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Microcirculation (New York, N.Y. : 1994) Nov 2023The objective of this study was to evaluate the association between serum albumin levels and microcirculation changes, glycocalyx degradation, and the clinical outcomes... (Observational Study)
Observational Study
OBJECTIVE
The objective of this study was to evaluate the association between serum albumin levels and microcirculation changes, glycocalyx degradation, and the clinical outcomes of interest.
METHODS
Observational, prospective study in children with sepsis. The primary outcome was the association between hypoalbuminemia and microcirculation disorders, endothelial activation and glycocalyx degradation using a perfused boundary region (PBR) (abnormal >2.0 μm on sublingual video microscopy) or plasma biomarkers (syndecan-1, angiopoietin-2).
RESULTS
A total of 125 patients with sepsis were included. The median age was 2.0 years (IQR 0.5-12.5). Children with hypoalbuminemia had more abnormal microcirculation with a higher PBR (2.16 μm [IQR 2.03-2.47] vs. 1.92 [1.76-2.28]; p = .01) and more 4-6 μm capillaries recruited (60% vs. 40%; p = .04). The low albumin group that had the worst PBR had the most 4-6 μm capillaries recruited (rho 0.29; p < .01), 48% higher Ang-2 (p = .04), worse annexin A5 (p = 0.03) and no syndecan-1 abnormalities (p = .21). Children with hypoalbuminemia and a greater percentage of blood volume in their capillaries needed mechanical ventilation more often (56.3% vs. 43.7%; aOR 2.01 95% CI 1.38-3.10: p < .01).
CONCLUSIONS
In children with sepsis, an association was found between hypoalbuminemia and microcirculation changes, vascular permeability, and greater endothelial glycocalyx degradation.
Topics: Humans; Child; Child, Preschool; Glycocalyx; Microcirculation; Prospective Studies; Hypoalbuminemia; Endothelium; Sepsis
PubMed: 37639384
DOI: 10.1111/micc.12829 -
Vascular Pharmacology Dec 2023The term "coronary microvascular dysfunction" (CMD) encompasses several pathogenetic mechanisms resulting in functional and/or structural changes in the coronary...
The term "coronary microvascular dysfunction" (CMD) encompasses several pathogenetic mechanisms resulting in functional and/or structural changes in the coronary microcirculation. CMD often determines angina and myocardial ischemia in a broad spectrum of cardiovascular diseases, including patients with ischemia with non-obstructive coronary arteries or ischemia with obstructive coronary artery disease, infarction with non-obstructive coronary arteries, cardiomyopathies, the Takotsubo syndrome and heart failure, especially heart failure with preserved ejection fraction. In this article, we provide updated evidence regarding the pathophysiological mechanisms underlying CMD across the different cardiovascular diseases, aiming to pave the way for further research and the development of novel strategies for a precision medicine approach.
Topics: Humans; Cardiovascular Diseases; Coronary Circulation; Myocardial Ischemia; Coronary Artery Disease; Coronary Vessels; Heart Failure; Ischemia; Microcirculation
PubMed: 37898380
DOI: 10.1016/j.vph.2023.107239 -
Animal Models and Experimental Medicine Aug 2023Pericytes are the main cellular components of tiny arteries and capillaries. Studies have found that pericytes can undergo morphological contraction or relaxation under... (Review)
Review
Pericytes are the main cellular components of tiny arteries and capillaries. Studies have found that pericytes can undergo morphological contraction or relaxation under stimulation by cytokines, thus affecting the contraction and relaxation of microvessels and playing an essential role in regulating vascular microcirculation. Moreover, due to the characteristics of stem cells, pericytes can differentiate into a variety of inflammatory cell phenotypes, which then affect the immune function. Additionally, pericytes can also participate in angiogenesis and wound healing by interacting with endothelial cells in vascular microcirculation disorders. Here we review the origin, biological phenotype and function of pericytes, and discuss the potential mechanisms of pericytes in vascular microcirculation disorders, especially in pulmonary hypertension, so as to provide a sound basis and direction for the prevention and treatment of vascular microcirculation diseases.
