was present in only 4.3% of the patients with measurable density, and 75% occurred in CAC1-100. The number of diseased vessels did not increase mortality overall when simultaneously accounting for CAC and CAC density.

CONCLUSION

CAC density contributes to mortality risk primarily when it is very low ≤0.75, which is primarily observed in CAC 1-100. CAC and CAC density are more important for mortality prediction than the number of diseased vessels, and improve prediction of CV but not all-cause mortality. Explainable ML techniques are useful to describe granular relationships in otherwise opaque prediction models.

Incidental coronary calcium in cancer patients treated with anthracycline and/or trastuzumab

AIMS

Cancer patients are at increased risk of cardiovascular disease (CVD) after treatment with potentially cardiotoxic treatments. Many cancer patients undergo non-gated chest computed tomography (NCCT) for cancer staging prior to treatment. We aimed to assess whether coronary artery calcification on NCCT predicts CVD risk in cancer patients.

METHODS AND RESULTS

Six hundred and three patients (mean age: 61.3 years, 30.8% male) with either breast cancer, lymphoma, or sarcoma were identified retrospectively. Primary endpoint was a major adverse cardiac event (MACE) composite including non-fatal myocardial infarction, new heart failure (HF) diagnosis, HF hospitalization, and cardiac death, with Fine-Gray analysis for non-cardiac death as competing risk. Secondary endpoints included a coronary composite and a HF composite. Coronary artery calcification was present in 194 (32.2%) and clinically reported in 85 (43.8%) patients. At a median follow-up of 5.3 years, 256 (42.5%) patients died of non-cardiac causes. Coronary artery calcification presence or extent was not an independent predictor of MACE [sub-distribution hazards ratio (SHR) 1.28; 0.73-2.27]. Coronary artery calcification extent was a significant predictor of the coronary composite outcome (SHR per two-fold increase 1.14; 1.01-1.28), but not of the HF composite outcome (SHR per two-fold increase 1.04; 0.95-1.14).

CONCLUSION

Coronary artery calcification detected incidentally on NCCT scans in cancer patients is prevalent and often not reported. Coronary artery calcification presence or extent did not independently predict MACE. Coronary artery calcification extent was independently associated with increased risk of CAD events but not HF events.

Discordance Between Coronary Artery Calcium Area and Density Predicts Long-Term Atherosclerotic Cardiovascular Disease Risk

BACKGROUND

Coronary artery calcium (CAC) is commonly quantified as the product of 2 generally correlated measures: plaque area and calcium density.

OBJECTIVES

The authors sought to determine whether discordance between calcium area and density has long-term prognostic importance in atherosclerotic cardiovascular disease (ASCVD) risk.

METHODS

The authors studied 10,373 primary prevention participants from the CAC Consortium with CAC >0. Based on their median values, calcium area and mean calcium density were divided into 4 mutually exclusive concordant/discordant groups. Cox proportional hazards regression assessed the association of calcium area/density groups with ASCVD mortality over a median of 11.7 years, adjusting for traditional risk factors and the Agatston CAC score.

RESULTS

The mean age was 56.7 years, and 24% were female. The prevalence of plaque discordance was 19% (9% low calcium area/high calcium density, 10% high calcium area/low calcium density). Female sex (odds ratio [OR]: 1.48 [95% CI: 1.27-1.74]) and body mass index (OR: 0.81 [95% CI: 0.76-0.87], per 5 kg/m2 higher) were significantly associated with high calcium density discordance, whereas diabetes (OR: 2.23 [95% CI: 1.85-3.19]) was most strongly associated with discordantly low calcium density. Compared to those with low calcium area/low calcium density, individuals with low calcium area/high calcium density had a 71% lower risk of ASCVD death (HR: 0.29 [95% CI: 0.09-0.95]).

CONCLUSIONS

For a given CAC score, high calcium density relative to plaque area confers lower long-term ASCVD risk, likely serving as an imaging marker of biological resilience for lesion vulnerability. Additional research is needed to define a robust definition of calcium area/density discordance for routine clinical risk prediction.

Coronary Artery Calcium for Risk Stratification of Sudden Cardiac Death: The Coronary Artery Calcium Consortium

BACKGROUND

Coronary artery calcium (CAC) is a marker of plaque burden. Whether CAC improves risk stratification for incident sudden cardiac death (SCD) beyond atherosclerotic cardiovascular disease (ASCVD) risk factors is unknown.

OBJECTIVES

SCD is a common initial manifestation of coronary heart disease (CHD); however, SCD risk prediction remains elusive.

METHODS

The authors studied 66,636 primary prevention patients from the CAC Consortium. Multivariable competing risks regression and C-statistics were used to assess the association between CAC and SCD, adjusting for demographics and traditional risk factors.

RESULTS

The mean age was 54.4 years, 33% were women, 11% were of non-White ethnicity, and 55% had CAC >0. A total of 211 SCD events (0.3%) were observed during a median follow-up of 10.6 years, 91% occurring among those with baseline CAC >0. Compared with CAC = 0, there was a stepwise higher risk (P trend < 0.001) in SCD for CAC 100 to 399 (subdistribution hazard ratio [SHR]: 2.8; 95% CI: 1.6-5.0), CAC 400 to 999 (SHR: 4.0; 95% CI: 2.2-7.3), and CAC >1,000 (SHR: 4.9; 95% CI: 2.6-9.9). CAC provided incremental improvements in the C-statistic for the prediction of SCD among individuals with a 10-year risk <7.5% (ΔC-statistic = +0.046; P = 0.02) and 7.5% to 20% (ΔC-statistic = +0.069; P = 0.003), which were larger when compared with persons with a 10-year risk >20% (ΔC-statistic = +0.01; P = 0.54).

CONCLUSIONS

Higher CAC burden strongly associates with incident SCD beyond traditional risk factors, particularly among primary prevention patients with low-intermediate risk. SCD risk stratification can be useful in the early stages of CHD through the measurement of CAC, identifying patients most likely to benefit from further downstream testing.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Coronary artery calcium scores indicating secondary prevention level risk: Findings from the CAC consortium and FOURIER trial

BACKGROUND AND AIMS

Coronary artery calcium (CAC) burden displays a stepwise association with atherosclerotic cardiovascular disease (ASCVD) risk. Among primary prevention patients, we sought to determine the CAC scores equivalent to ASCVD mortality rates observed in the FOURIER trial, a modern secondary prevention cohort.

METHODS AND RESULTS

For the main analysis, we included participants from the CAC Consortium ≥50 years old with a 10-year ASCVD risk ≥7.5% (n = 20,207). Poisson regression was used to define the relationship between CAC and annual ASCVD mortality. Equations generated from the regression models were then used to derive CAC scores associated with equivalent annual ASCVD mortality as observed in FOURIER placebo participants from the overall trial and in key trial subgroups. The CAC Consortium participants had a similar age (65.5 versus 62.5 years) and sex (22% versus 24% female) distribution as FOURIER. The annualized ASCVD mortality rate in FOURIER participants (0.766 per 100 person-years) corresponded to a CAC score of 781 (418-1467). A CAC score of 255 (162-394) corresponded to an ASCVD mortality rate equivalent to the lowest risk FOURIER subgroup (presence of myocardial infarction >2 years prior to trial enrollment). No CAC score produced a risk equivalent to high-risk FOURIER subgroups, particularly those with symptomatic peripheral arterial disease and/or multivessel coronary heart disease.

