Impact Of Calcification Research Articles

Impact of calcification on Murray law-based quantitative flow ratio for physiological assessment of intermediate coronary stenoses.

To investigate the influence of coronary calcification on the diagnostic performance of Murray law-based quantitative flow ratio (μQFR) in identifying hemodynamically significant coronary lesions referenced to fractional flow reserve (FFR). A total of 571 intermediate lesions from 534 consecutive patients (66.1 ± 10.0 years, 67.2% males) who underwent coronary angiography and simultaneous FFR measurement were included. Calcific deposits were graded by angiography as none or mild (spots), moderate (involving ≤ 50% of the reference vessel diameter), and severe (> 50%). Performance of μQFR to detect functional ischemia (FFR ≤ 0.80) was evaluated, including diagnostic parameters and areas under the receiver-operating curves (AUCs). The discrimination of ischemia by μQFR was comparable between none/mild and moderate/severe calcification (AUC: 0.91 [95% confidence interval: 0.88-0.93] vs. 0.87 [95% confidence interval: 0.78-0.94]; p = 0.442). No statistically significant difference was observed for μQFR between the two categories in sensitivity (0.70 vs. 0.69, p = 0.861) and specificity (0.94 vs. 0.90, p = 0.192). Moreover, μQFR showed significantly higher AUCs than quantitative coronary angiographic diameter stenosis in both vessels with none/mild (0.91 vs. 0.78, p < 0.001) and moderate/severe calcification (0.87 vs. 0.69, p < 0.001). By multivariable analysis, there was no association between calcification and μQFR-FFR discordance (adjusted odds ratio: 1.529, 95% confidence interval: 0.788-2.968, p = 0.210) after adjustment for other confounding factors. μQFR demonstrated robust and superior diagnostic performance for lesion-specific ischemia compared with angiography alone regardless of coronary calcification.

Stiffness and axial pain are associated with the progression of calcification in a mouse model of diffuse idiopathic skeletal hyperostosis

BackgroundDiffuse idiopathic skeletal hyperostosis (DISH) is characterized by progressive calcification of spinal tissues; however, the impact of calcification on pain and function is poorly understood. This study examined the association between progressive ectopic spine calcification in mice lacking equilibrative nucleoside transporter 1 (ENT1−/−), a preclinical model of DISH, and behavioral indicators of pain.MethodsA longitudinal study design was used to assess radiating pain, axial discomfort, and physical function in wild-type and ENT1−/− mice at 2, 4, and 6 months. At endpoint, spinal cords were isolated for immunohistochemical analysis of astrocytes (GFAP), microglia (IBA1), and nociceptive innervation (CGRP).ResultsIncreased spine calcification in ENT1−/− mice was associated with reductions in flexmaze exploration, vertical activity in an open field, and self-supporting behavior in tail suspension, suggesting flexion-induced discomfort or stiffness. Grip force during the axial stretch was also reduced in ENT1−/− mice at 6 months of age. Increased CGRP immunoreactivity was detected in the spinal cords of female and male ENT1−/− mice compared to wild-type. GFAP- and IBA1-immunoreactivity were increased in female ENT1−/− mice compared to wild-type, suggesting an increase in nociceptive innervation.ConclusionThese data suggest that ENT1−/− mice experience axial discomfort and/or stiffness and importantly that these features are detected during the early stages of spine calcification.

Impact of calcification on clinical outcomes after drug‐coated balloon angioplasty for superficial femoral artery disease: Assessment using the peripheral artery calcification scoring system

