Microvascular Dysfunction as a Systemic Disease: A Review of the Evidence

Relationship between peripheral and intracoronary blood flow in patients with angina and nonobstructive coronary arteries

Coronary vasomotor dysfunction, an important underlying cause of angina and nonobstructive coronary arteries (ANOCA), encompassing coronary vasospasm, coronary endothelial dysfunction, and/or coronary microvascular dysfunction, is clinically assessed by invasive coronary function testing (ICFT). As ICFT imposes a high burden on patients and carries risks, developing noninvasive alternatives is important. We evaluated whether coronary vasomotor dysfunction is a component of systemic microvascular endothelial and smooth muscle dysfunction and can be detected using laser speckle contrast analysis (LASCA). Forty-three consecutive patients with ANOCA underwent ICFT, with intracoronary acetylcholine, adenosine, and flow measurements, to assess coronary vasomotor dysfunction. Cutaneous microvascular function was assessed using LASCA in the forearm, combined with vasodilators acetylcholine, sodium nitroprusside, and insulin and using EndoPAT, by measuring the reactive hyperemia index (RHI). Of the 43 included patients with ANOCA (79% women, 59 ± 9 yr old), 38 patients had coronary vasomotor dysfunction, including 28 with coronary vasospasm, 26 with coronary endothelial dysfunction, and 18 with coronary microvascular dysfunction, with overlapping endotypes. Patients with and without coronary vasomotor dysfunction had similar peripheral flow responses to acetylcholine, insulin, and RHI. In contrast, coronary vasomotor dysfunction was associated with lower peripheral flow responses to sodium nitroprusside (P < 0.001). An absolute flow response to sodium nitroprusside of 83.95 APU resulted in 86.1% sensitivity and 80.0% specificity for coronary vasomotor dysfunction (area under the ROC curve, 0.883; P = 0.006). In conclusion, this study provides evidence of systemic vascular smooth muscle dysfunction in patients with ANOCA with coronary vasomotor dysfunction and the diagnostic value of peripheral microvascular function testing as a noninvasive tool for detecting coronary vasomotor dysfunction.NEW & NOTEWORTHY This study provides proof of concept that assessment of the peripheral vasculature, particularly vascular smooth muscle cells measured using the LASCA technology holds potential as a noninvasive tool for detecting coronary vasomotor dysfunction. This finding highlights the potential of the LASCA technology in, for example, medication studies for coronary vasomotor dysfunction, especially when investigating whether medication improves vascular function, as repeated peripheral measurements are less invasive than invasive coronary function testing, the current gold standard.

EASIX (endothelial activation and stress index) predicts mortality in patients with coronary artery disease

BACKGROUND

Coronary interventions reduce morbidity and mortality in patients with acute coronary syndrome. However, the risk of mortality for patients with coronary artery disease (CAD) additionally depends on their systemic endothelial health status. The 'Endothelial Activation and Stress Index' (EASIX) predicts endothelial complications and survival in diverse clinical settings.

OBJECTIVE

We hypothesized that EASIX may predict mortality in patients with CAD.

METHODS

In 1283 patients undergoing coronary catheterization (CC) and having a diagnosis of CAD, EASIX was measured within 52 days (range - 1 year to - 14 days) before CC and correlated with overall survival. In an independent validation cohort of 1934 patients, EASIXval was measured within 174 days (+ 28 days to + 11 years) after CC.

RESULTS

EASIX predicted the risk of mortality after CC (per log2: hazard ratio (HR) 1.29, 95% confidence interval: [1.18-1.41], p < 0.001) in multivariable Cox regression analyses adjusting for age, sex, a high-grade coronary stenosis ≥ 90%, left ventricular ejection fraction, arterial hypertension and diabetes. In the independent cohort, EASIX correlated with EASIXval with rho = 0.7. The long-term predictive value of EASIXval was confirmed (per log2: HR 1.53, [1.42-1.64], p < 0.001) and could be validated by integrated Brier score and concordance index. Pre-established cut-offs (0.88-2.32) associated with increased mortality (cut-off 0.88: HR training: 1.63; HR validation: 1.67, p < 0.0001 and cut-off 2.32: HR training: 3.57; HR validation: 4.65, p < 0.0001).

CONCLUSIONS

We validated EASIX as a potential biomarker to predict death of CAD patients, irrespective of the timing either before or after catheterization.

[The association between preterm birth and hypertension]

In recent years, the number of premature births worldwide has been increasing, and their long-term prognoses, particularly the cardiovascular outcomes of preterm individuals in adulthood, have become a growing concern. Adults who were born prematurely are at a higher risk for cardiovascular diseases, which may be related to changes in cardiovascular structure, renal structure alterations, changes in body composition, and overactivation of the hypothalamic-pituitary-adrenal axis. To improve the outcomes for preterm individuals, long-term follow-up monitoring and effective prevention and treatment measures are necessary. This article aims to review the relevant literature, summarize the risks and mechanisms of hypertension during childhood and adulthood in those born prematurely, and enhance awareness and understanding of the risk of hypertension in adults who were born prematurely.