CONCLUSIONS

Primary prevention individuals with increased CAC burden may have annualized ASCVD mortality rates equivalent to persons with stable secondary prevention-level risk. These findings argue for a risk continuum between higher risk primary prevention and stable secondary prevention patients, as their ASCVD risks may overlap.

Mean Versus Peak Coronary Calcium Density on Non-Contrast CT: Calcium Scoring and ASCVD Risk Prediction

OBJECTIVES

This study sought to assess the relationship between mean vs peak calcified plaque density and their impact on calculating coronary artery calcium (CAC) scores and to compare the corresponding differential prediction of atherosclerotic cardiovascular disease (ASCVD) and coronary heart disease (CHD) mortality.

BACKGROUND

The Agatston CAC score is quantified per lesion as the product of plaque area and a 4-level categorical peak calcium density factor. However, mean calcium density may more accurately measure the heterogenous mixture of lipid-rich, fibrous, and calcified plaque reflective of ASCVD risk.

METHODS

We included 10,373 individuals from the CAC Consortium who had CAC >0 and per-vessel measurements of peak calcium density factor and mean calcium density. Area under the curve and continuous net reclassification improvement analyses were performed for CHD and ASCVD mortality to compare the predictive abilities of mean calcium density vs peak calcium density factor when calculating the Agatston CAC score.

RESULTS

Participants were on average 53.4 years of age, 24.4% were women, and the median CAC score was 68 Agatston units. The average values for mean calcium density and peak calcium density factor were 210 ± 50 HU and 3.1 ± 0.5, respectively. Individuals younger than 50 years of age and/or those with a total plaque area <100 mm2 had the largest differences between the peak and mean density measures. Among persons with CAC 1-99, the use of mean calcium density resulted in a larger improvement in ASCVD mortality net reclassification improvement (NRI) (NRI = 0.49; P < 0.001 vs. NRI = 0.18; P = 0.08) and CHD mortality discrimination (Δ area under the curve (AUC) = +0.169 vs +0.036; P < 0.001) compared with peak calcium density factor. Neither peak nor mean calcium density improved mortality prediction at CAC scores >100.

CONCLUSION

Mean and peak calcium density may differentially describe plaque composition early in the atherosclerotic process. Mean calcium density performs better than peak calcium density factor when combined with plaque area for ASCVD mortality prediction among persons with Agatston CAC 1-99.

Contemporary Review of Risk Scores in Prediction of Coronary and Cardiovascular Deaths

PURPOSE OF REVIEW

Explore the current literature supporting risk stratification scores for prediction of coronary and cardiovascular disease deaths.

RECENT FINDINGS

Accurate risk prediction remains the foundation of management choice in primary prevention. When applied to new populations, the calibration of a predictive model will deteriorate, although discrimination changes minimally. One of the approaches with better performance and validation is the initial use of pooled cohort equation to identify low and high-risk patients, followed by coronary artery calcium scoring in those with borderline to intermediate risk. It is important to utilize a risk stratification tool that has been validated in a patient population that resembles the one used to develop the original tool to maintain adequate calibration. It is likely that the future of mortality risk prediction will develop in combined clinical risk predictors and cardiovascular imaging, such coronary artery calcium (CAC) scoring that renders the highest predictive accuracy.

Coronary artery calcium is associated with long-term mortality from lung cancer: Results from the Coronary Artery Calcium Consortium

BACKGROUND AND AIMS

Coronary artery calcium (CAC) scores have been shown to be associated with CVD and cancer mortality. The use of CAC scores for overall and lung cancer mortality risk prediction for patients in the Coronary Artery Calcium Consortium was analyzed.

METHODS

We included 55,943 patients aged 44-84 years without known heart disease from the CAC Consortium. There were 1,088 cancer deaths, among which 231 were lung cancer, identified by death certificates with a mean follow-up of 12.2 ± 3.9 years. Fine-and-Gray competing-risk regression was used for overall and lung cancer-specific mortality, accounting for the competing risk of CVD death and after adjustment for CVD risk factors. Subdistribution hazard ratios (SHR) were reported.

RESULTS

The mean age of all patients was 57.1 ± 8.6 years, 34.9% were women, and 89.6% were white. Overall, CAC was strongly associated with cancer mortality. Lung cancer mortality increased with increasing CAC scores, with rates per 1000-person years of 0.2 (95% CI: 0.1-0.3) for CAC = 0 and 0.8 (95% CI: 0.6-1.0) for CAC ≥400. Compared with CAC = 0, hazards were increased for those with CAC ≥400 for lung cancer mortality [SHR: 1.7 (95% CI: 1.2-2.6)], which was driven by women [SHR: 2.3 (95% CI: 1.1-4.8)], but not significantly increased for men. Risks were higher in those with positive smoking history [SHR: 2.2 (95% CI: 1.2-4.2)], with associations driven by women [SHR: 4.0 (95% CI: 1.4-11.5)].

CONCLUSIONS

CAC scores were associated with increased risks for lung cancer mortality, with strongest associations for current and former smokers, especially in women. Used in conjunction with other clinical variables, our data pinpoint a potential synergistic use of CAC scanning beyond CVD risk assessment for identification of high-risk lung cancer screening candidates.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prognostic significance of aortic valve calcium in relation to coronary artery calcification for long-term, cause-specific mortality: results from the CAC Consortium

AIMS

Aortic valve calcification (AVC) has been shown to be associated with increased cardiovascular disease (CVD) risk; however, whether this is independent of traditional risk factors and coronary artery calcification (CAC) remains unclear.

METHODS AND RESULTS

From the multicentre CAC Consortium database, 10 007 patients (mean 55.8±11.7 years, 64% male) with concomitant CAC and AVC scoring were included in the current analysis. AVC score was quantified using the Agatston score method and categorized as 0, 1-99, and ≥100. The endpoints were all-cause, CVD, and coronary heart disease (CHD) deaths. AVC (AVC>0) was observed in 1397 (14%) patients. During a median 7.8 (interquartile range: 4.7-10.6) years of study follow-up, 511 (5.1%) deaths occurred; 179 (35%) were CVD deaths, and 101 (19.8%) were CHD deaths. A significant interaction between CAC and AVC for mortality was observed (P<0.001). The incidence of mortality events increased with higher AVC; however, AVC ≥100 was not independently associated with all-cause, CVD, and CHD deaths after adjusting for CVD risk factors and CAC (P=0.192, 0.063, and 0.206, respectively). When further stratified by CAC<100 or ≥100, AVC ≥100 was an independent predictor of all-cause and CVD deaths only in patients with CAC <100, after adjusting for CVD risk factors and CAC [hazard ratio (HR): 1.93, 95% confidence interval (CI): 1.14-3.27; P=0.013 and HR: 2.71, 95% CI: 1.15-6.34; P=0.022, respectively].