To investigate whether the severity of calcification assessed by the peripheral artery calcification scoring system (PACSS) was associated with clinical outcomes of drug-coated balloon (DCB) angioplasty for femoropopliteal lesions. We retrospectively analyzed 733 limbs with intermittent claudication of 626 patients, who underwent DCB angioplasty for de novo femoropopliteal lesions between January 2017 and February 2021 at sevencardiovascular centers in Japan. The patients were categorized using the PACSS classification (grades 0-4: no visible calcification of the target lesion, unilateral wall calcification < 5 cm, unilateral calcification ≥ 5 cm, bilateral wall calcification < 5 cm, and bilateral calcification ≥ 5 cm, respectively). The main outcome was primary patency at 1 year. The Cox proportional hazards analysis was used to explore whether the PACSS classification was an independent predictor of clinical outcomes. The distribution of PACSS was grade 0 in 38%, grade 1 in 17%, grade 2 in 7%, grade 3 in 16%, and grade 4 in 23%. The 1-year primary patency rates in these grades, respectively, were 88.2%, 89.3%, 71.9%, 96.5%, and 82.6%, respectively (p < 0.001). Multivariate analysis disclosed that PACSS grade 4 (hazard ratio: 1.82, 95% confidence interval 1.15-2.87, p = 0.010) was associated with restenosis. The PACSS grade 4 calcification was independently associated with poor clinical outcomes after DCB angioplasty for de novo femoropopliteal lesions.

Effect of Calcification Based on Computer-Aided System on CT-Fractional Flow Reserve in Diagnosis of Coronary Artery Lesion.

This study was to analyze the diagnostic value of coronary computed tomography angiography (CCTA) and fractional flow reserve (FFR) based on computer-aided diagnosis (CAD) system for coronary lesions and the possible impact of calcification. 80 patients who underwent CCTA and FFR examination in hospital were selected as the subjects. The FFR value of 0.8 was used as the dividing line and divided into the ischemic group (FFR ≤ 0.8) and nonischemic group (FFR > 0.8). The basic data and imaging characteristics of patients were analyzed. The maximum diameter stenosis rate (MDS %), maximum area stenosis rate (MAS %), and napkin ring sign (NRS) in the ischemic group were significantly lower than those in the nonischemic group (P < 0.05). Remodeling index (RI) and eccentric index (EI) compared with the nonischemic group had no significant difference (P > 0.05). The total plaque volume (TPV), total plaque burden (TPB), calcified plaque volume (CPV), lipid plaque volume (LPV), and lipid plaque burden (LPB) in the ischemic group were significantly different from those in the non-ischemic group (P < 0.05). MAS % had the largest area under curve (AUC) for the diagnosis of coronary myocardial ischemia (0.74), followed by MDS % (0.69) and LPV (0.68). CT-FFR had high diagnostic sensitivity, specificity, accuracy, truncation value, and AUC area data for patients in the ischemic group and nonischemic group. The diagnostic sensitivity, specificity, accuracy, cutoff value, and AUC area data of CT-FFR were higher in the ischemic group (89.93%, 92.07%, 95.84%, 60.51%, 0.932) and nonischemic group (93.75%, 90.88%, 96.24%, 58.22%, 0.944), but there were no significant differences between the two groups (P > 0.05). In summary, CT-FFR based on CAD system has high accuracy in evaluating myocardial ischemia caused by coronary artery stenosis, and within a certain range of calcification scores, calcification does not affect the diagnostic accuracy of CT-FFR.

Impact of calcification on potato yield

By seed surfaces according to the information the Federal Bureau of Statistics and the Institute of Statistics Republic of Srpska of the total area under vegetables potatoes occupies 57% sowing area, so that after the corn and wheat, potatoes the most important agricultural plant in Bosnia and Herzegovina. Most are lighter types of land - permeable, loose, sandy-humus and sandy-clay ground with crumb structure, rich in mineral and organic matter, with favorable water – air characteristics. Does not match his tough swampy lands with a high level of underground water. Tolerate acid soil reaction, and the optimum pH is 5,4-6,5. Given that the area of Tuzla canton mainly acid soil with pH values from 4.5 to 5.5 made the production of a sample on the plot that had a pH value of 4.6 as a material for the reparation of land or quality of calcification was Fertdolomit in order to increase in pH, after you apply Fertdolomit analysis has found that the increased pH value to 5.8. Calcification is a measure of repair of chemical properties of soil, primarily reducing its acidity, ie. bringing the pH value to the optimum level for the cultivation of certain plant species calcium use of fertilizers. At the same time, this measure of the repair water-air, mechanical, physical and biological properties of soil. Reflected in the potatoes plant in four different variants: the control, with the use of 40 t / ha of manure, the use of 40 t / ha manure and NPK 7:20:30 400 kg / ha and the use of manure 40 t / ha, NPK 7:20: 30 in the amount of 400 kg / ha with supplements Fertdolomit in the amount of 3 t / ha. The results reflected a big point to the importance of calcification in the production of potatoes.

