Implementation of a quality improvement project using the patient as the observer to improve hand hygiene compliance in ambulatory care practices.

BACKGROUND: Monitoring hand hygiene compliance in the ambulatory setting remains a challenge because a healthcare trained observer loses line of sight once the examination room door closes. This quality improvement project focused on the implementation of a hand hygiene compliance improvement programme that is amenable to the routines and work flows of the ambulatory setting. METHODS: After a review of the literature, nursing leadership and infection prevention implemented the 'patient as the observer' hand hygiene programme across 32 ambulatory practices. RESULTS: Patients completed 281,000 observations with an overall compliance rate of ≥90%. The average overall compliance rate by role was 91% for providers, 89% for nurses, and 91% for medical assistants/technicians/others. A 92% compliance average was noted 'before caring for you' and 89% 'after caring for you' for providers, 90% and 87% for nurses, and 92% and 89% for medical assistants/technicians/others. DISCUSSION: This study demonstrated that the implementation of a hand hygiene compliance improvement programme using the patient as the observer can be adopted successfully in the ambulatory setting. CONCLUSION: Hand hygiene compliance can be monitored effectively in the ambulatory setting with the involvement of the patient as the observer.

Interfacility Transport of Critically Ill Patients.

OBJECTIVES: To assess recent advances in interfacility critical care transport. DATA SOURCES: PubMed English language publications plus chapters and professional organization publications. STUDY SELECTION: Manuscripts including practice manuals and standard (1990-2021) focused on interfacility transport of critically ill patients. DATA EXTRACTION: Review of society guidelines, legislative requirements, objective measures of outcomes, and transport practice standards occurred in work groups assessing definitions and foundations of interfacility transport, transport team composition, and transport specific considerations. Qualitative analysis was performed to characterize current science regarding interfacility transport. DATA SYNTHESIS: The Task Force conducted an integrative review of 496 manuscripts combined with 120 from the authors' collections including nonpeer reviewed publications. After title and abstract screening, 40 underwent full-text review, of which 21 remained for qualitative synthesis. CONCLUSIONS: Since 2004, there have been numerous advances in critical care interfacility transport. Clinical deterioration may be mitigated by appropriate patient selection, pretransport optimization, and transport by a well-resourced team and vehicle. There remains a dearth of high-quality controlled studies, but notable advances in monitoring, en route management, transport modality (air vs ground), as well as team composition and training serve as foundations for future inquiry. Guidance from professional organizations remains uncoupled from enforceable regulations, impeding standardization of transport program quality assessment and verification.

Systems Approach to Integrating Preclinical Apolipoprotein E-Knockout Investigations Reveals Novel Etiologic Pathways and Master Atherosclerosis Network in Humans.

OBJECTIVE: Animal models of atherosclerosis are used extensively to interrogate molecular mechanisms in serial fashion. We tested whether a novel systems biology approach to integration of preclinical data identifies novel pathways and regulators in human disease. Approach and Results: Of 716 articles published in ATVB from 1995 to 2019 using the apolipoprotein E knockout mouse to study atherosclerosis, data were extracted from 360 unique studies in which a gene was experimentally perturbed to impact plaque size or composition and analyzed using Ingenuity Pathway Analysis software. TREM1 (triggering receptor expressed on myeloid cells) signaling and LXR/RXR (liver X receptor/retinoid X receptor) activation were identified as the top atherosclerosis-associated pathways in mice (both P<1.93×10-4, TREM1 implicated early and LXR/RXR in late atherogenesis). The top upstream regulatory network in mice (sc-58125, a COX2 inhibitor) linked 64.0% of the genes into a single network. The pathways and networks identified in mice were interrogated by testing for associations between the genetically predicted gene expression of each mouse pathway-identified human homolog with clinical atherosclerosis in a cohort of 88 660 human subjects. Homologous human pathways and networks were significantly enriched for gene-atherosclerosis associations (empirical P<0.01 for TREM1 and LXR/RXR pathways and COX2 network). This included 12(60.0%) TREM1 pathway genes, 15(53.6%) LXR/RXR pathway genes, and 67(49.3%) COX2 network genes. Mouse analyses predicted, and human study validated, the strong association of COX2 expression (PTGS2) with increased likelihood of atherosclerosis (odds ratio, 1.68 per SD of genetically predicted gene expression; P=1.07×10-6). CONCLUSIONS: PRESCIANT (Preclinical Science Integration and Translation) leverages published preclinical investigations to identify high-confidence pathways, networks, and regulators of human disease.

