Utility Of Coronary Artery Calcium Research Articles

Prognostic importance of extensive coronary calcium on lung cancer screening chest computed tomography.

Low-dose chest computed tomography (CT) is used for lung cancer screening, but can also detect coronary artery disease as coronary artery calcium. We sought to determine the prevalence and prognostic utility of coronary artery calcium in a population at high risk of cancer. We reviewed CT scans from consecutive participants screened for lung cancer between March 2017 and November 2018 as part of the Ontario Health Lung Cancer Screening Pilot for People at High Risk. We quantified coronary artery calcium using an estimated Agatston score. We identified the composite primary outcome of all-cause death and cardiovascular events using linked electronic medical record data from The Ottawa Hospital to December 2023. Among 1486 people who underwent screening CT, coronary artery calcium was detected in 1232 (82.9%) and was extensive in 439 (29.5%). On multivariable analysis, extensive coronary artery calcium was associated with the composite primary outcome (hazard ratio [HR] 2.13, 95% confidence interval [CI] 1.35-3.38), all-cause death (HR 2.39, 95% CI 1.34-4.27), and cardiovascular events (HR 2.06, 95% CI 1.13-3.77). Extensive coronary artery calcium remained predictive of cardiovascular events after we adjusted for noncardiovascular death as a competing risk (HR 2.05, 95% CI 1.09-3.85). Among people undergoing low-dose chest CT for lung cancer screening, extensive coronary artery calcium was an independent predictor of all-cause death and cardiovascular events, even after adjustment for noncardiovascular death. The opportunity to identify and reduce risks from coronary artery disease may represent an additional benefit of lung cancer screening.

Utility of coronary artery calcium in refining 10-year ASCVD risk prediction using a Thai CV risk score.

Coronary artery calcium (CAC) scanning is a valuable additional tool for calculating the risk of cardiovascular (CV) events. We aimed to determine if a CAC score could improve performance of a Thai CV risk score in prediction of 10-year atherosclerotic cardiovascular disease (ASCVD) risk for asymptomatic patients with CV risk factors. This was a retrospective cohort study that enrolled asymptomatic patients with CV risk factors who underwent CAC scans between 2005 and 2013. The patients were classified as low-, intermediate-, or high-risk (<10%, 10%-<20%, and ≥20%, respectively) of having ASCVD within 10-years based on a Thai CV risk score. In each patient, CAC score was considered as a categorical variable (0, 1-99, and ≥100) and natural-log variable to assess the risk of developing CV events (CV death, non-fatal MI, or non-fatal stroke). The C statistic and the net reclassification improvement (NRI) index were applied to assess whether CAC improved ASCVD risk prediction. A total of 6,964 patients were analyzed (mean age: 59.0 ± 8.4 years; 63.3% women). The majority of patients were classified as low- or intermediate-risk (75.3% and 20.5%, respectively), whereas only 4.2% were classified as high-risk. Nearly half (49.7%) of patients had a CAC score of zero (no calcifications detected), while 32.0% had scores of 1-99, and 18.3% of ≥100. In the low- and intermediate-risk groups, patients with a CAC ≥100 experienced higher rates of CV events, with hazard ratios (95% CI) of 1.95 (1.35, 2.81) and 3.04 (2.26, 4.10), respectively. Incorporation of ln(CAC + 1) into their Thai CV risk scores improved the C statistic from 0.703 (0.68, 0.72) to 0.716 (0.69, 0.74), and resulted in an NRI index of 0.06 (0.02, 0.10). To enhance the performance of the Thai CV risk score, a revision of the CV risk model was performed, incorporating ln(CAC + 1), which further increased the C statistic to 0.771 (0.755, 0.788). The addition of CAC to traditional risk factors improved CV risk stratification and ASCVD prediction. Whether this adjustment leads to a reduction in CV events and is cost-effective will require further assessment.

