Abstract Background The transition from no coronary artery calcium (CAC) to detectable CAC is important, as even mild CAC is associated with increased cardiovascular events. We sought to characterize ...the anatomic distribution and burden of newly detectable CAC over 10-year follow-up. Methods We evaluated 3112 participants (mean age, 58 years; 64% female) with baseline CAC = 0 from the Multi-Ethnic Study of Atherosclerosis. Participants underwent repeat CAC testing at different time intervals (between 2–10 years after baseline) per the Multi-Ethnic Study of Atherosclerosis protocol. Among participants who developed CAC on a follow-up scan, we used logistic regression and marginal probability modeling to describe the coronary distribution and burden of new CAC by age, sex, and race after adjustment for cardiovascular risk factors and time to detection. Results A total of 1125 participants developed detectable CAC during follow-up with a mean time to detection of 6.1 ± 3 years. New CAC was most commonly isolated to 1 vessel (72% of participants), with the left anterior descending artery (44% of total) most commonly affected followed by the right coronary (12%), left circumflex (10%), and left main (6%). These patterns were similar across age, sex, and race. In multivariate models, residual predictors of multivessel CAC (28% of total) included male sex, African American or Hispanic race, hypertension, obesity, and diabetes. At the first detection of CAC >0, burden was usually low with median Agatston CAC score of 7.1 and <5% with CAC scores >100. Conclusion New-onset CAC most commonly involves just 1 vessel, occurs in the left anterior descending artery, and has low CAC burden. New CAC can be detected at an early stage when aggressive preventive strategies may provide benefit.
Abstract Objectives The goal of this study was to determine the long-term prognostic value of coronary computed tomography angiography (CTA) among patients with diabetes mellitus (DM) compared with ...nondiabetic subjects. Background The long-term prognostic value of coronary CTA in patients with DM is not well established. Methods Patients enrolled in the CONFIRM (Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter) registry with 5-year follow-up data were identified. The extent and severity of coronary artery disease (CAD) were analyzed at baseline coronary CTA and in relation to outcomes between diabetic and nondiabetic patients. CAD according to coronary CTA was defined as none (0% stenosis), nonobstructive (1% to 49% stenosis), or obstructive (≥50% stenosis). Time to death (and in a subgroup, time to major adverse cardiovascular event) was estimated by using multivariable Cox proportional hazards models. Results A total of 1,823 patients were identified as having DM with 5-year clinical follow-up and were propensity-matched to 1,823 patients without DM (mean age 61.8 ± 10.9 years; 54.4% male). Patients with DM did not exhibit a heightened risk of death compared with the propensity-matched nondiabetic subjects in the absence of CAD on coronary CTA (risk-adjusted hazard ratio HR of DM: 1.32; 95% confidence interval CI: 0.78 to 2.24; p = 0.296). Patients with DM were at increased risk of dying compared with nondiabetic subjects in the setting of nonobstructive CAD (in the propensity-matched cohort: HR, 2.10; 95% CI: 1.43 to 3.09; p < 0.001) with a mortality risk greater than nondiabetic subjects with obstructive disease (p < 0.001). In a risk-adjusted hazard analysis among patients with DM, both per-patient obstructive CAD and nonobstructive CAD conferred an increase in all-cause mortality risk compared with patients without atherosclerosis on coronary CTA (nonobstructive disease—HR: 2.07; 95% CI: 1.33 to 3.24; p = 0.001; obstructive disease—HR: 2.22; 95% CI: 1.47 to 3.36; p < 0.001). Conclusions Among patients with DM, nonobstructive and obstructive CAD according to coronary CTA were associated with higher rates of all-cause mortality and major adverse cardiovascular events at 5 years, and this risk was significantly higher than in nondiabetic subjects. Importantly, patients with DM without CAD according to coronary CTA were at a risk comparable to that of nondiabetic subjects.
Abstract Background The American College of Cardiology (ACC)/American Heart Association (AHA) cholesterol management guidelines have significantly broadened the scope of candidates eligible for ...statin therapy. Objectives This study evaluated the implications of the absence of coronary artery calcium (CAC) in reclassifying patients from a risk stratum in which statins are recommended to one in which they are not. Methods MESA (Multi-Ethnic Study of Atherosclerosis) is a longitudinal study of 6,814 men and women 45 to 84 years of age without clinical atherosclerotic cardiovascular disease (ASCVD) risk at enrollment. We excluded 1,100 participants (16%) on lipid-lowering medication, 87 (1.3%) without low-density lipoprotein levels, 26 (0.4%) with missing risk factors for calculation of 10-year risk of ASCVD, 633 (9%) >75 years of age, and 209 (3%) with low-density lipoprotein <70 mg/dl from the analysis. Results The study population consisted of 4,758 participants (age 59 ± 9 years; 47% males). A total of 247 (5.2%) ASCVD and 155 (3.3%) hard coronary heart disease events occurred over a median (interquartile range) follow-up of 10.3 (9.7 to 10.8) years. The new ACC/AHA guidelines recommended 2,377 (50%) MESA participants for moderate- to high-intensity statins; the majority (77%) was eligible because of a 10-year estimated ASCVD risk ≥7.5%. Of those recommended statins, 41% had CAC = 0 and had 5.2 ASCVD events/1,000 person-years. Among 589 participants (12%) considered for moderate-intensity statin, 338 (57%) had a CAC = 0, with an ASCVD event rate of 1.5 per 1,000 person-years. Of participants eligible (recommended or considered) for statins, 44% (1,316 of 2,966) had CAC = 0 at baseline and an observed 10-year ASCVD event rate of 4.2 per 1,000 person-years. Conclusions Significant ASCVD risk heterogeneity exists among those eligible for statins according to the new guidelines. The absence of CAC reclassifies approximately one-half of candidates as not eligible for statin therapy.
