Agatston Coronary Calcium Score Research Articles

Coronary calcification on invasive angiography and the Agatston score—a single-center experience

Aim: The pattern and severity of coronary artery calcification (CAC) can influence prognosis and outcome in percutaneous coronary intervention. An objective assessment of CAC during invasive angiography may provide additional prognostic information. This study aimed to assess the correlation between the angiographic Birmingham calcium score (BCS) and the Agatston coronary calcium score (CCS) performed as part of single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). Methods: In this retrospective observational study, patients undergoing SPECT-MPI and invasive coronary angiography as part of their routine management were included. BCS was calculated by reviewing angiography images in retrospect by an observer blinded to the SPECT-MPI calcium score. Spearman’s correlation was used to analyze the correlation between BCS and SPECT-MPI. Receiver operating characteristic curve was used to detect cut-off for BCS that would detect clinically significant CAC [> 400 Agatston units (AU)]. Kaplan-Meier was used to report on outcomes at 5 years follow-up. Results: In this cohort of 151 patients, there was a positive correlation between BCS and CCS [Spearman correlation coefficient (r) = 0.558, P < 0.001]. Cumulative BCS of 1 was able to identify clinically significant CAC [area under the curve 0.788, 95% confidence interval (CI) 0.714–0.863]. Cumulative BCS ≥ 3 was associated with major adverse outcomes at 5 years follow-up (log rank P = 0.013). Conclusion: BCS correlates well with established higher CCS. Application of BCS during invasive coronary angiography will aid risk stratification, management, and follow-up with no extra patient involvement, radiation, or costs.

Additional value of the coronary calcium score to conventional cardiovascular risk factors in predicting significant coronary disease diagnosed by computed tomography angiography in Angola

In Angola, coronary artery disease (CAD) has increased in prevalence in recent years. This study aims to evaluate the additional value of the coronary calcium score (CCS) to conventional risk factors (CRF) in predicting the presence of CAD. Results: This study comprises 204 patients. The mean age was 56.46±9.19 years. 123(60.3%) patients are male. The patients with CAD are older (mean age 56.00±9,4 years vs. 59.83±6.8 years, p=0.017), had higher proportion of men [20(83.3%) vs. 103(57.2), p=0.014], diabetes [10(41.7%) vs. 37(20.6%), p=0.021], dyslipidemia [23(95.8%) vs. 108(60.0%], p=0.001) smoking in the past, [9(37.5%) vs 27(15.0%), p=0.007], higher number of risk factors (NRF) (p 0.001), and higher Agatston CCS (p<0.001). A logistic regression was performed to ascertain the effect age CRF, NRF, and CCS on the likelihood that participants have CAD. Based on the Backward conditional method after step 5, we identified that NFR and CCS variables added statistically significantly to the prediction (p<0.05). We identified increasing NFR (B= 0.583, Wald 5.086; OR 1.791: p=0-0024 95%CI =1.07-2.97) and CCS (B= 0.016, Wald 30.951; OR 1.016: p<0.001 95% CI =1.01-1.02) were associated with an increased likelihood of exhibiting significant CAD. Conclusion: The NRF and the CCS proved to be strong predictors of CAD.

MO556: Markers of Oxidative Stress and Coronary Calcifications in Chronic Hemodialysis Patients