Myeloid Mineralocorticoid Receptor Transcriptionally Regulates P-Selectin Glycoprotein Ligand-1 and Promotes Monocyte Trafficking and Atherosclerosis.

Objective: MR (mineralocorticoid receptor) activation associates with increased risk of cardiovascular ischemia while MR inhibition reduces cardiovascular-related mortality and plaque inflammation in mouse atherosclerosis. MR in myeloid cells (My-MR) promotes inflammatory cell infiltration into injured tissues and atherosclerotic plaque inflammation by unclear mechanisms. Here, we examined the role of My-MR in leukocyte trafficking and the impact of sex. Approach and Results: We confirm in vivo that My-MR deletion (My-MR-KO) in ApoE-KO mice decreased plaque size. Flow cytometry revealed fewer plaque macrophages with My-MR-KO. By intravital microscopy, My-MR-KO significantly attenuated monocyte slow-rolling and adhesion to mesenteric vessels and decreased peritoneal infiltration of myeloid cells in response to inflammatory stimuli in male but not female mice. My-MR-KO mice had significantly less PSGL1 (P-selectin glycoprotein ligand 1) mRNA in peritoneal macrophages and surface PSGL1 protein on circulating monocytes in males. In vitro, MR activation with aldosterone significantly increased PSGL1 mRNA only in monocytes from MR-intact males. Similarly, aldosterone induced, and MR antagonist spironolactone inhibited, PSGL1 expression in human U937 monocytes. Mechanistically, aldosterone stimulated MR binding to a predicted MR response element in intron-1 of the PSGL1 gene by ChIP-qPCR. Reporter assays demonstrated that this PSGL1 MR response element is necessary and sufficient for aldosterone-activated, MR-dependent transcriptional activity. Conclusions: These data identify PSGL1 as a My-MR target gene that drives leukocyte trafficking to enhance atherosclerotic plaque inflammation. These novel and sexually dimorphic findings provide insight into increased ischemia risk with MR activation, cardiovascular protection in women, and the role of MR in atherosclerosis and tissue inflammation.

Vascular cell-specific roles of mineralocorticoid receptors in pulmonary hypertension.

Abnormalities that characterize pulmonary arterial hypertension include impairment in the structure and function of pulmonary vascular endothelial and smooth muscle cells. Aldosterone levels are elevated in human pulmonary arterial hypertension and in experimental pulmonary hypertension, while inhibition of the aldosterone-binding mineralocorticoid receptor attenuates pulmonary hypertension in multiple animal models. We explored the role of mineralocorticoid receptor in endothelial and smooth muscle cells in using cell-specific mineralocorticoid receptor knockout mice exposed to sugen/hypoxia-induced pulmonary hypertension. Treatment with the mineralocorticoid receptor inhibitor spironolactone significantly reduced right ventricular systolic pressure. However, this is not reproduced by selective mineralocorticoid receptor deletion in smooth muscle cells or endothelial cells. Similarly, spironolactone attenuated the increase in right ventricular cardiomyocyte area independent of vascular mineralocorticoid receptor with no effect on right ventricular weight or interstitial fibrosis. Right ventricular perivascular fibrosis was significantly decreased by spironolactone and this was reproduced by specific deletion of mineralocorticoid receptor from endothelial cells. Endothelial cell-mineralocorticoid receptor deletion attenuated the sugen/hypoxia-induced increase in the leukocyte-adhesion molecule, E-selectin, and collagen IIIA1 in the right ventricle. Spironolactone also significantly reduced pulmonary arteriolar muscularization, independent of endothelial cell-mineralocorticoid receptor or smooth muscle cell-mineralocorticoid receptor. Finally, the degree of pulmonary perivascular inflammation was attenuated by mineralocorticoid receptor antagonism and was fully reproduced by smooth muscle cell-specific mineralocorticoid receptor deletion. These studies demonstrate that in the sugen/hypoxia pulmonary hypertension model, systemic-mineralocorticoid receptor blockade significantly attenuates the disease and that mineralocorticoid receptor has cell-specific effects, with endothelial cell-mineralocorticoid receptor contributing to right ventricular perivascular fibrosis and smooth muscle cell-mineralocorticoid receptor participating in pulmonary vascular inflammation. As mineralocorticoid receptor antagonists are being investigated to treat pulmonary arterial hypertension, these findings support novel mechanisms and potential mineralocorticoid receptor targets that mediate therapeutic benefits in patients.