CONCLUSION

Although the overall prognostic significance of AVC was attenuated after accounting for CAC, high AVC was independently associated with all-cause and CVD deaths in patients with low coronary atherosclerosis burden.

Implication of thoracic aortic calcification over coronary calcium score regarding the 2018 ACC/AHA Multisociety cholesterol guideline: results from the CAC Consortium

•

TAC in segments of the ascending and descending thoracic aorta can be assessed by routine CAC scanning.

•

TAC assessment with the threshold of 300 improved risk prediction and reclassification for CVD mortality when added to the ASCVD risk score and CAC.

•

TAC >300 may improve patient selection for those who would benefit more strongly from statin use, from intermediate ASCVD risk patients who should consider a statin (CAC=1-100), and those where a statin is not recommended (CAC=0).

Objective

TAC is associated with an increased atherosclerotic cardiovascular disease (ASCVD) risk, but it is unclear how to interpret thoracic aortic calcification (TAC) findings in conjunction with ASCVD risk and coronary artery calcium (CAC) score according to 2018 ACC/AHA Multisociety cholesterol guidelines. We evaluate the incremental value of thoracic aortic calcification TAC over CAC for predicting and reclassifying ASCVD mortality risk.

Method

The study included 30,630 asymptomatic individuals (mean age: 55 ± 8 years, male: 64%) from the CAC Consortium. TAC was categorized as TAC 0, 1-300, and >300. Patients were categorized as low (<5%), borderline (5–7.5%), intermediate (7.5–20%), or high (≥20%) 10-year ASCVD risk according to the Pooled Cohorts Equation. In the intermediate risk group, the utility of TAC beyond CAC for statin eligibility was assessed according to the guideline. CAC was categorized as CAC=0 (no statin), CAC 1-100 (favors statin), or CAC>100 (initiate stain).

Results

During the median 11.2 years (IQR 9.2–12.4) follow-up, 345 (1.1%) CVD deaths occurred. TAC>300 was associated with increased CVD mortality after adjusting for ASCVD risk and CAC (HR:4.72, 95% CI: 3.39–6.57, p<0.001). In borderline and intermediate risk groups, TAC improved discrimination when added to a model included ASCVD risk and CAC (C-statistic: 0.77 vs. 0.68 in borderline group; 0.67 vs. 0.63 in intermediate group, both p < 0.05). The addition of TAC over CAC improved risk reclassification in borderline, intermediate and high-risk groups (categorical net reclassification index: 0.40, 0.29, and 0.49, respectively, all p < 0.001). Of intermediate risk participants for whom consideration of CAC was recommended based on the guideline, TAC >300 was associated with an increased CVD mortality risk across each statin eligibility group (all p < 0.001, compared to TAC 0).

Conclusion

TAC was independently associated with CVD death. Among individuals with borderline or intermediate ASCVD risk, a TAC threshold of 300 may provide added prognostic and reclassification value beyond the current guideline-based approach.

Thoracic Aortic Calcium for the Prediction of Stroke Mortality (from the Coronary Artery Calcium Consortium)

Thoracic aortic calcium(TAC) is an important marker of extracoronary atherosclerosis with established predictive value for all-cause mortality. We sought to explore the predictive value of TAC for stroke mortality, independent of the more established coronary artery calcium (CAC) score. The CAC Consortium is a retrospectively assembled database of 66,636 patients aged ≥18 years with no previous history of cardiovascular disease, baseline CAC scans for risk stratification, and follow-up for 12 ± 4 years. CAC scans capture the adjacent thoracic aorta, enabling assessment of TAC from the same images. TAC was available in 41,066 (62%), and was primarily analyzed as present or not present. To account for competing risks for nonstroke death, we utilized multivariable-adjusted Fine and Gray competing risk regression models adjusted for traditional cardiovascular risk factors and CAC score. The mean age of participants was 53.8 ± 10.3 years, with 34.4% female. There were 110 stroke deaths during follow-up. The unadjusted subdistribution hazard ratio (SHR) for stroke mortality in those who had TAC present compared with those who did not was 8.80 (95% confidence interval [CI]: 5.97, 12.98). After adjusting for traditional risk factors and CAC score, the SHR was 2.21 (95% CI:1.39,3.49). In sex-stratified analyses, the fully adjusted SHR for females was 3.42 (95% CI: 1.74, 6.73) while for males it was 1.55 (95% CI: 0.83, 2.90). TAC was associated with stroke mortality independent of CAC and traditional risk factors, more so in women. The presence of TAC appears to be an independent risk marker for stroke mortality.

Very High Coronary Artery Calcium (≥1000) and Association With Cardiovascular Disease Events, Non-Cardiovascular Disease Outcomes, and Mortality: Results From MESA

BACKGROUND

There are limited data on the unique cardiovascular disease (CVD), non-CVD, and mortality risks of primary prevention individuals with very high coronary artery calcium (CAC; ≥1000), especially compared with rates observed in secondary prevention populations.

METHODS

Our study population consisted of 6814 ethnically diverse individuals 45 to 84 years of age who were free of known CVD from MESA (Multi-Ethnic Study of Atherosclerosis), a prospective, observational, community-based cohort. Mean follow-up time was 13.6±4.4 years. Hazard ratios of CAC ≥1000 were compared with both CAC 0 and CAC 400 to 999 for CVD, non-CVD, and mortality outcomes with the use of Cox proportional hazards regression adjusted for age, sex, and traditional risk factors. Using a sex-adjusted logarithmic model, we calculated event rates in MESA as a function of CAC and compared them with those observed in the placebo group of stable secondary prevention patients in the FOURIER clinical trial (Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk).

RESULTS

Compared with CAC 400 to 999, those with CAC ≥1000 (n=257) had a greater mean number of coronary vessels with CAC (3.4±0.5), greater total area of CAC (586.5±275.2 mm²), similar CAC density, and more extensive extracoronary calcification. After full adjustment, CAC ≥1000 demonstrated a 4.71- (3.63-6.11), 7.57- (5.50-10.42), 4.86-(3.32-7.11), and 1.94-fold (1.57-2.41) increased risk for all CVD events, all coronary heart disease events, hard coronary heart disease events, and all-cause mortality, respectively, compared with CAC 0 and a 1.65- (1.25-2.16), 1.66- (1.22-2.25), 1.51- (1.03-2.23), and 1.34-fold (1.05-1.71) increased risk compared with CAC 400 to 999. With increasing CAC, hazard ratios increased for all event types, with no apparent upper CAC threshold. CAC ≥1000 was associated with a 1.95- (1.57-2.41) and 1.43-fold (1.12-1.83) increased risk for a first non-CVD event compared with CAC 0 and CAC 400 to 999, respectively. CAC 1000 corresponded to an annualized 3-point major adverse cardiovascular event rate of 3.4 per 100 person-years, similar to that of the total FOURIER population (3.3) and higher than those of the lower-risk FOURIER subgroups.

CONCLUSIONS

Individuals with very high CAC (≥1000) are a unique population at substantially higher risk for CVD events, non-CVD outcomes, and mortality than those with lower CAC, with 3-point major adverse cardiovascular event rates similar to those of a stable treated secondary prevention population. Future guidelines should consider a less distinct stratification algorithm between primary and secondary prevention patients in guiding aggressive preventive pharmacotherapy.

