Autoantibodies against the chemokine receptor 3 predict cardiovascular risk.

BACKGROUND AND AIMS: Chronic inflammation and autoimmunity contribute to cardiovascular (CV) disease. Recently, autoantibodies (aAbs) against the CXC-motif-chemokine receptor 3 (CXCR3), a G protein-coupled receptor with a key role in atherosclerosis, have been identified. The role of anti-CXCR3 aAbs for CV risk and disease is unclear. METHODS: Anti-CXCR3 aAbs were quantified by a commercially available enzyme-linked immunosorbent assay in 5000 participants (availability: 97.1%) of the population-based Gutenberg Health Study with extensive clinical phenotyping. Regression analyses were carried out to identify determinants of anti-CXCR3 aAbs and relevance for clinical outcome (i.e. all-cause mortality, cardiac death, heart failure, and major adverse cardiac events comprising incident coronary artery disease, myocardial infarction, and cardiac death). Last, immunization with CXCR3 and passive transfer of aAbs were performed in ApoE(-/-) mice for preclinical validation. RESULTS: The analysis sample included 4195 individuals (48% female, mean age 55.5 ± 11 years) after exclusion of individuals with autoimmune disease, immunomodulatory medication, acute infection, and history of cancer. Independent of age, sex, renal function, and traditional CV risk factors, increasing concentrations of anti-CXCR3 aAbs translated into higher intima-media thickness, left ventricular mass, and N-terminal pro-B-type natriuretic peptide. Adjusted for age and sex, anti-CXCR3 aAbs above the 75th percentile predicted all-cause death [hazard ratio (HR) (95% confidence interval) 1.25 (1.02, 1.52), P = .029], driven by excess cardiac mortality [HR 2.51 (1.21, 5.22), P = .014]. A trend towards a higher risk for major adverse cardiac events [HR 1.42 (1.0, 2.0), P = .05] along with increased risk of incident heart failure [HR per standard deviation increase of anti-CXCR3 aAbs: 1.26 (1.02, 1.56), P = .03] may contribute to this observation. Targeted proteomics revealed a molecular signature of anti-CXCR3 aAbs reflecting immune cell activation and cytokine-cytokine receptor interactions associated with an ongoing T helper cell 1 response. Finally, ApoE(-/-) mice immunized against CXCR3 displayed increased anti-CXCR3 aAbs and exhibited a higher burden of atherosclerosis compared to non-immunized controls, correlating with concentrations of anti-CXCR3 aAbs in the passive transfer model. CONCLUSIONS: In individuals free of autoimmune disease, anti-CXCR3 aAbs were abundant, related to CV end-organ damage, and predicted all-cause death as well as cardiac morbidity and mortality in conjunction with the acceleration of experimental atherosclerosis.

Clinical profile and outcome of isolated pulmonary embolism: a systematic review and meta-analysis.

Background: Isolated pulmonary embolism (PE) appears to be associated with a specific clinical profile and sequelae compared to deep vein thrombosis (DVT)-associated PE. The objective of this study was to identify clinical characteristics that discriminate both phenotypes, and to characterize their differences in clinical outcome. Methods: We performed a systematic review and meta-analysis of studies comparing PE phenotypes. A systematic search of the electronic databases PubMed and CENTRAL was conducted, from inception until January 27, 2023. Exclusion criteria were irrelevant content, inability to retrieve the article, language other than English or German, the article comprising a review or case study/series, and inappropriate study design. Data on risk factors, clinical characteristics and clinical endpoints were pooled using random-effects meta-analyses. Findings: Fifty studies with 435,768 PE patients were included. In low risk of bias studies, 30% [95% CI 19-42%, I 2 = 97%] of PE were isolated. The Factor V Leiden [OR: 0.47, 95% CI 0.37-0.58, I 2 = 0%] and prothrombin G20210A mutations [OR: 0.55, 95% CI 0.41-0.75, I 2 = 0%] were significantly less prevalent among patients with isolated PE. Female sex [OR: 1.30, 95% CI 1.17-1.45, I 2 = 79%], recent invasive surgery [OR: 1.31, 95% CI 1.23-1.41, I 2 = 65%], a history of myocardial infarction [OR: 2.07, 95% CI 1.85-2.32, I 2 = 0%], left-sided heart failure [OR: 1.70, 95% CI 1.37-2.10, I 2 = 76%], peripheral artery disease [OR: 1.36, 95% CI 1.31-1.42, I 2 = 0%] and diabetes mellitus [OR: 1.23, 95% CI 1.21-1.25, I 2 = 0%] were significantly more frequently represented among isolated PE patients. In a synthesis of clinical outcome data, the risk of recurrent VTE in isolated PE was half that of DVT-associated PE [RR: 0.55, 95% CI 0.44-0.69, I 2 = 0%], while the risk of arterial thrombosis was nearly 3-fold higher [RR: 2.93, 95% CI 1.43-6.02, I 2 = 0%]. Interpretation: Our findings suggest that isolated PE appears to be a specific entity that may signal a long-term risk of arterial thrombosis. Randomised controlled trials are necessary to establish whether alternative treatment regimens are beneficial for this patient subgroup. Funding: None.

