Acute Ischemic Stroke, Depressed Left Ventricular Ejection Fraction, and Sinus Rhythm: Prevalence and Practice Patterns.

BACKGROUND: There are limited data about the epidemiology and secondary stroke prevention strategies used for patients with depressed left ventricular ejection fraction (LVEF) and sinus rhythm following an acute ischemic stroke (AIS). We sought to describe the prevalence of LVEF ≤40% and sinus rhythm among patients with AIS and antithrombotic treatment practice in a multi-center cohort from 2002 to 2018. METHODS: This was a multi-center, retrospective cohort study comprised of patients with AIS hospitalized in the Greater Cincinnati Northern Kentucky Stroke Study and 4 academic, hospital-based cohorts in the United States. A 1-stage meta-analysis of proportions was undertaken to calculate a pooled prevalence. Univariate analyses and an adjusted multivariable logistic regression model were performed to identify demographic, clinical, and echocardiographic characteristics associated with being prescribed an anticoagulant upon AIS hospitalization discharge. RESULTS: Among 14 338 patients with AIS with documented LVEF during the stroke hospitalization, the weighted pooled prevalence of LVEF ≤40% and sinus rhythm was 5.0% (95% CI, 4.1-6.0%; I2, 84.4%). Of 524 patients with no cardiac thrombus and no prior indication for anticoagulant who survived postdischarge, 200 (38%) were discharged on anticoagulant, 289 (55%) were discharged on antiplatelet therapy only, and 35 (7%) on neither. There was heterogeneity by site in the proportion discharged with an anticoagulant (22% to 45%, P<0.0001). Cohort site and National Institutes of Health Stroke Severity scale >8 (odds ratio, 2.0 [95% CI, 1.1-3.8]) were significant, independent predictors of being discharged with an anticoagulant in an adjusted analysis. CONCLUSIONS: Nearly 5% of patients with AIS have a depressed LVEF and are in sinus rhythm. There is significant variation in the clinical practice of antithrombotic therapy prescription by site and stroke severity. Given this clinical equipoise, further study is needed to define optimal antithrombotic treatment regimens for secondary stroke prevention in this patient population.

Comparing Socio-Demographics and HIV Testing and Prevention Outcomes Between Low-Income HIV-Negative Heterosexually Active Black Women and Men with Health Insurance.

OBJECTIVE: This study is to compare socio-demographic, HIV testing, and prevention factors experienced by insured low-income heterosexual Black women and men. METHODS: We examined cross-sectional data from Black women and men (n = 5837) recruited in 23 U.S. cities for National HIV Behavioral Surveillance June-December 2019. We compared socio-demographic and behavioral factors between groups using log-linked Poisson regression models, producing adjusted prevalence ratios and 95% confidence intervals. RESULTS: Black women were less likely than Black men to have private insurance (aPR 0.61, 95% CI 0.50-0.74, p < 0.0001). Black women were more likely than Black men to have incomes at or below the poverty line (aPR 1.04, 95% CI 1.01-1.07, p = 0.02), be aware of PrEP (aPR 1.20, 95% CI 1.12-1.28, p < 0.0001), and have been recently tested for HIV (aPR 1.12, 95% CI 1.04, 1.20, p < 0.01). CONCLUSIONS: Despite insured status, many Black women and men experienced suboptimal access to and utilization of HIV testing and prevention services. Understanding how social conditions produce differential access to care may help inform HIV prevention interventions.

Characterisation of internal tremors and vibration symptoms.

