METHODS: This was a prospective observational cohort study, performed at Mater Mother's Hospital in Brisbane, Queensland, Australia, from May 2022 to June 2023, of pregnancies complicated by FGR and appropriate-for-gestational-age (AGA) pregnancies. Maternal serum PlGF levels, sFlt-1/PlGF ratio, UA-PI and UtA-PI were measured at 2-4-weekly intervals from recruitment until delivery. Harrell's concordance statistic (Harrell's C) was used to evaluate multivariable Cox proportional hazards regression models featuring various combinations of placental biomarkers and fetoplacental Doppler indices to ascertain the best combination to predict PTB ( 95th centile or UtA-PI > 95th centile alone (Harrell's C, 0.82, 0.75 and 0.76, respectively). Predictive utility for PTB was best when PlGF 95th centile and UtA-PI > 95th centile were combined (Harrell's C, 0.88) (hazard ratio, 32.99; 95% CI, 10.74-101.32).
CONCLUSIONS: Low maternal serum PlGF level ( 95th centile and UtA-PI > 95th centile) in combination have the greatest predictive utility for PTB in pregnancies complicated by FGR. Their assessment may help guide clinical management of these complex pregnancies. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
OBJECTIVE: The current study aims to elucidate the two-way fluid-structure interaction (FSI) analysis of the blood flow and the effect of stenosis on hemodynamic parameters.
METHODS: A patient-specific 3D model of the left coronary artery was constructed based on computed tomography (CT) images. The blood is assumed to be incompressible, homogenous, and behaves as Non-Newtonian, while the artery is considered as a nonlinear elastic, anisotropic, and incompressible material. Pulsatile flow conditions were applied at the boundary. Two-way coupled FSI modeling approach was used between fluid and solid domain. The hemodynamic parameters such as the pressure, velocity streamline, and wall shear stress were analyzed in the fluid domain and the solid domain deformation.
RESULTS: The simulated results reveal that pressure drop exists in the vicinity of stenosis and a recirculation region after the stenosis. It was noted that stenosis leads to high wall stress. The results also demonstrate an overestimation of wall shear stress and velocity in the rigid wall CFD model compared to the FSI model.
OBJECTIVE: The aim of this study is to analyze the multiphase pulsatile blood flow in the left coronary artery tree with stenosis.
METHODS: The 3D left coronary artery model was reconstructed using 2D computerized tomography (CT) scan images. The Red Blood Cell (RBC) and varying hemodynamic parameters for single and multiphase blood flow conditions were analyzed.
RESULTS: Results asserted that the multiphase blood flow modeling has a maximum velocity of 1.017 m/s and1.339 m/s at the stenosed region during the systolic and diastolic phases respectively. The increase in Wall Shear Stress (WSS) observed at the stenosed region during the diastole phase as compared during the systolic phase. It was also observed that the highest Oscillatory Shear Index (OSI) regions are found in the downstream area of stenosis and across the bifurcations. The increase in RBCs velocity from 0.45 m/s to 0.6 m/s across the stenosis was also noticed.
CONCLUSION: The computational multiphase blood flow analysis improves the understanding and accuracy of the complex flow conditions of blood elements (RBC and Plasma) and provides the progression of the disease development in the coronary arteries. This study helps to enhance the diagnosis of the blocked (stenosed) arteries more precisely compared to the single-phase blood flow modeling.
METHODS: A cross-sectional observational study was designed. Forty normotensive (median age 47 +/- 6 yrs.) and twenty untreated hypertensive Malay men (median age 50 +/- 7 yrs.) without clinical evidence of cardiovascular complications were selected. Pulse wave velocity measured using the automated Complior machine was used as an index of arterial stiffness. Other measurements obtained were blood pressure, body mass index, fasting insulin, cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, glucose and creatinine level.
RESULTS: The blood pressure and pulse wave velocity (PWV) were significantly higher in the hypertensives compared to the normotensives (blood pressure 169/100 mm Hg +/- 14/7 vs. 120/80 mm Hg +/- 10/4, p < 0.001; PWV 11.69 m/s +/- 1.12 vs. 8.83 m/s +/- 1.35, p < 0.001). Other variables such as body mass index, fasting insulin, cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and haematocrit were comparable among the two groups. Within each group, there was a significant positive correlation between pulse wave velocity and systolic blood pressure (r = 0.76, p < 0.001 in normotensives; r = 0.73, p < 0.001 in hypertensives) and mean arterial pressure (r = 0.74, p < 0.001 in normotensives; r = 0.73, p < 0.001 in hypertensives). No correlation was noted between pulse wave velocity and diastolic blood pressure, age, body mass index, fasting insulin level, cholesterol, HDL-cholesterol, LDL-cholesterol or triglyceride levels.
CONCLUSION: Arterial stiffness as determined by PWV is increased in newly diagnosed untreated hypertensive subjects even before clinically evident cardiovascular disease. However, arterial stiffness is not correlated with the fasting insulin level in normotensives and newly diagnosed hypertensives.