Mineralocorticoid Receptor in Smooth Muscle Contributes to Pressure Overload-Induced Heart Failure.

BACKGROUND: Mineralocorticoid receptor (MR) antagonists decrease heart failure (HF) hospitalization and mortality, but the mechanisms are unknown. Preclinical studies reveal that the benefits on cardiac remodeling and dysfunction are not completely explained by inhibition of MR in cardiomyocytes, fibroblasts, or endothelial cells. The role of MR in smooth muscle cells (SMCs) in HF has never been explored. METHODS: Male mice with inducible deletion of MR from SMCs (SMC-MR-knockout) and their MR-intact littermates were exposed to HF induced by 27-gauge transverse aortic constriction versus sham surgery. HF phenotypes and mechanisms were measured 4 weeks later using cardiac ultrasound, intracardiac pressure measurements, exercise testing, histology, cardiac gene expression, and leukocyte flow cytometry. RESULTS: Deletion of MR from SMC attenuated transverse aortic constriction-induced HF with statistically significant improvements in ejection fraction, cardiac stiffness, chamber dimensions, intracardiac pressure, pulmonary edema, and exercise capacity. Mechanistically, SMC-MR-knockout protected from adverse cardiac remodeling as evidenced by decreased cardiomyocyte hypertrophy and fetal gene expression, interstitial and perivascular fibrosis, and inflammatory and fibrotic gene expression. Exposure to pressure overload resulted in a statistically significant decline in cardiac capillary density and coronary flow reserve in MR-intact mice. These vascular parameters were improved in SMC-MR-knockout mice compared with MR-intact littermates exposed to transverse aortic constriction. CONCLUSIONS: These results provide a novel paradigm by which MR inhibition may be beneficial in HF by blocking MR in SMC, thereby improving cardiac blood supply in the setting of pressure overload-induced hypertrophy, which in turn mitigates the adverse cardiac remodeling that contributes to HF progression and symptoms.

Unmet Dental Care Need and Associated Barriers by Race/Ethnicity among US Adults.

INTRODUCTION: Ability to access needed dental care may vary among population subgroups. We assessed 1) the differences in the proportions of adults who reported unmet dental care needs in the past 12 months and the associated barriers (structural, financial, and cognitive) in 2015 to 2016 versus 2003 to 2004 by race/ethnicity and 2) the subgroups that are more likely to report unmet dental care needs. METHODS: Data of 10,029 respondents aged ≥19 y from the 2003-2004 and 2015-2016 National Health and Nutrition Examination Surveys were used. Chi-square tests assessed the differences in the proportions of adults who reported not getting the needed dental care between the periods. A multiple logistic regression model was run to identify characteristics that were significantly associated with unmet need after adjusting for other factors. RESULTS: Overall, 19.4% of the adults reported an unmet dental care need in 2015 to 2016, as compared with 21% in 2003 to 2004. The overall unmet dental care need decreased only in the Hispanic groups (34% to 28%, P = 0.045) between 2003-2004 and 2015-2016. Between the periods, unmet need decreased among Hispanics aged 19 to 64 y (35% to 28%, P = 0.02), Hispanics with some college education or above (33.5% to 21.0%, P = 0.008), and nonpoor Hispanic adults (29.8% to 20.4%, P = 0.048). No significant differences were observed in the proportions of adults reporting structural (P = 0.09), financial (P = 0.86), or cognitive (P = 0.07) barriers between the periods. When compared with their counterparts, nonelderly adults, women, Hispanics, adults with a high school education, those with less than a high school education, and poor adults were significantly more likely to report unmet dental care needs. CONCLUSIONS: Racial and ethnic disparities in accessing and receiving the needed dental care still exist. Financial barriers to dental care are the most commonly cited reasons for not getting the needed dental care. KNOWLEDGE TRANSFER STATEMENT: The results of the study will inform policy makers, public health planners, and dental professionals about subgroups that still face difficulty in receiving the dental care they need. Policy makers should develop new policies to mitigate the financial barriers that are still prevalent. Dental professionals can mitigate the public's cognitive and financial barriers by educating the community through outreach programs and by providing services to low-income populations at reduced charges or through alternative payment plans.

