Hemodynamics analysis of the serial stenotic coronary arteries.

Coronary arterial stenoses, particularly serial stenoses in a single branch, are responsible for complex hemodynamic properties of the coronary arterial trees, and the uncertain prognosis of invasive intervention. Critical information of the blood flow redistribution in the stenotic arterial segments is required for the adequate treatment planning. Therefore, in this study, an image based non-invasive functional assessment is performed to investigate the hemodynamic significances of serial stenoses. Twenty patient-specific coronary arterial trees with different combinations of stenoses were reconstructed from the computer tomography angiography for the evaluation of the hemodynamics. Our results showed that the computed FFR based on CTA images (FFRCT) pullback curves with wall shear stress (WSS) distribution could provide more effectively examine the physiological significance of the locations of the segmental narrowing and the curvature of the coronary arterial segments. The paper thus provides the diagnostic efficacy of FFRCT pullback curve for noninvasive quantification of the hemodynamics of stenotic coronary arteries with serial lesions, compared to the gold standard invasive FFR, to provide a reliable physiological assessment of significant amount of coronary artery stenosis. Further, we were also able to demonstrate the potential of carrying out virtual revascularization, to enable more precise PCI procedures and improve their outcomes.

Hypoxia-induced miR-27 and miR-195 regulate ATP consumption, viability, and metabolism of rat cardiomyocytes by targeting PPARγ and FASN expression.

This study examined whether hypoxia-induced microRNA (miRNA) upregulation was related to the inhibition of chondriosome aliphatic acid oxidation in myocardial cells under anoxia. We showed that anoxia induced high expression of hypoxia-inducible factor-1-alpha, muscle carnitine palmitoyltransferase I, and vascular endothelial growth factor in cardiomyocytes. Meanwhile, miR-27 and miR-195 were also upregulated in hypoxia-induced cardiomyocytes. Furthermore, hypoxia induction led to reductions in the adenosine triphosphate (ATP) consumption rate and oxidative metabolism as well as an increase in cardiomyocyte glycolysis. Metabolic reprogramming was reduced by hypoxia, as evidenced by the downregulation of sirtuin 1, forkhead box protein O1, sterol regulatory element-binding protein 1c, ATP citrate lyase, acetyl-coenzyme A carboxylase 2, adiponutrin, adipose triglyceride lipase, and glucose transporter type 4, while miR-27 and miR-195 inhibition partially recovered the expression of these transcription factors. In addition, hypoxia induction reduced cell viability and survival by triggering apoptosis; however, miR-27 and miR-195 inhibition partially increased cell viability. Moreover, miR-27 and miR-195 targeted the 3'untranslated regions of two key lipid-associated metabolic players, peroxisome proliferator-activated receptor gamma and fatty acid synthase. In conclusion, miR-27 and miR-195 are related to hypoxia-mediated ATP levels, glycolysis, oxidation, cell survival, and a cascade of transcription factors that control metabolism in cardiomyocytes.

Screening on platelet LncRNA expression profile discloses novel residual platelet reactivity biomarker.

INTRODUCTION: Double antiplatelet therapy (DAPT) has wide inter-individual variabilities in coronary heart disease (CHD) patients' responses, which undermines the prognosis effect in clinical practice. Long noncoding RNAs (lncRNAs) have been reported to be widely existed in platelets, albeit their potential roles in platelet responses to DAPT largely remains in the realm of the unknown. This study aims to screen differentially expressed lncRNAs responsible for high residual platelet reactivities under DAPT. METHODS: We enrolled 144 CHD patients that received DAPT and assigned them to high platelet reactivity (HPR) group and baseline group according to their residual platelet reactivities. Statistical analysis and a series of experiments including microarray analysis, platelet reactivity screening, RNA isolation and lncRNA microarray analysis were explored to the research. RESULTS: We detected a total of 22,424 kinds of co-expressed lncRNAs in three pairs of patients between the HPR and baseline groups. We identified twenty differentially expressed lncRNAs and successfully validated three of them in the 144 patients. Ultimately, the expression of ensemble transcript ENST00000433442 was demonstrated as significantly correlated with high platelet reactivity (OR = 0.487, P = .035) by logistic regression analysis. CONCLUSION: There is a considerable amount of lncRNAs in platelets, and the downregulated expression of ENST00000433442 is an independent risk factor for high residual platelet reactivity in CHD patients under DAPT.

Privileged Modality Distillation for Vessel Border Detection in Intracoronary Imaging.