Impact of Peripheral Angioplasty on Wound Oxygenation and Healing in Patients with Chronic Limb-Threatening Ischemia Measured by Near-Infrared Spectroscopy

Managing chronic limb-threatening ischemia (CLTI) is challenging due to difficulties in assessing tissue oxygen saturation in ulcers. Near-infrared spectroscopy (NIRS) is a non-invasive method for measuring tissue oxygen saturation (StO2). This study evaluated the effects of endovascular treatment (EVT) on StO2 and wound healing in CLTI patients, comparing NIRS to standard ankle-brachial index (ABI) measurements. Using the Duesseldorf PTA Registry, 43 CLTI patients were analyzed: 27 underwent EVT, and 16 received conservative treatment. ABI assessed macrocirculation, while NIRS measured wound, wound area, and mean foot StO2 at baseline, post-EVT, and four-month follow-up. Wound severity was classified by wound area and wound, ischemia, and foot infection (WIfI) score. Wound StO2 increased significantly (median (interquartile range (IQR)), 38 (49.3) to 60 (34.5)%, p = 0.004), as did wound area StO2 (median (IQR), 70.9 (21.6) to 72.8 (18.3)%, p < 0.001), with no significant changes in the control group by four-month follow-up. Wound area decreased significantly after EVT (mean ± SD, 343.1 ± 267.8 to 178.1 ± 268.5 mm2, p = 0.01) but not in the control group. Changes in wound StO2, wound area StO2, and WIfI score correlated with wound area reduction, unlike ABI. This small exploratory study shows that NIRS-measured StO2 improvements after EVT correlate with reduced wound area and WIfI scores, highlighting NIRS as a potential enhancement for CLTI wound management in addition to ABI.

Signals From Inflamed Perivascular Adipose Tissue Contribute to Small-Vessel Dysfunction in Women With Human Immunodeficiency Virus

BACKGROUND

People with the human immunodeficiency virus (PWH) have microvascular disease. Because perivascular adipose tissue (PVAT) regulates microvascular function and adipose tissue is inflamed in PWH, we tested the hypothesis that PWH have inflamed PVAT that impairs the function of their small vessels.

METHODS

Subcutaneous small arteries were dissected with or without PVAT from a gluteal skin biopsy from 11 women with treated HIV (WWH) aged < 50 years and 10 matched women without HIV, and studied on isometric myographs. Nitric oxide (NO) and reactive oxygen species (ROS) were measured by fluorescence microscopy. Adipokines and markers of inflammation and ROS were assayed in PVAT.

RESULTS

PVAT surrounding the small arteries in control women significantly (P < .05) enhanced acetylcholine-induced endothelium-dependent relaxation and NO, and reduced contractions to thromboxane and endothelin-1. However, these effects of PVAT were reduced significantly (P < .05) in WWH whose PVAT released less adiponectin but more markers of ROS and inflammation. Moderation of contractions by PVAT were correlated positively with adipose adiponectin.

CONCLUSIONS

PVAT from WWH has oxidative stress, inflammation, and reduced release of adiponectin, which may contribute to enhanced contractions and therefore could promote small-artery dysfunction.

Smoking and Respiratory Diseases in Patients with Coronary Microvascular Dysfunction

BACKGROUND

Coronary microvascular disease (CMD) is common in patients with and without obstructive coronary artery disease, and is associated with adverse clinical outcomes. Respiratory-related variables are associated with pulmonary and systemic microvascular dysfunction, while evidence about their relationship with CMD is limited. We aim to evaluate respiratory-related variables as risk factors of CMD.

METHODS

This is an observational, single-center study enrolling consecutive patients undergoing invasive evaluation of coronary microvascular function in the catheterization laboratory. Patients with evidence of obstructive coronary artery disease or with missing data were excluded. Associations between respiratory-related variables and indices of CMD were assessed using univariate and multivariate regression models.

RESULTS

Overall, 266 patients (mean age 67 ± 11 years, 59% females) were included in the current analysis. Of those, 155 (58%) had evidence of CMD. Among the respiratory variables, independent predictors of CMD were current smoking (adjusted odds ratio [AOR] 2.5; 95% confidence interval [CI], 1.2-5; P = .01) and obstructive sleep apnea (AOR 5.7; 95% CI, 1.2-26; P = .03), while chronic obstructive pulmonary disease was not. Among ever-smokers, higher smoking pack-years was an independent risk factor for CMD (median 35 vs 25 pack-years, AOR 1.09; 95% CI, 1.04-1.13; P < .01), and was associated with higher rates of pathologic index of microcirculatory resistance and resistive reserve ratio.

CONCLUSION

In patients undergoing invasive coronary microvascular evaluation, current smoking and obstructive sleep apnea are independently associated with CMD. Among smokers, higher pack-years is a strong predictor for CMD. Our findings should raise awareness for prevention and possible treatment options.