Endothelial Mineralocorticoid Receptors Contribute to Vascular Inflammation in Atherosclerosis in a Sex-Specific Manner.

OBJECTIVE: MR (mineralocorticoid receptor) activation is associated with cardiovascular ischemia in humans. This study explores the role of the MR in atherosclerotic mice of both sexes and identifies a sex-specific role for endothelial cell (EC)-MR in vascular inflammation. Approach and Results: In the AAV-PCSK9 (adeno-associated virus-proprotein convertase subtilisin/kexin type 9) mouse atherosclerosis model, MR inhibition attenuated vascular inflammation in males but not females. Further studies comparing male and female littermates with intact MR or EC-MR deletion revealed that although EC-MR deletion did not affect plaque size in either sex, it reduced aortic arch inflammation specifically in male mice as measured by flow cytometry. Moreover, MR-intact females had larger plaques but were protected from vascular inflammation compared with males. Intravital microscopy of the mesenteric vasculature demonstrated that EC-MR deletion attenuated TNFα (tumor necrosis factor α)-induced leukocyte slow rolling and adhesion in males, while females exhibited fewer leukocyte-endothelial interactions with no additional effect of EC-MR deletion. These effects corresponded with decreased TNFα-induced expression of the endothelial adhesion molecules ICAM-1 (intercellular adhesion molecule-1) and E-selectin in males with EC-MR deletion compared with MR-intact males and females of both genotypes. These observations were also consistent with MR and estrogen regulation of ICAM-1 transcription and E-selectin expression in primary cultured mouse ECs and human umbilical vein ECs. CONCLUSIONS: In male mice, EC-MR deletion attenuates leukocyte-endothelial interactions, plaque inflammation, and expression of E-selectin and ICAM-1, providing a potential mechanism by which the MR promotes vascular inflammation. In females, plaque inflammation and leukocyte-endothelial interactions are decreased relative to males and EC-MR deletion is not protective.

The endothelial mineralocorticoid receptor: Contributions to sex differences in cardiovascular disease.

Cardiovascular disease remains the leading cause of death for both men and women. The observation that premenopausal women are protected from cardiovascular disease relative to age-matched men, and that this protection is lost with menopause, has led to extensive study of the role of sex steroid hormones in the pathogenesis of cardiovascular disease. However, the molecular basis for sex differences in cardiovascular disease is still not fully understood, limiting the ability to tailor therapies to male and female patients. Therefore, there is a growing need to investigate molecular pathways outside of traditional sex hormone signaling to fully understand sex differences in cardiovascular disease. Emerging evidence points to the mineralocorticoid receptor (MR), a steroid hormone receptor activated by the adrenal hormone aldosterone, as one such mediator of cardiovascular disease risk, potentially serving as a sex-dependent link between cardiovascular risk factors and disease. Enhanced activation of the MR by aldosterone is associated with increased risk of cardiovascular disease. Emerging evidence implicates the MR specifically within the endothelial cells lining the blood vessels in mediating some of the sex differences observed in cardiovascular pathology. This review summarizes the available clinical and preclinical literature concerning the role of the MR in the pathophysiology of endothelial dysfunction, hypertension, atherosclerosis, and heart failure, with a special emphasis on sex differences in the role of endothelial-specific MR in these pathologies. The available data regarding the molecular mechanisms by which endothelial-specific MR may contribute to sex differences in cardiovascular disease is also summarized. A paradigm emerges from synthesis of the literature in which endothelial-specific MR regulates vascular function in a sex-dependent manner in response to cardiovascular risk factors to contribute to disease. Limitations in this field include the relative paucity of women in clinical trials and, until recently, the nearly exclusive use of male animals in preclinical investigations. Enhanced understanding of the sex-specific roles of endothelial MR could lead to novel mechanistic insights underlying sex differences in cardiovascular disease incidence and outcomes and could identify additional therapeutic targets to effectively treat cardiovascular disease in men and women.

