Coronary calcium scoring: are the results comparable to computed tomography coronary angiography for screening coronary artery disease in a South Asian population?

Prediction of high coronary artery calcium (CAC) scores from aortic arch calcification: An efficient tool for selection of non-optimal candidates for coronary CTA?

PURPOSE

Overutilization of healthcare resources is causing a high socioeconomic burden. Patients with high coronary artery calcium (CAC) scores > 1000AU are not optimal candidates for coronary CTA and better suited for other diagnostic strategies. Therefore, our objective was to evaluate whether a 4-scale aortic arch calcification severity (AoArCa) score from CT and X-Ray predicts high-CAC scores.

METHODS

Patients referred to coronary/aortic CT-Angiography were enrolled. The severity of aortic arch calcification (AoArCa) was scored as grade: 0 = absent, 1 = minimal (<25 % of circumference), 2 = mild (25-50 %), 3 = moderate (50-75 %) and 4 = severe (75-100 %) on both thoracic CT and X-ray.

RESULTS

In 130 patients, the absence of AoArCa by CT was highly accurate to rule out CAC > 1000AU (sens. 100 %). No or minimal AoArCa had a high NPV of 95.6 % to rule out CAC > 1000 and grade 0,1 + 2 a NPV of 86.96 %. The AUC of AoArCa by CT for predicting high CAC > 1000 was c = 0.84 (p < 0.001; 95 %CI: 0.771--0.91). For moderate-to-severe AoArCa, accuracy was c = 0.792 (p < 0.001). The intermodality agreement between CT and X-Ray based AoArCa Scores was good (r = 0.824, p < 0.001); ICC = 0.902. For X-ray, AUC was c = 0.715 to predict CAC > 1000 (p < 0.001). In regression models, only moderate-or-severe AoArCa, but not the other CVRF predicted CAC > 1000 (p < 0.001), and there was an association of the number of CVRF.

CONCLUSIONS

Patients with moderate-to-severe aortic arch calcification have a high probability of CAC > 1000AU, but not those with no, minimal and mild. The absence of AoArCa rules out CAC > 1000AU. AoArCa severity may serve as valuable tool for selecting the diagnostic strategy.

Coronary Artery Stenosis Severity in Patients With Different Coronary Artery Calcium Scores on Coronary Computed Tomography Angiography

Background In this study, we aimed to determine coronary artery stenosis severity in patients with different coronary artery calcium (CAC) scores. Methodology A total of 145 patients were included in the study. All patients were given beta-blockers 12 hours and two hours before the test to keep their heart rate between 55 and 65 beats per minute. Computed tomography angiography was done from the pulmonary hilum up to the base of the heart and the patients were asked to hold their breath. The CAC score and stenosis were assessed. Results The mean age of the patients was 41.35 ± 4.95 years. In total, 112 (77.24%) patients were male and 33 (22.76%) were female. Regarding the frequency of the CAC score, a score of 0-9 was observed in 43 (29.66%) patients, 10-99 was observed in 55 (37.93%) patients, and 100-400 was observed in 47 (32.41%) patients. The CAC score was 0-9 in 86.4% of patients having normal coronary arteries. Two (5.2%) patients with a CAC score of 100-400 had mild coronary artery stenosis, 11 (32.3%) patients had moderate coronary artery disease, and 33 (66.0%) patients had severe coronary artery disease (p < 0.00001). Conclusions There is a strong association between CAC scores and the severity of coronary artery stenosis. A CAC score of zero is associated with a very low risk of having coronary artery stenosis.

Biological age for chronic kidney disease patients using index model

The estimation of biological age (BA) is an important asymptomatic measure that can be used to understand the physical changes and the aging process of a living being. Factors that contribute towards profiling the human biological age can be diverse. Therefore, this study focuses on developing a BA model for patients with Chronic Kidney Disease (CKD). The procedure commences with the selection of significant biomarkers using a correlation test. Appropriate weighting is then assigned to each selected biomarker using the indexing method to produce a BA index. The BA index is matched to the age variation within the sample to acquire additional terms for the chronological age leading ultimately to the estimated BA. From a sample of 190 patients (133 trained data and 57 testing data) obtained from the University of Malaya Medical Centre (UMMC), Malaysia, the intensity of the BA is found to be between three to nine years from the chronological age. Visual observations further validate the high similarities between the training and testing data sets.

Can post-mortem coronary artery calcium scores aid diagnosis in young sudden death?