Coronary artery calcium and atherosclerotic cardiovascular disease risk in women with early menopause: The Multi-Ethnic Study of Atherosclerosis (MESA)

Background and AimsWe aimed to determine the utility of coronary artery calcium (CAC) for atherosclerotic cardiovascular disease (ASCVD) risk stratification in women with and without early menopause (EM). MethodsTo examine the association between CAC and incident ASCVD, we performed Kaplan-Meier survival analysis and multivariable Cox proportional hazards modeling using data from 2,456 postmenopausal women in the Multi-Ethnic Study of Atherosclerosis (MESA) with or without EM, defined as occurring at <45 years of age. ResultsThe cohort was 64.1 ± 9.1 years old and 28.0% experienced EM. There were 291 ASCVD events over 12.5 ± 3.6 year follow-up with a higher event rate among those with EM compared to those without EM of 13.6 vs. 9.0 per 1,000 year follow-up (p < 0.01). Women with EM had a slightly lower prevalence of CAC = 0 (55.1%) than women without EM (59.7%) (p = 0.04) despite no difference in mean age. Among women with CAC = 0, the cumulative incidence of ASCVD at 10 years was low-to-borderline for women with (5.4%) and without EM (3.2%) (p = 0.06). However, women with EM had a significantly higher 15-year risk with an adjusted HR of 1.96 (95% CI: 1.26–3.04). In multivariable Cox models, women with CAC ≥ 1 had progressively increased ASCVD risk that did not significantly differ by EM status. ConclusionIn MESA, >50% of middle-aged postmenopausal women with EM had CAC = 0, similar to those without EM. Among women with CAC = 0, those with EM had a low to borderline 10-year risk of ASCVD, but the 15-year risk was significantly higher for women with EM versus those without EM. When CAC ≥ 1, the incidence of ASCVD was similar for women with and without EM. These findings support the use of CAC to help improve ASCVD risk stratification in women with EM. Condensed abstractThis study investigated the association between coronary artery calcium (CAC) and incident atherosclerotic cardiovascular disease (ASCVD) in postmenopausal women with and without early menopause (EM). We found that >50% of women had CAC = 0 and an associated low-to-borderline 10-year cumulative incidence of ASCVD. However, the risk for ASCVD was significantly higher for women with EM after 15-years follow-up. Additional research is needed to better understand the differences in long-term ASCVD risk between women with and without EM who have CAC = 0.

Coronary Artery Calcium for Risk Assessment in Young Adults.

To review the prognostic significance and clinical utility of coronary artery calcium (CAC) for risk assessment for atherosclerotic cardiovascular disease (ASCVD) in younger adults. Data from over 3000 young adults (mean age of 40.3 ± 3.6 followed for 12.5years) in the CARDIA registry found that in an asymptomatic, community representative sample, there was a low prevalence of CAC (~ 10%) but those with CAC had an exponential increase in CAC over time and significantly higher rates of ASCVD events. Alternatively, data from the CAC consortium analyzed 22,346 asymptomatic individuals undergoing CAC for clinical indications (mean age 43.5 ± 4.5years, followed for 13 ± 4years) and found a much higher prevalence of CAC at 34% with rates of coronary heart disease mortality that varied significantly according to CAC. In younger adults, CAC provides clear prognostic value and can be considered in select individuals with uncertainties about their ASCVD risk or the benefit of preventive therapies.

Abstract 16627: Coronary Artery Calcium Scoring and Cardiovascular Events in Patients With Cancer: Analysis of CLARIFY Registry

Introduction: Cardiovascular disease and cancer co-exist due to shared risk factors. The utility of coronary artery calcium (CAC) scoring in this population to predict cardiovascular events is not certain. Methods: We studied all patients enrolled in the CLARIFY registry of no-charge CAC (Clinicaltrials.gov NCT04075162) with diagnosis of any cancer. We followed patients for major adverse cardiovascular events (myocardial infarction, stroke, heart failure, coronary revascularization or mortality). Results: A total of 3,432 patients with cancer were identified. Mean age was 64±9 years, 1965 (57%) were women and 2937 (86%) were white. Overall distribution of CAC scores were as follows: CAC 0 in 35%, CAC 1-99 in 31%, CAC 100-399 in 20%, and CAC ≥ 400 in 15%. CAC distribution varied by cancer type (figure A). At a median follow-up of 663 [294-1086] days, 343 patients had MACE event. Compared with CAC 0, patients with CAC ≥ 400 had increased unadjusted risk of MACE (HR 2.57 [1.93-3.41], P&lt;0.001), which was not attenuated after adjusting for age and sex (HR 2.09 [1.50-2.90], P&lt;0.001). Conclusions: In this large cohort of patients with cancer, coronary artery atherosclerotic calcifications are common, vary by cancer type, and are associated with major adverse cardiovascular events, independently of age and sex. Further research should focus on utility of routine CAC for cardiovascular risk stratification in patients with cancer.