Abstract BACKGROUND AND AIMS Cardiovascular morbidity and mortality are increased in hemodialysis patients. Oxidative stress is considered to be an important factor in these cardiovascular complications in these patients. The aim of this research is to establish the link between the levels of advanced oxidation protein products (AOPP) in the serum of hemodialysis patients and coronary calcifications. METHOD This is a longitudinal study involving 67 hemodialysis patients, all patients underwent a Coro-CT scan to assess coronary calcifications according to the Agatston coronary calcium score (SCCA). We divided the patients into three groups according to their low (0–100), medium (101–400) and severe calcification score > 400, we measured the levels of AOPP in the three groups and we studied the correlation between the rate of AOPP at the level of the different groups. RESULTS The mean age of the patients is 55 ± 12.5 years, the sex ratio is 1.3, the mean us-CRP level is 12.5 mg/L, the mean NO, AOPP, MDA level, MPO and LDLox are respectively (62.188 ± 5.598, 70.82 ± 10, 6.97 ± 0.488 µmol/L, 61.466 ± 8.82 IU/mL and 31.755 ± 3.9 µmol/l), we divided the patients into three groups according to the agtston coronary calcium score (SCCA), we found 27% of the patients had a low score (0–100), 48% had a moderate sore (101–400) and 25% had a severe score >400. We found that the rate of oxidative stress markers worsened with increasing calcification score, patients with a low score had levels of NO, AOPP, MDA, MPO and LDLox are respectively (67.2 ± 6.5, 64.9 ± 7, 3.24 ± 0.32, 57.8 ± 6.9 IU/mL and 10.17 ± 1.9 µmol/l), the mean score had respective levels of NO, AOPP, MDA, MPO and LDLox are respectively (62.5 ± 3.2, 72.7 ± 12, 7.2 ± 0.24 µmol/L, 60.34 ± 5.7 IU/mL and 27.6 ± 2.1 µmol/L) and patients with a severe calcification score had NO, AOPP, MDA, MPO and LDLox levels respectively (59.3 ± 2.4, 82.82 ± 12, 9.45 ± 0.34 µmol/L, 74.23 ± 9.7 IU/mL and 42.89 ± 5.19 µmol/L), there are positive correlations between the rate of coronary calcifications and the levels of markers oxidative stress NO, AOPP, MDA, MPO and LDLox) which are respectively (r = 0744, P = 0.0001; r = 0.777, P = 0.000; r = 0.318, P = 0.000; r = 0.620, P = 0.000; r = 0.526, P = 0.0001). CONCLUSION Markers of oxidative stress are higher in hemodialysis patients with vascular calcifications, they can be predictors of cardiovascular complications in hemodialysis patients.

Pericoronary adipose tissue attenuation, low-attenuation plaque burden and 5-year risk of myocardial infarction

Abstract Introduction Pericoronary adipose tissue (PCAT) attenuation has emerged as a surrogate marker of pericoronary inflammation. To date, no studies have compared the impact of pericoronary adipose tissue (PCAT) attenuation and quantitative plaque burden on cardiac outcomes. Purpose We aimed to establish the relative merits of these approaches to risk prediction and hypothesised that the combination of PCAT attenuation and quantitative plaque burden measures could provide additive and improved prediction of myocardial infarction in patients with stable chest pain. Methods In a post-hoc analysis of a randomized controlled trial, we investigated the association between the future risk of fatal or non-fatal myocardial infarction and PCAT attenuation measured from CT coronary angiography using multivariable Cox regression models including plaque burden, obstructive coronary disease and cardiac risk score (incorporating age, sex, diabetes, smoking, hypertension, hyperlipidaemia and family history of cardiovascular disease). Results In 1697 evaluable participants (mean age 58±10 years), there were 37 myocardial infarctions after a median follow-up of 4.7 [interquartile interval, 4.0–5.7] years. Median low-attenuation plaque burden was 4.20 [0–6.86] % and mean PCAT −76±8 Hounsfield units (HU). PCAT attenuation of the right coronary artery (RCA) was predictive of myocardial infarction (hazard ratio [HR] 1.55, 95% CI 1.08–2.22; p=0.017, per 1 standard deviation increment) with an optimum threshold of −70.5 HU [Hazards ratio (HR) 2.45, 95% CI 1.2–4.9; p=0.01]. Univariable analysis also identified the burden of non-calcified, low-attenuation and calcified plaque as well as Agatston coronary calcium score, presence of obstructive coronary artery disease and cardiovascular risk score were predictors of myocardial infarction (Figure 1). In multivariable analysis, only the low-attenuation plaque burden (HR 1.80, 95% CI 1.16 to 2.81, p=0.011, per doubling) and PCAT-RCA (HR 1.47 95%1.02 to 2.13, p=0.040, per standard deviation increment) remained predictors of myocardial infarction (Figure 1). In multivariable analysis, adding PCAT-RCA ≥-70.5 HU to low-attenuation plaque burden >4% (optimum threshold for future myocardial infarction; HR = 4.87, 95% CI 2.03–11.78; p<0.0001) led to improved prediction of future myocardial infarction (HR 11.7, 95% CI 3.3–40.9; p<0.0001); Figure 2. In ROC analysis, integration of PCAT-RCA attenuation and LAP burden, increased the prediction for myocardial infarction compared to LAP alone (ΔAUC=0.04; p=0.01). Conclusion CT coronary angiography defined PCAT attenuation and low-attenuation plaque have marked and additive predictive value for the risk of fatal or non-fatal myocardial infarction. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Chief Scientist Office of the Scottish Government Health and Social Care Directorates, British Heart Foundation, National Institute of Health/National Heart, Lung, and Blood Institute grant

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

BackgroundCoronary 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. MethodsThe 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. ResultsAmong 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. ConclusionsBoth 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.

