Coronary "Microvascular Dysfunction": Evolving Understanding of Pathophysiology, Clinical Implications, and Potential Therapeutics

Applications of Stem Cell-Derived Extracellular Vesicles in Nerve Regeneration

Extracellular vesicles (EVs), including exosomes, microvesicles, and other lipid vesicles derived from cells, play a pivotal role in intercellular communication by transferring information between cells. EVs secreted by progenitor and stem cells have been associated with the therapeutic effects observed in cell-based therapies, and they also contribute to tissue regeneration following injury, such as in orthopaedic surgery cases. This review explores the involvement of EVs in nerve regeneration, their potential as drug carriers, and their significance in stem cell research and cell-free therapies. It underscores the importance of bioengineers comprehending and manipulating EV activity to optimize the efficacy of tissue engineering and regenerative therapies.

The Molecular Mechanisms and Therapeutic Targets of Atherosclerosis: From Basic Research to Interventional Cardiology

The goal of this Special Issue was to collect original pieces as well as state-of-the-art review articles from scientists and research groups with specific interests in atherosclerosis research [...].

Insights into the Molecular Mechanism of Endothelial Glycocalyx Dysfunction during Heart Surgery

The endothelial glycocalyx (EGC) is a layer of proteoglycans (associated with glycosaminoglycans) and glycoproteins, which adsorbs plasma proteins on the luminal surface of endothelial cells. Its main function is to participate in separating the circulating blood from the inner layers of the vessels and the surrounding tissues. Physiologically, the EGC stimulates mechanotransduction, the endothelial charge, thrombocyte adhesion, leukocyte tissue recruitment, and molecule extravasation. Hence, severe impairment of the EGC has been implicated in various pathological conditions, including sepsis, diabetes, chronic kidney disease, inflammatory disorders, hypernatremia, hypervolemia, atherosclerosis, and ischemia/reperfusion injury. Moreover, alterations in EGC have been associated with altered responses to therapeutic interventions in conditions such as cardiovascular diseases. Investigation into the function of the glycocalyx has expanded knowledge about vascular disorders and indicated the need to consider new approaches in the treatment of severe endothelial dysfunction. This review aims to present the current understanding of the molecular mechanisms underlying cardiovascular diseases and to elucidate the impact of heart surgery on EGC dysfunction.

Nuciferine reduces vascular leakage and improves cardiac function in acute myocardial infarction by regulating the PI3K/AKT pathway

The destruction of the microvascular structure and function can seriously affect the survival and prognosis of patients with acute myocardial infarction (AMI). Nuciferine has a potentially beneficial effect in the treatment of cardiovascular disease, albeit its role in microvascular structure and function during AMI remains unclear. This study aimed to investigate the protective effect and the related mechanisms of nuciferine in microvascular injury during AMI. Cardiac functions and pathological examination were conducted in vivo to investigate the effect of nuciferine on AMI. The effect of nuciferine on permeability and adherens junctions in endothelial cells was evaluated in vitro, and the phosphorylation level of the PI3K/AKT pathway (in the presence or absence of PI3K inhibitors) was also analyzed. In vivo results indicated that nuciferine inhibited ischemia-induced cardiomyocyte damage and vascular leakage and improved cardiac function. In addition, the in vitro results revealed that nuciferine could effectively inhibit oxygen-glucose deprivation (OGD) stimulated breakdown of the structure and function of human coronary microvascular endothelial cells (HCMECs). Moreover, nuciferine could significantly increase the phosphorylation level of the PI3K/AKT pathway. Finally, the inhibitor wortmannin could reverse the protective effect of nuciferine on HCMECs. Nuciferine inhibited AMI-induced microvascular injury by regulating the PI3K/AKT pathway and protecting the endothelial barrier function in mice.

Hypertension Related Co-Morbidities and Complications in Women of Sub-Saharan Africa: A Brief Review