Optimising the biocompatibility of 3D printed photopolymer constructs in vitro and in vivo.

3D printing is a rapid and accessible fabrication technology that engenders creative custom design solutions for cell scaffolds, perfusion systems and cell culture systems for tissue engineering. Critical to its success is the biocompatibility of the materials used, which should allow long-term tissue culture without affecting cell viability or inducing an inflammatory response for in vitro and in vivo applications. Polyjet 3D printers offer arguably the highest resolution with the fewest design constraints of any commercially available 3D printing systems. Although widely used for rapid-prototyping of medical devices and 3D anatomical modelling, polyjet printing has not been adopted by the tissue engineering field, largely due to the cytotoxicity of leachates from the printed parts. Biocompatibility in the context of cell culture is not commonly addressed for polyjet materials, as they tend to be optimised for their ability to fabricate complex structures. In order to study the potential issues surrounding the leaching of toxins, we prepared cell culture substrates using the commercially available MED610 photopolymer. The substrates were cleaned using either the manufacturer-specified 'biocompatible' washing procedures, or a novel protocol incorporating a sonication in isopropanol and water step. We then compared the effectiveness of these both in vitro and in vivo. Using primary mouse myoblast cultures, the manufacturer's protocol led to inconsistent and poorer cell viability when compared to the sonication protocol (p = 0.0002 at 48 h after indirect exposure). Subdermal implantation of MED610 into nude rats demonstrated a significant foreign body response with a greater number of giant cells (p = 0.0161) and foreign bodies (p = 0.0368) when compared to the sonication protocol, which was comparable to the control (sham) groups. These results present an improved, cytocompatible cleaning protocol of printable photopolymers to facilitate creative 3D-printed custom designs for cell culture systems for both in vitro and in vivo tissue engineering applications.

Obstacles to translating the promise of nanoparticles into viable amyloid disease therapeutics.

Nanoparticles (NPs) constitute a powerful therapeutic platform with exciting prospects as potential inhibitors of amyloid-[Formula: see text] (Aß) aggregation, a process associated with Alzheimer's disease (AD). Researchers have synthesized and tested a large collection of NPs with disparate sizes, shapes, electrostatic properties and surface ligands that evoke a variety of responses on Aß aggregation. In spite of a decade of research on the NP-Aß system and many promising experimental results, NPs have failed to progress to any level of clinical trials for AD. A theoretical framework with which to approach this physical system is presented featuring two simple metrics, (1) the extent to which NPs adsorb Aß, and (2) the degree to which interaction with a NP alters Aß conformation relative to aggregation propensity. Most of our current understanding of these two interactions has been gained through experimentation, and many of these studies are reviewed herein. We also provide a potential roadmap for studies that we believe could produce viable NPs as an effective AD therapeutic platform.

Evaluation of unfractionated heparin versus low-molecular-weight heparin and fondaparinux for pharmacologic venous thromboembolic prophylaxis in critically ill patients with cancer.

Essentials Critically ill cancer patients require pharmacologic prophylaxis for venous thromboembolism (VTE). Patients from 566 hospitals in the United States between 2010 and 2014 were included. Low-molecular-weight heparin (LMWH) prophylaxis was not associated in a reduction of VTE rates. LMWH prophylaxis was associated with a reduction in bleeding and heparin induced thrombocytopenia. SUMMARY: Background Critically ill patients with cancer are at increased risk of venous thromboembolism (VTE) from physical and cellular factors, requiring pharmacologic prophylaxis to reduce the risk of VTE. Objectives To assess whether low-molecular-weight heparin (LMWH) prophylaxis reduces in-hospital rates of VTE or improves clinical outcomes compared with unfractionated heparin (UFH) prophylaxis in critically ill patients with cancer. Methods We used a propensity-matched comparative-effectiveness cohort from the Premier Database. Patients aged 18 years or older with a primary diagnosis of cancer, intensive care unit admission and VTE prophylaxis within 2 days of admission between 1 January 2010 and 31 December 2014 were included. Patients were divided into LMWH or UFH prophylaxis groups. Results A total of 103 798 patients were included; 75 321 (72.6%) patients received LMWH and 28 477 (27.4%) patients received UFH. Propensity analysis matched (2 : 1) 42 343 LMWH patients and 21 218 UFH patients. Overall, LMWH was not associated with a decreased incidence of VTE (5.32% vs. 5.50%). LMWH prophylaxis was associated with a reduction in pulmonary embolism (0.70% vs. 0.99%), significant bleeding (13.3% vs. 14.8%) and heparin-induced thrombocytopenia (HIT) (0.06% vs. 0.19%). In non-metastatic solid disease, LMWH was associated with decreased VTE (4.27% vs. 4.84%) and PE (0.47% vs. 0.95%). Conclusions The use of an LMWH for VTE prophylaxis was not associated with a reduction in the incidence of in-hospital VTE as compared with UFH, but was associated with significant reductions in PE, clinically important bleeding events, and incidence of HIT in critically ill patients with cancer.