This study sought to explore the feasibility and utility of post-mortem coronary artery calcium (CAC) scoring in identifying patients with ischemic heart disease as cause of sudden death. 100 deceased patients aged 18-50 years underwent post-mortem examination in the setting of sudden death. At post-mortem, fifty cases were determined to have ischemic heart disease, and fifty had death attributed to trauma or unascertained causes. The CAC score was calculated in a blinded manner from post-mortem CTs performed on all cases. CAC scores were assessable in 97 non-decomposed cases (feasibility 97%). The median CAC score was 88 Agatston units [IQR 0-286] in patients deceased from ischemic heart disease vs 0 [IQR 0-0] in patients deceased from other causes (p < 0.0001). Presence of any coronary calcification differed significantly between ischemic heart disease and non-ischemic groups (adjusted odds ratio 10.7, 95% CI 3.2-35.5). All cases with a CAC score > 100 (n = 22) had ischemic heart disease as the cause of death. Fifteen cases had a CAC score of zero but severe coronary disease at post-mortem examination. Post-mortem CAC scoring is highly feasible. An elevated CAC score in cases 18-50 years old with sudden death predicts ischemic heart disease at post-mortem examination. However, a CAC score of zero does not exclude significant coronary artery disease. Post-mortem CAC score may be considered as a further assessment tool to help predict likely cause of death when there is an objection to or unavailability of post-mortem examination.

Differentially expressed microRNA profiles in exosomes from vascular smooth muscle cells associated with coronary artery calcification

OBJECTIVE

The pathogenesis of coronary artery calcification (CAC) in coronary heart disease (CHD) is mediated by exosomes derived from vascular smooth muscle cells (VSMCs). However, little is known about their underlying mechanism. In this study, we aimed to investigate the differentially expressed miRNAs in VSMCs undergoing induced calcification.

METHODS

A cellular calcification model was established using the mouse VSMC line MOVAS-1. Calcium deposition was evaluated by Alizarin Red staining. Exosome sizes were determined by Nanoparticle Tracking Analysis (NTA), and exosome morphology was examined by transmission electron microscopy (TEM). The expression of exosome and calcification biomarkers was analyzed by quantitative real-time PCR (qPCR) and western blotting. Differential miRNA profiles were determined by deep sequencing and bioinformatics. Protein levels in VSMCs experiencing interference by a miR-324-3p inhibitor were detected by western blotting.

RESULTS

The MOVAS-1 calcification model was confirmed by Alizarin Red staining and expressional alteration of α-SMA, BMP-2, OPN, and MGP. Exosomes from the calcification model showed expression of exosomal biomarkers and regular exosome diameters, which caused significant calcification in MOVAS-1 cells. In total, 987 and 92 miRNAs were significantly upregulated and downregulated in exosomes from the cellular calcification model as compared with those from MOVAS-1 cells, respectively. Target genes of differential miRNAs were involved in various biological processes such as development, metabolism, and cellular component organization and biogenesis as well as multiple signaling pathways such as protein kinase B (AKT) signaling. The most differentially expressed miRNAs were validated by qPCR, which showed that mmu-let-7e-5p was downregulated and mmu-miR-324-3p was upregulated in exosomes from the MOVAS-1 cellular calcification model. The expression of IGF1R was increased, and the expressions of PIK3CA and MAP2K1 were reduced in MOVAS-1 transfected with a miR-324-3p inhibitor.

CONCLUSION

microRNA profiles were significantly altered in exosomes from VSMCs undergoing calcification.

Statin eligibility and cardiovascular risk burden assessed by coronary artery calcium score: comparing the two guidelines in a large Korean cohort

OBJECTIVE

To investigate the statin eligibility and the predictabilities for cardiovascular disease between AHA/ACC and ATPIII guidelines, comparing those results to concomitant coronary artery calcium scores (CACS) in a large cohort of Korean individuals who met statin-eligibility criteria.

METHODS

Among 19,920 participants in a health screening program, eligibility for statin treatment was assessed by the two guidelines. The presence and extent of coronary artery calcification (CAC) was measured by multi-detector computed tomography and compared among the various groups defined by the two guidelines.

RESULTS

Applying the new ACC/AHA guideline to the health screening cohort increased the statin-eligible population from 18.7% (as defined by ATP III) to 21.7%. Statin-eligible subjects as defined only by ACC/AHA guideline manifested a higher proportion of subjects with CAC compared with those meeting only ATP-III criteria even after adjustment for age and sex (47.1 vs. 33.8%, p<0.01). Statin-eligible subjects as defined by ACC/AHA guideline showed higher odds ratio for the presence of CACS>0 compared with those meeting ATP-III criteria {3.493 (3.245∼3.759) vs. 2.865 (2.653∼3.094)}, which was attenuated after adjusted for age and sex.