Abstract 13711: Coronary Artery Calcium, Ankle-brachial Index, High Sensitivity C-reactive Protein, and a Family History of Coronary Artery Disease as Predictors of Incident Cardiovascular Events at Different Stages of Hypertension: The Multi-ethnic Study of Atherosclerosis

Background: Coronary artery calcium (CAC), ankle-brachial index (ABI), high-sensitivity CRP (hsCRP), and family history (FHx) of coronary artery disease (CAD) are used as complementary aids in cardiac risk stratification. The 2017 ACC/AHA hypertension guideline’s new Stage I hypertension group has created uncertainty regarding intensity of blood pressure (BP) treatment in this group. We evaluated the comparative utility of CAC, ABI, hsCRP and FHx CAD as risk predictors of cardiovascular (CVD) events within different BP strata. Methods: The MESA cohort was followed for a median of 13 years with regards to incident coronary heart disease (CHD) and CVD events. BP was categorized per ACC/AHA guideline: normal- &lt;120/&lt;80, elevated 120-129/&lt;80, stage I 130-139/80-89, and stage II ≥140/≥90. Participants on BP medications were assigned stage II. Cox regression was used to compare prediction of CHD and CVD events by CAC&gt;300, CAC&gt;75 t h %, ABI&lt;0.9, hsCRP&gt;2 mg/L and FHx CAD, stratifying by BP groups after adjusting for demographics, CVD risk factors and use of BP and cholesterol medications. Results: Of 6268 persons, 539 incident CHD events and 572 incident CVD events were noted. CAC&gt;300 and CAC&gt;75 th % predicted an increased CHD event risk throughout all BP groups. ABI&lt;0.9 was predictive of CHD events in stage I and II, while hsCRP was not predictive in any group. CAC&gt;300 predicted a 2-fold increased CVD risk in all BP groups after adjustment. In the Stage I group, CAC&gt;300, CAC&gt;75 th % and ABI&lt;0.9 showed additive predictive value in incident CHD and CVD events. Using the adjusted model to predict CHD survival, CAC&gt;300 had a consistently higher C-statistic throughout all BP categories compared to other risk markers. Conclusion: CAC&gt;300 was associated with increased CHD and CVD risk in all BP groups and demonstrated superior prognostic utility compared to other risk markers. CAC&gt;300, CAC&gt;75 th % and ABI&lt;0.9 showed potential as risk modifiers in the new Stage I hypertension group.

The utility of coronary artery calcium in non-gated high resolution CT thorax scans in predicting cardiac events as compared to the Framingham risk score: a retrospective study

Abstract Background There is existing evidence to suggest a correlation between coronary artery calcification (CAC) measured using ECG-triggered chest computed tomography and cardiovascular disease. Further evidence has emerged to suggest a correlation between CAC measured using non-gated CT scans and cardiovascular disease. Herein, we sought to ascertain the utility of incidental findings of CAC on non-triggered high resolution CT (HRCT) thorax used for patients undergoing lung cancer screening or follow-up for interstitial lung disease and Framingham risk score (FRS) in predicting cardiovascular events. Methods The Computerised Radiology Information Service (CRIS) database was manually searched to determine all HRCT scans performed in a single trust from 05/2015 to 05/2016. The reports issued by Radiologists and images of selected studies were reviewed. For patients with CAC, we calculated the calcium score for patients using the Agatston method. Clinical events were determined from the electronic medical record without knowledge of patients' CAC findings. For these patients, the Framingham Risk Score (FRS) was also calculated. The primary end point of the study was composite of all-cause mortality and cardiac events (non-fatal myocardial infarction, coronary revascularization, new atrial fibrillation or heart failure episode requiring hospitalization). Results We selected 300 scans from a total of approximately 2000 scans performed over this time. Data at follow up was available for 100% of the patients, with a median duration of follow up of 1.6 years. Moderate to severe CAC was found in 35% of people. Multivariable analysis showed good concordance between CAC and FRS in predicting composite clinical end point. The Odds Ratio for cardiac events in patients with moderate to severe CAC was 5.3 (p&amp;lt;0.01) and for composite clinical end point was 3.4 (p&amp;lt;0.01). This is similar to the OR predicted by the FRS: 4.8; p&amp;lt;0.01 and 3.1; p&amp;lt;0.01 respectively. Only 6.2% of patients with moderate to severe CAC were currently statin treated. Conclusion In this retrospective study of patients with respiratory disease attending for HRCT scanning, co-incidentally detected CAC predicts cardiac events, with good concordance with the FRS. The incidental finding of CAC on non-gated CT scanning should be reported with Agatston score calculation allowing consideration of intervention to mitigate cardiovascular risk and optimize. Further multi-centre prospective studies of this strategy, with a larger patient cohort should be conducted to clarify the utility of CAC as a prediction tool to modify cardiac risk. Funding Acknowledgement Type of funding source: None