Topics: Pericytes; Microcirculation; Endothelial Cells; Capillaries; Biology
PubMed: 37317664
DOI: 10.1002/ame2.12334 -
Comprehensive Physiology Dec 2019The microcirculation maintains tissue homeostasis through local regulation of blood flow and oxygen delivery. Perturbations in microvascular function are characteristic... (Review)
Review
The microcirculation maintains tissue homeostasis through local regulation of blood flow and oxygen delivery. Perturbations in microvascular function are characteristic of several diseases and may be early indicators of pathological changes in the cardiovascular system and in parenchymal tissue function. These changes are often mediated by various reactive oxygen species and linked to disruptions in pathways such as vasodilation or angiogenesis. This overview compiles recent advances relating to redox regulation of the microcirculation by adopting both cellular and functional perspectives. Findings from a variety of vascular beds and models are integrated to describe common effects of different reactive species on microvascular function. Gaps in understanding and areas for further research are outlined. © 2020 American Physiological Society. Compr Physiol 10:229-260, 2020.
Topics: Animals; Cardiovascular Diseases; Humans; Microcirculation; Oxidation-Reduction
PubMed: 31853967
DOI: 10.1002/cphy.c180039 -
American Journal of Physiology. Heart... Dec 2022Microvascular disease plays a critical role in systemic end-organ dysfunction, and treatment of microvascular pathologies may greatly reduce cardiovascular morbidity and... (Review)
Review
Microvascular disease plays a critical role in systemic end-organ dysfunction, and treatment of microvascular pathologies may greatly reduce cardiovascular morbidity and mortality. The Call for Papers collection: New Developments in Translational Microcirculatory Research highlights key advances in our understanding of the role of microvessels in the development of chronic diseases as well as therapeutic strategies to enhance microvascular function. This Mini Review provides a concise summary of these advances and draws from other relevant research to provide the most up-to-date information on the influence of cutaneous, cerebrovascular, coronary, and peripheral microcirculation on the pathophysiology of obesity, hypertension, cardiovascular aging, peripheral artery disease, and cognitive impairment. In addition to these disease- and location-dependent research articles, this Call for Papers includes state-of-the-art reviews on coronary endothelial function and assessment of microvascular health in different organ systems, with an additional focus on establishing rigor and new advances in clinical trial design. These articles, combined with original research evaluating cellular, exosomal, pharmaceutical, exercise, heat, and dietary interventional therapies, establish the groundwork for translating microcirculatory research from bench to bedside. Although numerous studies in this collection are focused on human microcirculation, most used robust preclinical models to probe mechanisms of pathophysiology and interventional benefits. Future work focused on translating these findings to humans are necessary for finding clinical strategies to prevent and treat microvascular dysfunction.
Topics: Humans; Microcirculation; Microvessels; Hypertension; Endothelium; Peripheral Vascular Diseases
PubMed: 36306213
DOI: 10.1152/ajpheart.00566.2022 -
Journal of Cardiothoracic and Vascular... Oct 2023Cardiogenic shock causes hypoperfusion within the microcirculation, leading to impaired oxygen delivery, cell death, and progression of multiple organ failure.... (Review)
Review
Cardiogenic shock causes hypoperfusion within the microcirculation, leading to impaired oxygen delivery, cell death, and progression of multiple organ failure. Mechanical circulatory support (MCS) is the last line of treatment for cardiac failure. The goal of MCS is to ensure end-organ perfusion by maintaining perfusion pressure and total blood flow. However, machine-blood interactions and the nonobvious translation of global macrohemodynamics into the microcirculation suggest that the use of MCS may not necessarily be associated with improved capillary flow. With the use of hand-held vital microscopes, it is possible to assess the microcirculation at the bedside. The paucity of literature on the use of microcirculatory assessment suggests the need for an in-depth look into microcirculatory assessment within the context of MCS. The purpose of this review is to discuss the possible interactions between MCS and microcirculation, as well as to describe the research conducted in this area. Regarding sublingual microcirculation, 3 types of MCS will be discussed: venoarterial extracorporeal membrane oxygenation, intra-aortic balloon counterpulsation, and microaxial flow pumps (Impella).