Impact of calcification on potato yield

Impact of calcification on potato yield

The Impact of Calcification on Intraplaque Hemorrhage in Coronary Atherosclerosis from Autopsy Samples: The Hisayama Study

The Impact of Calcification on Intraplaque Hemorrhage in Coronary Atherosclerosis from Autopsy Samples: The Hisayama Study

Tissue-nonspecific alkaline phosphatase inhibition reduces atherosclerotic plaque development

Background and Aims: The calcium score predicts cardiovascular mortality but the impact of calcification on plaque stability remains controversial. Tissue-nonspecific alkaline phosphatase (TNAP), the main enzyme involved in bone mineralization, is expressed in calcified mouse plaques, and is also elevated in the blood of individuals with metabolic syndrome, in whom it is associated with cardiovascular mortality. Therefore, we aimed to determine the involvement of TNAP in plaque calcification and progression.

Impact of calcifications on diagnostic yield of endoscopic ultrasound-guided fine-needle aspiration for pancreatic ductal adenocarcinoma.

Chronic calcific pancreatitis (CCP) is a major risk factor for pancreatic ductal adenocarcinoma (PDAC) and is common in southern India. Endoscopic ultrasound fine-needle aspiration (EUS-FNA) is useful for tissue acquisition in patients with solid pancreatic lesions. Multiple factors may affect the diagnostic yield ofFNA samples. The present study was performed to assess the impact of pancreatic calcifications on the diagnostic yield of EUS-FNA in PDAC. All patients with confirmed PDAC from January 2013 to December 2017 were included. CCP was diagnosed based on typicalimaging characteristics with or without evidence of pancreatic insufficiency along with surgical histopathology reports showing features of chronic pancreatitis. The diagnostic yield and adequacy of cellularity were assessed by a pathologist who was blinded and were compared between the two groups: group 1: PDAC patients with no evidence of CCP and, group 2: PDAC patients with CCP. A total of 122 patients were included in the study. The diagnostic yield was lower in patients in group 2 (n= 42, 25 [59.52%]) as compared to those in group 1 (n= 80, 63 [78.75%]) (p-value = 0.01). On multivariate analysis, only the presence of calcifications was found to have an independent association with diagnostic yield (odds ratio 3.83 [95% confidence interval 1.22-11.9]). CCP had a significant impact on the diagnostic yield of EUS-FNA for pancreatic adenocarcinoma. Novel techniques and newer technology that may mitigate the negative effect of calcification on diagnostic yield of EUS-FNA in patients withCCP.

Impact of calcification and infrapopliteal outflow on the outcome of endovascular treatment of femoropopliteal occlusive disease.