Coronary artery calcium progresses rapidly and discriminates incident cardiovascular events in chronic kidney disease regardless of diabetes: The Multi-Ethnic Study of Atherosclerosis (MESA)

Background and aimsChronic kidney disease (CKD) is associated with high prevalence of cardiovascular disease (CVD) events. We sought to assess the prognostic utility of coronary artery calcium (CAC) scores in discriminating incident CVD events among subpopulations of CKD, particularly those without diabetes mellitus (DM). MethodsUsing the Multi-Ethnic Study of Atherosclerosis, we identified 4 groups based on present/absent CKD/diabetes (CKD-/DM-, n = 5308; CKD-/DM+, n = 586, CKD+/DM-, n = 620; CKD+/DM+, n = 266). Baseline and follow-up CAC (Agatston units) measurements, and association between CAC and incident CVD events in median follow-up of 13 years were evaluated using proportional hazards regression adjusting for demographics, clinical, biomarker variables. ResultsPrevalence of CKD and DM in the cohort was 13% and 12.5% respectively. Annual progression in adjusted median CAC score was 24.8%, 27.9%, 26.7%, 36.8% and unadjusted cumulative incident CVD rates were 12.6%, 22.3%, 23.1%, 39.8% for CKD-/DM-, CKD-/DM+, CKD+/DM-, CKD+/DM+, respectively. After full adjustment (CKD-/DM-referent), hazard ratios (HR, 95% CI) for incident CVD events were 1.25 (1.01–1.53) CKD-/DM+, 1.10 (0.90–1.33) CKD+/DM- and 2.18 (1.73–2.76) CKD+/DM+. Using CKD-/DM-/baseline CAC = 0 referent, adjusted HRs (95% CI) for incident CVD in CKD+/DM- were 1.30 (0.81–2.07), 2.05 (1.4–2.99), and 4.15 (2.94–5.86) for baseline CAC = 0, 1–100, and >300 Agatston units respectively while for CKD+/DM+, adjusted HRs were 3.15 (2.04–4.86), 3.56 (2.26–5.62), 7.90 (5.35–11.67), respectively. ConclusionsCAC provides incremental prognostic information to predict incident CVD events in CKD regardless of DM. Moreover, baseline CAC categories discriminate incident CVD among CKD without DM, which may have implications in individualizing approach to primary prevention in this high-risk population.

CORONARY ARTERY CALCIUM SCORE AND CARDIOVASCULAR OUTCOMES IN PATIENTS WITH MILD TO MODERATE CHRONIC KIDNEY DISEASE INSIGHTS FROM CLARIFY

Chronic kidney disease (CKD) is associated with increased risk of cardiovascular disease. Current cardiovascular risk scores are not well validated in patients with CKD. We sought to study the utility of coronary artery calcium (CAC) scoring in risk stratification of patients with CKD. Community

Utility of Coronary Artery Calcium Score for Coronary Artery Disease Screening among Severely Ill Liver Transplant Candidates: Case Series

Noninvasive cardiac stress testing is essential to screen liver transplant (LT) candidates for the presence of coronary artery disease (CAD). However, cardiac stress testing may not be clinically feasible in some patients, especially among those who require intensive care for an extended period of time, before being listed for LT. The utility of coronary artery calcium (CAC) score as a potential noninvasive screening test for CAD in place of cardiac stress testing among critically ill intensive care unit (ICU)-bound LT recipients has not been well studied. We report 4 LT recipients who were screened for CAD only with CAC score before listing for LT. Our results suggest that CAC score may be a useful test to screen for CAD in severely ill ICU-bound LT recipients with low risk for coronary heart disease, who are not candidates for cardiac stress testing. Such recipients requiring intensive care, with CAC score of 0A may safely forgo cardiac stress testing prior to LT. Future prospective studies with a bigger sample size and longer follow-up would be helpful to validate our findings.