Retinal microcirculation: A window into systemic circulation and metabolic disease

The retinal microcirculation system constitutes a unique terminal vessel bed of the systemic circulation, and its perfusion status is directly associated with the neural function of the retina. This vascular network, essential for nourishing various layers of the retina, comprises two primary microcirculation systems: the retinal microcirculation and the choroidal microcirculation, with each system supplying blood to distinct retinal layers and maintaining the associated neural function. The blood flow of those capillaries is regulated via different mechanisms. However, a range of internal and external factors can disrupt the normal architecture and blood flow within the retinal microcirculation, leading to several retinal pathologies, including diabetic retinopathy, macular edema, and vascular occlusions. Metabolic disturbances such as hyperglycemia, hypertension, and dyslipidemia are known to modify retinal microcirculation through various pathways. These alterations are observable in chronic metabolic conditions like diabetes, coronary artery disease, and cerebral microvascular disease due to advances in non-invasive or minimally invasive retinal imaging techniques. Thus, examination of the retinal microcirculation can provide insights into the progression of numerous chronic metabolic disorders. This review discusses the anatomy, physiology and pathophysiology of the retinal microvascular system, with a particular emphasis on the connections between retinal microcirculation and systemic circulation in both healthy states and in the context of prevalent chronic metabolic diseases.

Proteomic Profiles of Human Arterioles Isolated From Fresh Adipose Tissue or Following Overnight Storage

Arterioles are key determinants of the total peripheral vascular resistance, which, in turn, is a key determinant of arterial blood pressure. However, the amount of protein available from one isolated human arteriole may be less than 5 μg, making proteomic analysis challenging. In addition, obtaining human arterioles requires manual dissection of unfrozen clinical specimens. This limits its feasibility, especially for powerful multicenter clinical studies in which clinical specimens need to be shipped overnight to a research laboratory for arteriole isolation. We performed a study to address low-input, test overnight tissue storage and develop a reference human arteriolar proteomic profile. In tandem mass tag proteomics, use of a booster channel consisting of human induced pluripotent stem cell-derived endothelial and vascular smooth muscle cells (1:5 ratio) increased the number of proteins detected in a human arteriole segment with a false discovery rate of <0.01 from 1051 to more than 3000. The correlation coefficient of proteomic profile was similar between replicate arterioles isolated freshly, following cold storage, or before and after the cold storage (1-way analysis of variance; P = .60). We built a human arteriolar proteomic profile consisting of 3832 proteins based on the analysis of 12 arteriole samples from 3 subjects. Of 1945 blood pressure-relevant proteins that we curated, 476 (12.5%) were detected in the arteriolar proteome, which was a significant overrepresentation (χ2 test; P < .05). These findings demonstrate that proteomic analysis is feasible with arterioles isolated from human adipose tissue following cold overnight storage and provide a reference human arteriolar proteome profile highly valuable for studies of arteriole-related traits.

Microvascular vasoregulatory dysfunction in African Americans - An enhanced opportunity for early prevention and treatment of atherosclerotic cardiovascular disease

Atherosclerotic cardiovascular disease and its risk factors and precursors are a major driver of disparities in cardiovascular health. This review examines reported evidence that vascular endothelial dysfunction, and its manifestation as coronary microvascular dysfunction, underlies observed excess morbidity and mortality in African Americans. Advanced imaging insights that reveal patho-mechanisms, along with population evidence from the Jackson Heart Study, and the growing evidence emanating from national and international clinical trials and registries are presented. We examine a physiological framework that recognizes insulin-resistant cardiometabolic underpinnings of the conditions of the American Heart Associations' Life's Essential Eight construct of cardiovascular health as a unifying basis that affords early prevention. Mechanistic-based therapeutic approaches, can subsequently be implemented to interrupt progression to adverse outcomes employing layered, or personalized, treatment strategies of a well-defined set of conditions or diseases. Remaining knowledge gaps are acknowledged.

Systemic reserve dysfunction and contrast-associated acute kidney injury following percutaneous coronary intervention

BACKGROUND

Developing contrast-associated acute kidney injury (CA-AKI) following percutaneous coronary intervention (PCI) is closely related to patient-related risk factors as well as contrast administration. The diagnostic and prognostic roles of neutrophil gelatinase-associated lipocalin (NGAL) in CA-AKI following PCI are not well established.

METHODS

Consecutive patients undergoing PCI were enrolled prospectively. CA-AKI was defined as an increase in the serum creatinine level ≥0.3 mg/dL within 48 hours or ≥1.5 times the baseline within 7 days after PCI. Serum NGAL concentrations were determined immediately before and 6 hours after PCI. The participants were classified into four NGAL groups according to the pre- and post-PCI NGAL values at 75th percentile.

RESULTS

CA-AKI occurred in 38 (6.4%) of 590 patients. With chronic kidney disease status (hazard ratio [HR] 1.63, 95% confidence interval [CI]: 1.06-2.52), NGAL groups defined by the combination of pre- and 6 h post-PCI values were independently associated with the occurrence of CA-AKI (HR 1.69, 95% CI: 1.16-2.45). All-cause mortality for 29-month follow-ups was different among NGAL groups (log-rank p<0.001). Pre-PCI NGAL levels significantly correlated with baseline cardiac, inflammatory, and renal markers. Although post-PCI NGAL levels increased in patients with larger contrast administration, contrast media made a relatively limited contribution to the development of CA-AKI.