ObjectivesIn this paper, we report the long-term outcomes of the endovascular treatment of femoropopliteal occlusive disease, focusing on the importance of calcification and runoff outflow on limb salvage and patency, and the factors associated with these outcomes at a single center.MethodsThis retrospective cohort study included consecutive patients with femoropopliteal occlusive who underwent femoropopliteal angioplasty at the Division of Vascular and Endovascular Surgery, Hospital do Servidor Público Estadual, São Paulo, Brazil, between January 2015 and July 2017.ResultsIn total, 86 femoropopliteal occlusive angioplasties were performed in 86 patients, with an initial technical success rate of 95.34%. The mean ± standard deviation follow-up time was 880 ± 68.84 days. The analysis was performed at 720 days. Technical failure occurred in four patients, who were excluded from the analysis, leaving 82 patients and 82 femoropopliteal occlusive angioplasties. The estimated primary patency, secondary patency, limb salvage, and overall survival rates at 720 days were 60%, 96%, 90%, and 82.5%, respectively. In univariate and multivariate analyses, Cox regression showed worse primary patency rates in patients with one tibial vessel or isolated popliteal artery runoff (p = 0.005), calcification grade 4 (p = 0.019), calcification grade > 2 (p = 0.017), small vessel diameter < 4 mm (p = 0.03) or primary angioplasty without stenting (p = 0.021). A univariate analysis showed worse limb salvage in patients with one tibial vessel or isolated popliteal artery runoff (p = 0.039).ConclusionsIn this study, the main factors associated with worse outcomes in the endovascular treatment of femoropopliteal occlusive in terms of loss of primary patency were one tibial vessel or isolated popliteal artery runoff, calcification grade 4, or calcification grade > 2, small vessel diameter < 4 mm, and no stents use. One tibial vessel or isolated popliteal artery runoff was also associated with limb loss in a univariate Cox regression analysis.

Cartilage calcification of the ankle joint is associated with osteoarthritis in the general population

BackgroundCartilage calcification (CC) is associated with osteoarthritis (OA) in weight-bearing joints, such as the hip and the knee. However, little is known about the impact of CC and degeneration on other weight-bearing joints, especially as it relates to the occurrence of OA in the ankles. The goal of this study is to analyse the prevalence of ankle joint cartilage calcification (AJ CC) and to determine its correlation with factors such as histological OA grade, age and BMI in the general population.MethodsCC of the distal tibia and talus in 160 ankle joints obtained from 80 donors (mean age 62.4 years, 34 females, 46 males) was qualitatively and quantitatively analysed using high-resolution digital contact radiography (DCR). Correlations with factors, such as the joint’s histological OA grade (OARSI score), donor’s age and BMI, were investigated.ResultsThe prevalence of AJ CC was 51.3% (95% CI [0.40, 0.63]), independent of gender (p = 0.18) and/or the joint’s side (p = 0.82). CC of the distal tibia was detected in 35.0% (28/80) (95% CI [0.25, 0.47]) and talar CC in 47.5% (38/80) (95% CI [0.36, 0.59]) of all cases. Significant correlations were noted between the mean amount of tibial and talar CC (r = 0.59, p = 0.002), as well as between the mean amount of CC observed in one ankle joint with that of the contralateral side (r = 0.52, p = 0.02). Furthermore, although the amount of AJ CC observed in the distal tibia and talus correlated with the histological OA-grade of the joint (r = 0.70, p < 0.001 and r = 0.72, p < 0.001, respectively), no such correlation was seen in the general population with relation to age (p = 0.32 and p = 0.49) or BMI (p = 0.51 and p = 0.87).ConclusionThe prevalence of AJ CC in the general population is much higher than expected. The relationship between the amount of AJ CC and OA, independent of the donors’ age and BMI, indicates that CC may play a causative role in the development of OA in ankles.

Mammographic calcification can predict outcome in women with breast cancer treated with breast-conserving surgery.

The impact of calcification in patients with breast carcinoma treated with breast-conserving surgery (BCS) is unclear. The present study aimed to determine the outcome of breast cancer patients with calcification treated with BCS. The records of 409 patients with breast carcinoma treated with BCS from January 2005 to December 2008 were reviewed. Patients were categorized as those with calcification (on mammography or ultrasonography), or those without calcification (neither on mammography nor ultrasonography). The local relapse free survival time (LRFS), disease free survival time (DFS) and overall survival time (OS) were compared, and subgroup analysis was performed based on morphological types and distribution patterns of mammographic calcification. Survival analysis demonstrated that patients with calcification had a significantly increased risk of local recurrence, distant metastasis and mortality compared with those without calcification [relative risk (RR) and 95% confidence interval (CI): local recurrence, 2.46 and 1.11–5.44; distant metastasis, 2.24 and 1.19–4.24; mortality, 2.50 and 1.06–5.86]. Subgroup analysis revealed that the distribution patterns (rather than morphological types of calcification) accounted for the increased risk of recurrence following BCS. Patients with mammographic calcification of liner/segmental distribution had significantly decreased LRFS (RR=6.20; 95% CI, 2.26–16.98), DFS (RR=6.81; 95% CI, 2.86–16.20) and OS (RR=9.14; 95% CI, 2.53–33.00), while patients with mammographic calcification of clustered distribution did not have significantly decreased LRFS, DFS and OS (P>0.05), compared with those without calcification. In addition, the mammographic calcification spreading along the ducts was more likely to be accompanied by an extensive intraductal component (P<0.001). Finally, the outcome of patients with calcification on breast ultrasound was as good as those without calcification. Patients with mammographic calcification, particularly those with calcification spreading along the ducts, have a higher risk of recurrence following BCS, which has a negative impact on long-term survival. Calcification identified on breast ultrasonography does not affect the survival of patients treated with BCS.