Coronary Artery Calcification, Statin Use and Long-Term Risk of Atherosclerotic Cardiovascular Disease Events (from the Multi-Ethnic Study of Atherosclerosis)

The prognostic utility of coronary artery calcium (CAC) for individuals taking statins is unclear. We hypothesized that CAC remains associated with atherosclerotic cardiovascular disease (ASCVD) events in individuals using statins at baseline or among those started on statin at follow-up. The Multi-Ethnic Study of Atherosclerosis is a prospective cohort study of 6,814 participants who were enrolled between 2000 and 2002 and were free of clinical ASCVD at baseline. Four follow-up visits were conducted in 2002 to 2004, 2004 to 2006, 2005 to 2007, and 2010 to 2012. CAC was assessed at baseline and follow-up using either an electron-beam CT scanner or a multidetector CT system. Statin use at baseline and follow up was self-reported. Among 6,811 participants with complete information on statin use, mean age was 62 (SD = 10) years, 53% were women, 38% white, 12% Chinese-American, 28% African American, and 22% Hispanic. In multivariable analyses, CAC >0 was associated with a significantly higher risk of ASCVD events regardless of baseline or incident statin use. For example, hazard ratios (95% confidence interval) for the association between CAC >0 and ASCVD were 2.46 (1.41, 4.28) for baseline statin users, 2.08 (1.68, 2.57) for baseline-statin nonusers, and 2.21 (1.56, 3.15) for those started on a statin at follow-up. In conclusion, current statin use does not weaken the prognostic utility of CAC. CAC is associated with incident ASCVD regardless of baseline or incident statin use.

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.

Coronary Artery Calcium Scoring: a Valuable Aid in Shared Decision Making Among Non-traditional Risk Markers

Purpose of the Review The purpose of this study was to evaluate the utility of coronary artery calcium (CAC) scoring and compare it with other non-traditional cardiovascular risk markers for improvement in cardiovascular risk assessment.

Abstract 17258: Incremental Value of Coronary CT Angiography over Calcium Score in Predicting Intermediate-Term Outcomes and Resource Utilization

Background: Prognostic utility of coronary artery calcium (CAC) is well-established. The incremental value of CAD severity assessed by coronary CT angiography (CCTA) over CAC is not well known. Methods: This retrospective analysis included patients who underwent CAC + CCTA at our institution and had complete 2-year follow-up. The study group was divided into four: CAC ≤400 + stenosis ≤50% (Group I), CAC ≤400 + stenosis &gt;50% (Group II), CAC &gt;400 + stenosis ≤50% (Group III) and CAC &gt;400 + stenosis &gt;50% (Group IV). Baseline demographics and 2-year follow-up data were compared among the groups for downstream major adverse cardiac events (MACE) (death, acute coronary syndromes and revascularization) and total resource utilization (CAD-related hospitalizations and emergency department (ED) evaluations, stress testing, invasive coronary angiography (ICA) and surgical or percutaneous revascularization). Results: The study group included 1496 patients (mean age 56 ± 12 years, 54% males) who underwent CAC and CCTA. Distribution among the four groups were: Group I = 1092 (73%), Group II = 236 (15.7%), Group III = 102 (6.8%) and Group IV = 66 (4.4%). Patients in Groups II and IV (stenosis &gt;50%) were more frequently male, older, diabetic, hypertensive and dyslipidemic (all p&lt;0.0001). At 2 years, patients in Groups II and IV had higher rates of MACE as well as resource utilization (p&lt;0.0001). On stepwise multivariable analysis of Framingham Risk Score, additional risk factors (peripheral, cerebrovascular and chronic obstructive lung disease), symptoms, CAC and CCTA findings, stenosis &gt;50% on CCTA alone was the strongest predictor of MACE and resource utilization, with significant incremental value over the combined effect of all clinical variables and CAC (Figure). Conclusions: CAD severity assessed by CCTA provides significant and incremental value over clinical risk scoring and CAC for predicting MACE and resource utilization at intermediate-term follow-up.