High consumption of ultra-processed food may double the risk of subclinical coronary atherosclerosis: the Aragon Workers\u2019 Health Study (AWHS)

BackgroundUltra-processed food (UPF) consumption, which is increasing worldwide, has recently been associated with an increased risk of death and cardiovascular disease. We aimed to assess whether consumption of UPF is directly associated with subclinical coronary atherosclerosis in middle-aged men.MethodsA computed tomography scan was performed on 1876 men from the Aragon Workers’ Health Study, recruited from January 2011 to December 2014, to assess coronary calcium. All participants were free of coronary heart disease. Dietary intake was collected by a validated 136-item semi-quantitative food frequency questionnaire. UPF was defined according to the NOVA classification. Associations between consumption of total energy-adjusted UPF and Coronary Calcium Agatston Score (CACS)—categorized into CACS of 0, > 0 and < 100, and ≥ 100—were cross-sectionally assessed by generalized ordered logistic regression adjusted for main confounders.ResultsNo coronary calcium was detected in 60.2% of the participants, whereas 10.2% had a CACS ≥ 100. A significant dose-response association was observed between energy-adjusted UPF consumption and the risk of having a CACS ≥ 100, when compared with those in the lowest CACS categories (CACS of 0 together with CACS > 0 and < 100). The fully adjusted ORs (95% CI) of having a CACS ≥ 100 across quartiles of energy-adjusted UPF consumption (approximately 100 g/day in the lowest quartile (ref.) and 500 g/day in the highest) were 1.00 (ref.), 1.50 (0.93, 2.42), 1.56 (0.96, 2.52), and 2.00 (1.26, 3.16), p trend .005.ConclusionIn this middle-aged worker’s sample, approximately 500 g/day of UPF consumption was associated with a 2-fold greater prevalence of subclinical coronary atherosclerosis than consuming only 100 g/day, independently of total energy intake and other well-established cardiovascular risk factors.

Epicardial adipose tissue volume and annexin A2/fetuin-A signalling are linked to coronary calcification in advanced coronary artery disease: Computed tomography and proteomic biomarkers from the EPICHEART study

Background & aimsThe role of epicardial adipose tissue (EAT) in the pathophysiology of late stage-coronary artery disease (CAD) has not been investigated. We explored the association of EAT volume and its proteome with advanced coronary atherosclerosis. MethodsThe EPICHEART Study prospectively enrolled 574 severe aortic stenosis patients referred to cardiac surgery. Before surgery, EAT volume was quantified by computed tomography (CT). During surgery, epicardial, mediastinal (MAT) and subcutaneous (SAT) adipose tissue samples were collected to explore fat phenotype by analyzing the proteomic profile using SWATH-mass spectrometry; pericardial fluid and peripheral venous blood were also collected. CAD presence was defined as coronary artery stenosis ≥50% in invasive angiography and by CT-derived Agatston coronary calcium score (CCS). ResultsEAT volume adjusted for body fat was associated with higher CCS, but not with the presence of coronary stenosis. In comparison with mediastinal and subcutaneous fat depots, EAT exhibited a pro-calcifying proteomic profile in patients with CAD characterized by upregulation of annexin-A2 and downregulation of fetuin-A; annexin-A2 protein levels in EAT samples were also positively correlated with CCS. We confirmed that the annexin-A2 gene was overexpressed in EAT samples of CAD patients and positively correlated with CCS. Fetuin-A gene was not detected in EAT samples, but systemic fetuin-A was higher in CAD than in non-CAD patients, suggesting that fetuin-A was locally downregulated. ConclusionsIn an elderly cohort of stable patients, CCS was associated with EAT volume and annexin-A2/fetuin-A signaling, suggesting that EAT might orchestrate pro-calcifying conditions in the late phases of CAD.

Pulse pressure correlates with coronary artery calcification and risk for coronary heart disease: a study of elderly individuals in the rural region of Southwest China.