Cardiovascular and All-Cause Mortality Risk by Coronary Artery Calcium Scores and Percentiles Among Older Adult Males and Females

BACKGROUND

Coronary calcium is a marker of coronary atherosclerosis and established predictor of cardiovascular risk in general populations; however, there are limited studies examining its prognostic value among older adults (≥75 years) and even less regarding its utility in older males compared with females. Accordingly, we sought to examine the prognostic significance of both absolute and percentile coronary calcium scores among older adults.

METHODS

The multicenter Coronary Artery Calcium Consortium consists of 66,636 asymptomatic patients without cardiovascular disease. Participants ages ≥75 were included in this study and stratified by sex. Multivariable Cox regression models were constructed to assess cardiovascular and all-cause mortality risk by Agatston coronary calcium scores and percentiles.

RESULTS

Among 2,474 asymptomatic patients (mean age 79 years, 10.4-year follow-up), prevalence of coronary artery calcium was 92%. For both sexes, but in females more so than males, higher coronary calcium score and percentiles were associated with increased cardiovascular and all-cause mortality risk. Those at the lowest coronary calcium categories (0-9 and <25 percentile) had significantly lower risk of cardiovascular and all-cause mortality relative to the rest of the population. Multivariable analyses of traditional cardiovascular risk factors and coronary artery calcium variables revealed that age and coronary calcium were the strongest independent predictors for adverse outcomes.

CONCLUSIONS

Both coronary artery calcium scores and percentiles are strongly predictive of cardiovascular and all-cause mortality among older adults, with greater risk-stratification among females than males. Both low coronary artery calcium scores 0-9 and <25th percentile define relatively low risk older adults.

Prognostic value of coronary artery calcium score, area, and density among individuals on statin therapy vs. non-users: The coronary artery calcium consortium

BACKGROUND AND AIMS

Statins do not decrease coronary artery calcium (CAC) and may increase existing calcification or its density. Therefore, we examined the prognostic significance of CAC among statin users at the time of CAC scanning.

METHODS

We included 28,025 patients (6151 statin-users) aged 40-75 years from the CAC Consortium. Cox regression models were used to assess the association of CAC with coronary heart disease (CHD) and cardiovascular disease (CVD) mortality. Models were adjusted for traditional CVD risk factors. Additionally, we examined the predictive performance of CAC components including CAC area, volume, and density using an age- and sex-adjusted Cox regression model.

RESULTS

Participants (mean age 53.9 ± 10.3 years, 65.0% male) were followed for median 11.2 years. There were 395 CVD and 182 CHD deaths. One unit increase in log CAC score was associated with increased risk of CVD mortality (hazard ratio (HR), 1.2; 95% CI = 1.1-1.3) and CHD mortality (HR, 1.2; 95% CI = 1.1-1.4)) among statin users. There was a small but significant negative interaction between CAC score and statin use for the prediction of CHD (p-value = 0.036) and CVD mortality (p-value = 0.025). The volume score and CAC area were similarly associated with outcomes in statin users and non-users. Density was associated with CVD and CHD mortality in statin naïve patients, but with neither in statin users.

CONCLUSION

CAC scoring retains robust risk prediction in statin users, and the changing relationship of CAC density with outcomes may explain the slightly weaker relationship of CAC with outcomes in statin users.

Coronary Artery Calcium Scoring: New Insights into Clinical Interpretation-Lessons from the CAC Consortium

Coronary artery calcium (CAC) is a highly specific marker for coronary atherosclerosis. The CAC Consortium, a multicenter, retrospective, real-world cohort study, was established to investigate the association between CAC and long-term, cause-specific mortality. This review summarizes findings from CAC Consortium studies published between 2016 and 2020, aiming to demystify CAC as a clinical decision-guiding tool and push the limits of who might benefit from CAC in clinical practice. CAC has been shown to effectively stratify cardiovascular risk across ethnicities irrespective of age, sex, and risk factor burden. In comparison to other widely used risk scores, CAC appears to be most consistent in its ability to add to cardiovascular disease (CVD) event prediction. Beyond risk stratification, CAC has been shown to identify high-risk patient subgroups. While currently recommended only for patients at borderline or intermediate risk by the American College of Cardiology/American Heart Association (10-year atherosclerotic CVD event risk, 5% to < 20%), CAC scoring may also provide value in select young patients aged 30-49 years and in low-risk patients with a family history. While new studies emphasize that patients with a CAC greater than or equal to 1000 be considered a distinct patient group, a CAC of 0 has additionally emerged to be a reliable negative risk factor, identifying patients at low risk of both CVD and non-CVD mortality. © RSNA, 2020.

Relation of Absence of Coronary Artery Calcium to Cardiovascular Disease Mortality Risk Among Individuals Meeting Criteria for Statin Therapy According to the 2018/2019 ACC/AHA Guidelines

The 2013 American College of Cardiology and the American Heart Association (ACC/AHA) guidelines resulted in broad recommendations for preventive statin therapy allocation in patients without known cardiovascular disease (CVD). Subsequent studies demonstrated significant heterogeneity of atherosclerotic cardiovascular disease risk across the primary prevention population. In 2018/2019, the guidelines were revised to optimize risk assessment and cholesterol management. We sought to evaluate the heterogeneity of risk in statin-recommended patients, using coronary artery calcium (CAC) according to 2018/2019 ACC/AHA guidelines in a primary prevention cohort. We evaluated 5,800 statin-naive patients aged 40 to 75 years without known coronary heart disease from the Cedars-Sinai Medical Center study cohort. All participants underwent clinical CAC scoring for risk stratification and were followed for all-cause and CVD-specific mortality. A total of 181 deaths occurred including 54 CVD deaths over a follow-up of 9.5 years. Overall, 1,939 participants would have been recommended statin therapy, 32% of whom had no detectable CAC. CAC = 0 participants had the lowest all-cause and CVD mortality rates in both statin-recommended and nonrecommended groups (0.2 and 0.4 CVD deaths per 1,000 person-years, respectively). Absence of CAC in statin-naive patients portends an approximately 12-fold lower CVD mortality (0.2% vs 2.4%) in those recommended for statin therapy compared with any CAC present. In conclusion, in a cohort of patients meeting the 2018/2019 ACC/AHA guidelines for statin therapy for primary prevention, there was a marked heterogeneity of CAC scores, with about one-third of the statin recommended population having no detectable CAC (CAC = 0) with a significantly lower CVD mortality compared with CAC>0.

Association between coronary artery calcium and cardiovascular disease as a supporting cause in cancer: The CAC consortium

BACKGROUND

Identifying cancer patients at high risk of CVD is important for targeting CVD prevention strategies and evaluating chemotherapy options in the context of cardiotoxicity. Coronary artery calcium (CAC), a strong marker of coronary atherosclerosis, is used clinically to enhance risk assessment, yet the value of CAC for assessing risk of CVD complications in cancer is poorly understood.

OBJECTIVE

In cases of cancer mortality, to determine the value of CAC for predicting risk of CVD as a supporting cause of death.

