Adjustment for Renal Function Improves the Prognostic Performance of Urinary Thromboxane Metabolites.

BACKGROUND: Systemic thromboxane A2 generation, assessed by quantifying the concentration of stable thromboxane B2 metabolites (TXB2-M) in the urine adjusted for urinary creatinine, is strongly associated with mortality risk. We sought to define optimal TXB2-M cutpoints for aspirin users and nonusers and determine if adjusting TXB2-M for estimated glomerular filtration rate (eGFR) in addition to urinary creatinine improved mortality risk assessment. METHODS: Urinary TXB2-M were measured by competitive ELISA in 1363 aspirin users and 1681 nonusers participating in the Framingham Heart Study. Cutpoints were determined for TXB2-M and TXB2-M/eGFR using log-rank statistics and used to assess mortality risk by Cox proportional hazard modeling and restricted mean survival time. Multivariable models were compared using the Akaike Information Criterion (AIC). A cohort of 105 aspirin users with heart failure was used for external validation. RESULTS: Optimized cutpoints of TXB2-M were 1291 and 5609 pg/mg creatinine and of TXB2-M/eGFR were 16.6 and 62.1 filtered prostanoid units (defined as pg·min/creatinine·mL·1.73 m2), for aspirin users and nonusers, respectively. TXB2-M/eGFR cutpoints provided more robust all-cause mortality risk discrimination than TXB2-M cutpoints, with a larger unadjusted hazard ratio (2.88 vs 2.16, AIC P < 0.0001) and greater differences in restricted mean survival time between exposure groups (1.46 vs 1.10 years), findings that were confirmed in the external validation cohort of aspirin users. TXB2-M/eGFR cutpoints also provided better cardiovascular/stroke mortality risk discrimination than TXB2-M cutpoints (unadjusted hazard ratio 3.31 vs 2.13, AIC P < 0.0001). CONCLUSION: Adjustment for eGFR strengthens the association of urinary TXB2-M with long-term mortality risk irrespective of aspirin use.

Anti-PF4 antibodies associated with disease severity in COVID-19.

Severe COVID-19 is characterized by a prothrombotic state associated with thrombocytopenia, with microvascular thrombosis being almost invariably present in the lung and other organs at postmortem examination. We evaluated the presence of antibodies to platelet factor 4 (PF4)-polyanion complexes using a clinically validated immunoassay in 100 hospitalized patients with COVID-19 with moderate or severe disease (World Health Organization score, 4 to 10), 25 patients with acute COVID-19 visiting the emergency department, and 65 convalescent individuals. Anti-PF4 antibodies were detected in 95 of 100 hospitalized patients with COVID-19 (95.0%) irrespective of prior heparin treatment, with a mean optical density value of 0.871 ± 0.405 SD (range, 0.177 to 2.706). In contrast, patients hospitalized for severe acute respiratory disease unrelated to COVID-19 had markedly lower levels of the antibodies. In a high proportion of patients with COVID-19, levels of all three immunoglobulin (Ig) isotypes tested (IgG, IgM, and IgA) were simultaneously elevated. Antibody levels were higher in male than in female patients and higher in African Americans and Hispanics than in White patients. Anti-PF4 antibody levels were correlated with the maximum disease severity score and with significant reductions in circulating platelet counts during hospitalization. In individuals convalescent from COVID-19, the antibody levels returned to near-normal values. Sera from patients with COVID-19 induced higher levels of platelet activation than did sera from healthy blood donors, but the results were not correlated with the levels of anti-PF4 antibodies. These results demonstrate that the vast majority of patients with severe COVID-19 develop anti-PF4 antibodies, which may play a role in the clinical complications of COVID-19.

Association of Thromboxane Generation With Survival in Aspirin Users and Nonusers.

