Association between aortic calcification and stable obstructive coronary artery disease

Lower extremity arterial calcifications assessed by multislice CT as a correlate to coronary artery disease

Background

Patients with peripheral artery disease (PAD) frequently have concomitant coronary artery disease (CAD) and display a higher risk for myocardial infarction, stroke, and death due to cardiovascular events. In order to prevent cardiovascular events, there is an increasing interest in new markers of atherosclerosis. Vascular calcifications (VC) are often present in the early stages of atherogenesis and could be considered an early marker. The aim of this study is to correlate the extent of lower limbs, aortic, and coronary arterial calcification diagnosed by non-contrast multislice CT with the severity of coronary artery disease diagnosed by conventional coronary angiography.

Results

There is borderline significant association between CAD (Gensini score) and each of total lower limb and aorto-iliac calcifications. There is significant association between the number of diseased coronaries and lower limb calcifications. Also, there is significant association between the coronary artery calcifications and lower limb arterial calcifications (total and segmental).

Diabetes mellitus and hypertension are significantly associated with lower limb calcification (total, aorto-iliac, and infra-popliteal). Moreover, lower limb arterial calcifications (total and segmental) are positively correlated with increasing age.

Conclusion

Lower limb arterial calcifications, as diagnosed by non-contrast MSCT, is a noninvasive measure for evaluation of the atherosclerotic burden that correlate to the CAD; it can aid to refine risk stratification and the need for more aggressive preventive strategies.

Can aortic atherosclerosis or epicardial adipose tissue volume be used as a marker for predicting coronary artery disease?

PURPOSE

To investigate whether aortic atherosclerosis or epicardial adipose tissue (EAT) volume on multidetector computed tomography (CT) can predict the presence of significant coronary artery disease (CAD).

MATERIALS AND METHODS

Coronary CT angiography was performed in 202 cases of CAD that were known or based on suspicion. Based on coronary CT angiography results, the patients with significant stenosis (≥50%) and without significant stenosis (<50%) were compared in terms of demographic characteristics, traditional cardiovascular risk factors, aortic atherosclerosis, and EAT volume.

RESULTS

Significant coronary artery stenosis was detected in 92 cases (45.5%). Although EAT volume was higher in the patients with significant stenosis, the difference between the two groups was not statistically significant. The presence of calcification in the descending aorta was significantly higher in the patients with significant stenosis than the patients without significant stenosis (50.4% and 15.4%, respectively, p=0.0001). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy rates of the presence of calcification in the descending aorta in predicting the presence of significant coronary artery stenosis were respectively found as 53.8%, 84.4%, 74.6%, 68.1%, and 70.3%. The sensitivity, specificity, PPV, NPV, and accuracy rates of the ≥2.45mm wall thickness of the descending aorta in predicting the presence of significant coronary artery stenosis were respectively found as 75.3%, 74.3%, 71.4%, 77.9%, and 74.8%.

CONCLUSION

There is a strong relationship between thoracic aortic atherosclerosis and CAD. However, the relationship between EAT volume and CAD is not significant. The presence of aortic atherosclerosis can be used as an additional marker together with traditional cardiovascular risk factors for predicting CAD.

Positron emission tomography of the vulnerable atherosclerotic plaque in man--a contemporary review

Atherosclerosis is the primary underlying cause of cardiovascular disease (CVD). It is the leading cause of morbidity and mortality in the Western world today and is set to become the prevailing disease and major cause of death worldwide by 2020. In the 1950s surgical intervention was introduced to treat symptomatic patients with high-grade carotid artery stenosis due to atherosclerosis – a procedure known as carotid endarterectomy (CEA). By removing the atherosclerotic plaque from the affected carotid artery of these patients, CEA is beneficial by preventing subsequent ipsilateral ischemic stroke. However, it is known that patients with low to intermediate artery stenosis may still experience ischemic events, leading clinicians to consider plaque composition as an important feature of atherosclerosis. Today molecular imaging can be used for characterization, visualization and quantification of cellular and subcellular physiological processes as they take place in vivo; using this technology we can obtain valuable information on atherosclerostic plaque composition. Applying molecular imaging clinically to atherosclerotic disease therefore has the potential to identify atherosclerotic plaques vulnerable to rupture. This could prove to be an important tool for the selection of patients for CEA surgery in a health system increasingly focused on individualized treatment. This review focuses on current advances and future developments of in vivo atherosclerosis PET imaging in man.