Dual-Energy CTA in Patients with Symptomatic Peripheral Arterial Occlusive Disease: Study of Diagnostic Accuracy and Impeding Factors.

Purpose The purpose of this study was to assess the diagnostic performance of dual-energy CT angiography (DE-CTA) in patients with symptomatic peripheral artery occlusive disease (PAOD) and to identify factors that impede its diagnostic accuracy. Materials and Methods Dual-source DE-CTA scans of the lower extremities of 94 patients were retrospectively compared to the diagnostic reference standard, digital subtraction angiography (DSA). Two independent observers assessed PAOD incidence, image quality, artifacts, and diagnostic accuracy of DE-CTA in 1014 arterial segments on axial, combined 80/140 kVp reconstructions and on 3 D maximum intensity projections (MIP) after automated bone and plaque removal. The impact of calcifications, image quality, and image artifacts on the diagnostic accuracy was evaluated using Fisher's exact test. Furthermore, interobserver agreement was analyzed. Results Two observers achieved sensitivities of 98.0 % and 93.9 %, respectively, and specificities of 75.0 % and 66.7 %, respectively, for detecting stenoses of > 50 % of the lower extremity arteries. Calcifications impeded specificity, e. g. from 81.2 % to 46.2 % for reader 1 (p < 0.001). Specificity increased with higher image quality, e. g. from 70.0 % to 76.4 % for reader 1 (p < 0.001). Artifacts decreased the specificity of reader 2 (p < 0.001). The overall interobserver agreement ranged between moderate and substantial for stenosis detection and calcified plaques. Conclusion DE-CTA is accurate in the detection of arterial stenoses of > 50 % in symptomatic PAOD patients. Calcified atherosclerotic plaques, image quality, and artifacts may impede specificity. Key Points: · Sensitivities of DE-CTA were 98.0 and 93.9 %, specificities 75.0 % and 66.7 %.. · Interobserver agreement was moderate to substantial for stenosis and plaque detection.. · Calcified atherosclerotic plaques, image quality, and artifacts may impede specificity.. Citation Format · Klink T, Wilhelm T, Roth C et al. Dual-Energy CTA in Patients with Symptomatic Peripheral Arterial Occlusive Disease: Study of Diagnostic Accuracy and Impeding Factors. Fortschr Röntgenstr 2017; 189: 441 - 452.

Impact of Calcification on Clinical Outcomes After Endovascular Therapy for Superficial Femoral Artery Disease