METHODS

The CAC Consortium is a multi-center cohort of 66,636 asymptomatic adults without CVD who underwent CAC scanning. During a follow-up of 12.5 years, 1129 patients died of cancer and were included in this analysis. The primary outcome was presence of CVD listed as a supporting cause of cancer mortality on official death certificates obtained from the National Death Index. Logistic regression models were used to assess the odds of CVD being listed as a supporting cause of death by CAC.

RESULTS

CVD was listed as a supporting cause of death in 306 (27%) cancer mortality cases. Baseline CAC was significantly higher in individuals with CVD-supported mortality. Odds ratios of having CVD-supported death increased by ASCVD risk score category [1.15 (0.81, 1.65) for 5-20% 10-year risk and 1.97 (1.36, 2.89) for ≥20% risk, in reference to <5% 10-year ASCVD risk] and CAC category [1.07 (0.73, 1.57) for CAC 1-99, 1.29 (0.87, 1.93) for CAC 100-399, and 2.14 (1.48, 3.09) for CAC ≥400 relative to CAC 0]. In the CAC ≥400 group, these associations remained significantly elevated after adjustment for traditional CVD risk factors [1.66 (1.08, 2.55)]. A sensitivity analysis using a more specific ASCVD-supported mortality outcome, defined as coronary heart disease, stroke, and peripheral artery disease, demonstrated that adjusted odds of ASCVD-supported cancer mortality were significantly elevated in the CAC ≥400 group relative to CAC 0 [3.09 (1.39, 7.38)].

CONCLUSIONS

In cancer mortality cases, high antecedent CAC predicted risk of having CVD as a supporting cause of death on official death certificates, independently of ASCVD risk score and CVD risk factors. CAC may be useful for identifying cancer patients at high CVD risk who might benefit from more intense preventive cardiovascular therapies.

Machine Learning Adds to Clinical and CAC Assessments in Predicting 10-Year CHD and CVD Deaths

OBJECTIVES

The aim of this study was to evaluate whether machine learning (ML) of noncontrast computed tomographic (CT) and clinical variables improves the prediction of atherosclerotic cardiovascular disease (ASCVD) and coronary heart disease (CHD) deaths compared with coronary artery calcium (CAC) Agatston scoring and clinical data.

BACKGROUND

The CAC score provides a measure of the global burden of coronary atherosclerosis, and its long-term prognostic utility has been consistently shown to have incremental value over clinical risk assessment. However, current approaches fail to integrate all available CT and clinical variables for comprehensive risk assessment.

METHODS

The study included data from 66,636 asymptomatic subjects (mean age 54 ± 11 years, 67% men) without established ASCVD undergoing CAC scanning and followed for cardiovascular disease (CVD) and CHD deaths at 10 years. Clinical risk assessment incorporated the ASCVD risk score. For ML, an ensemble boosting approach was used to fit a predictive classifier for outcomes, followed by automated feature selection using information gain ratio. The model-building process incorporated all available clinical and CT data, including the CAC score; the number, volume, and density of CAC plaques; and extracoronary scores; comprising a total of 77 variables. The overall proposed model (ML all) was evaluated using a 10-fold cross-validation framework on the population data and area under the curve (AUC) as metrics. The prediction performance was also compared with 2 traditional scores (ASCVD risk and CAC score) and 2 additional models that were trained using all the clinical data (ML clinical) and CT variables (ML CT).

RESULTS

The AUC by ML all (0.845) for predicting CVD death was superior compared with those obtained by ASCVD risk alone (0.821), CAC score alone (0.781), and ML CT alone (0.804) (p < 0.001 for all). Similarly, for predicting CHD death, AUC by ML all (0.860) was superior to the other analyses (0.835 for ASCVD risk, 0.816 for CAC, and 0.827 for ML CT; p < 0.001).

CONCLUSIONS

The comprehensive ML model was superior to ASCVD risk, CAC score, and an ML model fitted using CT variables alone in the prediction of both CVD and CHD death.

Sex Differences in Coronary Artery Calcium and Mortality From Coronary Heart Disease, Cardiovascular Disease, and All Causes in Adults With Diabetes: The Coronary Calcium Consortium

OBJECTIVE

While diabetes has been previously noted to be a stronger risk factor for cardiovascular disease (CVD) in women compared with men, whether this is still the case is not clear. Coronary artery calcium (CAC) predicts coronary heart disease (CHD) and CVD in people with diabetes; however, its sex-specific impact is less defined. We compared the relation of CAC in women versus men with diabetes for total, CVD, and CHD mortality.

RESEARCH DESIGN AND METHODS

We studied adults with diabetes from a large registry of patients with CAC scanning with mortality follow-up over 11.5 years. Cox regression examined the relation of CAC with mortality end points.

RESULTS

Among 4,503 adults with diabetes (32.5% women) aged 21-93 years, 61.2% of women and 80.4% of men had CAC >0. Total, CVD, and CHD mortality rates were directly related to CAC; women had higher total and CVD death rates than men when CAC >100. Age- and risk factor-adjusted hazard ratios (HRs) per log unit CAC were higher among women versus men for total mortality (1.28 vs. 1.18) (interaction P = 0.01) and CVD mortality (1.47 vs. 1.27) (interaction P = 0.04) but were similar for CHD mortality (1.48 and 1.48). For CVD mortality, HRs with CAC scores of 101-400 and >400 were 3.67 and 6.27, respectively, for women and 1.63 and 3.48, respectively, for men (interaction P = 0.04). For total mortality, HRs were 2.56 and 4.05 for women, respectively, and 1.88 and 2.66 for men, respectively (interaction P = 0.01).

CONCLUSIONS

CAC predicts CHD, CVD, and all-cause mortality in patients with diabetes; however, greater CAC predicts CVD and total mortality more strongly in women.

Coronary Artery Calcium and the Age-Specific Competing Risk of Cardiovascular Versus Cancer Mortality: The Coronary Artery Calcium Consortium

BACKGROUND

Coronary artery calcium (CAC) is a guideline recommended cardiovascular disease (CVD) risk stratification tool that increases with age and is associated with non-cardiovascular disease outcomes including cancer. We sought to define the age-specific change in the association between CAC and cause-specific mortality.

METHODS

The Coronary Artery Calcium Consortium includes 59,502 asymptomatic patients age 40-75 without known CVD. Age-stratified mortality rates and parametric survival regression modeling was performed to estimate the age-specific CAC score at which CVD and cancer mortality risk were equal.

RESULTS

The mean age was 54±8 years (67% men) and there were 2,423 deaths over a mean 12±3 years follow-up. Among individuals with CAC = 0, cancer was the leading cause of death, with low CVD mortality rates for both younger (40-54 years) 0.2/1,000 person-years and older participants (65-75 years) 1.3/1,000 person-years. When CAC ≥400, CVD was consistently the leading cause of death among younger (71% of deaths) and older participants (56% of deaths). The CAC score at which CVD overtook cancer as the leading cause of death increased exponentially with age and was approximately 115 at age 50 and 380 at age 65.