AimThis study aimed to define the relationship between pulse pressure (PP) and coronary artery calcification (CAC), a proven surrogate marker for coronary heart disease.Patients and methodsA total of 170 participants 50–70 years of age from 11 villages of Yunnan Province of China were enrolled randomly into this study. They were examined routinely for diastolic and systolic blood pressure, PP, and CAC.ResultsThe average PP in the CAC-positive group was significantly higher than that in the CAC-negative group. In the positive CAC group, there were significantly positive correlations between PP and CAC score, volume, mass, as well as density. The area under the receiver operating characteristic curve analysis showed that PP performed well in predicting CAC.ConclusionIn conclusion, among the rural people of southwest of China, PP correlates positively with the coronary calcium Agatston score, volume, mass, and density. PP predicted CAC as well as Framingham Risk Score. The measurement of PP widening may serve as an alternative and convenient method for assessing CAC risk in rural populations with poor accessibility and economic disadvantage over coronary computed tomography scanning.

Coronary lesions in patients with COPD (Global Initiative for Obstructive Lung Disease stages I-III) and suspected or confirmed coronary arterial disease.

BackgroundSystemic inflammation is the pathophysiological link between coronary artery disease (CAD) and COPD. However, the influence of subclinical COPD on patients with suspected or diagnosed CAD is largely unknown. Thus, this study was designed to evaluate the degree of coronary involvement in patients with COPD and suspected or confirmed CAD.MethodsIn this cross-sectional study, carried out between March 2015 and June 2017, 210 outpatients with suspected or confirmed CAD were examined by both spirometry and coronary angiography or multidetector computed tomography. These patients were divided into two groups: with and without COPD. Size, site, extent, and calcification of the coronary lesions, and the severity of COPD were analyzed.ResultsCOPD patients (n = 101) presented with a higher frequency of obstructive coronary lesions ≥50% (n = 72, 71.3%), multivessels (n = 29, 28.7%), more lesions of the left coronary trunk (n = 18, 17.8%), and more calcified atherosclerotic plaques and higher Agatston coronary calcium score than the patients without COPD (P < 0.0001). The more severe the COPD in the Global Initiative for Obstructive Lung Disease stages, the more severe the CAD and the more calcified coronary plaques (P < 0.0001). However, there was no difference between the two groups with respect to the main risk factors for CAD. In the univariate analysis, COPD was an independent predictor of obstructive CAD (odds ratio [OR] 4.78; 95% confidence interval: 2.21–10.34; P < 0.001).ConclusionIn patients with suspected CAD, comorbid COPD was associated with increased severity and extent of coronary lesions, calcific plaques, and elevated calcium score independent of the established risk factors for CAD. In addition, the more severe the COPD, the greater the severity of coronary lesions and calcification present.

Equivocal tests after contrast stress-echocardiography compared with invasive coronary angiography or with CT angiography: CT calcium score in mildly positive tests may spare unnecessary coronary angiograms

BackgroundImaging stress tests are not ideally accurate to predict anatomically obstructive CAD, leading to a non-trivial rate of unnecessary iCA. This may depend on the threshold used to indicate iCA, and maybe CTA or, one step earlier, CT calcium score could spare most unnecessary iCA in only mildly positive cSE. We assessed the diagnostic accuracy of contrast stress-echocardiography (cSE) in comparison with invasive coronary angiography (iCA), and CT angiography (CTA) only in case of equivocal tests, to find hints helping reduce falsely positive cSE in the suspicion of coronary artery disease (CAD).MethodsPatients who were indicated cSE for suspected CAD between 2012 and 2016, who also underwent iCA were selected and diagnostic results compared. A second group, specifically with equivocal cSE who underwent CTA was also analyzed.Results137 subjects with equivocal cSE and CTA and 314 with cSE (any result) and iCA were selected. In the CTA-equivocal cSE group, an Agatston score < 105 and a coronary flow reserve (CFR-LAD) <1.7 had very high negative predictive value (99%, 92% respectively) to exclude obstructive CAD. The Agatston score was the most significant incremental predictor of CAD beyond clinical variables (chi square 31 to 47, p < 0.001). In the iCA group a more-than-mild reversible wall motion abnormality (WMA) demonstrated high positive predictive value for CAD (89%), while CFR-LAD appeared less useful. More-than-mild reversible WMA was the most significant predictor of CAD beyond clinical variables (chi square 37.5 to 56, p < 0.001).ConclusionsOur data suggest iCA should be indicated only for more-than-mild reversible WMA at cSE, due to the very high positive predictive value for CAD of this finding, while mildly positive tests should be shifted to non-invasive CT, with CTA performed only for coronary calcium Agatston score > 100, since lower scores demonstrated very high negative predictive value for CAD, not justifying proceeding to CTA and even less to iCA.