Hypertension is the leading cause of cardiovascular disease in women, and sub-Saharan African (SSA) countries have some of the highest rates of hypertension in the world. Expanding knowledge of causes, management, and awareness of hypertension and its co-morbidities worldwide is an effective strategy to mitigate its harms, decrease morbidities and mortality, and improve individual quality of life. Hypertensive disorders of pregnancy (HDPs) are a particularly important subset of hypertension, as pregnancy is a major stress test of the cardiovascular system and can be the first instance in which cardiovascular disease is clinically apparent. In SSA, women experience a higher incidence of HDP compared with other African regions. However, the region has yet to adopt treatment and preventative strategies for HDP. This delay stems from insufficient awareness, lack of clinical screening for hypertension, and lack of prevention programs. In this brief literature review, we will address the long-term consequences of hypertension and HDP in women. We evaluate the effects of uncontrolled hypertension in SSA by including research on heart disease, stroke, kidney disease, peripheral arterial disease, and HDP. Limitations exist in the number of studies from SSA; therefore, we will use data from countries across the globe, comparing and contrasting approaches in similar and dissimilar populations. Our review highlights an urgent need to prioritize public health, clinical, and bench research to discover cost-effective preventative and treatment strategies that will improve the lives of women living with hypertension in SSA.

Microvascular reperfusion of fibrinolysis followed by percutaneous coronary intervention versus primary percutaneous coronary intervention for ST-segment-elevation acute myocardial infarction

Background

Primary percutaneous coronary intervention (PPCI) has been widely recognized as the preferred treatment for ST-segment-elevation myocardial infarction (STEMI). However, substantial numbers of STEMI patients cannot receive timely PPCI. Early fibrinolysis followed by routine percutaneous coronary intervention (FPCI) has been proposed as an effective and safe alternative for eligible patients. To date, few studies have compared FPCI with PPCI in terms of microvascular reperfusion. This study aimed to evaluate the microvascular function of FPCI and PPCI.

Methods

STEMI patients at the Peking University First Hospital and Miyun Hospital were enrolled in this retrospective study between January 2015 to December 2020. Microvascular function documented by the coronary angiography-derived index of microvascular resistance (caIMR) was measured at the final angiogram after revascularization. The primary end point was the caIMR of the culprit vessels. The secondary end points were in-hospital and follow-up major adverse cardiovascular events (MACE), including cardiovascular death, non-fatal recurrent myocardial infarction, target-vessel revascularization (TVR), and non-fatal stroke/transient ischemic attacks (TIA). Details of the adverse clinical events were obtained from telephone interviews and electronic medical record systems until January 2022.

Results

In total, 496 STEMI patients were enrolled in this cross-sectional retrospective study. Of these patients, 81 underwent FPCI, and 415 underwent PPCI. At the baseline, the PPCI patients had a higher-risk profile than the FPCI patients. The time from symptom onset to reperfusion therapy was significantly shorter in the FPCI group than the PPCI group (median 3.0 vs. 4.5 hours; P<0.001). The caIMR was significantly lower in the FPCI group than the PPCI group (median 20.34 vs. 40.33; P<0.001). The median follow-up duration was 4.1 years. During the follow-up period, the rate of MACE was lower in the FPCI group than the PPCI group [7 (10.1%) vs. 82 (20.8%), P=0.048]. After propensity score matching to adjust for the imbalances at the baseline, the caIMR remained significant and the clinical outcomes did not differ significantly between the two groups.

Conclusions

In eligible STEMI patients, clinically successful FPCI may be associated with better microvascular reperfusion and comparable clinical outcomes as compared with PPCI.

The evolving role of cardiopulmonary exercise testing in ischemic heart disease - state of the art review

PURPOSE OF REVIEW

Cardiopulmonary exercise testing (CPET) is the gold standard for directly assessing cardiorespiratory fitness (CRF) and has a relatively new and evolving role in evaluating atherosclerotic heart disease, particularly in detecting cardiac dysfunction caused by ischemic heart disease. The purpose of this review is to assess the current literature on the link between cardiovascular (CV) risk factors, cardiac dysfunction and CRF assessed by CPET.

RECENT FINDINGS

We summarize the basics of exercise physiology and the key determinants of CRF. Prognostically, several studies have been published relating directly measured CRF by CPET and outcomes allowing for more precise risk assessment. Diagnostically, this review describes in detail what is considered healthy and abnormal cardiac function assessed by CPET. New studies demonstrate that cardiac dysfunction on CPET is a common finding in asymptomatic individuals and is associated with CV risk factors and lower CRF. This review covers how key CPET parameters change as individuals transition from the asymptomatic to the symptomatic stage with progressively decreasing CRF. Finally, a supplement with case studies with long-term longitudinal data demonstrating how CPET can be used in daily clinical decision making is presented.

SUMMARY

In summary, CPET is a powerful tool to provide individualized CV risk assessment, monitor the effectiveness of therapeutic interventions, and provide meaningful feedback to help patients guide their path to improve CRF when routinely used in the outpatient setting.