Decreased Thrombin Generation is Associated with Increased Thrombin Generation Biomarkers and Blood Cellular Indices in Pulmonary Embolism.

Pulmonary embolism (PE) is a heterogenous condition with variable clinical presentations. Thrombin generation potential (TGP) and biomarkers, and blood cellular indices can reflect the underlying pathophysiology and risk stratification of PE. This case-control study analyzed TGP in 209 PE patients from Loyola University, Pulmonary Embolism Response Team program compared to normal human plasma (NHP) controls. The present study evaluates TGP and biomarkers, and cellular indices in relation to PE severity, according to the European Society of Cardiology (ESC) guidelines. Statistical analysis including median with interquartile range (IQR), 2-tailed Wilcoxon Mann-Whitney test, Chi-square test, and Spearman Correlational analysis were performed. There were 209 patients with PE, with an almost equal distribution between sex, and a median age of 63 years. Significant downregulation in peak thrombin and endogenous thrombin potential (ETP), as well as upregulation in lag time, were observed in PE patients versus controls. Biomarker analysis revealed pronounced elevations, with D-dimer demonstrating the most significant increase. Blood cellular indices also rose in PE patients, correlating with disease severity. PE severity was associated with higher TGP and biomarker levels. Mortality rates differed significantly across risk categories and were highest in patients with elevated cellular indices. TGP and biomarkers are intricately linked to PE severity and can aid in risk stratification. Elevated cellular indices are associated with increased mortality, highlighting their potential as prognostic markers. These findings could enhance the precision of PE management strategies.

The prognostic value of blood cellular indices in pulmonary embolism.

Prognostication in acute pulmonary embolism (PE) requires reliable markers. While cellular indices such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) appear promising, their utility in PE prognostication needs further exploration. We utilized data from the RIETE registry and the Loyola University Medical Center (LUMC) to assess the prognostic value of NLR, PLR, and SII in acute PE, using logistic regression models. The primary outcome was 30-day all-cause mortality. We compared their prognostic value versus the simplified Pulmonary Embolism Severity Index (sPESI) alone. We included 10 085 patients from RIETE and 700 from the LUMC. Thirty-day mortality rates were 4.6% and 8.3%, respectively. On multivariable analysis, an elevated NLR (>7.0) was associated with increased mortality (adjusted odds ratio [aOR]: 3.46; 95% CI: 2.60-4.60), outperforming the PLR > 220 (aOR: 2.36; 95% CI: 1.77-3.13), and SII > 1600 (aOR: 2.52; 95% CI: 1.90-3.33). The c-statistic for NLR in patients with low-risk PE was 0.78 (95% CI: 0.69-0.86). Respective numbers were 0.66 (95% CI: 0.63-0.69) and 0.68 (95% CI: 0.59-0.76) for intermediate-risk and high-risk patients. These findings were mirrored in the LUMC cohort. Among 9810 normotensive patients in RIETE, those scoring 0 points in sPESI and with an NLR ≤ 7.0 (35% of the population) displayed superior sensitivity (97.1%; 95% CI: 95.5-98.7) and negative predictive value (99.7%; 95% CI: 99.5-99.8) than sPESI alone (87.1%; 95% CI: 83.9-90.3, and 98.7%; 95% CI: 98.4-99.1, respectively) for 30-day mortality. The NLR is a significant prognostic marker for 30-day mortality in PE patients, especially useful to identify patients with very low-risk PE.

Andexanet Alfa Neutralizes the Anticoagulant Effects of Unfractionated Heparin of Bovine, Ovine and Porcine Origin Almost as Protamine Sulfate.

INTRODUCTION: Andexanet alfa (AA) - zhzo, recombinant coagulation factor Xa, is an approved antidote for oral Xa inhibitors (apixaban and rivaroxaban). Unfractionated heparin (UFH) is commonly used for therapeutic, interventional, and surgical indications. Protamine sulfate (PrSO4) is frequently used to neutralize UFH. This study aimed to investigate the comparative neutralization profiles of AA and PrSO4 for heparins of bovine, ovine, and porcine origin. MATERIALS AND METHODS: The neutralization effect of PrSO4 at 25 µg/ml and AA at 100 µg/ml was studied on an approximate surgical/interventional concentration of heparin by supplementing whole blood with each of the heparins at 25 µg/ml. For the clotting profile (activated partial thromboplastin time: aPTT), amidolytic (anti-Xa and anti-IIa), and thrombin generation assay each of the heparin were supplemented from -10-0.62 µg/ml. RESULTS: In the whole blood ACT studies, all three heparins produced strong anti-coagulant effects (400-450 seconds) compared to saline (130-150 seconds). Both AA and PrSO4 almost fully neutralized the anti-coagulant effects of heparins (140-160 seconds). Both antidotes completely reversed the anticoagulant effects of all three heparins in the aPTT and thrombin generation assay. However, PrSO4 was more effective in neutralizing the anti-Xa, and anti-IIa effects than AA, which only partially neutralized these effects. CONCLUSION: Andexanet alfa at 100 µg/ml effectively neutralizes the therapeutic and surgical/interventional concentrations of heparins in in-vitro settings. While differences in the anti-Xa, and anti-IIa effects between heparins were noted, anti-coagulant effect of these agents in the aPTT assay were comparable. A similar neutralization profile was observed in the ACT and thrombin generation assays by both agents.