Ethnic Differences in the Prognostic Value of Coronary Artery Calcification for All-Cause Mortality Khurram Nasir, Leslee J. Shaw, Sandy T. Liu, Steven R. Weinstein, Tristen R. Mosler, Phillip R. ...Flores, Ferdinand R. Flores, Paolo Raggi, Daniel S. Berman, Roger S. Blumenthal, Matthew J. Budoff The aim of the current study was to evaluate the prognostic value of coronary artery calcium (CAC) in a large ethnically diverse cohort of 14,812 patients followed for a mean of 6.8 years (range 0.7 to 14.5 years).When comparing prognosis by CAC scores in ethnic minorities with non-Hispanic whites, relative risk ratios were highest for African Americans with CAC scores ≥400 exceeding 16.1 (p < 0.0001). Hispanics with CAC scores ≥400 had relative risk ratios from 7.9 to 9.0, whereas Asians with CAC scores ≥1,000 had relative risk ratios 6.6-fold higher than non-Hispanic whites (p < 0.0001). Increasing CAC burden was associated with greater mortality in all ethnic/racial groups.
Objectives This study sought to examine patterns of follow-up invasive coronary angiography (ICA) and revascularization (REV) after coronary computed tomography angiography (CCTA). Background CCTA is ...a noninvasive test that permits direct visualization of the extent and severity of coronary artery disease (CAD). Post-CCTA patterns of follow-up ICA and REV are incompletely defined. Methods We examined 15,207 intermediate likelihood patients from 8 sites in 6 countries; these patients were without known CAD, underwent CCTA, and were followed up for 2.3 ± 1.2 years for all-cause mortality. Coronary artery stenosis was judged as obstructive when ≥50% stenosis was present. A multivariable logistic regression was used to estimate ICA use. A Cox proportional hazards model was used to estimate all-cause mortality. Results During follow-up, ICA rates for patients with no CAD to mild CAD according to CCTA were low (2.5% and 8.3%), with similarly low rates of REV (0.3% and 2.5%). Most ICA procedures (79%) occurred ≤3 months of CCTA. Obstructive CAD was associated with higher rates of ICA and REV for 1-vessel (44.3% and 28.0%), 2-vessel (53.3% and 43.6%), and 3-vessel (69.4% and 66.8%) CAD, respectively. For patients with <50% stenosis, early ICA rates were elevated; over the entirety of follow-up, predictors of ICA were mild left main, mild proximal CAD, respectively, or higher coronary calcium scores. In patients with <50% stenosis, the relative hazard for death was 2.2 (p = 0.011) for ICA versus no ICA. Conversely, for patients with CAD, the relative hazard for death was 0.61 for ICA versus no ICA (p = 0.047). Conclusions These findings support the concept that CCTA may be used effectively as a gatekeeper to ICA.
Abstract Coronary artery calcium (CAC) scanning is an important tool for risk stratification in intermediate-risk, asymptomatic subjects without previous coronary disease. However, the clinical ...benefit of improved risk prediction needs to be balanced against the risk of the use of ionizing radiation. Although there is increasing emphasis on the need to obtain CAC scans at low-radiation exposure to the patient, very few practical documents exist to aid laboratories and health care professionals on how to obtain such low-radiation scans. The Tomographic Imaging Council of the Society for Atherosclerosis Imaging and Prevention, in collaboration with the Prevention Council and the Society of Cardiovascular Computed Tomography, created a task force and writing group to generate a practical document to address parameters that can be influenced by careful attention to image acquisition. Patient selection for CAC scanning should be based on national guidelines. It is recommended that laboratories performing CAC examinations monitor radiation exposure (dose-length-product DLP) and effective radiation dose (E) in all patients. DLP should be <200 mGy × cm; E should average 1.0–1.5 mSv and should be <3.0 mSv. On most scanner platforms, CAC imaging should be performed in an axial mode with prospective electrocardiographic triggering, using tube voltage of 120 kVp. Tube current should be carefully selected on the basis of patient size, potentially using chest lateral width measured on the topogram. Scan length should be limited for the coverage of the heart only. When patients and imaging parameters are selected appropriately, CAC scanning can be performed with low levels of radiation exposure.