CONCLUSION

In patients undergoing PCI, the combination of pre- and post-PCI NGAL values may be a useful adjunct to current risk-stratification of CA-AKI and long-term mortality. CA-AKI is likely caused by systemic reserve deficiency rather than contrast administration itself.

Underlying Mechanisms and Treatment of Hypertension in Glomerular Diseases

PURPOSE OF REVIEW

This review aims to explore the underlying mechanisms that lead to hypertension in glomerular diseases and the advancements in treatment strategies and to provide clinicians with valuable insights into the pathophysiological mechanisms and evidence-based therapeutic approaches for managing hypertension in patients with glomerular diseases.

RECENT FINDINGS

In recent years, there have been remarkable advancements in our understanding of the immune and non-immune mechanisms that are involved in the pathogenesis of hypertension in glomerular diseases. Furthermore, this review will encompass the latest data on management strategies, including RAAS inhibition, endothelin receptor blockers, SGLT2 inhibitors, and immune-based therapies. Hypertension (HTN) and cardiovascular diseases are leading causes of mortality in glomerular diseases. The latter are intricately related with hypertension and share common pathophysiological mechanisms. Hypertension in glomerular disease represents a complex and multifaceted interplay between kidney dysfunction, immune-mediated, and non-immune-mediated pathology. Understanding the complex mechanisms involved in this relationship has evolved significantly over the years, shedding light on the pathophysiological processes underlying the development and progression of glomerular disease-associated HTN, and is crucial for developing effective therapeutic strategies and improving patients' outcomes.

Critical limb-threatening ischaemia and microvascular transformation: clinical implications

BACKGROUND AND AIMS

Clinical management of critical limb-threatening ischaemia (CLTI) is focused on prevention and treatment of atherosclerotic arterial occlusions. The role of microvascular pathology in disease progression is still largely unspecified and more importantly not utilized for treatment. The aim of this explorative study was to characterize the role of the microvasculature in CLTI pathology.

METHODS

Clinical high-resolution imaging of CLTI patients (n = 50) and muscle samples from amputated CLTI limbs (n = 40) were used to describe microvascular pathology of CLTI at the level of resting muscle blood flow and microvascular structure, respectively. Furthermore, a chronic, low arterial driving pressure-simulating ischaemia model in rabbits (n = 24) was used together with adenoviral vascular endothelial growth factor A gene transfers to study the effect of microvascular alterations on muscle outcome.

RESULTS

Resting microvascular blood flow was not depleted but displayed decreased capillary transit time (P < .01) in CLTI muscles. Critical limb-threatening ischaemia muscle microvasculature also exhibited capillary enlargement (P < .001) and further arterialization along worsening of myofibre atrophy and detaching of capillaries from myofibres. Furthermore, CLTI-like capillary transformation was shown to worsen calf muscle force production (P < .05) and tissue outcome (P < .01) under chronic ischaemia in rabbits and in healthy, normal rabbit muscle.

CONCLUSIONS

These findings depict a progressive, hypoxia-driven transformation of the microvasculature in CLTI muscles, which pathologically alters blood flow dynamics and aggravates tissue damage under low arterial driving pressure. Hypoxia-driven capillary enlargement can be highly important for CLTI outcomes and should therefore be considered in further development of diagnostics and treatment of CLTI.

Examining Outcomes in Patients Admitted With Comorbid Peripheral Artery Disease and Microvascular Disease

BACKGROUND

Peripheral artery disease (PAD) and microvascular disease (MVD) are highly prevalent conditions that share common risk factors. This observational study aimed to characterize patients with both conditions and determine the impact of comorbid PAD/MVD on outcomes.

METHODS AND RESULTS

Patients admitted across 31 states January 2011 through December 2018 with a primary or secondary diagnosis of PAD or MVD were included from the National Readmissions Database and weighted to approximate a national sample. Those age <18 years or with nonatherosclerotic leg injuries were excluded. Patients were divided into 3 groups: PAD-only, MVD-only, or comorbid PAD/MVD. Multiple logistic regression was used to evaluate associations with major and minor amputations, major adverse cardiac events, and in-hospital mortality. Cox regression was used to evaluate associations with readmission within 1 year. The PAD group was used as reference. The final cohort included 33 972 772 admissions: 9.1 million with PAD, 21.3 million with MVD, and 3.6 million with both. Annual admissions for PAD/MVD increased to >500 000 in 2018. Major and minor amputations increased ≈50% for PAD/MVD between 2011 and 2018. Compared with PAD-only, PAD/MVD was associated with a higher risk for major amputation (odds ratio [OR], 1.30 [95% CI, 1.28-1.32]), minor amputation (OR, 2.15 [95% CI, 2.12-2.18]), major adverse cardiac events (OR, 1.04 [95% CI, 1.03-1.04]), in-hospital mortality (OR, 1.07 [95% CI, 1.05-1.09]), and readmission (hazard ratio, 1.02 [95% CI, 1.02-1.02]) after adjustment for baseline factors.