Accuracy of coronary artery calcium scoring with tube current reduction by 75%, using an adaptive iterative reconstruction algorithm.

To assess the accuracy of an iterative reconstruction (IR) technique for coronary artery calcium scoring with reduced radiation dose. 163 consecutive patients underwent twofold scanning by 320-row detector CT at 120 kVp. A low-dose scan at 25% tube current but with standard scan length (14 cm) was followed by a standard dose scan with routine tube current but reduced scan length (10 cm). Reduced dose images were constructed using filtered back-projection (FBP) and IR (adaptive iterative dose reduction in three dimensions). The standard dose scan reconstructed with FBP served as the gold standard for comparisons. Image noise and Agatston coronary calcium scores were determined and compared between the groups. Compared with FBP at standard dose, noise at reduced dose increased markedly with FBP but remained low with IR. Mean Agatston score with FBP at reduced dose showed a significant increase as compared with FBP at standard dose. No significant difference was observed when applying IR at reduced dose. At reduced dose, 38 (23.3%) patients were reassigned to a different cardiovascular risk category with FBP but only 8 (4.9%) with IR. Out of 47 patients with a zero Agatston score, 15 patients (31.9%) were false-positive with FBP at reduced dose, but no false positives were found with IR. IR allows accurate coronary artery calcium scoring with a radiation dose reduced by 75%. Advances in knowledge: The application of adaptive iterative dose reduction in three dimensions allows the maintenance of accurate Agatston scores and risk stratification at significantly reduced tube current, thus reducing the patient's exposure to ionizing radiation.

Prognostic value of visually detected coronary artery calcification on unenhanced non-gated thoracic computed tomography for prediction of non-fatal myocardial infarction and all-cause mortality

PurposeTo determine the prognostic value of visually detected coronary artery calcification (CAC) on unenhanced non-gated thoracic computed tomography (CT) for non-fatal myocardial infarction (MI) and all-cause mortality. MethodsThis retrospective single-centre cohort study comprised of 410 consecutive patients aged 40–80 years without any known cardiovascular disease at baseline. CT images without electrocardiogram-gating were acquired for a variety of respiratory medicine indications. CAC was examined by a single reader blinded to clinical data and outcome, using 1) the Agatston coronary calcium score (CCS), 2) visual CAC and 3) number of visually calcified coronary arteries. ResultsVisible CAC was identified in 201 (49.0%) of the 410 patients (60.5 ± 10.0 years old, 42.4% males). After a median follow up of 7.0 years, 39 patients (9.5%) experienced an event (death or non-fatal MI). After adjustment for cardiovascular risk factors, those with 1) higher CCS, 2) presence of visual CAC or 3) greater number of calcified coronary arteries by visual assessment, had an increased risk of adverse outcome (all p-value <0.05). There was no significant difference in c-statistics of the three methods of assessment (0.81, 0.80, 0.81 respectively), indicating that simple visual assessment of CAC may have a prognostic value similar to CCS. ConclusionAmong patients with no known cardiovascular disease who underwent unenhanced non-gated CT for a pulmonary-related indication, visually detected CAC was a strong independent predictor of non-fatal MI and all-cause mortality.

Visual estimation of coronary calcium on computed tomography for attenuation correction

BackgroundThe coronary calcium score (CCS) provides independent diagnostic and prognostic information on top of myocardial perfusion imaging (MPI) in patients suspected for coronary artery disease, but requires an additional computed tomography (CT) scan. ObjectiveWe investigated the accuracy and inter-reader reproducibility of visual estimation of the CCS on the CT used for attenuation correction. Methods250 patients undergoing single photon emission computed tomography MPI and Agatston CCS were included. The CCS was also visually estimated on the CT for attenuation correction by two separate readers blinded to the Agatston CCS, and was categorized into a six-point scale (0, 1–10, 11–100, 101–400, 401–1000 and > 1000). ResultsThe median Agatston CCS was 82 [25th–75th percentile: 0-562], with a range from 0 to 7287. Of the visually estimated CCS, 60% (reader 1) and 65% (reader 2) were classified correctly into the 6 categories. 93% (reader 1) and 88% (reader 2) of the visually estimated CCS did not vary by more than one category from the Agatston CCS. The intraclass correlation coefficient for agreement between the Agatston CCS and the visually estimated CCS was 0.95 for reader 1 and 0.94 for reader 2. The intraclass correlation coefficient for inter-reader reproducibility of the visually estimated CCS was 0.96. ConclusionThe CCS can be accurately estimated on the CT for attenuation correction, as high agreement is demonstrated with the Agatston CCS and inter-reader reproducibility is excellent. If no traditional Agatston CCS is performed, the degree of atherosclerosis should be assessed by means of estimating CCS on the CT for attenuation correction.