No Significant Role for Smooth Muscle Cell Mineralocorticoid Receptors in Atherosclerosis in the Apolipoprotein-E Knockout Mouse Model.

Objective: Elevated levels of the hormone aldosterone are associated with increased risk of myocardial infarction and stroke in humans and increased progression and inflammation of atherosclerotic plaques in animal models. Aldosterone acts through the mineralocorticoid receptor (MR) which is expressed in vascular smooth muscle cells (SMCs) where it promotes SMC calcification and chemokine secretion in vitro. The objective of this study is to explore the role of the MR specifically in SMCs in the progression of atherosclerosis and the associated vascular inflammation in vivo in the apolipoprotein E knockout (ApoE-/-) mouse model. Methods and Results: Male ApoE-/- mice were bred with mice in which MR could be deleted specifically from SMCs by tamoxifen injection. The resulting atheroprone SMC-MR-KO mice were compared to their MR-Intact littermates after high fat diet (HFD) feeding for 8 or 16 weeks or normal diet for 12 months. Body weight, tail cuff blood pressure, heart and spleen weight, and serum levels of glucose, cholesterol, and aldosterone were measured for all mice at the end of the treatment period. Serial histologic sections of the aortic root were stained with Oil Red O to assess plaque size, lipid content, and necrotic core area; with PicroSirius Red for quantification of collagen content; by immunofluorescent staining with anti-Mac2/Galectin-3 and anti-smooth muscle α-actin antibodies to assess inflammation and SMC marker expression; and with Von Kossa stain to detect plaque calcification. In the 16-week HFD study, these analyses were also performed in sections from the brachiocephalic artery. Flow cytometry of cell suspensions derived from the aortic arch was also performed to quantify vascular inflammation after 8 and 16 weeks of HFD. Deletion of the MR specifically from SMCs did not significantly change plaque size, lipid content, necrotic core, collagen content, inflammatory staining, actin staining, or calcification, nor were there differences in the extent of vascular inflammation between MR-Intact and SMC-MR-KO mice in the three experiments. Conclusion: SMC-MR does not directly contribute to the formation, progression, or inflammation of atherosclerotic plaques in the ApoE-/- mouse model of atherosclerosis. This indicates that the MR in non-SMCs mediates the pro-atherogenic effects of MR activation.

Stability of complete blood count in different storage conditions using the ABX PENTRA 60 analyzer.

INTRODUCTION: Sample stability is essential to obtain reliable results in the clinical laboratory. This study was conducted to investigate the reliability of hematological parameters using ABX Pentra 60 in samples stored for up to 72 hours at different temperatures. METHODS: A total of 651 blood samples were analyzed at different analysis times: 2, 24, 48, and 72 hours and forms and storage: room temperature (25°C) and at 4°C. The imprecision of the results was evaluated by the analytical coefficient of variation (CVa%) obtained by the typical error (TE) and Kruskal-Wallis analysis, to compare the averages. The reliability of the results was evaluated by the CVa (%) within the maximum allowable analytical variation and by the difference of means of the results in relation to the baseline sample (2 hours). RESULTS: Red blood count, hemoglobin, and MCH parameters showed stability up to 72 hours at room temperature and at 4°C. The other complete blood count parameters showed imprecision results emitted by the ABX Pentra 60 from 24 hours of sample storage, independent of the storage temperature. In addition, there were significant oscillations in the mean values, particularly for the samples stored at room temperature, with the exception of platelet parameters that exhibited mean changes also at 4°C. CONCLUSION: The results demonstrate the importance of the clinical analyst's knowledge about the behavior of the CBC parameters over time under different storage conditions, and mainly the imprecision of the hematological equipment used, for the suitable interpretation of the results.