BACKGROUND: Persistent systemic thromboxane generation, predominantly from nonplatelet sources, in aspirin (ASA) users with cardiovascular disease (CVD) is a mortality risk factor. OBJECTIVES: This study sought to determine the mortality risk associated with systemic thromboxane generation in an unselected population irrespective of ASA use. METHODS: Stable thromboxane B2 metabolites (TXB2-M) were measured by enzyme-linked immunosorbent assay in banked urine from 3,044 participants (mean age 66 ± 9 years, 53.8% women) in the Framingham Heart Study. The association of TXB2-M to survival over a median observation period of 11.9 years (IQR: 10.6-12.7 years) was determined by multivariable modeling. RESULTS: In 1,363 (44.8%) participants taking ASA at the index examination, median TXB2-M were lower than in ASA nonusers (1,147 pg/mg creatinine vs 4,179 pg/mg creatinine; P < 0.0001). TXB2-M were significantly associated with all-cause and cardiovascular mortality irrespective of ASA use (HR: 1.96 and 2.41, respectively; P < 0.0001 for both) for TXB2-M in the highest quartile based on ASA use compared with lower quartiles, and remained significant after adjustment for mortality risk factors for similarly aged individuals (HR: 1.49 and 1.82, respectively; P ≤ 0.005 for both). In 2,353 participants without CVD, TXB2-M were associated with cardiovascular mortality in ASA nonusers (adjusted HR: 3.04; 95% CI: 1.29-7.16) but not in ASA users, while ASA use was associated with all-cause mortality in those with low (adjusted HR: 1.46; 95% CI: 1.14-1.87) but not elevated TXB2-M. CONCLUSIONS: Systemic thromboxane generation is an independent risk factor for all-cause and cardiovascular mortality irrespective of ASA use, and its measurement may be useful for therapy modification, particularly in those without CVD.

A Tale of 3 Pandemics: Severe Acute Respiratory Syndrome Coronavirus 2, Hepatitis C Virus, and Human Immunodeficiency Virus in an Urban Emergency Department in Baltimore, Maryland.

Background: We sought to determine the prevalence and sociodemographic and clinical correlates of acute and convalescent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infections among emergency department (ED) patients in Baltimore. Methods: Remnant blood samples from 7450 unique patients were collected over 4 months in 2020 for SARS-CoV-2 antibody (Ab), HCV Ab, and HIV-1/2 antigen and Ab. Among them, 5012 patients were tested by polymerase chain reaction for SARS-CoV-2 based on clinical suspicion. Sociodemographics, ED clinical presentations, and outcomes associated with coinfections were assessed. Results: Overall, 729 (9.8%) patients had SARS-CoV-2 (acute or convalescent), 934 (12.5%) HCV, 372 (5.0%) HIV infection, and 211 patients (2.8%) had evidence of any coinfection (HCV/HIV, 1.5%; SARS-CoV-2/HCV, 0.7%; SARS-CoV-2/HIV, 0.3%; SARS-CoV-2/HCV/HIV, 0.3%). The prevalence of SARS-CoV-2 (acute or convalescent) was significantly higher in those with HCV or HIV vs those without (13.6% vs 9.1%, P < .001). Key sociodemographic disparities (race, ethnicity, and poverty) and specific ED clinical characteristics were significantly correlated with having any coinfections vs no infection or individual monoinfection. Among those with HCV or HIV, aged 18-34 years, Black race, Hispanic ethnicity, and a cardiovascular-related chief complaint had a significantly higher odds of having SARS-CoV-2 (prevalence ratios: 2.02, 2.37, 5.81, and 2.07, respectively). Conclusions: The burden of SARS-CoV-2, HCV, and HIV co-pandemics and their associations with specific sociodemographic disparities, clinical presentations, and outcomes suggest that urban EDs should consider implementing integrated screening and linkage-to-care programs for these 3 infections.

Monocyte distribution width as part of a broad pragmatic sepsis screen in the emergency department.