Purpose: To investigate whether the severity of lesion calcification assessed by the novel peripheral artery calcification scoring system (PACSS) was associated with clinical outcomes after endovascular therapy (EVT) for superficial femoral artery (SFA) lesions. Methods: A retrospective analysis was conducted of 394 consecutive patients (mean age 72±8 years; 290 men) with intermittent claudication [223 (57%) with diabetes, 81 (21%) on hemodialysis] who underwent successful EVT for de novo SFA lesions [length 152.1±95.7 mm; 199 (50%) TransAtlantic Inter-Society Consensus II class C/D] between January 2010 and December 2013. The patients were retrospectively categorized using the PACSS classification (grades 0–4: no visible calcification of the target lesion, unilateral wall calcification <5 cm, unilateral calcification ≥5 cm, bilateral wall calcification <5 cm, and bilateral calcification ≥5 cm, respectively). The main outcome was primary patency, while the secondary outcome measures were mortality and major adverse limb events [MALE: any intervention (repeat EVT or surgical revision) or major (above ankle) amputation]. Cox proportional hazards analysis was used to explore whether the PACSS classification was an independent predictor of clinical outcomes. Results are presented as the hazard ratio (HR) and 95% confidence interval (CI). Results: The distribution of PACSS grades was 0 in 54%, grade 1 in 16%, grade 2 in 12%, grade 3 in 9%, and grade 4 in 9%. The 2-year primary patency rates in these grades, respectively, were 70.0%, 66.6%, 72.1%, 55.6%, and 36.3% (p<0.001). After multivariate analysis, PACSS grade 4 (HR 2.74, 95% CI 1.56 to 4.83, p<0.001), diabetes (HR 1.52, 95% CI 1.06 to 2.20, p=0.022), lesion length (HR 1.04, 95% CI 1.01 to 1.07, p=0.006), and vessel diameter (HR 0.80, 85% CI 0.65 to 0.98, p=0.038) were associated with loss of primary patency. PACSS grade 4 was also associated with MALE and mortality (p=0.048 and 0.011, respectively). Bare metal stent use (HR 0.47, 95% CI 0.30 to 0.73, p<0.001) was positively associated with primary patency. Conclusion: PACSS grade 4 calcification was independently associated with clinical outcomes after EVT for de novo SFA lesions.

Calcification in a changing ocean

Hard parts are emblematic features of marine calcifiers. These calcium carbonate structures can be instrumental for supporting body mass, providing defense against predatory attempts, or protecting from environmental extremes. Some of the most iconic calcifiers (mussel beds, oyster reefs, and coral reefs) are ecosystem engineers and provide substantial ecosystem services. Albeit the vast diversity of calcifying taxa in the ocean, corals, and to a lesser extent bivalves, were the focus of most research presented in the 2016 Ocean Sciences Meeting session, “Coral Reef Calcification in a Changing Ocean: From Microscale Mechanisms to Macroscale Responses.” This emphasis reflects the realized effects of changing ocean chemistry for these particular animals. The day began with a focus on the mechanistic impacts of climate change on calcification—the means by which the organism can mediate the precipitation of calcium carbonate in a favorable or unfavorable environment. Calcification is more than just the facilitated movement of calcium ions and inorganic carbon by the organism; unanticipated enzymes are suspected to play a role as well. For example, Joshua Rosenthal from the University of Puerto Rico demonstrated that during early calcification in the coral, Porites astreoides, vitamin C is transported via a sodium-dependent transporter and seems to play a critical role in collagen formation. Collagen is considered an integral backbone of calcium carbonate. Other mechanistic impacts of changing ocean chemistry on calcification include the ability for both bivalves and corals to increase pH at the site of calcification. Increasing pH can favor the calcification reaction. Observations of pH were mostly accomplished through the use of micro-electrodes, where progress in micromanipulation of the electrode through the animal tissue and into the calcifying space is being mastered. The impact of changing climate on bivalves has been another area of emphasis given the economic value of the aquaculture industry. The majority of talks on bivalves considered the larval stage during which the shell is first calcified. Larval production is a bottleneck in the aquaculture industry, and climate change has been observed to have direct impacts on larval production through effects on first shell formation. Research presented by Kirti Ramesh from GEOMAR targeted identification of the calcium carbonate polymorph first precipitated, which is important for both calcification and dissolution kinetics. Members of Donal Manahan's lab at the University of Southern California (including the author) presented a calcification budget for first shell formation to demonstrate why shells are smaller at undersaturation, and also developed a bioenergetics framework for the energetic cost of calcification. The impact of calcification on biogeochemistry on coral reefs was another major theme of the session. The autonomous sensing capabilities and the creativity of the scientists used to unravel the interplay between calcification and biogeochemistry are becoming impressive. The purview spanned past, present, and future climate change perspectives. A few of the highlights included: Rebecca Albright from the Carnegie Institution for Science presented work in which she and colleagues turned back the clock on coral reefs by manipulating seawater in situ to closely reflect pre-industrial conditions. This ‘reversal of ocean acidification' enhanced net coral reef calcification indicating that ocean acidification may already be impairing the state of coral reefs. Present-day climate oscillations, in particular the 2015 “Godzilla” El Niño, which was ongoing at the time, also made the list of hot topics. Wade McGillis from Lamont-Doherty Earth Observatory utilized biogeochemical sensing packages at Panama coral reefs to quantify the negative impact of El Niño on net calcification rates. The final talk of the session considered coral reefs into the future. Dennis Hubbard from Oberlin College discussed whether coral reefs can maintain accretion rates to keep pace with rising sea levels. The take away: greater than 50% of reefs appear to be lagging behind sea level rise. The implication is that low-lying island communities will become increasingly vulnerable to storms as the reef's capacity to temper wave energy becomes capacitated. These sobering findings led Hubbard to refer to humans as “Homo stupidus.” Can research on calcification in a changing ocean keep up with the pace of change in the ocean? There are still many uncertainties with regards to resilience and adaptation potential that will regulate the actual impact of anthropogenic climate change on marine calcifiers. And while resilience and adaptation have proved challenging to assess, it is a much-needed next-step forward for research efforts. Indications from this session are that these topics should be on the agenda at future Ocean Sciences Meetings. Christina A. Frieder, University of Southern California, Los Angeles, California; cafriede@usc.edu