CONCLUSIONS

Regardless of age, when CAC = 0 cancer was the leading cause of death and the cardiovascular disease mortality rate was low. Our age-specific estimate for the CAC score at which CVD overtakes cancer mortality allows for a more precise approach to synergistic prediction and prevention strategies for CVD and cancer.

Cardiorespiratory Fitness Associates with Cerebral Vessel Pulsatility in a Cohort Enriched with Risk for Alzheimer's Disease

BACKGROUND

There is increasing evidence that vascular disease risk factors contribute to evolution of the dementia syndrome of Alzheimer's disease (AD). One important measure of cerebrovascular health is pulsatility index (PI) which is thought to represent distal vascular resistance, and has previously been reported to be elevated in AD clinical syndrome. Physical inactivity has emerged as an independent risk factor for cardiovascular disease.

OBJECTIVE

This study aims to examine the relationship between a measure of habitual physical activity, cardiorespiratory fitness (CRF), and PI in the large cerebral vessels.

METHODS

Ninety-two cognitively-healthy adults (age = 65.34±5.95, 72% female) enrolled in the Wisconsin Registry for Alzheimer's Prevention participated in this study. Participants underwent 4D flow brain MRI to measure PI in the internal carotid artery (ICA), basilar artery, middle cerebral artery (MCA), and superior sagittal sinus. Participants also completed a self-report physical activity questionnaire. CRF was calculated using a previously-validated equation that incorporates sex, age, body-mass index, resting heart rate, and self-reported physical activity. A series of linear regression models adjusted for age, sex, APOE4 status, and 10-year atherosclerotic cardiovascular disease risk were used to analyze the relationship between CRF and PI.

RESULTS

Inverse associations were found between CRF and mean PI in the inferior ICA (p = .001), superior ICA (p = .035), and basilar artery (p = .040). No other cerebral vessels revealed significant associations between CRF and PI (p≥.228).

CONCLUSIONS

Higher CRF was associated with lower PI in several large cerebral vessels. Since increased pulsatility has been associated with poor brain health and reported in persons with AD, this suggests that aerobic fitness might provide protection against cerebrovascular changes related to the progression of AD clinical syndrome.

Association of Body Mass Index With Coronary Artery Calcium and Subsequent Cardiovascular Mortality: The Coronary Artery Calcium Consortium

BACKGROUND

Obesity is associated with higher risk for coronary artery calcium (CAC), but the relationship between body mass index (BMI) and mortality is complex and frequently paradoxical.

METHODS

We analyzed BMI, CAC, and subsequent mortality using data from the CAC Consortium, a multi-centered cohort of individuals free of established cardiovascular disease (CVD) who underwent CAC testing. Mortality was assessed through linkage to the Social Security Death Index and cause of death from the National Death Index. Multivariable logistic regression was used to determine odds ratios for the association of clinically relevant BMI categories and prevalent CAC. Cox proportional hazards regression modeling was used to determine hazard ratios for coronary heart disease, CVD, and all-cause mortality according to categories of BMI and CAC.

RESULTS

Our sample included 36 509 individuals, mean age 54.1 (10.3) years, 34.4% female, median BMI 26.6 (interquartile range, 24.1-30.1), 46.6% had zero CAC, and 10.5% had CAC ≥400. Compared with individuals with normal BMI, the multivariable adjusted odds of CAC >0 were increased in those overweight (odds ratio, 1.13 [95% CI, 1.1-1.2]) and obese (odds ratio, 1.5 [95% CI, 1.4-1.6]). Over a median follow-up of 11.4 years, there were 1550 deaths (4.3%). Compared with normal BMI, obese individuals had a higher risk of coronary heart disease, CVD, and all-cause mortality while overweight individuals, despite a higher odds of CAC, showed no significant increase in mortality. In a sex-stratified analysis, the increase in coronary heart disease, CVD, and all-cause mortality in obese individuals appeared largely limited to men, and there was a lower risk of all-cause mortality in overweight women (hazard ratio, 0.79 [95% CI, 0.63-0.98]).

CONCLUSIONS

In a large sample undergoing CAC scoring, obesity was associated with a higher risk of CAC and subsequent coronary heart disease, CVD, and all-cause mortality. However, overweight individuals did not have a higher risk of mortality despite a higher risk for CAC.

Coronary Artery Calcium as a Synergistic Tool for the Age- and Sex-Specific Risk of Cardiovascular and Cancer Mortality: The Coronary Artery Calcium Consortium

Background

Coronary artery calcium (CAC) is a predictor for the development of cardiovascular disease (CVD) and to a lesser extent cancer. The age‐ and sex‐specific relationship of CAC with CVD and cancer mortality is unknown.

Methods and Results

Asymptomatic patients aged 40 to 75 years old without known CVD were included from the CAC Consortium. We calculated sex‐specific mortality rates per 1000 person‐years’ follow‐up. Using parametric survival regression modeling, we determined the age‐ and sex‐specific CAC score at which the risk of death from CVD and cancer were equal. Among the 59 502 patients included in this analysis, the mean age was 54.9 (±8.5) years, 34% were women, and 89% were white. There were 671 deaths attributable to CVD and 954 deaths attributable to cancer over a mean follow‐up of 12±3 years. Among patients with CAC=0, cancer was the leading cause of death, the total mortality rate was low (women, 1.8; men, 1.5), and the CVD mortality rate was exceedingly low for women (0.3) and men (0.3). The age‐specific CAC score at which the risk of CVD and cancer mortality were equal had a U‐shaped relationship for women, while the relationship was exponential for men.

Conclusions

The age‐ and sex‐specific relationship of CAC with CVD and cancer mortality differed significantly for women and men. Our age‐ and sex‐specific CAC score provides a more precise estimate and further facilitates the use of CAC as a synergistic tool in strategies for the prediction and prevention of CVD and cancer mortality.

Predictors of coronary artery calcium among 20-30-year-olds: The Coronary Artery Calcium Consortium

BACKGROUND AND AIMS

We sought to understand the risk factor correlates of very early coronary artery calcium (CAC), and the potential investigational value of CAC phenotyping in adults aged 20-30 years.

METHODS

We studied all participants aged 20-30 years at baseline (N = 373) in the Coronary Artery Calcium Consortium, a large multi-center cohort study of patients aged 18 years or older without known atherosclerotic cardiovascular disease (ASCVD) at baseline, referred for CAC scoring for clinical risk stratification. We described the prevalence of CAC in men and women, the frequency of risk factors by the presence of CAC (CAC = 0 vs CAC >0), and assessed the association between traditional non-demographic CVD risk factors (hypertension, hyperlipidemia, smoking, family history of CHD, and diabetes) and prevalent CAC, using age- and sex-adjusted logistic regression models.

RESULTS

The mean age of the study participants was 27.5 ± 2.4 years; 324 (86.9%) had CAC = 0, and 49 (13.1%) had CAC >0. Among the 49 participants with CAC, 38 (77.6%) were men, and median CAC score was low at 4.6. In age- and sex-adjusted models, there was a graded increase in the odds of CAC >0 with increasing traditional cardiovascular disease (CVD) risk factor burden (p = 0.001 for linear trend). Participants with ≥3 traditional risk factors had a statistically significant higher odds of having prevalent CAC (OR 5.57, 95% CI; 1.82-17.03) compared to participants with no risk factors.