STUDY OBJECTIVE: Enhancement of a routine complete blood count (CBC) for detection of sepsis in the emergency department (ED) has pragmatic utility for early management. This study evaluated the performance of monocyte distribution width (MDW) alone and in combination with other routine CBC parameters as a screen for sepsis and septic shock in ED patients. METHODS: A prospective cohort analysis of adult patients with a CBC collected at an urban ED from January 2020 through July 2021. The performance of MDW, white blood count (WBC) count, and neutrophil-to-lymphocyte-ratio (NLR) to detect sepsis and septic shock (Sepsis-3 Criteria) was evaluated using diagnostic performance measures. RESULTS: The cohort included 7952 ED patients, with 180 meeting criteria for sepsis; 43 with septic shock and 137 without shock. MDW was highest for patients with septic shock (median 24.8 U, interquartile range [IQR] 22.0-28.1) and trended downward for patients with sepsis without shock (23.9 U, IQR 20.2-26.8), infection (20.4 U, IQR 18.2-23.3), then controls (18.6 U, IQR 17.1-20.4). In isolation, MDW detected sepsis and septic shock with an area under the receiver operator characteristic curve (AUC) of 0.80 (95% confidence interval [CI] 0.77-0.84) and 0.85 (95% CI 0.80-0 .91), respectively. Optimal performance was achieved in combination with WBC count and NLR for detection of sepsis (AUC 0.86, 95% CI 0.83-0.89) and septic shock (0.86, 95% CI 0.80-0.92). CONCLUSION: A CBC differential panel that includes MDW demonstrated strong performance characteristics in a broad ED population suggesting pragmatic value as a rapid screen for sepsis and septic shock.

Differentiation of Individuals Previously Infected with and Vaccinated for SARS-CoV-2 in an Inner-City Emergency Department.

Emergency departments (EDs) can serve as surveillance sites for infectious diseases. The objective of this study was to determine the burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and to monitor the prevalence of vaccination against coronavirus disease 2019 (COVID-19) among patients attending an urban ED in Baltimore City. Using 1,914 samples of known exposure status, we developed an algorithm to differentiate previously infected, vaccinated, and unexposed individuals using a combination of antibody assays. We applied this testing algorithm to 4,360 samples from ED patients obtained in the spring of 2020 and 2021. Using multinomial logistic regression, we determined factors associated with infection and vaccination. For the algorithm, sensitivity and specificity for identifying vaccinated individuals were 100% and 99%, respectively, and 84% and 100% for previously infected individuals. Among the ED subjects, seroprevalence to SARS-CoV-2 increased from 2% to 24% between April 2020 and March 2021. Vaccination prevalence rose to 11% by mid-March 2021. Marked differences in burden of disease and vaccination coverage were seen by sex, race, and ethnicity. Hispanic patients, though accounting for 7% of the study population, had the highest relative burden of disease (17% of total infections) but with similar vaccination rates. Women and white individuals were more likely to be vaccinated than men or Black individuals. Individuals previously infected with SARS-CoV-2 can often be differentiated from vaccinated individuals using a serologic testing algorithm. The utility of this algorithm can aid in monitoring SARS-CoV-2 exposure and vaccination uptake frequencies and can potentially reflect gender, race, and ethnic health disparities.

The APB study: apixaban pharmacokinetics in bariatric patients before to 1 year after vertical sleeve gastrectomy or Roux-en-Y gastric bypass.