Objective Coronary artery calcification (CAC) and thoracic aortic calcification, (TAC) are frequently detected on ungated multidetector computed tomography (MDCT) performed for lung evaluations. We ...sought to evaluate concordance of CAC and TAC scores on ungated (thoracic) and electrocardiogaphically (ECG)–gated (cardiac) MDCT scans. Methods Fifty patients, enrolled in the Genetic Epidemiology of COPD study (COPDGene), were recruited to undergo gated CAC scans with 64-detector row CT, in addition to the ungated thoracic studies already being obtained as part of their study evaluation. Coronary and thoracic calcium were measured similarly (Agatston score, requiring 3 contiguous voxels of >130 Hounsfield units) with low-dose ungated studies and ECG-gated MDCT performed at the same scanning session. Intertechnique scoring variability and concordance were calculated. Results Correlations between gated and ungated CAC and TAC were excellent ( r = 0.96). The relative differences (median variability) measured by ECG-gated versus ungated MDCT were relatively high for CAC (44%) but not for TAC (8%). Prevalence of depicted CAC (n = 33; 66%) and TAC (n = 21; 42%) were coincident between ECG-gated and ungated MDCT, respectively (intertechnique concordance, 100%). Bland-Altman plots for CAC showed mean differences of 354 (confidence interval, 169–538) and 16.1 (confidence interval, −89 to 121). Conclusion Low-dose ungated MDCT is reliable for prediction of the presence of CAC and assessment of Agatston score. Concordance between methods and between TAC and CAC is high. This technique should allow for atherosclerotic disease risk stratification among patients undergoing ungated lung CT evaluation without requiring additional scanning. Measurement of TAC is almost as accurate from gated CT, and CAC scores are highly concordant.
Although family history (FH) of coronary artery disease (CAD) is considered a risk factor for future cardiovascular events, the prevalence, extent, severity, and prognosis of young patients with FH ...of CAD have been inadequately studied. From 27,125 consecutive patients who underwent coronary computed tomographic angiography, 6,308 young patients (men aged <55 years and women aged <65 years) without known CAD were identified. Obstructive CAD was defined as >50% stenosis in a coronary artery >2 mm diameter. Risk-adjusted logistic regression, Kaplan-Meier, and Cox proportional-hazards models were used to compare patients with and without FH of CAD. Compared with subjects without FH of CAD, those with FH of CAD (FH+) had higher prevalences of any CAD (40% vs 30%, p <0.001) and obstructive CAD (11% vs 7%, p <0.001), with multivariate odds of FH+ increasing the likelihood of obstructive CAD by 71% (p <0.001). After a mean follow-up period of 2 ± 1 years (42 myocardial infarctions and 39 all-cause deaths), FH+ patients experienced higher annual rates of myocardial infarction (0.5% vs 0.2%, log-rank p = 0.001), with a positive FH the strongest predictor of myocardial infarction (hazard ratio 2.6, 95% confidence interval 1.4 to 4.8, p = 0.002). In conclusion, young FH+ patients have higher presence, extent, and severity of CAD, which are associated with increased risk for myocardial infarction. Compared with other clinical CAD risk factors, positive FH in young patients is the strongest clinical predictor of future unheralded myocardial infarction.
Prevention and management of coronary artery disease (CAD) is of great concern in patients with diabetes mellitus. Although the impact of coronary atherosclerosis described well for individuals over ...40 years of age, the prevalence and types of coronary atherosclerosis in young patients is not well-known. The aim of this study was to evaluate the prevalence, extent, severity and volumes of coronary plaque in type 2 DM (T2DM) population under the age of 40 years. This prospective study enrolled 181 individuals (25-40 years old) undergoing coronary CT angiography, with 86 T2DM and 95 non-diabetic age/sex matched individuals. Coronary artery calcium (CAC), plaque assessment including total segment stenosis (sum of individual segmental stenosis-TSS), total plaque scores (sum of semi-quantitative segmental plaque burden-TPS), segment involvement scores (number of segments with plaque-SIS) were evaluated. Also, we quantitatively measured plaque volumes in total, fibrous, fibrous fatty, dense calcified, and low attenuation plaque using novel plaque software. Compared to non-diabetic patients, the prevalence of CAD, calcified and non-calcified plaques, was higher in T2DM patients (19% vs. 58%; p<0.001). In patients with a zero CAC, T2DM had a higher prevalence (46%) of non-calcified plaque (p<0.0001). In multivariate linear regression models after adjusting for traditional cardiovascular risk factors, increased TSS, TPS, and SIS were associated with T2DM. Regarding quantitative plaque assessment, all volumes in non-calcified plaque type were approximately 3-fold higher in T2DM patients. In conclusion, young patients with T2DM are susceptible to premature CAD with more calcified and non-calcified plaques. Early prevention program using CT angiography might be helpful in identifying young diabetic patients with subclinical atherosclerosis.
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