Not at random location of atherosclerotic lesions in thoracic aorta and their prognostic significance in relation to the risk of cardiovascular events

Thoracic aortic calcium deposits are frequently detected on tomography of the chest, and in other imaging modalities. Numerous studies indicated the correlation of hemodynamic parameters such as wall shear stress in relation to distribution aortic calcifications. This publication discusses similarities and differences of two distinct pathomechanisms of arterial calcifications: intimal associated with atherosclerosis and medial knows as Mönckeberg’s arteriosclerosis. This review also analyzes the frequent coexistence of aortic calcification and coronary artery disease in terms of risk of cardiovascular events.

Association of aortic knob calcification with intracranial stenosis in ischemic stroke patients

Background and Purpose

Aortic knob calcification (AC) is associated with increased risks of cardiovascular and cerebrovascular events. We evaluated the clinical importance of AC in ischemic stroke patients with intracranial (IC) stenosis using simple, non-invasive and routine chest radiography.

Methods

The presence of AC was assessed in a chest posteroanterior view in 307 acute ischemic stroke patients admitted from May 2009 to April 2010, and who underwent magnetic resonance angiography or distal subtraction angiography. The association of AC with IC stenosis was analyzed.

Results

Patient age (68.3±8.7 vs. 65.9±8.27 years, P=0.04), and the prevalence of IC stenosis (70.7 vs. 41.3%, P<0.01) were higher in patients with AC than in patients without calcification. After adjusting for age, gender and vascular risk factors, logistic regression analysis showed that AC (Odds ratio, 3.54; 95% confidence interval, 1.90 to 6.61, P<0.01) and age (Odds ratio, 1.79; 95% confidence interval, 1.01 to 3.19; P=0.04) were independent factors affecting IC stenosis.

Conclusions

AC appears to be a reliable predictor for IC stenosis, an important mechanism of ischemic stroke.

Dual-energy X-ray absorptiometry in the evaluation of abdominal aortic calcifications

The objective of this study was to evaluate the diagnostic performance of the new dual-energy X-ray absorptiometry equipment vs digital radiography (DR) in the detection and scoring of abdominal aortic calcifications (AACs). Seventy-five patients with indication for morphometric evaluation of the spine underwent vertebral fracture assessment (VFA) and spinal DR (gold standard). The radiographic and VFA images were analyzed to detect AAC using a previously validated 24-point scale (AAC-24) and a simplified 8-point scale (AAC-8). The evaluation was conducted by 2 expert radiologists and repeated by the more experienced of the 2 after 7d to verify the results. Patients with a score of 5 or more in AAC-24 and 3 or more in AAC-8 were considered at risk for cardiovascular diseases (CVDs). The aorta was not completely visible in 11 VFA and 1 DR images. DR detected AAC in 42 of the 63 patients (66.7%), whereas 15 patients (23.8%) were considered at risk for CVD. The VFA showed sensitivity, specificity, and accuracy in the detection of AAC with values of 78.6%, 85.7%, and 81.0%, respectively, with both AAC-24 and AAC-8; in the identification of patients at risk for CVD, VFA demonstrated sensitivity, specificity, and accuracy, respectively, with values of 86.7%, 100%, and 96.8% using AAC-24 and 86.7%, 93.8%, and 92.1% using AAC-8. In the detection of AAC, intraobserver agreement was superimposable using both the techniques (κ=1.00), whereas in the identification of patients at risk for CVD, kappa values were 0.96 and 0.95 using AAC-24 and 1.00 and 0.96 using AAC-8 for DR and VFA, respectively. Interobserver agreement in the evaluation of the presence/absence of AAC showed a kappa value of 0.76 for DR and 0.71 for VFA, whereas kappa values of 0.91 and 0.87 for DR and 0.85 and 0.83 for VFA were achieved for CVD risk using AAC-24 and AAC-8, respectively. AAC can be easily and accurately diagnosed by VFA with satisfactory accuracy, reproducibility, and repeatability. VFA may be used in the assessment and monitoring of AAC.