Exploring phenotypes of deep vein thrombosis in relation to clinical outcomes beyond recurrence.

BACKGROUND: Deep vein thrombosis (DVT) is a multifactorial disease with several outcomes, but current classifications solely stratify it based on recurrence risk. OBJECTIVES: We aimed to identify DVT phenotypes and assess their relation to recurrent venous thromboembolism (VTE), postthrombotic syndrome, arterial events, and cancer. PATIENTS/METHODS: Hierarchical clustering was performed on a DVT cohort with a follow-up of up to 5 years using 23 baseline characteristics. Phenotypes were summarized by discriminative characteristics. Hazard ratios (HRs) were calculated using Cox regression; the recurrence risk was adjusted for the anticoagulant therapy duration. The study was carried out in accordance with the Declaration of Helsinki and approved by the medical ethics committee. RESULTS: In total, 825 patients were clustered into 4 phenotypes: 1. women using estrogen therapy (n = 112); 2. patients with a cardiovascular risk profile (n = 268); 3. patients with previous VTE (n = 128); and 4. patients without discriminant characteristics (n = 317). Overall, the risks of recurrence, postthrombotic syndrome, arterial events, and cancer were low in phenotype 1 (reference), intermediate in phenotype 4 (HR: 4.6, 1.2, 2.2, 1.8), and high in phenotypes 2 (HR: 6.1, 1.6, 4.5, 2.9) and 3 (HR: 5.7, 2.5, 2.3, 3.7). CONCLUSIONS: This study identified 4 distinct phenotypes among patients with DVT that are not only associated with the increasing recurrence risk but also with outcomes beyond recurrence. Our results thereby highlight the limitations of current risk stratifications that stratify based on the predictors of the recurrence risk only. Overall, risks were lowest in women using estrogen therapy and highest in patients with a cardiovascular risk profile. These findings might inform a more personalized approach to clinical management.

Variation of platelet function in clinical phenotypes of acute venous thromboembolism - Results from the GMP-VTE project.

BACKGROUND: The role of platelets in the pathogenesis of venous thromboembolism (VTE) is receiving increasing attention; however, limited information is available on platelet function in the acute phase of the disease. OBJECTIVE: To characterize platelet function according to VTE phenotypes. PATIENTS/METHODS: In total, 154 subjects (isolated pulmonary embolism [iPE], n = 28; isolated deep vein thrombosis [iDVT], n = 35; DVT+PE, n = 91) were included. In this study platelet function analyzer (PFA)-200, light transmission aggregometry (LTA), thrombin generation (TG) in presence (PRP) and absence (PFP) of platelets and platelet flow cytometry were investigated. LASSO regression was used to select clinical and platelet biomarkers that distinguish between VTE phenotypes. RESULTS: PFA-200 results did not differ between VTE phenotypes. LTA from DVT+PE subjects showed lowest maximum aggregation after epinephrine and adenosine diphosphate compared to iPE and iDVT. Lower % of PAC-1-positive platelets after in-vitro trigger were present in DVT+PE and iPE compared to iDVT. TG in PRP had lower peak height and velocity in DVT+PE and iPE against iDVT. The results of LASSO regression for the distinction between DVT+PE vs iDVT identified 18 variables (AUC =0.93) of which 72% were platelet biomarkers. For distinction between iPE and iDVT, 10 variables were selected (AUC = 0.96) of which 50% were platelet-related. Obesity was the only variable weakly discriminating between DVT+PE vs iPE (AUC = 0.66). CONCLUSION: This explorative study suggests an important distinction between PE-related phenotypes and iDVT when considering clinical and platelet function data. Lower platelet-dependent TG along with reduced platelet reactivity suggest higher platelet degranulation in PE-dependent phenotypes compared to iDVT.