The Functional Effects of Intramural Course of Coronary Arteries and its Relation to Coronary Atherosclerosis

ObjectivesThis study observed hemodynamic consequences of myocardial bridging and its relation to coronary atherosclerosis. BackgroundMyocardial bridging is seen as intramural course by computed tomography angiography (CTA) or systolic compression by invasive coronary angiography. Segments with myocardial bridging are in previous studies closely associated with proximal atherosclerotic plaques. MethodsWe prospectively studied 100 patients 63 ± 7 years of age with intermediate likelihood of coronary artery disease. Segments with superficial (>1 mm) or deep (>2 mm) intramural course were identified using CTA. Myocardial perfusion was studied by 15-Oxygen water positron emission tomography and systolic compression by invasive coronary angiography. ResultsMyocardial bridging was detected in 34 (34%) patients in 48 different vascular segments. Of these, 24 (50%) were deep and systolic compression was present in 14 (29%). In patients without obstructive coronary artery disease, myocardial stress perfusion distal to myocardial bridging was comparable with remote control regions (3.3 ± 0.9 ml/g/min vs. 3.3 ± 0.7 ml/g/min, n = 24, p = 0.88). Stress perfusion was comparable in segments with and without systolic compression (3.0 ± 0.9 vs. 2.7 ± 1.0 ml/g/min, p = 0.43). Atherosclerotic plaques were more frequent in proximal (71%) than myocardial bridging (7%) or distal (21%) segments. The presence of atherosclerosis and the average number of plaques were comparable in coronary arteries with and without myocardial bridging (73% vs. 60%, p = 0.14 and 2.0 ± 1.7 vs. 1.5 ± 1.6, p = 0.06). Median Agatston coronary calcium score was not elevated in vessels with myocardial bridge (15 [interquartile range: 0, 129] vs. 50 [interquartile range: 0, 241], p = 0.21). ConclusionsMyocardial bridging of coronary arteries is common on CTA, but only approximately one-third of these show systolic compression. Myocardial bridging is not associated with reduced myocardial perfusion during vasodilator stress. Atherosclerosis is located predominantly proximal to myocardial bridging but atherosclerotic burden and presence of vulnerable plaques were comparable.

Subclinical detection of atherosclerosis and myocardial ishemia in asymptomatic patients with intermediate and high cardiovascular risk: therapeutic and prognostic implications

Background: We wanted to evaluate the presence of coronary atherosclerosis and myocardial ischemia in asymptomatic patients with intermediate and high cardiovascular (CV) risk, the influencing clinical factors and the impact of ischemia on the final management decision and prognosis. Patients and Methods: 75 asymptomatic patients (35 with intermediate and 40 patients with high CV risk-SCORE risk system), underwent single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for the detection of suspected coronary artery disease. We used a 17-segment model for the scan perfusion and function analysis using perfusion scores. All of the patients have full blood laboratory analyses including lipid values, and presence of urine albuminuria. Multislice computer tomography with coronary calcium Agatston score (CAC) for coronary atherosclerosis detection was also performed. The patients were followed up for 12-18 months for cardiovascular events (new chest pain, hospitalization for acute coronary syndrome, revascularization, cardiac death). Logistic regression analysis was used to assess predictive parameters for myocardial ischemia and cardiovascular events. Results: Stress-inducible ischemia was found in 19 patients (33%), fixed defects were found in 13% and mixed defects in 9% of cases. The average ischemia amount was 10%. Mild ischemia was found in 12 patients (64%) summed stress score (SDS) 7. Severe ischemia was only related to the duration of diabetes (DM). Patients with at least moderate ischemia had Agatston CAC score 465+/-112. The patients with normal MPI scan had CAC score 98+/-45. 3 pts with moderate risk were reclassified to high risk by using CAC and MPI scan results. Stepwise logistic regression analysis for the prediction of stress-induced ischemia showed OR 2.4 (95% CI 1.7_3.6) for the stress-induced ECG changes, OR 2.8 for CAC >400 (95% CI 1.9-3.2) and OR 3.9 for the presence of DM over 10y (95% CI 2.3_6.6). Seven patients with ischemia >10%, were referred for coronary angiography. One patient was hospitalized due to the acute coronary syndrome and no cardiac death was registered during the 12 months follow-up. Conclusions: MPI is a valuable method for preclinical assessment of myocardial ischemia in asymptomatic intermediate and high risk patients, which can improve the prognosis and guide the treatment decision. Coronary calcium score can predict the presence of myocardial ischemia and reclassify the patient's risk.