Sex-Specific Mechanisms of Resistance Vessel Endothelial Dysfunction Induced by Cardiometabolic Risk Factors.

BACKGROUND: The incidence of obesity is rising, particularly among women. Microvascular dysfunction is more common with female sex, obesity, and hyperlipidemia and predicts adverse cardiovascular outcomes, but the molecular mechanisms are unclear. Because obesity is associated with mineralocorticoid receptor (MR) activation, we tested the hypothesis that MR in endothelial cells contribute to sex differences in resistance vessel dysfunction in response to cardiometabolic risk factors. METHODS AND RESULTS: Male and female endothelial cell-specific MR knockout mice and MR-intact littermates were randomized to high-fat-diet-induced obesity or obesity with hyperlipidemia induced by adeno-associated virus-based vector targeting transfer of the mutant stable form (DY mutation) of the human PCSK9 (proprotein convertase subtilisin/kexin type 9) gene and compared with control diet. Female but not male mice were sensitive to obesity-induced endothelial dysfunction, whereas endothelial function was impaired in obese hyperlipidemic males and females. In males, obesity or hyperlipidemia decreased the nitric oxide component of vasodilation without altering superoxide production or endothelial nitric oxide synthase expression or phosphorylation. Decreased nitric oxide content in obese males was overcome by enhanced endothelium-derived hyperpolarization-mediated relaxation along with increased SK3 expression. Conversely, in females, endothelium-derived hyperpolarization was significantly impaired by obesity with lower IK1 expression and by hyperlipidemia with lower IK1 and SK3 expression, loss of H2O2-mediated vasodilation, and increased superoxide production. Endothelial cell-MR deletion prevented endothelial dysfunction induced by risk factors only in females. Rather than restoring endothelium-derived hyperpolarization in females, endothelial cell-MR deletion enhanced nitric oxide and prevented hyperlipidemia-induced oxidative stress. CONCLUSIONS: These data reveal distinct mechanisms driving resistance vessel dysfunction in males versus females and suggest that personalized treatments are needed to prevent the progression of vascular disease in the setting of obesity, depending on both the sex and the metabolic profile of each patient.

Smooth Muscle Cell-Mineralocorticoid Receptor as a Mediator of Cardiovascular Stiffness With Aging.

Stiffening of the vasculature with aging is a strong predictor of adverse cardiovascular events, independent of all other risk factors including blood pressure, yet no therapies target this process. MRs (mineralocorticoid receptors) in smooth muscle cells (SMCs) have been implicated in the regulation of vascular fibrosis but have not been explored in vascular aging. Comparing SMC-MR-deleted male mice to MR-intact littermates at 3, 12, and 18 months of age, we demonstrated that aging-associated vascular stiffening and fibrosis are mitigated by MR deletion in SMCs. Progression of cardiac stiffness and fibrosis and the decline in exercise capacity with aging were also mitigated by MR deletion in SMC. Vascular gene expression profiling analysis revealed that MR deletion in SMC is associated with recruitment of a distinct antifibrotic vascular gene expression program with aging. Moreover, long-term pharmacological inhibition of MR in aged mice prevented the progression of vascular fibrosis and stiffness and induced a similar antifibrotic vascular gene program. Finally, in a small trial in elderly male humans, short-term MR antagonism produced an antifibrotic signature of circulating biomarkers similar to that observed in the vasculature of SMC-MR-deleted mice. These findings suggest that SMC-MR contributes to vascular stiffening with aging and is a potential therapeutic target to prevent the progression of aging-associated vascular fibrosis and stiffness.

Endothelial Mineralocorticoid Receptor Mediates Parenchymal Arteriole and Posterior Cerebral Artery Remodeling During Angiotensin II-Induced Hypertension.