CONCLUSIONS

Our study demonstrates the non-negligible prevalence of CAC among very high-risk young US adults, reinforcing the critical importance of traditional risk factors in the earliest development of detectable subclinical ASCVD.

Comparing Risk Scores in the Prediction of Coronary and Cardiovascular Deaths: Coronary Artery Calcium Consortium

OBJECTIVES

This study compared risk discrimination for the prediction of coronary heart disease (CHD) and cardiovascular disease (CVD) deaths for the Pooled Cohort Equations (PCE), the MESA (Multi-Ethnic Study of Atherosclerosis) Risk Score (with and without coronary artery calcium [CAC]), and of simple addition of CAC to the PCE.

BACKGROUND

The PCE predict 10-year risk of atherosclerotic CVD events, and the MESA Risk Score predicts risk of CHD. Their comparative performance for the prediction of fatal events is poorly understood.

METHODS

We evaluated 53,487 patients ages 45 to 79 years from the CAC Consortium, a retrospective cohort study of asymptomatic individuals referred for clinical CAC scoring. Risk discrimination was measured using C-statistics.

RESULTS

Mean age was 57 years, 35% were women, and 39% had CAC of 0. There were 421 CHD and 775 CVD deaths over a mean 12-year follow-up. In the overall study population, discrimination with the MESA Risk Score with CAC and the PCE was almost identical for both outcomes (C-statistics: 0.80 and 0.79 for CHD death, 0.77 and 0.78 for CVD death, respectively). Addition of CAC to the PCE improved risk discrimination, yielding the largest C-statistics. The MESA Risk Score with CAC and the PCE plus CAC showed the best discrimination among the 45% of patients with 5% to 20% estimated risk. Secondary analyses by estimated CVD risk strata showed modestly improved risk discrimination with CAC also among low- and high-estimated risk groups.

CONCLUSIONS

Our findings support the current guideline recommendation to use, among available risk scores, the PCE for initial risk assessment and to use CAC for further risk assessment in a broad borderline and intermediate risk group. Also, in select individuals at low or high estimated risk, CAC modestly improved discrimination. Studies in unselected populations will lead to further understanding of the potential value of tools combining risk scores and CAC for optimal risk assessment.

Validation of the Coronary Artery Calcium Data and Reporting System (CAC-DRS): Dual importance of CAC score and CAC distribution from the Coronary Artery Calcium (CAC) consortium

BACKGROUND

The Coronary Artery Calcium Data and Reporting System (CAC-DRS), which takes into account the Agatston score category (A) and the number of calcified vessels (N) has not yet been validated in terms of its prognostic significance.

METHODS

We included 54,678 patients from the CAC Consortium, a large retrospective clinical cohort of asymptomatic individuals free of baseline cardiovascular disease (CVD). CAC-DRS groups were derived from routine, cardiac-gated CAC scans. Cox proportional hazards regression models, adjusted for traditional CVD risk factors, were used to assess the association between CAC-DRS groups and CHD, CVD, and all-cause mortality. CAC-DRS was then compared to CAC score groups and regional CAC distribution using area under the curve (AUC) analysis.

RESULTS

The study population had a mean age of 54.2 ± 10.7, 34.4% female, and mean ASCVD score 7.3% ± 9.0. Over a mean follow-up of 12 ± 4 years, a total of 2,469 deaths (including 398 CHD deaths and 762 CVD deaths) were recorded. There was a graded risk for CHD, CVD and all-cause mortality with increasing CAC-DRS groups ranging from an all-cause mortality rate of 1.2 per 1,000 person-years for A0 to 15.4 per 1,000 person-years for A3/N4. In multivariable-adjusted models, those with CAC-DRS A3/N4 had significantly higher risk for CHD mortality (HR 5.9 (95% CI 3.6-9.9), CVD mortality (HR4.0 (95% CI 2.8-5.7), and all-cause mortality a (HR 2.5 (95% CI 2.1-3.0) compared to CAC-DRS A0. CAC-DRS had higher AUC than CAC score groups (0.762 vs 0.754, P < 0.001) and CAC distribution (0.762 vs 0.748, P < 0.001).

CONCLUSION

The CAC-DRS system, combining the Agatston score and the number of vessels with CAC provides better stratification of risk for CHD, CVD, and all-cause death than the Agatston score alone. These prognostic data strongly support new SCCT guidelines recommending the use CAC-DRS scoring.

The association of coronary artery calcium score and mortality risk among smokers: The coronary artery calcium consortium

BACKGROUND AND AIMS

Cardiovascular disease (CVD) and cancer are the two leading causes of death in smokers. Lung cancer screening is recommended in a large proportion of smokers. We examined the implication of coronary artery calcium (CAC) score (quantitative and qualitative) for cardiovascular disease (CVD), coronary heart disease (CHD), and cancer mortality risk prediction among current smokers.

METHODS

We included current smokers without known heart disease from the CAC Consortium. Cox regression (for all-cause mortality) and Fine-and-Gray competing-risk regression (for CVD, CHD, and cancer mortality) models, adjusted for traditional CVD risk factors, were used to assess the association between CAC and each mortality outcome, with CAC as a continuous (log2-transformed) or categorical variable (CAC = 0, CAC = 1-99, CAC = 100-399, and CAC ≥400). We used number of vessels with CAC as a surrogate for the qualitative measure of CAC and mortality outcomes. Analyses were repeated for lung cancer screening-eligible population (defined as ever smokers with >30 pack years smoking history) (n = 1,149). Hazard ratios (HR) for all-cause mortality and Subdistribution HRs (sHR) with 95% confidence intervals (CI) were reported.

RESULTS

Over a median of 11.9 years (25th-75th percentile: 10.2-13.3) of follow-up, of 5,147 current smokers (mean age 52.5 ± 9.4, 32.4% women) 337 died (102 of CVD, 54 of CHD, and 123 of cancer). A doubling of CAC score was associated with increased HRs of all-cause mortality (1.10 (1.06-1.14)), and sHRs for CVD (1.15 (1.07-1.24)), CHD (1.26 (1.11-1.42)) and cancer mortality (1.06 (1.00-1.13)). Those with CAC ≥400 had increased sHR of CVD (3.55 (1.70-7.41)), CHD (8.80 (2.41-32.10)), and cancer mortality (1.85 (1.07-3.22)), compared with those with CAC = 0. A diffuse CAC pattern significantly increased the risk of all-cause, CVD, and CHD mortality among smokers. Results were consistent for the lung cancer screening-eligible population.

CONCLUSIONS

Qualitative and quantitative CAC scores can prognosticate risk of all-cause, CVD, CHD, and cancer mortality beyond traditional risk factors among all smokers as well as those eligible for lung cancer screening.

Coronary artery calcium as a predictor of coronary heart disease, cardiovascular disease, and all-cause mortality in Asian-Americans: The Coronary Artery Calcium Consortium

BACKGROUND

Coronary artery calcium (CAC) has been shown in multiple populations to predict atherosclerotic cardiovascular disease. However, its predictive value in Asian-Americans is poorly described.