Protein expression profiling suggests relevance of noncanonical pathways in isolated pulmonary embolism.

Patients with isolated pulmonary embolism (PE) have a distinct clinical profile from those with deep vein thrombosis (DVT)-associated PE, with more pulmonary conditions and atherosclerosis. These findings suggest a distinct molecular pathophysiology and the potential involvement of alternative pathways in isolated PE. To test this hypothesis, data from 532 individuals from the Genotyping and Molecular Phenotyping of Venous ThromboEmbolism Project, a multicenter prospective cohort study with extensive biobanking, were analyzed. Targeted, high-throughput proteomics, machine learning, and bioinformatic methods were applied to contrast the acute-phase plasma proteomes of isolated PE patients (n = 96) against those of patients with DVT-associated PE (n = 276) or isolated DVT (n = 160). This resulted in the identification of shared molecular processes between PE phenotypes, as well as an isolated PE-specific protein signature. Shared processes included upregulation of inflammation, response to oxidative stress, and the loss of pulmonary surfactant. The isolated PE-specific signature consisted of 5 proteins: interferon-γ, glial cell line-derived neurotrophic growth factor, polypeptide N-acetylgalactosaminyltransferase 3, peptidyl arginine deiminase type-2, and interleukin-15 receptor subunit α. These proteins were orthogonally validated using cis protein quantitative trait loci. External replication in an independent population-based cohort (n = 5778) further validated the proteomic results and showed that they were prognostic for incident primary isolated PE in individuals without history of VTE (median time to event: 2.9 years; interquartile range: 1.6-4.2 years), supporting their possible involvement in the early pathogenesis. This study has identified molecular overlaps and differences between VTE phenotypes. In particular, the results implicate noncanonical pathways more commonly associated with respiratory and atherosclerotic disease in the acute pathophysiology of isolated PE.

Missing value imputation in proximity extension assay-based targeted proteomics data.

Targeted proteomics utilizing antibody-based proximity extension assays provides sensitive and highly specific quantifications of plasma protein levels. Multivariate analysis of this data is hampered by frequent missing values (random or left censored), calling for imputation approaches. While appropriate missing-value imputation methods exist, benchmarks of their performance in targeted proteomics data are lacking. Here, we assessed the performance of two methods for imputation of values missing completely at random, the previously top-benchmarked 'missForest' and the recently published 'GSimp' method. Evaluation was accomplished by comparing imputed with remeasured relative concentrations of 91 inflammation related circulating proteins in 86 samples from a cohort of 645 patients with venous thromboembolism. The median Pearson correlation between imputed and remeasured protein expression values was 69.0% for missForest and 71.6% for GSimp (p = 5.8e-4). Imputation with missForest resulted in stronger reduction of variance compared to GSimp (median relative variance of 25.3% vs. 68.6%, p = 2.4e-16) and undesired larger bias in downstream analyses. Irrespective of the imputation method used, the 91 imputed proteins revealed large variations in imputation accuracy, driven by differences in signal to noise ratio and information overlap between proteins. In summary, GSimp outperformed missForest, while both methods show good overall imputation accuracy with large variations between proteins.

Characterization of Thrombin Generation Curve Shape in Presence of Platelets from Acute Venous Thromboembolism Patients.