Detection of silent coronary artery disease by computed tomographic scan

Multislice computerized tomographic scan can identify coronary artery disease (CAD) with quantification of coronary artery calcium (CAC) and computed tomographic coronary angiography (CTA). The utility of CAC in comparison with CTA in asymptomatic patients has not been assessed. Patients with risk factors for CAD, who were referred for screening, were studied using CAC and CTA, using a Phillips Mx8000 IDT 16 multislice computed tomographic scanner. Three hundred and forty-seven patients with a mean age of 55 years, 89.9% male, were included. CAC showed calcium deposits in 171 patients (49.3%) whereas CTA found lesions in 157 patients (45%). CAC correctly identified 309 patients with respect to CTA (presence of any disease) implying a test accuracy of 89%, sensitivity of 85%, specificity of 86%, and negative predictive value of 93%. Obstructive lesions were shown by 7.7% of the patients (stenosis >50%), 22% of the patients with CAC greater than 400, and 2.8% of the patients with CAC of 0. To undergo a CTA scan after CAC permits to re-classify 11% of the patients on the basis of CTA. CAC, in detecting silent CAD, seems to be a good alternative to CTA, in these asymptomatic patients, but CAC is inappropriate to predict the presence or absence of a coronary artery obstruction.

Coronary Artery Calcium to Predict All-Cause Mortality in Elderly Men and Women

We sought to study the prognostic utility of coronary artery calcium (CAC) in the elderly. The prognostic significance of CAC in the elderly is not well known. All-cause mortality was assessed in 35,388 patients (3,570 were >or=70 years old at screening, and 50% were women) after a mean follow-up of 5.8 +/- 3 years. In older patients, risk factors and CAC were more prevalent. Overall survival was 97.9% at the end of follow-up. Mortality increased with each age decile with a relative hazard of 1.09 (95% confidence interval: 1.08 to 1.10, p < 0.0001), and rates were greater for men than women (hazard ratio: 1.53; 95% confidence interval: 1.32 to 1.77, p < 0.0001). Increasing CAC scores were associated with decreasing survival across all age deciles (p < 0.0001). Survival for a <40-year and >or=80-year-old man with a CAC score >or=400 was 88% and 19% (95% and 44% for a woman, p < 0.0001), respectively. Among the 20,562 patients with no CAC, annual mortality rates ranged from 0.3% to 2.2% for patients age 40 to 49 years or >or=70 years (p < 0.0001). The use of CAC allowed us to reclassify more than 40% of the patients >or=70 years old more often by excluding risk (i.e., CAC <400) in those with >3 risk factors. Despite their limited life expectancy, the use of CAC discriminates mortality risk in the elderly. Furthermore, the use of CAC allows physicians to reclassify risk in the elderly.

All High-Risk Patients Should Not Be Screened With Computed Tomographic Angiography

On the basis of the most recent American Heart Association/American College of Cardiology guidelines for assessment of cardiac risk,1 high-risk patients are defined as those with a 10-year coronary heart disease risk of >20% based on Framingham risk criteria or the presence of diabetes mellitus. The major independent risk factors for coronary heart disease comprising the Framingham Risk Score are cigarette smoking, hypertension, elevated total cholesterol and low-density lipoprotein cholesterol, low serum high-density lipoprotein cholesterol, diabetes mellitus, advanced age, and male gender.1 Derived from National Health and Nutrition Examination Survey statistics from 1999 to 2000,2 the prevalence of risk factors in patients aged 20 to 74 years is 17% for total cholesterol ≥240 mg/dL, 14.9% for hypertension, 26.4% for smoking, and 8% for diabetes (including undiagnosed). Data from the 2003 Behavioral Risk Factor Surveillance System survey of 103 191 adults aged >18 years3 show that >37% of the population surveyed had ≥2 risk factors for coronary heart disease and thus are considered to be at high risk. These figures together suggest that the number of high-risk patients who are potential candidates for screening programs is quite high. Response by Gottlieb p 1339 Multiple studies over the last 2 decades have confirmed the prognostic utility of coronary artery calcium (CAC) measurements primarily with electron-beam computed tomography (EBCT) and more recently with multidetector CT (MDCT) technology (Figures 1 and 2⇓). The 2 techniques are fairly equivalent as long as the latter is performed with at least a 4-detector scanner.4,5 The reproducibility of MDCT, however, may not be as good as EBCT at lower calcium scores.4 Figure 1. Noncontrast ECG-gated CT for CAC scoring in a single axial plane demonstrating dense calcification of the left anterior descending artery. Figure 2. Noncontrast ECG-gated CT for CAC scoring …