Abstract 14875: Impact of Calcification and Long-Term Outcomes of Intravascular Ultrasound-Guided Stent Implantation for Atherosclerotic Subclavian Artery Obstructive Lesions

Background: Currently, stent implantation for Subclavian artery obstructive lesions (SAOD) is an established method. Intravascular ultrasound (IVUS) provides valuable information for vessel and lumen at pre and post stenting, but there are a few reports on the effect of calcification and long-term outcomes of these methods using IVUS. Methods: We performed IVUS-guided stent implantations for SAOD in 14 arteries of 14 patients between February 2010 and December 2014. The main indications for subclavian artery stenting were arm claudication (10 patients), subclavian steal syndrome (3 patients) and coronary steal syndrome (1 pateint). Ten lesions were stenotic and four lesions were completely obstructed. We divided our patients into 2 groups according to the grade of calcification using IVUS: mild-calc group who showed none or 1/3 circumference calcification in the lesion and severe-calc group who showed more than 1/3 circumference calcification. We compared the IVUS parameters including pre minimum lumen diameter (MLD) (short axis), pre minimum lumen area (MLA), post minimum stent area (MSA), post minimum stent diameter (MSD) (short axis) and symmetric index (minimum/maximum stent diameter) between the two groups. Resutls: IVUS-guided stent implantations for SAOD were successful without perioperative complications in all patients. During follow-up observation (4-60 months, mean 21.8 months), 1 restenosis occurred. Post MSD (short axis) and post MSA were significantly lower in severe-calc group than mild-calc group while there were no significant differences between the two groups. Conclusion: IVUS-guided stent implantation for SAOD achieved satisfactory long-term outcomes. However, calcification may be correlated with worse outcomes in these lesions.

How Does Juxtaluminal Calcium Affect Critical Mechanical Conditions in Carotid Atherosclerotic Plaque? An Exploratory Study

The impact of calcification on the carotid atherosclerotic plaque vulnerability remains controversial and unclear. This study assesses the critical mechanical conditions induced by the calcium at the lumen surface, i.e., juxtaluminal calcification (JLCa), within human carotid atherosclerotic plaque. Eleven patients with evidence of JLCa were included for the analysis. The plaque geometry was reconstructed based on computed tomography and magnetic resonance images and 3-D fluid-structure interaction simulation was used for mechanical analysis. The presence of JLCa increased local stresses compared to when calcification was artificially covered with a 0.2-mm-thick fibrous cap (107.87 kPa [76.99, 129.14] versus 63.17 kPa [34.55, 75.13]; Median, [interquartile range]; ). Stretch ratio decreased from 1.18 [1.07, 1.27] to 1.13 [1.10, 1.18] (p = 0.03). The presence of JLCa significantly elevates local stress and stretch level. Further exploration of this plaque feature is warranted as a possible risk factor causing plaque vulnerability.