Background. Anticoagulant therapy, the cornerstone treatment in acute venous thromboembolism (VTE), strongly impacts thrombin generation (TG). Until now, the appearance of the TG curve in platelet rich plasma (PRP) from patients with acute VTE has not been investigated. Methods. We analyzed the shape of TG curves measured in PARP of 180 acute VTE patients. Results. Normal shape of TG curves was observed in 110 patients, 50 patients showed no TG and 20 patients showed biphasic TG curve. The linear regression analysis, adjusted for age, sex, VTE clinical phenotypes and therapy showed that the appearance of biphasic curves is significantly associated with female sex, presence of cancer and therapy with Factor Xa inhibitors. Conclusions. This study demonstrated that despite taking anticoagulants, TG in presence of platelets is still present in the majority of acute VTE patients. Appearance of unusual TG curves is strongly related to the intake of anti-Factor Xa inhibitors. The clinical relevance of biphasic TG curve appearance requires further investigation.

Comprehensive platelet phenotyping supports the role of platelets in the pathogenesis of acute venous thromboembolism - results from clinical observation studies.

BACKGROUND: The pathogenesis of arterial and venous thrombosis is in large part interlaced. How much platelet phenotype relates to acute venous thromboembolism (VTE) independent of the underlying cardiovascular profile is presently poorly investigated. METHODS: Platelet count and mean platelet volume (MPV), platelet aggregation in whole blood and platelet rich plasma (PRP), platelet-dependent thrombin generation (TG) and platelet surface activation markers were measured under standardized conditions. Machine learning was applied to identify the most relevant characteristics associated with VTE from a large array (N = 58) of clinical and platelet-related variables. FINDINGS: VTE cases (N = 159) presented with lower platelet count and MPV vs controls (N = 140). Whole blood aggregation showed shorter collagen/Epinephrine closure times in cases, particularly within acetylsalicylic acid (ASA) users. Within ASA users, higher PRP aggregation after adenosine diphosphate (ADP), epinephrine, collagen and arachidonic acid was observed in cases vs controls. Within non-ASA and/or subjects on anticoagulants, cases presented with lower aggregation after ADP and collagen vs controls. Lower platelet-dependent TG, higher CD63 on resting and lower PAC-1 expression after collagen/ADP in-vitro stimulated platelets further characterized VTE cases vs controls, independent of therapy. Lasso regression analysis identified 26 variables associated with VTE of which 69% were platelet-related. INTERPRETATION: Comprehensive phenotyping of platelet function identified a large proportion of low responders to ASA in VTE cases. Lower platelet-dependent TG and lower platelet reactivity after ex-vivo stimulation characterized the "platelet exhausted syndrome" in cases. Finally, from a large array of covariates including clinical risk factors, platelet biomarkers comprised 69% of all selected variables differentiating VTE cases vs controls. FUNDING: German Federal Ministry of Education and Research, CTH-Mainz and Bayer AG.

Anticoagulation in thrombocytopenic patients with hematological malignancy: A multinational clinical vignette-based experiment.

BACKGROUND: Thrombocytopenia in cancer patients with an indication for anticoagulation poses a unique clinical challenge. There are guidelines for the setting of venous thromboembolism but not atrial fibrillation (AF). Evidence is lacking and current practice is unclear. OBJECTIVE: To identify patient and physician characteristics associated with anticoagulation management in hematological malignancy and thrombocytopenia. METHODS: A clinical vignette-based experiment was designed. Eleven hematologists were interviewed, identifying 5 relevant variable categories with 2-5 options each. Thirty hypothetical vignettes were generated. Each physician received 5 vignettes and selected a management strategy (hold anticoagulation; no change; transfuse platelets; modify type/dose). The survey was distributed to hematologists and thrombosis specialists in 3 countries. Poisson regression models with cluster robust variance estimates were used to calculate relative risks for using one management option over the other, for each variable in comparison to a reference variable. RESULTS: 168 physicians answered 774 cases and reported continuing anticoagulation for venous thromboembolism or AF in 607 (78%) cases, usually with dose reduction or platelet transfusion support. Overall, management was affected by platelet count, anticoagulation indication, time since indication, type of hematological disease and treatment, and prior major bleeding, as well as physician demographics and practice setting. The CHA2DS2-VASc score and time since AF diagnosis affected anticoagulation management in AF. CONCLUSION: This study indicates what the widely accepted management strategies are. These strategies, and possibly others, should be assessed prospectively to ascertain effectiveness. The decision process is intricate and compatible with current venous thromboembolism guidelines.