Intracoronary imaging is a crucial imaging technology in coronary disease diagnosis as it visualizes the internal tissue morphologies of coronary arteries. Vessel border detection in intracoronary images (VBDI) is desired because it can help the succeeding procedures of computer-aided disease diagnosis. However, existing VDBI methods suffer from the challenge of vessel-environment variability (i.e. high intra- and inter-subject diversity of vessels and their surrounding tissues appeared in images). This challenge leads to the ineffectiveness in the vessel region representation for hand-crafted features, in the receptive field extraction for deeply-represented features, as well as performance suppression derived from clinical data limitation. To solve this challenge, we propose a novel privileged modality distillation (PMD) framework for VBDI. PMD transforms the single-input-single-task (SIST) learning problem in the single-mode VBDI to a multiple-input-multiple-task (MIMT) problem by using the privileged image modality to help the learning model in the target modality. This learns the enriched high-level knowledge with similar semantics and generalizes PMD on diversity-increased low-level image features for improving the model adaptation to diverse vessel environments. Moreover, PMD refines MIMT to SIST by distilling the learned knowledge from multiple to one modality. This eliminates the reliance on privileged modality in the test phase, and thus enables the applicability to each of different intracoronary modalities. A structure-deformable neural network is proposed as an elaborately-designed implementation of PMD. It expands a conventional SIST network structure to the MIMT structure, and then recovers it to the final SIST structure. The PMD is validated on intravascular ultrasound imaging and optical coherence tomography imaging. One modality is the target, and the other one can be considered as the privileged modality owing to their semantic relatedness. The experiments show that our PMD is effective in VBDI (e.g. the Dice index is larger than 0.95), as well as superior to six state-of-the-art VBDI methods.

Flow-mediated dilation can be used to predict incident hypertension in patients with hyperuricemia.

INTRODUCTION: The aim of the study was to evaluate whether flow-mediated dilation (FMD) can be used to predict incident hypertension in patients with hyperuricemia. MATERIAL AND METHODS: Normotensive participants with and without hyperuricemia at baseline were prospectively enrolled. Flow-mediated dilation was assessed at baseline, and after 1 year's follow-up the incidence of hypertension was compared between those with and without hyperuricemia. The predictive value of baseline FMD for incident hypertension among hyperuricemia patients was evaluated. RESULTS: A total of 222 participants were included. Mean systolic and diastolic blood pressure (BP) was 129.5 ±8.4 mm Hg and 78.3 ±7.9 mm Hg. Mean serum uric acid (UA) level was 4.4 ±2.8 mg/dl. Mean FMD was 5.1 ±2.7%. Compared to normal UA group, hyperuricemia group had higher proportion of male (58.4% vs. 61.2%), higher systolic BP (125.4 ±7.9 mm Hg vs. 132.1 ±7.3 mm Hg), serum high sensitivity C-reactive protein (3.9 ±2.2 mg/dl vs. 4.5 ±3.0 mg/dl) and UA (3.5 ±1.4 mg/dl vs. 5.7 ±0.7 mg/dl) levels, but lower mean FMD (5.6 ±2.4% vs. 4.8 ±2.0%) (p < 0.05 for all comparisons). No participant in normal UA group developed hypertension, while in hyperuricemia group, 6 participants developed hypertension. In hyperuricemia participants, after adjusted for covariates, per 1-standard deviation decrease in baseline FMD remained significantly associated with 15% increased risk of incident hypertension. CONCLUSIONS: Patients with hyperuricemia have an increased risk of developing hypertension, and low baseline FMD in hyperuricemia patients is associated with significantly increased risk of incident hypertension.

The Impact of the Geometric Characteristics on the Hemodynamics in the Stenotic Coronary Artery.

The alterations of the hemodynamics in the coronary arteries, which result from patient-specific geometric significances are complex. The effect of the stenosis on the blood flow alteration had been wildly reported, but the combinational contribution from geometric factors required a comprehensive investigation to provide patient-specific information for diagnosis and assisting in the decision on the further treatment strategies. In the present study, we investigated the correlation between hemodynamic parameters and individual geometric factors in the patient-specific coronary arteries. Computational fluid dynamic simulations were performed on 22 patient-specific 3-dimensional coronary artery models that were reconstructed based on computed tomography angiography images. Our results showed that the increasing severity of the stenosis is associated with the increased maximum wall shear stress at the stenosis region (r = 0.752, P < 0.001). In contrast, the length of the recirculation zone has a moderate association with the curvature of the lesion segment (r = 0.505, P = 0.019) and the length of the lesions (r = 0.527, P = 0.064). Moreover, bifurcation in the coronary arteries is significantly correlated with the occurrence of recirculation, whereas the severity of distal stenosis demonstrated an effect on the alteration of the flow in the upstream bifurcation. These findings could serve as an indication for treatment planning and assist in prognosis evaluation.