BACKGROUND: The optimal regimen for prevention and treatment of venous thromboembolism in bariatric surgical patients remains controversial. Direct oral anticoagulants are potentially advantageous over other agents, but inadequate evidence exists regarding their effects in bariatric surgical patients. OBJECTIVES: To investigate single-dose pharmacokinetic (PK) and pharmacodynamic (PD) parameters of apixaban when administered to patients undergoing vertical sleeve gastrectomy (VSG) or Roux-en-Y gastric bypass (RYGB) and to determine whether the PK and PD parameters are affected by type of bariatric surgery and weight loss in the immediate and postoperative period up to 12 months. SETTING: University Hospital and A Bariatric Center of Excellence, Baltimore, Maryland. METHODS: Adults with a body mass index ≥35 kg/m2 approved for bariatric surgery were enrolled in a single-center, open-label, nonrandomized, single-dose clinical study (NCT No. 02406885; www. CLINICALTRIALS: gov). Apixaban PK and PD parameters were measured after a single 5 mg dose of the drug was given preoperatively and at 1, 6, and 12 months postoperatively in patients undergoing VSG and RYGB. Change in PK parameters was assessed as maximum concentration, time to maximum concentration, elimination half-life, and area under the concentration-time curve from 0-72 hours and change in PD parameters were assessed by chromogenic factor X activity. RESULTS: Of 33 patients enrolled, 28 (14 VSG, 14 RYGB) completed all visits and were analyzed. Most patients (89%) were female, with a mean age of 43.8 years and a body mass index of 48.7 kg/m2. Area under the concentration-time curve from 0-72 hours increased from baseline to 1 month (1009.1 to 1232.9 ng/mL/hr, P = .002), returned to baseline at 6 months (1000.9 ng/mL/hr, P = .88), and decreased significantly at 12 months (841.8 ng/mL/hr, P = .001). Maximum concentration did not change significantly. Predose factor X activity dropped significantly from 113% preoperatively to 89.8 % at 12 months postoperatively (P < .0001). Three-hour postdose factor X activity was significantly lower at 1, 6, and 12 months postoperatively versus preoperatively. However, the magnitude of the decrease from predose to 3-hour postdose was not significantly altered by surgery. CONCLUSION: The effect of either VSG or RYGB on apixaban PK and PD parameters is minimal. Factor X activity after 5 mg apixaban was lower in postoperative versus preoperative bariatric patients, but this effect appears to be primarily the result of a decrease in factor X activity from bariatric surgery itself and not a postoperative change in apixaban PK and PD parameters. Future studies should investigate the safety, efficacy, and clinical outcomes of apixaban and other direct oral anticoagulants perioperatively and beyond 12 months following bariatric surgery.

Differentiation of SARS-CoV-2 naturally infected and vaccinated individuals in an inner-city emergency department.

BACKGROUND: Emergency Departments (EDs) can serve as surveillance sites for infectious diseases. Our purpose was to determine the burden of SARS-CoV-2 infection and prevalence of vaccination against COVID-19 among patients attending an urban ED in Baltimore City. METHODS: Using 1914 samples of known exposure status, we developed an algorithm to differentiate previously infected, vaccinated, and unexposed individuals using a combination of antibody assays. We applied this testing algorithm to 4360 samples ED patients obtained in the springs of 2020 and 2021. Using multinomial logistic regression, we determined factors associated with infection and vaccination. RESULTS: For the algorithm, sensitivity and specificity for identifying vaccinated individuals was 100% and 99%, respectively, and 84% and 100% for naturally infected individuals. Among the ED subjects, seroprevalence to SARS-CoV-2 increased from 2% to 24% between April 2020 and March 2021. Vaccination prevalence rose to 11% by mid-March 2021. Marked differences in burden of disease and vaccination coverage were seen by sex, race, and ethnicity. Hispanic patients, though 7% of the study population, had the highest relative burden of disease (17% of total infections) but similar vaccination rates. Women and White individuals were more likely to be vaccinated than men or Black individuals (adjusted odds ratios [aOR] 1.35 [95% CI: 1.02, 1.80] and aOR 2.26 [95% CI: 1.67, 3.07], respectively). CONCLUSIONS: Individuals previously infected with SARS-CoV-2 can be differentiated from vaccinated individuals using a serologic testing algorithm. SARS-CoV-2 exposure and vaccination uptake frequencies reflect gender, race and ethnic health disparities in this urban context. SUMMARY: Using an antibody testing algorithm, we distinguished between immune responses from SARS-CoV-2-infected and vaccinated individuals. When applied to blood samples from an emergency department in Baltimore, disparities in disease burden and vaccine uptake by sex, race, and ethnicity were identified.

Upregulation of pulmonary tissue factor, loss of thrombomodulin and immunothrombosis in SARS-CoV-2 infection.