Coronary artery calcium scoring: Influence of adaptive statistical iterative reconstruction using 64-MDCT

ObjectiveAssessment of coronary artery calcification is increasingly used for cardiovascular risk stratification. We evaluated the reliability of calcium-scoring results using a novel iterative reconstruction algorithm (ASIR) on a high-definition 64-slice CT scanner, as such data is lacking. Methods and resultsIn 50 consecutive patients Agatston scores, calcium mass and volume score were assessed. Comparisons were performed between groups using filtered back projection (FBP) and 20–100% ASIR algorithms. Calcium score was measured in the coronary arteries, signal and noise were measured in the aortic root and left ventricle. In comparison with FBP, use of 20%, 40%, 60%, 80%, and 100% ASIR resulted in reduced image noise between groups (7.7%, 18.8%, 27.9%, 39.86%, and 48.56%, respectively; p<0.001) without difference in signal (p=0.60). With ASIR algorithms Agatston coronary calcium scoring significantly decreased compared with FBP algorithms (837.3±130.3; 802.2±124.9, 771.5±120.7; 744.7±116.8, 724.5±114.2, and 709.2±112.3 for 0%, 20%, 40%, 60%, 80%, and 100% ASIR, respectively, p<0.001). Volumetric score decreased in a similar manner (p<0.001) while calcium mass remained unchanged. Mean effective radiation dose was 0.81±0.08mSv. ConclusionASIR results in image noise reduction. However, ASIR image reconstruction techniques for HDCT scans decrease Agatston coronary calcium scores. Thus, one needs to be aware of significant changes of the scoring results caused by different reconstruction methods.

Very small calcifications are detected and scored in the coronary arteries from small voxel MDCT images using a new automated/calibrated scoring method with statistical and patient specific plaque definitions

A negative (zero) Agatston coronary calcium score (CCS) by current methods confers a very low risk for hard coronary events during the next years. However, controversy remains on how to use a negative score since some hard events still occur. We report on a new method with improved detection sensitivity for very small calcifications with the potential to more confidently rule out early atherosclerotic disease. Seventy-eight (78) patients with negative Agatston scores by conventional methods with 2.5 mm slices were selected from routine GE 64 MDCT scans. Each scan was reconstructed a second time from the same data to create 0.625 mm isotropic voxels. The 2.5 mm images were manually scored by the usual Agatston method using the GE SmartScore™ software. Both the 2.5 and 0.625 mm image sets were scored with a new automated and calibrated method (N-vivo™, Image Analysis). The software automatically computes dual scoring thresholds that are statistically defined and specific for each patient, scanner, and scan. The images were hybrid calibrated by simultaneous scanned phantoms in combination with in vivo blood/muscle references. The output reported the calibrated mass scores along with the number of plaques using 18 pt, 3-D connectivity criteria. A CCS Test phantom with known CaHA microspheres was used to validate the method. Twenty-three percent (18 of 78) of the patients with negative Agatston scores by the conventional method scored positive for coronary calcifications by the N-vivo method. The number of small plaques scored per patient varied from 1 to 4. One patient with a single small calcification suffered a hard coronary event during the CT scan. All of the detected plaques were located in the proximal heart. The conventional CCS method misclassified 23% of these patients as having negative coronary calcium scores. The N-vivo automated scoring method with small voxel CT images increased the detection sensitivity of small calcifications with no increase in radiation dose. Detection of small coronary calcified plaques occult to conventional scoring methods may increase the negative predictive power of calcium scoring and may improve plaque composition analysis.