CONCLUSIONS

Comorbid MVD is present in a large and growing number of patients with PAD and is associated with augmented risk for adverse outcomes. Further prospective research is merited to understand this vulnerable population.

Interrelation between cardiac and brain small-vessel disease: a pilot quantitative PET and MRI study

BACKGROUND

Small-vessel disease (SVD) plays a crucial role in cardiac and brain ischemia, but little is known about potential interrelation between both. We retrospectively evaluated 370 patients, aiming at assessing the interrelation between cardiac and brain SVD by using quantitative 82Rb cardiac PET/CT and brain MRI.

RESULTS

In our population of 370 patients, 176 had normal myocardial perfusion, 38 had pure cardiac SVD and 156 had obstructive coronary artery disease. All underwent both a cardiac 82Rb PET/CT and a brain 1.5T or 3T MRI. Left-ventricle myocardial blood flow (LV-MBF) and flow reserve (LV-MFR) were recorded from 82Rb PET/CT, while Fazekas score, white matter lesion (WMab) volume, deep gray matter lesion (GMab) volume, and brain morphometry (for z-score calculation) using the MorphoBox research application were derived from MRI. Groups were compared with Kruskal-Wallis test, and the potential interrelation between heart and brain SVD markers was assessed using Pearson's correlation coefficient. Patients with cardiac SVD had lower stress LV-MBF and MFR (P < 0.001) than patients with normal myocardial perfusion; Fazekas scores and WMab volumes were similar in those two groups (P > 0.45). In patients with cardiac SVD only, higher rest LV-MBF was associated with a lower left-putamen (rho = - 0.62, P = 0.033), right-thalamus (rho = 0.64, P = 0.026), and right-pallidum (rho = 0.60, P = 0.039) z-scores and with a higher GMab volume. Lower stress LV-MBF was associated with lower left-caudate z-score (rho = 0.69, P = 0.014), while lower LV-MFR was associated with lower left (rho = 0.75, P = 0.005)- and right (rho = 0.59, P = 0.045)-putamen z-scores, as well as higher right-thalamus GMab volume (rho = - 0.72, P = 0.009).

CONCLUSION

Significant interrelations between cardiac and cerebral SVD markers were found, especially regarding deep gray matter alterations, which supports the hypothesis of SVD as a systemic disease.

Quantitative study of spatial and temporal variation in retinal capillary network perfusion in rat eye by in vivo confocal imaging

Microvascular dysfunction is the underlying pathological process in many systemic diseases. However, investigation into its pathogenesis is impeded by the accessibility and complexity of the microvasculature within different organs, particularly for the central nervous system. The retina as an extension of the cerebrum provides a glimpse into the brain through which the microvasculature can be observed. Two major questions remain unanswered: How do the microvessels regulate spatial and temporal delivery to satisfy the varying cellular demands, and how can we quantify blood perfusion in the 3D capillary network? Here, quantitative measurements of red blood cell (RBC) speed in each vessel in the field were made in the in vivo rat retinal capillary network using an ultrafast confocal technique with fluorescently labelled RBCs. Retinal RBC speed and number were found to vary remarkably between microvessels ranging from 215 to 6641 microns per second with significant variations spatially and temporally. Overall, the RBC speed was significantly faster in the microvessels in the superficial retina than in the deep retina (estimated marginal means of 2405 ± 238.2 µm/s, 1641 ± 173.0 µm/s respectively). These observations point to a highly dynamic nature of microvasculature that is specific to its immediate cellular environment and is constantly changing.

Left ventricular systolic dyssynchrony: a novel imaging marker for early assessment of myocardial damage in Chinese type 2 diabetes mellitus patients with normal left ventricular ejection fraction and normal myocardial perfusion

OBJECTIVES

Myocardial damage is the important cause of heart failure (HF) in type 2 diabetes mellitus (T2DM), which is difficult to early diagnose, especially in T2DM with normal left ventricular ejection fraction (LVEF) and normal myocardial perfusion. The goal was to evaluate myocardial damage in T2DM with normal LVEF and normal myocardial perfusion by detecting left ventricular systolic dyssynchrony (LVSD), and find out the risk factors associated with LVSD.

METHODS

This study included 95 T2DM with normal LVEF, normal myocardial perfusion. 69 consecutive individuals without T2DM and CAD were enrolled as the control group with age-, sex- and BMI-matched. All participants underwent stress/rest 99mtechnetium-sestamibi (99mTc-MIBI) gated myocardial perfusion imaging (GMPI) and two-dimensional echocardiography within 1 week. Clinical data including age, gender, BMI, duration of diabetes, chronic diabetic complications, glycated haemoglobin A1c (HbA1c), fast blood glucose (FBG) and Brain Natriuretic Peptide (BNP) were collected from medical records. Left ventricular synchrony parameters were acquired, including phase standard deviation (PSD) and phase histogram bandwidth (PBW) by rest GMPI.