OBJECTIVES: To describe the experiences of patients who have postacute sequelae SARS-CoV-2 infection with internal vibrations and tremors as a prominent component, we leveraged the efforts by Survivor Corps, a grassroots COVID-19 patient advocacy group, to gather information from individuals belonging to its Facebook group with a history of COVID-19 suffering from vibrations and tremors. SETTING AND DESIGN: A narrative analysis was performed on 140 emails and 450 social media comments from 140 individuals collected as a response to a call to >180 000 individuals participating in Survivor Corps between 15 July and 27 July 2021. We used common coding techniques and the constant comparative method for qualitative data synthesis and categorising emails. Coded data were entered into NVivo V.12 to identify recurrent themes, theme connections and supporting quotations. Comments were analysed using Word Clouds, generated with R V.4.0.3 using quanteda, wordcloud and tm packages. MAIN OUTCOME MEASURES: Patient-reported long COVID symptom themes and domains related to internal tremors and vibration. RESULTS: The respondents' emails represented 22 themes and 7 domains pertaining to their experience with internal tremor and vibrations. These domains were as follows: (1) symptom experience, description and anatomic location; (2) initial symptom onset; (3) symptom timing; (4) symptom triggers or alleviators; (5) change from baseline health status; (6) experience with medical establishment and (7) impact on individuals' lives and livelihood. There were 22 themes in total, each corresponding to one of the broader domains. Among the responses, many described symptoms that varied in location, timing and triggers, occurred soon after their COVID-19 infection, and were markedly debilitating. There were often frustrating experiences with the healthcare system. CONCLUSIONS: This study describes key themes and experiences among a group of people reporting long COVID and having a prolonged and debilitating symptom complex that prominently features internal tremors and vibrations.

Restoration of PPARγ reverses lipid accumulation in alveolar macrophages of GM-CSF knockout mice.

Pulmonary alveolar proteinosis (PAP) is a lung disease characterized by a deficiency of functional granulocyte macrophage colony-stimulating factor (GM-CSF) resulting in surfactant accumulation and lipid-engorged alveolar macrophages. GM-CSF is a positive regulator of PPARγ that is constitutively expressed in healthy alveolar macrophages. We previously reported decreased PPARγ and ATP-binding cassette transporter G1 (ABCG1) levels in alveolar macrophages from PAP patients and GM-CSF knockout (KO) mice, suggesting PPARγ and ABCG1 involvement in surfactant catabolism. Because ABCG1 represents a PPARγ target, we hypothesized that PPARγ restoration would increase ABCG1 and reduce macrophage lipid accumulation. Upregulation of PPARγ was achieved using a lentivirus expression system in vivo. GM-CSF KO mice received intratracheal instillation of lentivirus (lenti)-PPARγ or control lenti-eGFP. Ten days postinstillation, 79% of harvested alveolar macrophages expressed eGFP, demonstrating transduction. Alveolar macrophages showed increased PPARγ and ABCG1 expression after lenti-PPARγ instillation, whereas PPARγ and ABCG1 levels remained unchanged in lenti-eGFP controls. Alveolar macrophages from lenti-PPARγ-treated mice also exhibited reduced intracellular phospholipids and increased cholesterol efflux to HDL, an ABCG1-mediated pathway. In vivo instillation of lenti-PPARγ results in: 1) upregulating ABCG1 and PPARγ expression of GM-CSF KO alveolar macrophages, 2) reducing intracellular lipid accumulation, and 3) increasing cholesterol efflux activity.

Prior Stroke and Age Predict Acute Ischemic Stroke Among Hospitalized COVID-19 Patients: A Derivation and Validation Study.

Objectives: Our objective was to identify characteristics associated with having an acute ischemic stroke (AIS) among hospitalized COVID-19 patients and the subset of these patients with a neurologic symptom. Materials and Methods: Our derivation cohort consisted of COVID-19 patients admitted to Yale-New Haven Health between January 3, 2020 and August 28, 2020 with and without AIS. We also studied a sub-cohort of hospitalized COVID-19 patients demonstrating a neurologic symptom with and without an AIS. Demographic, clinical, and laboratory results were compared between AIS and non-AIS patients in the full COVID-19 cohort and in the sub-cohort of COVID-19 patients with a neurologic symptom. Multivariable logistic regression models were built to predict ischemic stroke risk in these two COVID-19 cohorts. These 2 models were externally validated in COVID-19 patients hospitalized at a major health system in New York. We then compared the distribution of the resulting predictors in a non-COVID ischemic stroke control cohort. Results: A total of 1,827 patients were included in the derivation cohort (AIS N = 44; no AIS N = 1,783). Among all hospitalized COVID-19 patients, history of prior stroke and platelet count ≥ 200 × 1,000/µL at hospital presentation were independent predictors of AIS (derivation AUC 0.89, validation AUC 0.82), irrespective of COVID-19 severity. Among hospitalized COVID-19 patients with a neurologic symptom (N = 827), the risk of AIS was significantly higher among patients with a history of prior stroke and age <60 (derivation AUC 0.83, validation AUC 0.81). Notably, in a non-COVID ischemic stroke control cohort (N = 168), AIS patients were significantly older and less likely to have had a prior stroke, demonstrating the uniqueness of AIS patients with COVID-19. Conclusions: Hospitalized COVID-19 patients who demonstrate a neurologic symptom and have either a history of prior stroke or are of younger age are at higher risk of ischemic stroke.