Ruling Out Coronary Artery Disease with Noninvasive Coronary Multidetector CT Angiography before Noncoronary Cardiovascular Surgery

To assess the usefulness of preoperative coronary computed tomographic (CT) angiography in the detection of coronary artery disease (CAD) in nonselected patients scheduled to undergo noncoronary cardiovascular surgery to avoid unnecessary invasive coronary angiography (ICA). The institutional review board approved the study protocol; informed consent was given. This prospective study involved 161 consecutive patients who underwent coronary calcium scoring and coronary CT angiography before undergoing noncoronary cardiovascular surgery. Seven patients were excluded because of contraindications to CT angiography. The major indication of noncoronary cardiovascular surgery was valvular heart disease (121 patients). Follow-up was performed at a median of 20 months to define ischemic events described as acute coronary syndrome or death secondary to acute coronary syndrome, arrhythmias, or cardiac failure. Multivariate analysis was performed to determine predictors of nondiagnostic coronary CT angiography. Kaplan-Meier analysis was performed to evaluate outcome at follow-up. Twenty-one patients did not undergo surgery, which left 133 patients as the study group. Atrial fibrillation was present in 45 of 133 patients. The interquartile range of the Agatston coronary calcium score was 0-471. Coronary CT angiography was diagnostic in 108 of 133 patients. Of these, 93 of 108 had no significant CAD (≤ 50% stenosis), and noncoronary cardiovascular surgery was performed in them without preoperative ICA. No patients in this group had postoperative ischemic events at follow-up. Coronary CT angiography was nondiagnostic in 25 of 133 patients who were referred for preoperative ICA. Multivariate analysis showed Agatston score to be the only independent predictor of nondiagnostic coronary CT angiography (odds ratio = 1.002; 95% confidence interval: 1.001, 1.003; P = .001). The best Agatston score cutoff for diagnostic coronary CT angiography was 579. In nonselected patients scheduled to undergo noncoronary cardiovascular surgery, preoperative coronary CT angiography was diagnostic in 81% of cases. Preoperative ICA could be safely avoided in patients without significant CAD by using coronary CT angiography. The Agatston score, but not the presence of atrial fibrillation, was an independent predictor of nondiagnostic coronary CT angiography. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100384/-/DC1.

Comparison of the coronary calcium score with the estimated coronary risk

The role of coronary calcium scoring in coronary risk estimation is not well established. Calcium scoring could provide additional information in a certain subgroup of patients where the calcium score does not match the conventional Framingham risk estimates. We explored the characteristics of such a subgroup. The study participants were 1653 asymptomatic persons who underwent routine health screening and calcium scoring using the 16-slice multidetector computed tomography. Risk stratification was performed in five categories both by 10-year Framingham coronary risk and the Agatston coronary calcium score. Risk stratifications by coronary calcium score and absolute risk showed a large discrepancy (difference > or =3 classes) in about 9% of participants. The proportion increased with age (P for trend <0.0001). An exploratory analysis revealed that age (partial R=0.109, P<0.0001) and the presence of the metabolic syndrome (partial R=0.025, P<0.001) were independent variables that accounted for the variance of the residual of regression between the log-transformed value of coronary calcium score and the absolute risk. Calcium scoring may be clinically more useful in older (> or =50 years) participants and/or in participants with the metabolic syndrome because of the relatively higher probability of obtaining additional information that the conventional Framingham risk estimation cannot provide.

The latest on the calcium story

Coronary calcium scanning is no longer restricted to specialized centers but has become widely available as a test that can easily be performed in clinical practice. There have been parallel developments in scientific evaluation of coronary calcium scanning in numerous research studies and the practical use of this test. A number of reports have clarified the relation between the unstable coronary plaque and coronary calcium. Whereas calcium is a frequent feature of plaque rupture, there is too much overlap with more stable plaques to be specific. However, data are accumulating to indicate that calcium is associated with coronary atherosclerotic disease activity. Indeed, reports presented within the past year have demonstrated that very high calcium scores, in particular those >1,000, indicate a significantly increased cardiovascular risk. The advent of cardiac spiral computed tomography (CT) has made coronary calcium scanning widely available. As this methodology is continuously evolving, a number of challenges regarding standardization of test ordering, performance, and interpretation have arisen. Currently, 4-slice spiral CT scanners are most widely used. Protocols with prospective or retrospective electrocardiographic triggering are used, which appear to yield results similar to the Agatston coronary calcium score compared with electron-beam CT, despite the technical differences. New scoring algorithms are being evaluated. With electron-beam and spiral CT we have, for the first time, a readily available test for direct diagnostic visualization of the coronary arteries in clinical practice. This represents the opportunity and the challenge of a proof of principle.