CONCLUSIONS

In this large Korean cohort, more subjects would have qualified for statin initiation under the new ACC/AHA guideline as compared with the proportion recommended for statin treatment by ATP III guideline. Among statin-eligible Korean health screening subjects, the new ACC/AHA guideline identified a greater extent of atherosclerosis as assessed by CACS as compared to ATP III guideline assessment.

Using coronary artery calcification combined with pretest clinical risk assessment as a means of determining investigation and treatment in patients presenting with chest pain in a rural setting

462 patients presenting with chest pain to a rural district general hospital underwent calcium scoring and pretest clinical risk assessment in order to stratify subsequent investigations and treatment was retrospectively reviewed. The patients were followed up for two years and further investigations and outcomes recorded. Of the 206 patients with zero calcium score, 132 patients were immediately discharged from cardiac follow-up with no further investigation on the basis of their calcium score, low pretest risk of coronary artery disease, and no significant incidental findings. After further tests, 267 patients were discharged with no further cardiac therapy, 88 patients were discharged with additional medical therapy, and 19 patients underwent coronary artery by-pass grafting or percutaneous intervention. 164 patients with incidental findings on the chest CT (computed tomography) accompanying calcium scoring were reviewed, of which 88 patients underwent further tests and follow-up for noncardiac causes of chest pain. The correlations between all major risk factors and calcium scores were weak except for a combination of diabetes and hypertension in the male gender (P = 0.012), The use of calcium scoring and pretest risk appeared to reduce the number of unnecessary cardiac investigations in our patients: however, the calcium scoring test produced a high number of incidental findings on the associated CT scans.

Angiographic coronary artery disease and high-sensitivity troponin-T in a native Pakistani cohort presenting with chronic chest pain

OBJECTIVE

To determine the relationship between troponin-T levels and atheroma burden in Pakistanis presenting to an ambulatory centre with chest pain.

METHODS

A prospective case-control study of 400 patients selected for presence/absence of angiographic disease referred between 2001 and 2003. A comprehensive cardiovascular disease (CVD) risk factor profile was assessed including demographics, environmental and biochemical risk factors including insulin resistance and troponin-T levels. Coronary atheroma burden was quantified by Gensini score.

RESULTS

Clinically significant elevated troponin-T levels (> 30 pmol/l) were found in 40 patients (10%) with equal numbers in groups selected with or without angiographic disease. Troponin-T elevation (> 13 pmol/l) was present in 59 vs. 47 patients (30% vs. 24%; p = 0.04). Troponin-T levels did not correlate with any measured demographical, environmental, drug therapy or biochemical risk factor. No difference was found in concentrations of lipids, apolipoproteins, insulin resistance, C-reactive protein or sialic acid in cohorts stratified by troponin-T concentrations. In univariate analysis comparing patients with high (> 30 pmol/l) and low troponin-T levels (< 13 pmol/l) higher plasma total protein (91 g/l vs. 85 g/l; p = 0.01), increased immunoglobulin levels (41 g/l vs. 36 g/l; p = 0.02) and prevalence of hyperparathyroidism (40% vs. 21%; p = 0.04) were associated with higher troponin-T concentrations.

CONCLUSIONS

This study shows that measurement of troponin-T is not an alternative to imaging in an Indian asian population, but that it does identify a separate potentially high-risk population that would not be identified by the use of imaging alone which is potentially at higher risk of CVD events.

Bioimaging and subclinical cardiovascular disease in low- and middle-income countries

Cardiovascular disease (CVD) is the leading cause of mortality worldwide and also exerts a significant economic burden, especially in low- and middle-income countries (LMICs). Detection of subclinical CVD, before an individual experiences a major event, may therefore offer the potential to prevent or delay morbidity and mortality, if combined with an appropriate care response. In this review, we discuss imaging technologies that can be used to detect subclinical atherosclerotic CVD (carotid ultrasound, coronary artery calcification) and nonatherosclerotic CVD (echocardiography). We review these imaging modalities, including aspects such as rationale, relevance, feasibility, utilization, and access in LMICs. The potential gains in detecting subclinical CVD may be substantial in LMICs, if earlier detection leads to earlier engagement with the health care system to prevent or delay cardiac events, morbidity, and premature mortality. Thus, dedicated studies examining the feasibility, utility, and cost-effectiveness of detecting subclinical CVD in LMICs are warranted.