Extending venous thromboembolism secondary prevention with apixaban in cancer patients. The EVE trial.

BACKGROUND: Cancer-associated venous thromboembolism (VTE) management guideline recommendations include continued therapeutic anticoagulation while active cancer persists. The Federal Drug Administration label for apixaban for secondary VTE prevention includes a dose reduction to 2.5 mg twice daily after 6 months of treatment. OBJECTIVES: The study's purpose was to determine whether this dose reduction is advisable for cancer-associated VTE. METHODS: A randomized, double-blind trial compared apixaban 2.5 mg with 5 mg twice daily for 12 months among cancer patients with VTE who had completed 6 to 12 months of anticoagulation therapy. The primary outcome was combined major bleeding plus clinically relevant nonmajor bleeding. RESULTS: Of 370 patients recruited, 360 were included in the intention-to-treat analyses. Major plus clinically relevant nonmajor bleeding occurred in 16 of 179 patients (8.9%) in the apixaban 2.5 mg group compared with 22 of 181 patients (12.2%) in the 5 mg group (hazard ratio [HR], 0.72; 95% CI, 0.38-1.37; P = .39). Major bleeding occurred in 2.8% of the apixaban 2.5 mg group and in 2.2% of the 5 mg group (HR, 1.26; 95% CI, 0.34-4.66; P = .73). Recurrent VTE or arterial thrombosis occurred in 9 of 179 patients (5.0%) in the apixaban 2.5 mg group and 9 of 181 patients (5.0%) in the 5 mg group (HR, 1.0; 95% CI, 0.40-2.53; P = 1.00). All-cause mortality rates were similar between groups, 13% vs 12% (HR, 1.14; 95% CI, 0.63-2.04; P = .67). CONCLUSION: For secondary prevention of cancer-associated VTE, apixaban 2.5 mg compared with 5 mg twice daily did not lower combined bleeding events (EVE trial NCT03080883).

Anticoagulation Stewardship to Bridge the Implementation Gap in Perioperative Anticoagulation Management.

Lack of alignment of care protocols among providers in health care is a driver of increased costs and suboptimal patient outcomes. Perioperative anticoagulation management is a good example of a complex area where protocol creation is a clinical challenge that demands input from multiple experts. Questions regarding the need for anticoagulation interruptions are frequent. Yet, due to layers of complexity involving analysis of anticoagulation indication, surgical risk, and anesthesia-associated bleeding risk as well as institutional practices, there is heterogeneity in how these interruptions are approached. The recent perioperative anticoagulation guidelines from the American College of Chest Physicians summarize extensive evidence for the management of anticoagulant and antiplatelet medications in patients who undergo elective interventions. However, implementation of these guidelines by individual clinicians is highly varied and often does not follow the best available clinical evidence. Against this background, anticoagulation stewardship units, which exist to improve safety and quality monitoring for the anticoagulated patient, are of growing interest. These units provide a bridge for the implementation of value-based, high-quality guidelines for patients who need perioperative anticoagulation interruption. We use a case to pragmatically illustrate the problem and tactics for change management and implementation science that may facilitate the adoption of perioperative anticoagulation guidelines.

Combined polygenic scores for ischemic stroke risk factors aid risk assessment of ischemic stroke.

BACKGROUND: Current risk assessment for ischemic stroke (IS) is limited to clinical variables. We hypothesize that polygenic scores (PGS) of IS (PGSIS) and IS-associated diseases such as atrial fibrillation (AF), venous thromboembolism (VTE), coronary artery disease (CAD), hypertension (HTN), and Type 2 diabetes (T2D) may improve the performance of IS risk assessment. METHODS: Incident IS was followed for 479,476 participants in the UK Biobank who did not have an IS diagnosis prior to the recruitment. Lifestyle variables (obesity, smoking and alcohol) at the time of study recruitment, clinical diagnoses of IS-associated diseases, PGSIS, and five PGSs for IS-associated diseases were tested using the Cox proportional-hazards model. Predictive performance was assessed using the C-statistic and net reclassification index (NRI). RESULTS: During a median average 12.5-year follow-up, 8374 subjects were diagnosed with IS. Known clinical variables (age, gender, clinical diagnoses of IS-associated diseases, obesity, and smoking) and PGSIS were all independently associated with IS (P < 0.001). In addition, PGSIS and each PGS for IS-associated diseases was also independently associated with IS (P < 0.001). Compared to the clinical model, a joint clinical/PGS model improved the C-statistic for predicting IS from 0.71 to 0.73 (P < 0.001) and significantly reclassified IS risk (NRI = 0.017, P < 0.001), and 6.48% of subjects were upgraded from low to high risk. CONCLUSIONS: Adding PGSs of IS and IS-associated diseases to known clinical risk factors statistically improved risk assessment for IS, demonstrating the supplementary value of inherited susceptibility measurement . However, its clinical utility is likely limited due to modest improvements in predictive values.