Targeted PPAR{gamma} deficiency in alveolar macrophages disrupts surfactant catabolism.

Surfactant accumulates in alveolar macrophages of granulocyte-macrophage colony-stimulating factor (GM-CSF) knockout (KO) mice and pulmonary alveolar proteinosis (PAP) patients with a functional loss of GM-CSF resulting from neutralizing anti-GM-CSF antibody. Alveolar macrophages from PAP patients and GM-CSF KO mice are de-ficient in peroxisome proliferator-activated receptor-gamma (PPARgamma) and ATP-binding cassette (ABC) lipid transporter ABCG1. Previous studies have demonstrated that GM-CSF induces PPARgamma. We therefore hypothesized that PPARgamma promotes surfactant catabolism through regulation of ABCG1. To address this hypothesis, macrophage-specific PPARgamma (MacPPARgamma) knockout mice were utilized. MacPPARgamma KO mice develop foamy, lipid-engorged Oil Red O positive alveolar macrophages. Lipid analyses revealed significant increases in the cholesterol and phospholipid contents of MacPPARgamma KO alveolar macrophages and extracellular bronchoalveolar lavage (BAL)-derived fluids. MacPPARgamma KO alveolar macrophages showed decreased expression of ABCG1 and a deficiency in ABCG1-mediated cholesterol efflux to HDL. Lipid metabolism may also be regulated by liver X receptor (LXR)-ABCA1 pathways. Interestingly, ABCA1 and LXRbeta expression were elevated, indicating that this pathway is not sufficient to prevent surfactant accumulation in alveolar macrophages. These results suggest that PPARgamma mediates a critical role in surfactant homeostasis through the regulation of ABCG1.

PPARgamma regulates the expression of cholesterol metabolism genes in alveolar macrophages.

Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a nuclear transcription factor involved in lipid metabolism that is constitutively expressed in the alveolar macrophages of healthy individuals. PPARgamma has recently been implicated in the catabolism of surfactant by alveolar macrophages, specifically the cholesterol component of surfactant while the mechanism remains unclear. Studies from other tissue macrophages have shown that PPARgamma regulates cholesterol influx, efflux, and metabolism. PPARgamma promotes cholesterol efflux through the liver X receptor-alpha (LXRalpha) and ATP-binding cassette G1 (ABCG1). We have recently shown that macrophage-specific PPARgamma knockout (PPARgamma KO) mice accumulate cholesterol-laden alveolar macrophages that exhibit decreased expression of LXRalpha and ABCG1 and reduced cholesterol efflux. We hypothesized that in addition to the dysregulation of these cholesterol efflux genes, the expression of genes involved in cholesterol synthesis and influx was also dysregulated and that replacement of PPARgamma would restore regulation of these genes. To investigate this hypothesis, we have utilized a Lentivirus expression system (Lenti-PPARgamma) to restore PPARgamma expression in the alveolar macrophages of PPARgamma KO mice. Our results show that the alveolar macrophages of PPARgamma KO mice have decreased expression of key cholesterol synthesis genes and increased expression of cholesterol receptors CD36 and scavenger receptor A-I (SRA-I). The replacement of PPARgamma (1) induced transcription of LXRalpha and ABCG1; (2) corrected suppressed expression of cholesterol synthesis genes; and (3) enhanced the expression of scavenger receptors CD36. These results suggest that PPARgamma regulates cholesterol metabolism in alveolar macrophages.