Topics: Humans; Microcirculation; Mouth Floor; Shock, Cardiogenic; Heart Failure; Hemodynamics; Heart-Assist Devices; Intra-Aortic Balloon Pumping
PubMed: 37330330
DOI: 10.1053/j.jvca.2023.05.028 -
Microcirculation (New York, N.Y. : 1994) Apr 2021The past few decades have seen an explosion in the development and use of methods for imaging the human microcirculation during health and disease. The confluence of... (Review)
Review
The past few decades have seen an explosion in the development and use of methods for imaging the human microcirculation during health and disease. The confluence of innovative imaging technologies, affordable computing power, and economies of scale have ushered in a new era of "translational" imaging that permit us to peer into blood vessels of various organs in the human body. These imaging techniques include near-infrared spectroscopy (NIRS), positron emission tomography (PET), and magnetic resonance imaging (MRI) that are sensitive to microvascular-derived signals, as well as computed tomography (CT), optical imaging, and ultrasound (US) imaging that are capable of directly acquiring images at, or close to microvascular spatial resolution. Collectively, these imaging modalities enable us to characterize the morphological and functional changes in a tissue's microcirculation that are known to accompany the initiation and progression of numerous pathologies. Although there have been significant advances for imaging the microcirculation in preclinical models, this review focuses on developments in the assessment of the microcirculation in patients with optical imaging, NIRS, PET, US, MRI, and CT, to name a few. The goal of this review is to serve as a springboard for exploring the burgeoning role of translational imaging technologies for interrogating the structural and functional status of the microcirculation in humans, and highlight the breadth of current clinical applications. Making the human microcirculation "visible" in vivo to clinicians and researchers alike will facilitate bench-to-bedside discoveries and enhance the diagnosis and management of disease.
Topics: Humans; Magnetic Resonance Imaging; Microcirculation; Positron-Emission Tomography; Tomography, X-Ray Computed; Ultrasonography
PubMed: 33524206
DOI: 10.1111/micc.12683 -
Hypertension (Dallas, Tex. : 1979) Aug 2020
Topics: Blood Pressure; Child; Humans; Microcirculation; Retinal Vessels
PubMed: 32639891
DOI: 10.1161/HYPERTENSIONAHA.120.15471 -
Angiology Oct 2021
Topics: Coronary Circulation; Humans; Microcirculation
PubMed: 33827275
DOI: 10.1177/00033197211007702 -
Current Opinion in Nephrology and... Nov 2022Patients with chronic kidney disease characteristically exhibit microcirculatory dysfunction, in combination with vascular damage. Hemodialysis superimposes additional... (Review)
Review
PURPOSE OF REVIEW
Patients with chronic kidney disease characteristically exhibit microcirculatory dysfunction, in combination with vascular damage. Hemodialysis superimposes additional circulatory stress to the microvasculature (repetitive ischemic insults/cumulative damage) resulting in high mortality. Intradialytic monitoring and hemodialysis delivery is currently limited to macrovascular/systemic assessment and detection of intradialytic systemic hypotension. Monitoring of the microcirculation has the potential to provide valuable information on hemodialysis-induced circulatory stress likely to result in end-organ ischemia (with/without systemic hypotension) generating an opportunity to intervene before tissue injury occurs.
RECENT FINDINGS
Various noninvasive technologies have been used assessing the microcirculation in hemodialysis patients at rest. Some technologies have also been applied during hemodialysis studying the effects of treatment on the microcirculation. Despite the approach used, results are consistent. Hemodialysis patients have impaired microcirculations with treatment adding additional stress to inadequately regulated vascular beds. Utility/practicality/clinical relevance vary significantly between methodologies.
SUMMARY
Intradialytic monitoring of the microcirculation can provide additional insights into a patient's individual response to treatment. However, this valuable perspective has not been adopted into clinical practice. A microcirculatory view could provide a window of opportunity to enable a precision medicine approach to treatment delivery improving current woefully poor subjective and objective clinical outcomes.
Topics: Humans; Hypotension; Microcirculation; Renal Dialysis; Renal Insufficiency, Chronic
PubMed: 36172854
DOI: 10.1097/MNH.0000000000000831