Managing Anti-Platelet Therapy in Thrombocytopaenic Patients with Haematological Malignancy: A Multinational Clinical Vignette-Based Experiment.

Data on anti-platelet therapy (APT) for prevention of atherothrombotic events in thrombocytopaenic cancer patients is lacking. We aimed to identify patient and physician characteristics associated with APT management in thrombocytopaenic patients with haematological malignancy. A clinical vignette-based experiment was designed. Eleven haematologists were interviewed, identifying five variable categories. Next, 18 hypothetical vignettes were generated. Each physician received three vignettes and chose to: hold all APT; continue APT without platelet transfusion support; or continue APT with platelet transfusion support. The survey was distributed to haematologists and thrombosis specialists in three countries. Multivariate cluster robust Poisson regression models were used to calculate relative risks (RRs) of using one management option (over the other) for each variable in comparison to a reference variable. A total of 145 physicians answered 434 cases. Clinicians were more likely to hold APT in case of 20,000/µL platelets (vs. 40,000/µL; RR for continuing: 0.82 [95% confidence interval: 0.75-0.91]), recent major gastrointestinal bleeding (vs. none; RR 0.81 [0.72-0.92]) and when the physician worked at a university-affiliated community hospital (vs. non-academic community hospital; RR 0.84 [0.72-0.98]). Clinicians were more likely to continue APT in ST elevation myocardial infarction with dual APT (vs. unstable angina with single APT; RR 1.31 [1.18-1.45]) and when there were institutional protocols guiding management (vs. none; RR 1.15 [1.03-1.27]). When APT was continued, increased platelet transfusion targets were used in 34%. In summary, the decision process is complex and affected by multiple patient and physician characteristics. Platelet transfusions were frequently chosen to support APT, although no evidence supports this practice.

Relevance of Polypharmacy for Clinical Outcome in Patients Receiving Vitamin K Antagonists.

BACKGROUND: Although polypharmacy is associated with a negative clinical outcome in various settings and commonly observed in patients receiving oral anticoagulation therapy, evidence on the relevance for the clinical outcome of anticoagulated patients is currently limited. The aim of the study was to investigate the effect of polypharmacy on the clinical outcomes among patients taking phenprocoumon. DESIGN: Prospective cohort study. SETTING: Regular medical care. PARTICIPANTS: Information on 2011 individuals receiving vitamin K antagonists was available for analysis from the prospective multicenter thrombEVAL study. MEASUREMENTS: Data were obtained from clinical visits, computer-assisted interviews, and laboratory measurements. Information on clinical outcome was obtained during a 3-year follow-up period and subsequently validated via medical records. RESULTS: The prevalence of polypharmacy (five drugs or more) was 84.1% (n = 1691). Quality of anticoagulation therapy assessed by time in therapeutic range was lower in individuals on five to eight drugs and nine drugs or more (70.7% and 64.7%, respectively) compared with subjects without polypharmacy (73.4%). In addition, a significantly higher variability of international normalized ratio measurements was found in the presence of polypharmacy. The cumulative incidence of bleeding, hospitalization, and all-cause mortality, but not for thromboembolic events, increased across groups of medication. In adjusted Cox regression analysis, polypharmacy is an independent risk factor for bleeding (hazard ratio [HR]≥ 9 drugs vs 1-4 drugs = 1.62; 95% confidence interval [CI] = 1.04-2.52; p = .033); hospitalization (HR≥ 9 drugs vs 1-4 drugs = 1.60; 95% CI = 1.26-2.03; p < .001; and all-cause mortality (HR≥ 9 drugs vs 1-4 drugs = 2.16; 95% CI = 1.43-3.27; p < .001) in a dose-dependent relationship. Per additional drug, bleeding risk was increased by 4%. CONCLUSIONS: Polypharmacy influences the quality of anticoagulation therapy and translates into an elevated risk of adverse events in anticoagulated patients. This suggests that additional medication intake in such patients should be critically reviewed by physicians, and it highlights the importance of initiating investigations aimed at reducing multiple medication intake. J Am Geriatr Soc 67:463-470, 2019.