The brain is highly susceptible to injury caused by hypertension because the increased blood pressure causes artery remodeling that can limit cerebral perfusion. Mineralocorticoid receptor (MR) antagonism prevents hypertensive cerebral artery remodeling, but the vascular cell types involved have not been defined. In the periphery, the endothelial MR mediates hypertension-induced vascular injury, but cerebral and peripheral arteries are anatomically distinct; thus, these findings cannot be extrapolated to the brain. The parenchymal arterioles determine cerebrovascular resistance. Determining the effects of hypertension and MR signaling on these arterioles could lead to a better understanding of cerebral small vessel disease. We hypothesized that endothelial MR signaling mediates inward cerebral artery remodeling and reduced cerebral perfusion during angiotensin II (AngII) hypertension. The biomechanics of the parenchymal arterioles and posterior cerebral arteries were studied in male C57Bl/6 and endothelial cell-specific MR knockout mice and their appropriate controls using pressure myography. AngII increased plasma aldosterone and decreased cerebral perfusion in C57Bl/6 and MR-intact littermates. Endothelial cell MR deletion improved cerebral perfusion in AngII-treated mice. AngII hypertension resulted in inward hypotrophic remodeling; this was prevented by MR antagonism and endothelial MR deletion. Our studies suggest that endothelial cell MR mediates hypertensive remodeling in the cerebral microcirculation and large pial arteries. AngII-induced inward remodeling of cerebral arteries and arterioles was associated with a reduction in cerebral perfusion that could worsen the outcome of stroke or contribute to vascular dementia.

Endothelial mineralocorticoid receptor contributes to systolic dysfunction induced by pressure overload without modulating cardiac hypertrophy or inflammation.

Heart Failure (HF) is associated with increased circulating levels of aldosterone and systemic inflammation. Mineralocorticoid receptor (MR) antagonists block aldosterone action and decrease mortality in patients with congestive HF However, the molecular mechanisms underlying the therapeutic benefits of MR antagonists remain unclear. MR is expressed in all cell types in the heart, including the endothelial cells (EC), in which aldosterone induces the expression of intercellular adhesion molecule 1 (ICAM-1). Recently, we reported that ICAM-1 regulates cardiac inflammation and cardiac function in mice subjected to transverse aortic constriction (TAC). Whether MR specifically in endothelial cells (EC) contributes to the several mechanisms of pathological cardiac remodeling and cardiac dysfunction remains unclear. Basal cardiac function and LV dimensions were comparable in mice with MR selectively deleted from ECs (EC-MR-/-) and wild-type littermate controls (EC-MR+/+). MR was specifically deleted in heart EC, and in EC-containing tissues, but not in leukocytes of TAC EC-MR-/- mice. While EC-MR-/- TAC mice showed preserved systolic function and some alterations in the expression of fetal genes, the proinflammatory cytokine TNFα and the endothelin receptors in the LV as compared to EC-MR+/+ TAC mice, no difference was observed between both TAC groups in overall cardiac hypertrophy, ICAM-1 LV expression and leukocyte infiltration, cardiac fibrosis or capillary rarefaction, all hallmarks of pathological cardiac remodeling. Our data indicate that EC-MR contributes to the transition of cardiac hypertrophy to systolic dysfunction independently of other maladaptive changes induced by LV pressure overload.

Dofetilide in Overdose: A Case Series from Poison Center Data.

Dofetilide is a class III antiarrhythmic used for treating atrial dysrhythmias. Though its adverse effects are well described in routine use, very little is known about dofetilide toxicity in overdose. This is a retrospective case series of consecutive patients reported to our poison center after dofetilide overdose. Twenty-seven cases were included. Seventeen patients were treated at a healthcare facility, and of these, eight were admitted. Twenty-one patients took one extra capsule, four took someone else's medication, one took three extra capsules, and one had a large intentional overdose. Ten patients had co-ingestants reported, including three QT-prolonging agents. No one required cardioversion, defibrillation, CPR, or overdrive pacing. The patient who reported taking 90 times his usual dose in suicide attempt was the only patient to have significant clinical effects. He experienced an 8-beat run of non-sustained ventricular tachycardia, frequent multifocal PVCs, and ventricular bigeminy. He received magnesium sulfate and potassium chloride supplementation. In this series, unintentional small overdoses did not result in significant clinical effects and were often managed successfully at home, despite the fact that information showing a single capsule can cause torsades. This study is limited by its small sample size, retrospective design, and reliance on incomplete information.