460 Impact of calcification measured by dual-source computed tomography in aortic valve cups, annulus and root on hemodynamic severity of tricuspid and bicuspid aortic valve stenosis

460 Impact of calcification measured by dual-source computed tomography in aortic valve cups, annulus and root on hemodynamic severity of tricuspid and bicuspid aortic valve stenosis

Impact of calcifications on patient-specific wall stress analysis of abdominal aortic aneurysms

As a degenerative and inflammatory desease of elderly patients, about 80% of abdominal aortic aneurysms (AAA) show considerable wall calcification. Effect of calcifications on computational wall stress analyses of AAAs has been rarely treated in literature so far. Calcifications are heterogeneously distributed, non-fibrous, stiff plaques which are most commonly found near the luminal surface in between the intima and the media layer of the vessel wall. In this study, we therefore investigate the influence of calcifications as separate AAA constituents on finite element simulation results. Thus, three AAAs are reconstructed with regard to intraluminal thrombus (ILT), calcifications and vessel wall. Each patient-specific AAA is simulated twice, once including all three AAA constituents and once neglecting calcifications as it is still common in literature. Parameters for constitutive modeling of calcifications are thereby taken from experiments performed by the authors, showing that calcifications exhibit an almost linear stress-strain behavior with a Young's modulus E ≥ 40 MPa. Simulation results show that calcifications exhibit significant load-bearing effects and reduce stress in adjacent vessel wall. Average stress within the vessel wall is reduced by 9.7 to 59.2%. For two out of three AAAs, peak wall stress decreases when taking calcifications into consideration (8.9 and 28.9%). For one AAA, simulated peak wall stress increases by 5.5% due to stress peaks near calcification borders. However, such stress singularities due to sudden stiffness jumps are physiologically doubtful. It can further be observed that large calcifications are mostly situated in concavely shaped regions of the AAA wall. We deduce that AAA shape is influenced by existent calcifications, thus crucial errors occur if they are neglected in computational wall stress analyses. A general increase in rupture risk for calcified AAAs is doubted.

Impact of calcification and intraluminal thrombus on the computed wall stresses of abdominal aortic aneurysm

Increased biomechanical stresses within the abdominal aortic aneurysm (AAA) wall contribute to its rupture. Calcification and intraluminal thrombus can be commonly found in AAAs, but the relationship between calcification/intraluminal thrombus and AAA wall stress is not completely described. Patient-specific three-dimensional AAA geometries were reconstructed from computed tomographic images of 20 patients. Structural analysis was performed to calculate the wall stresses of the 20 AAA models and their altered models when calcification or intraluminal thrombus was not considered. A nonlinear large-strain finite element method was used to compute the wall stress distribution. The relationships between wall stresses and volumes of calcification and intraluminal thrombus were sought. Maximum stress was not correlated with the percentage of calcification, and was negatively correlated with the percentage of intraluminal thrombus (r = -0.56; P = .011). Exclusion of calcification from analysis led to a significant decrease in maximum stress by a median of 14% (range, 2%-27%; P < .01). When intraluminal thrombus was eliminated, maximum stress increased significantly by a median of 24% (range, 5%-43%; P < .01). The presence of calcification increases AAA peak wall stress, suggesting that calcification decrease the biomechanical stability of AAA. In contrast, intraluminal thrombus reduces the maximum stress in AAA. Calcification and intraluminal thrombus should both be considered in the evaluation of wall stress for risk assessment of AAA rupture.