PATIENTS AND METHODS

We studied 1621 asymptomatic Asian-Americans in the CAC Consortium, a large multicenter retrospective cohort. CAC was modeled in categorical (CAC = 0; CAC = 1-99; CAC = 100-399; CAC ≥ 400) and continuous [ln (CAC + 1)] forms. Participants were followed over a mean follow-up of 12 ± 4 years for coronary heart disease (CHD) death, cardiovascular disease (CVD) death, and all-cause mortality. The predictive value of CAC for individual outcomes was assessed using multivariable-adjusted Cox regression models adjusted for traditional cardiovascular risk factors and reported as hazard ratios (95% confidence interval).

RESULTS

The mean (SD) age of the population was 54 (11.2) years and 64% were men. The mean 10-year atherosclerotic cardiovascular disease risk score was 8%. Approximately half had a CAC score of 0, whereas 22.5% had a CAC score of greater than 100. A total of 56 deaths (16 CVD and 8 CHD) were recorded, with no CVD or CHD deaths in the CAC = 0 group. We noted a significantly increased risk of CHD [hazard ratio (HR): 2.6 (1.5-4.3)] and CVD [HR: 2.3 (1.8-2.9)] mortality per unit increase in In (CAC + 1). Compared to those with CAC scores of 0, individuals with CAC scores of at least 400 had over a three-fold increased risk of all-cause mortality [HR: 3.3 (1.3-8.6)].

CONCLUSION

Although Asian-Americans are a relatively low-risk group, CAC strongly predicts CHD, CVD, and all-cause mortality beyond traditional risk factors. These findings may help address existing knowledge gaps in CVD risk prediction in Asian-Americans.

All-cause and cause-specific mortality in individuals with zero and minimal coronary artery calcium: A long-term, competing risk analysis in the Coronary Artery Calcium Consortium

BACKGROUND AND AIMS

The long-term associations between zero, minimal coronary artery calcium (CAC) and cause-specific mortality are currently unknown, particularly after accounting for competing risks with other causes of death.

METHODS

We evaluated 66,363 individuals from the CAC Consortium (mean age 54 years, 33% women), a multi-center, retrospective cohort study of asymptomatic individuals undergoing CAC scoring for clinical risk assessment. Baseline evaluations occurred between 1991 and 2010.

RESULTS

Over a mean of 12 years of follow-up, individuals with CAC = 0 (45% prevalence, mean age 45 years) had stable low rates of coronary heart disease (CHD) death, cardiovascular disease (CVD) death (ranging 0.32 to 0.43 per 1000 person-years), and all-cause death (1.38-1.62 per 1000 person-years). Cancer was the predominant cause of death in this group, yet rates were also very low (0.47-0.79 per 1000 person-years). Compared to CAC = 0, individuals with CAC 1-10 had an increased multivariable-adjusted risk of CVD death only under age 40. Individuals with CAC>10 had multivariable-adjusted increased risks of CHD death, CVD death and all-cause death at all ages, and a higher proportion of CVD deaths.

CONCLUSIONS

CAC = 0 is a frequent finding among individuals undergoing CAC scanning for risk assessment and is associated with low rates of all-cause death at 12 years of follow-up. Our results support the emerging consensus that CAC = 0 represents a unique population with favorable all-cause prognosis who may be considered for more flexible treatment goals in primary prevention. Detection of any CAC in young adults could be used to trigger aggressive preventive interventions.

Role of Coronary Artery Calcium for Stratifying Cardiovascular Risk in Adults With Hypertension

We examined the utility of coronary artery calcium (CAC) for cardiovascular risk stratification among hypertensive adults, including those fitting eligibility for SPRINT (Systolic Blood Pressure Intervention Trial). Additionally, we used CAC to identify hypertensive adults with cardiovascular disease (CVD) mortality rates equivalent to those observed in SPRINT who may, therefore, benefit from the most intensive blood pressure therapy. Our study population included 16 167 hypertensive patients from the CAC Consortium, among whom 6375 constituted a "SPRINT-like" population. We compared multivariable-adjusted hazard ratios of coronary heart disease and CVD deaths by CAC category (0, 1-99, 100-399, ≥400). Additionally, we generated a CAC-CVD mortality curve for patients aged >50 years to determine what CAC scores were associated with CVD death rates observed in SPRINT. Mean age was 58.1±10.6 years. During a mean follow-up of 11.6±3.6 years, there were 409 CVD deaths and 207 coronary heart disease deaths. Increasing CAC scores were associated with increased coronary heart disease and CVD mortality (coronary heart disease-CAC 100-399: hazard ratio [95% CI] 1.88 [1.04-3.40], CAC ≥400: 4.16 [2.34-7.39]; CVD-CAC 100-399: 1.93 [1.31-2.83], CAC ≥400: 3.51 [2.40-5.13]). A similar increased risk was observed across 10-year atherosclerotic CVD risk categories and in the SPRINT-like population. A CAC score of 220 (confidence range, 165-270) was associated with the CVD mortality rate observed in SPRINT. CAC risk stratifies adults with hypertension, including those who are SPRINT eligible. A CAC score of 220 can identify hypertensive adults with SPRINT-level CVD mortality risk and, therefore, may be reasonable for identifying candidates for aggressive blood pressure therapy.

Interplay of Coronary Artery Calcium and Risk Factors for Predicting CVD/CHD Mortality: The CAC Consortium

OBJECTIVES

This study sought to evaluate the association and burden of coronary artery calcium (CAC) with long-term, cause-specific mortality across the spectrum of baseline risk.

BACKGROUND

Although CAC is a known predictor of short-term, all-cause mortality, data on long-term and cause-specific mortality are inadequate.

METHODS

The CAC Consortium cohort is a multicenter cohort of 66,636 participants without coronary heart disease (CHD) who underwent CAC testing. The following risk factors (RFs) were considered: 1) current cigarette smoking; 2) dyslipidemia; 3) diabetes mellitus; 4) hypertension; and 5) family history of CHD.

RESULTS

During the 12.5-years median follow-up, 3,158 (4.7%) deaths occurred; 32% were cardiovascular disease (CVD) deaths. Participants with CAC scores ≥400 had a significantly increased risk for CHD and CVD mortality (hazard ratio [HR]: 5.44; 95% confidence interval [CI]: 3.88 to 7.62; and HR: 4.15; 95% CI: 3.29 to 5.22, respectively) compared with CAC of 0. Participants with ≥3 RFs had a smaller increased risk for CHD and CVD mortality (HR: 2.09; 95% CI: 1.52 to 2.85; and HR: 1.84; 95% CI: 1.46 to 2.31, respectively) compared with those without RFs. Across RF strata, CAC added prognostic information. For example, participants without RFs but with CAC ≥400 had significantly higher all-cause, non-CVD, CVD, and CHD mortality rates compared with participants with ≥3 RFs and CAC of 0.

CONCLUSIONS

Across the spectrum of RF burden, a higher CAC score was strongly associated with long-term, all-cause mortality and a greater proportion of deaths due to CVD and CHD. Absence of CAC identified people with a low risk over 12 years of follow-up, with most deaths being non-CVD in nature, regardless of RF burden.