Computational Modelling of Multi-folded Balloon Delivery Systems for Coronary Artery Stenting: Insights into Patient-Specific Stent Malapposition

Aim. To evaluate the antihypertensive efficacy and tolerability of a fixed combination of amlodipine and ramipril in hypertensive patients with very high cardiovascular risk. Material and methods. A retrospective cohort study of real clinical practice of prescribing antihypertensive drugs according to 255 medical records of outpatient hypertensive patients with a history of acute coronary syndrome (ACS) and coronary artery stenting was performed in the first part. An open observational study was performed in the second part. 69 people older than 18 years with a history of ACS and coronary artery stenting, without reaching the target blood pressure (BP) level while using free combinations of antihypertensive drugs and with indications for a fixed combination of ramipril and amlodipine were included into the study. Analysis of self-monitoring of BP, office BP, daily BP monitoring (ABPM) and patients’ adherence to treatment (Morisky-Green test) initially, after 4 and after 12 weeks of taking the fixed combination of ramipril and amlodipine was performed to assess the clinical efficacy of the studied drug. Results. It was found that 42.0% of patients did not follow the recommendations for regular intake of antihypertensive drugs. So, hypertension of all patients regarded as false-refractory, which was the basis for the prescription of the fixed combination of ramipril and amlodipine in accordance with clinical guidelines for the diagnosis and treatment of hypertension. After 4 weeks of therapy, there was significant decrease in office BP with the achievement and preservation of the target level by the 12th week, normalization to the 12th week of day and night BP variability in 54.9% of patients. 78.0% of patients followed medical recommendations for regular administration of antihypertensive drugs, none of the patients had adverse events. Conclusion. The use of fixed combinations of drugs, in particular, amlodipine and ramipril as a part of multicomponent therapy in hypertensive patients with very high cardiovascular risk, led to the achievement of target BP by the 4th week of therapy and stable preservation of antihypertensive effect in 12 weeks of treatment as well as gradual normalization of day and night BP variability in more than half of patients. Fixed combination of ramipril and amlodipine allowed to improve adherence of patients to cardiovascular diseases.

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Fluid–structure interactions (FSI) based study of low-density lipoproteins (LDL) uptake in the left coronary artery

Scientific Reports ◽

10.1038/s41598-021-84155-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Xueping Chen ◽

Jian Zhuang ◽

Huanlei Huang ◽

Yueheng Wu

Keyword(s):

Shear Stress ◽

Coronary Artery ◽

Left Coronary Artery ◽

Arterial Wall ◽

Low Density Lipoproteins ◽

Patient Specific ◽

Low Density ◽

Fluid Structure ◽

Flowing Blood ◽

Stress Dependent

AbstractThe purpose of this study is to compare the effect of the different physical factors on low-density lipoproteins (LDL) accumulation from flowing blood to the arterial wall of the left coronary arteries. The three-dimensional (3D) computational model of the left coronary arterial tree is reconstructed from a patient-specific computed tomography angiography (CTA) image. The endothelium of the coronary artery is represented by a shear stress dependent three-pore model. Fluid–structure interaction ($$FSI$$ FSI ) based numerical method is used to study the LDL transport from vascular lumen into the arterial wall. The results show that the high elastic property of the arterial wall decreases the complexity of the local flow field in the coronary bifurcation system. The places of high levels of LDL uptake coincide with the regions of low wall shear stress. In addition, hypertension promotes LDL uptake from flowing blood in the arterial wall, while the thickened arterial wall decreases this process. The present computer strategy combining the methods of coronary CTA image 3D reconstruction, $$FSI$$ FSI simulation, and three-pore modeling was illustrated to be effective on the simulation of the distribution and the uptake of LDL. This may have great potential for the early prediction of the local atherosclerosis lesion in the human left coronary artery.

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Evaluating a calcium-aware kernel for CT CAC scoring with varying surrounding materials and heart rates: a dynamic phantom study

European Radiology ◽

10.1007/s00330-021-08076-5 ◽

2021 ◽

Author(s):

Niels R. van der Werf ◽

Ronald Booij ◽

Bernhard Schmidt ◽

Thomas G. Flohr ◽

Tim Leiner ◽

...

Keyword(s):

Coronary Artery ◽

Soft Tissue ◽

Patient Specific ◽

Reconstruction Technique ◽

Ct Reconstruction ◽

Raw Data ◽

Heart Rates ◽

Tissue Equivalent ◽

Tin Filtration ◽

Reconstruction Kernel

Abstract Objectives The purpose of this study was twofold. First, the influence of a novel calcium-aware (Ca-aware) computed tomography (CT) reconstruction technique on coronary artery calcium (CAC) scores surrounded by a variety of tissues was assessed. Second, the performance of the Ca-aware reconstruction technique on moving CAC was evaluated with a dynamic phantom. Methods An artificial coronary artery, containing two CAC of equal size and different densities (196 ± 3, 380 ± 2 mg hydroxyapatite cm−3), was moved in the center compartment of an anthropomorphic thorax phantom at different heart rates. The center compartment was filled with mixtures, which resembled fat, water, and soft tissue equivalent CT numbers. Raw data was acquired with a routine clinical CAC protocol, at 120 peak kilovolt (kVp). Subsequently, reduced tube voltage (100 kVp) and tin-filtration (150Sn kVp) acquisitions were performed. Raw data was reconstructed with a standard and a novel Ca-aware reconstruction technique. Agatston scores of all reconstructions were compared with the reference (120 kVp) and standard reconstruction technique, with relevant deviations defined as > 10%. Results For all heart rates, Agatston scores for CAC submerged in fat were comparable to the reference, for the reduced-kVp acquisition with Ca-aware reconstruction kernel. For water and soft tissue, medium-density Agatston scores were again comparable to the reference for all heart rates. Low-density Agatston scores showed relevant deviations, up to 15% and 23% for water and soft tissue, respectively. Conclusion CT CAC scoring with varying surrounding materials and heart rates is feasible at patient-specific tube voltages with the novel Ca-aware reconstruction technique. Key Points • A dedicated calcium-aware reconstruction kernel results in similar Agatston scores for CAC surrounded by fatty materials regardless of CAC density and heart rate. • Application of a dedicated calcium-aware reconstruction kernel allows for radiation dose reduction. • Mass scores determined with CT underestimated physical mass.

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