RESULTS

PSD and PBW in T2DM group were significantly higher than control group (P < .05). LVSD was detected in 20 (21%) T2DM patients. Compared to non-LVSD T2DM group, LVSD T2DM group had higher BMI, higher prevalence of BNP [Formula: see text] 35 pg/mL and chronic diabetic complications (P < .05). BNP [Formula: see text] 35 pg/mL had mild positive association with LVSD (r = 0.318, P = .004). In multivariate logistic regression, chronic diabetic complications and high BMI (> 23.4 kg/m2) were independent risk factors of LVSD (OR 5.64, 95% CI 1.58-20.16, P = .008; OR 6.77, 95% CI 1.59-28.89, P = .010).

CONCLUSIONS

LVSD existed in T2DM patients with normal LVEF and normal myocardial perfusion. Chronic diabetic complications and high BMI (> 23.4 kg/m2) were the independent risk factors of LVSD. LVSD based on GMPI can be the novel imaging marker to early assess myocardial damage in T2DM patients.

The importance of microvascular inflammation in ageing and age-related diseases: a position paper from the ESH working group on small arteries, section of microvascular inflammation

Microcirculation is pervasive and orchestrates a profound regulatory cross-talk with the surrounding tissue and organs. Similarly, it is one of the earliest biological systems targeted by environmental stressors and consequently involved in the development and progression of ageing and age-related disease. Microvascular dysfunction, if not targeted, leads to a steady derangement of the phenotype, which cumulates comorbidities and eventually results in a nonrescuable, very high-cardiovascular risk. Along the broad spectrum of pathologies, both shared and distinct molecular pathways and pathophysiological alteration are involved in the disruption of microvascular homeostasis, all pointing to microvascular inflammation as the putative primary culprit. This position paper explores the presence and the detrimental contribution of microvascular inflammation across the whole spectrum of chronic age-related diseases, which characterise the 21st-century healthcare landscape. The manuscript aims to strongly affirm the centrality of microvascular inflammation by recapitulating the current evidence and providing a clear synoptic view of the whole cardiometabolic derangement. Indeed, there is an urgent need for further mechanistic exploration to identify clear, very early or disease-specific molecular targets to provide an effective therapeutic strategy against the otherwise unstoppable rising prevalence of age-related diseases.

A Case of Significant Improvement of Heart Failure With Reduced Ejection Fraction With a Small Dose of Candesartan in a Hemodialysis Patient With Hypertensive Heart Disease and Nephrosclerosis

Hypertension induces vascular damage followed by organ damage, including heart failure in hypertensive heart disease (HHD) and nephrosclerosis (the resultant renal pathologic change from long-standing hypertension affecting renal vascular supply), ultimately causing renal failure. Renin-angiotensin-aldosterone system (RAAS) inhibitors are well known as effective drugs for the treatment of hypertension and the anti-remodeling of affected organs. A 52-year-old male was evaluated. Right atrophic kidney and proteinuria were noted in his high school years; however, he had no symptoms for about 35 years. He had pollakiuria in November and oliguria and leg edema in December 2020. The edema deteriorated rapidly, and general fatigue and orthopnea emerged in January 2021. Anasarca, hypertension (198/151 mmHg), tachycardia (115/minute), and hypoxemia (oxygen saturation {SpO2} of 93%) were observed on admission. A bilateral pleural effusion and pulmonary congestion were found on a chest X-ray (CXR) examination. An echocardiogram showed a 22% left ventricle ejection fraction (LVEF). Blood urea nitrogen (BUN) and serum creatinine concentrations were 70 mg/dL and 6.05 mg/dL, respectively. He was diagnosed with nephrosclerosis and HHD-induced cardiac exhaustion. Hemodialysis was started in April 2021. Even though the dry weight was decreased by draining water, cardiomegaly (cardiothoracic ratio {CTR}: 60%), low LVEF (20%-30%), and hypertension, especially diastolic hypertension (140-150/100-120 mmHg), were sustained. After 2 mg of candesartan was added in November 2021, the cardiomegaly, blood pressure (BP), and LVEF were rapidly ameliorated. The CTR and LVEF recovered to 48.5% and 60%, respectively, in April 2022. Statistical analyses showed that the independent factors for CTR were the mean monthly diastolic BP (standard partial regression coefficient {[Formula: see text]}: 0.9058, p<0.0001) and candesartan ([Formula: see text]: -0.7389, p=0.0011) in vital signs and prescribed drugs, respectively. We experienced a case of a significant effect of candesartan treatment against heart failure with reduced ejection fraction (HFrEF) caused by HHD in a hemodialysis patient with nephrosclerosis. Statistical analyses suggested that the improvement of HFrEF resistant to fluid removal by hemodialysis was presumably due to a decrease in diastolic BP caused by a small dose of candesartan.

Microcirculatory dysfunction in cardiogenic shock

Cardiogenic shock is usually defined as primary cardiac dysfunction with low cardiac output leading to critical organ hypoperfusion, and tissue hypoxia, resulting in high mortality rate between 40% and 50% despite recent advances. Many studies have now evidenced that cardiogenic shock not only involves systemic macrocirculation, such as blood pressure, left ventricular ejection fraction, or cardiac output, but also involves significant systemic microcirculatory abnormalities which seem strongly associated with the outcome. Although microcirculation has been widely studied in the context of septic shock showing heterogeneous alterations with clear evidence of macro and microcirculation uncoupling, there is now a growing body of literature focusing on cardiogenic shock states. Even if there is currently no consensus regarding the treatment of microcirculatory disturbances in cardiogenic shock, some treatments seem to show a benefit. Furthermore, a better understanding of the underlying pathophysiology may provide hypotheses for future studies aiming to improve cardiogenic shock prognosis.