BACKGROUND: SARS-CoV-2 infection is associated with thrombotic and microvascular complications. The cause of coagulopathy in the disease is incompletely understood. METHODS: A single-center cross-sectional study including 66 adult COVID-19 patients (40 moderate, 26 severe disease), and 9 controls, performed between 04/2020 and 10/2020. Markers of coagulation, endothelial cell function [angiopoietin-1,-2, P-selectin, von Willebrand Factor Antigen (WF:Ag), von Willebrand Factor Ristocetin Cofactor, ADAMTS13, thrombomodulin, soluble Endothelial cell Protein C Receptor (sEPCR), Tissue Factor Pathway Inhibitor], neutrophil activation (elastase, citrullinated histones) and fibrinolysis (tissue-type plasminogen activator, plasminogen activator inhibitor-1) were evaluated using ELISA. Tissue Factor (TF) was estimated by antithrombin-FVIIa complex (AT/FVIIa) and microparticles-TF (MP-TF). We correlated each marker and determined its association with severity. Expression of pulmonary TF, thrombomodulin and EPCR was determined by immunohistochemistry in 9 autopsies. FINDINGS: Comorbidities were frequent in both groups, with older age associated with severe disease. All patients were on prophylactic anticoagulants. Three patients (4.5%) developed pulmonary embolism. Mortality was 7.5%. Patients presented with mild alterations in the coagulogram (compensated state). Biomarkers of endothelial cell, neutrophil activation and fibrinolysis were elevated in severe vs moderate disease; AT/FVIIa and MP-TF levels were higher in severe patients. Logistic regression revealed an association of D-dimers, angiopoietin-1, vWF:Ag, thrombomodulin, white blood cells, absolute neutrophil count (ANC) and hemoglobin levels with severity, with ANC and vWF:Ag identified as independent factors. Notably, postmortem specimens demonstrated epithelial expression of TF in the lung of fatal COVID-19 cases with loss of thrombomodulin staining, implying in a shift towards a procoagulant state. INTERPRETATION: Coagulation dysregulation has multifactorial etiology in SARS-Cov-2 infection. Upregulation of pulmonary TF with loss of thrombomodulin emerge as a potential link to immunothrombosis, and therapeutic targets in the disease. FUNDING: John Hopkins University School of Medicine.

Major adverse cardiovascular events in survivors of immune-mediated thrombotic thrombocytopenic purpura.

Cardiovascular disease is a leading cause of death in survivors of immune-mediated thrombotic thrombocytopenic purpura (iTTP), but the epidemiology of major adverse cardiovascular events (MACE) in iTTP survivors is unknown. We evaluated the prevalence and risk factors for MACE, defined as the composite of non-fatal or fatal myocardial infarction (MI), stroke, and cardiac revascularization, during clinical remission in two large iTTP cohorts (Johns Hopkins University and Ohio State University). Of 181 patients followed for ≥ 3 months after recovery from acute iTTP, 28.6% had a MACE event over a median follow up of 7.6 years. Stroke was the most common type of MACE (18.2%), followed by non-fatal MI (6.6%), cardiac revascularization (4.9%) and fatal MI (0.6%). Compared to the general United States population, iTTP survivors were younger at first stroke in remission (males [56.5 years vs. 68.6 years, p = 0.031], females [49.7 years vs. 72.9 years, p < 0.001]) or MI in remission (males [56.5 years vs. 65.6 years, p < 0.001] and females [53.1 years vs. 72.0 years, p < 0.001]). Age (HR 1.03 [95% CI 1.002-1.054]), race (Black/Other vs. White) (HR 2.32 [95% CI 1.12-4.82]), and diabetes mellitus (HR 2.37 [95% CI 1.09-0.03]) were associated with MACE in a Cox regression model also adjusted for sex, hypertension, obesity, hyperlipidemia, chronic kidney disease, atrial fibrillation, autoimmune disease, and relapsing iTTP. Remission ADAMTS13 activity was not significantly associated with MACE. In conclusion, iTTP survivors experience high rates of MACE and may benefit from aggressively screening for and managing cardiovascular risk factors.