Associations of Microvascular Dysfunction with Mild Cognitive Impairment and Cognitive Function Among Rural-Dwelling Older Adults in China

BACKGROUND

Microvascular dysfunction (MVD) may contribute to cognitive impairment and Alzheimer's disease, but evidence is limited.

OBJECTIVE

To investigate the association of composite and organ-specific MVD burden with mild cognitive impairment (MCI) and cognition among rural-dwelling Chinese older adults.

METHODS

In this population-based cross-sectional study, we assessed MVD makers using optical coherence tomographic angiography for retinal microvasculature features, brain magnetic resonance imaging scans for cerebral small vessel disease (CSVD), and serum biomarkers for MVD. A composite MVD score was generated from the aforementioned organ-specific parameters. We used a neuropsychological test battery to assess memory, verbal fluency, attention, executive function, and global cognitive function. MCI, amnestic MCI (aMCI), and non-amnestic MCI (naMCI) were diagnosed following the Petersen's criteria. Data was analyzed with the linear and logistic regression models.

RESULTS

Of the 274 dementia-free participants (age≥65 years), 56 were diagnosed with MCI, including 47 with aMCI and 9 with naMCI. A composite MVD score was statistically significantly associated with an odds ratio (OR) of 2.70 (95% confidence interval 1.12-6.53) for MCI and β-coefficient of -0.29 (-0.48--0.10) for global cognitive score after adjustment for socio-demographics, lifestyle factors, APOE genotype, the Geriatric Depression Scale score, serum inflammatory biomarkers, and cardiovascular comorbidity. A composite score of retinal microvascular morphology was associated with a multivariable-adjusted OR of 1.72 (1.09-2.73) for MCI and multivariable-adjusted β-coefficient of -0.11 (-0.22--0.01) for global cognitive score. A composite CSVD score was associated with a lower global cognitive score (β= -0.10; -0.17--0.02).

CONCLUSION

Microvascular dysfunction, especially in the brain and retina, is associated with MCI and poor cognitive function among rural-dwelling older adults.

Latest from the WISE: Contributions to the Understanding of Ischemia and Heart Failure among Women with No Obstructive Coronary Arteries

Since 1996, the National Heart, Lung, and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation (WISE) has been investigating pathophysiological processes underlying ischemic heart disease in women and related outcomes. Recent findings have focused on women with signs and symptoms of ischemia and no obstructive coronary arteries (INOCA) and their elevated risk for heart failure with preserved ejection fraction (HFpEF). This review summarizes the latest WISE findings related to INOCA and pre-HFpEF characteristics, addressing our understanding of contributions from traditional vs nontraditional risk factors in women.

Exosomes for angiogenesis induction in ischemic disorders

Ischaemic disorders are leading causes of morbidity and mortality worldwide. While the current therapeutic approaches have improved life expectancy and quality of life, they are unable to "cure" ischemic diseases and instate regeneration of damaged tissues. Exosomes are a class of extracellular vesicles with an average size of 100-150 nm, secreted by many cell types and considered a potent factor of cells for paracrine effects. Since exosomes contain multiple bioactive components such as growth factors, molecular intermediates of different intracellular pathways, microRNAs and nucleic acids, they are considered as cell-free therapeutics. Besides, exosomes do not rise cell therapy concerns such as teratoma formation, alloreactivity and thrombotic events. In addition, exosomes are stored and utilized more convenient. Interestingly, exosomes could be an ideal complementary therapeutic tool for ischemic disorders. In this review, we discussed therapeutic functions of exosomes in ischemic disorders including angiogenesis induction through various mechanisms with specific attention to vascular endothelial growth factor pathway. Furthermore, different delivery routes of exosomes and different modification strategies including cell preconditioning, gene modification and bioconjugation, were highlighted. Finally, pre-clinical and clinical investigations in which exosomes were used were discussed.

ANOCA/INOCA/MINOCA: Open artery ischemia

Ischemic heart disease continues to represent a major health threat for death, disability, and poor quality of life as it also consumes enormous health-related resources. For over a century, the major clinical phenotype was taken to be obstructive atherosclerosis involving the larger coronary arteries (e.g., coronary artery disease [CAD]). However, evolving evidence now indicates that nonobstructive CAD is the predominant phenotype. Patients within this phenotype have been termed to have angina with no obstructive CAD (ANOCA), ischemia with no obstructive CAD (INOCA), or myocardial infarction with no obstructive coronary arteries (MINOCA). But as methods to assess cardiomyocyte injury evolve, these phenotypic distinctions have begun to merge, raising concern about their usefulness. Also, considerable evidence has suggested several endotypes that link to potential mechanisms. These include coronary microvascular dysfunction, augmented vasoreactivity (failure to relax appropriately, exaggerated constriction ["spasm"], etc.), nonobstructive atherosclerosis, pre-heart failure with preserved ejection fraction, hypercoagulable states, and several others, alone or in combination. This review summarizes these syndromes and their associated clinical outcomes with an emphasis on potential mechanistic signals. These involve the endothelium, the microvasculature, and cardiomyocyte function. Biomarkers of injury/dysfunction involving these structures are discussed along with a hypothetical construct for management being tested in an ongoing trial.

A review of cardio-pulmonary microvascular dysfunction in pulmonary hypertension

Microvascular dysfunction progressing to pulmonary hypertension can be a primary cause of right ventricular failure or a secondary cause because of an underlying systemic illness. Little is known regarding the etiology and epidemiology of coronary microvascular dysfunction in pulmonary hypertension. Despite this limitation, its presence has been described in patients with pulmonary hypertension. This review focuses on the pathogenesis of cardiac and pulmonary microvascular dysfunction in pulmonary hypertension. Additionally, this review provides a contemporary assessment on the diagnosis and treatment of microvascular dysfunction in patients in pulmonary hypertension. This topic is important to raise awareness of microvascular dysfunction in the coronary and pulmonary circulation, so that future studies will investigate its impact on the pulmonary hypertension patient cohort.

Small vessel disease: Connections between the kidney and the heart

Small vessel disease is characterized by global dysfunction of the microvascular system leading to reduced perfusion of various organ systems. The kidney is significantly vulnerable for microvascular dysfunction given its intricate capillary network and extensive endocrine influence. Studies have demonstrated a relationship between impaired renal function and small vessel disease in other organ systems, particularly the heart. Here we discuss the relationship between the kidney and the heart in the setting of microvascular dysfunction and identify areas of future study to better understand this relationship and potentially identify novel therapeutic strategies.

Pathophysiology and Outcomes of Endothelium Function in Coronary Microvascular Diseases: A Systematic Review of Randomized Controlled Trials and Multicenter Study

BACKGROUND

Coronary macrovascular disease is a concept that has been well-studied within the literature and has long been the subject of debates surrounding coronary artery bypass grafting (CABG) vs. Percutaneous Coronary Intervention (PCI). ISCHEMIA trial reported no statistical difference in the primary clinical endpoint between initial invasive management and initial conservative management, while in the ORBITA trial PCI did not improve angina frequency score significantly more than placebo, albeit PCI resulted in more patient-reported freedom from angina than placebo. However, these results did not prove the superiority of the PCI against OMT, therefore do not indicate the benefit of PCI vs. the OMT. Please rephrase the sentence. We reviewed the role of different factors responsible for endothelial dysfunction from recent randomized clinical trials (RCTs) and multicentre studies.

METHODS

A detailed search strategy was performed using a dataset that has previously been published. Data of pooled analysis include research articles (human and animal models), CABG, and PCI randomized controlled trials (RCTs). Details of the search strategy and the methods used for data pooling have been published previously and registered with Open-Source Framework.

RESULTS

The roles of nitric oxide (NO), endothelium-derived contracting factors (EDCFs), and vasodilator prostaglandins (e.g., prostacyclin), as well as endothelium-dependent hyperpolarization (EDH) factors, are crucial for the maintenance of vasomotor tone within the coronary vasculature. These homeostatic mechanisms are affected by sheer forces and other several factors that are currently being studied, such as vaping. The role of intracoronary testing is crucial when determining the effects of therapeutic medications with further studies on the horizon.

CONCLUSION

The true impact of coronary microvascular dysfunction (CMD) is perhaps underappreciated, which supports the role of medical therapy in determining outcomes. Ongoing trials are underway to further investigate the role of therapeutic agents in secondary prevention.

Critical role of the coronary microvasculature in heart disease: From pathologic driving force to "innocent" bystander

The coronary microvasculature is responsible for providing oxygen and nutrients to myocardial tissue. A healthy microvasculature with an intact and properly functioning endothelium accomplishes this by seemless changes in vascular tone to match supply and demand. Perturbations in the normal physiology of the microvasculature, including endothelial and/or vascular smooth muscle dysfunction, result in impaired function (vasoconstriction, antithrombotic, etc.) and structural (hypertrophic, fibrotic) abnormalities that lead to microvascular ischemia and potential organ damage. While coronary microvascular dysfunction (CMD) is the primary pathologic driving force in ischemia with non-obstructive coronary artery disease (INOCA), angina with no obstructive coronary arteries (ANOCA), and myocardial infarction with non-obstructed coronary arteries (MINOCA), it may be a bystander in many cardiac disorders which later become pathologically associated with signs and/or symptoms of myocardial ischemia. Importantly, regardless of the primary or secondary basis of CMD in the heart, it is associated with important increases in morbidity and mortality. In this review we discuss salient features pertaining to known pathophysiologic mechanisms driving CMD, the spectrum of heart diseases where it places a critical role, invasive and non-invasive diagnostic testing, management strategies, and the gaps in knowledge where future research efforts are needed.