Algorithm for Rapid Exclusion of Clinically Relevant Plasma Levels of Direct Oral Anticoagulants in Patients Using the DOAC Dipstick: An Expert Consensus Paper.

BACKGROUND: With the widespread use of direct oral anticoagulants (DOACs), there is an urgent need for a rapid assay to exclude clinically relevant plasma levels. Accurate and rapid determination of DOAC levels would guide medical decision-making to (1) determine the potential contribution of the DOAC to spontaneous or trauma-induced hemorrhage; (2) identify appropriate candidates for reversal, or (3) optimize the timing of urgent surgery or intervention. METHODS AND RESULTS: The DOAC Dipstick test uses a disposable strip to identify factor Xa- or thrombin inhibitors in a urine sample. Based on the results of a systematic literature search followed by an analysis of a simple pooling of five retrieved clinical studies, the test strip has a high sensitivity and an acceptably high negative predictive value when compared with levels measured with liquid chromatography tandem mass spectrometry or calibrated chromogenic assays to reliably exclude plasma DOAC concentrations ≥30 ng/mL. CONCLUSION: Based on these data, a simple algorithm is proposed to enhance medical decision-making in acute care indications useful primarily in hospitals not having readily available quantitative tests and 24/7. This algorithm not only determines DOAC exposure but also differentiates between factor Xa and thrombin inhibitors to better guide clinical management.

In medical inpatients, the IMPROVE risk score had moderate predictive power for 14-d in-hospital bleeding.

SOURCE CITATION: Villiger R, Juillard P, Darbellay Farhoumand P, et al. Prediction of in-hospital bleeding in acutely ill medical patients: external validation of the IMPROVE bleeding risk score. Thromb Res. 2023;230:37-44. 37634309.

Dissecting the rationale for thromboprophylaxis in challenging surgical cases.

Pulmonary embolism (PE) is a leading preventable cause of death in surgical patients, and rates of fatal PE are increasing. Individual assessment, to balance the risks of thrombosis and bleeding, is the key to providing appropriate prophylaxis. The risk assessment process includes use of evidence-based guidelines, literature published since the latest guidelines, large registries, and risk scoring systems together with clinical experience and judgment. Risk assessment is a dynamic process and needs to be updated both during the hospital stay and just prior to discharge since clinical events may change the level of risk. The final assessment may identify patients who require ongoing anticoagulant prophylaxis after discharge. The Caprini risk score is widely used in surgical patients and is a composite of the number of risk factors and their relative weights. The Caprini risk score set point for risk levels requiring anticoagulant prophylaxis varies depending on the type of surgical procedure, surgical population, and number of risk factors. Mandatory implementation of evidence-based care pathways is helpful in lowering PE-related mortality. This review presents several challenging cases, emphasizing the importance of employing all available assessment tools, including dynamic assessment of risk during hospitalization. Finally, the limitations of evidence-based guidelines in complex scenarios and the need to employ all available tools to properly protect very high-risk patients are emphasized.

Temporal trends and outcomes of patients with chronic limb-threatening ischemia with and without history of coronary artery disease: insights from the us national inpatient sample database.

BACKGROUND: The burden and prognostic significance of coronary artery disease (CAD) in adults with peripheral artery disease and chronic limb-threatening ischemia (CLTI) is unknown. METHODS: Temporal trends in prevalence of significant CAD (history of myocardial infarction or coronary revascularizations) in hospitalizations for CLTI were determined using the 2000 to 2018 National Inpatient Sample (NIS) database. A multivariable regression analysis of outcomes was performed based on presence or absence of CAD. RESULTS: Among 13 575 099 hospitalizations for CLTI (41% female, 69% white, mean age 69 years), 23% had concomitant CAD, of which 11% underwent lower extremity arterial revascularization (43.6% endovascular and 56.4% surgical). The prevalence of concomitant CAD with CLTI increased from 15.3% in 2000 to 23.1% in 2018. Furthermore, the frequency of endovascular revascularization in adults with CAD and CLTI increased from 15.1% to 48.3%, while there was a decreasing trend of surgical revascularization, from 84.9% to 51.7%. After multivariate adjustments, CLTI with CAD was associated with increased risk of in-hospital mortality (OR, 1.40; 95% CI, 1.32-1.47; P less than .0001) and bleeding requiring transfusion (OR, 1.10; 95% CI, 1.06-1.12; P less than .0001) compared with patients with CLTI without CAD. As compared with surgical revascularization, endovascular revascularization was associated with lower risk of in-hospital mortality in both patients with CLTI with CAD (OR, 0.69; 95% CI, 0.63-0.76; P less than .001) and CLTI without CAD (OR, 0.71; 95% CI, 0.67-0.76; P less than .001). CONCLUSIONS: Prevalence of CAD has increased in adults presenting with CLTI and is associated with poor outcomes, warranting the need for effective interventions and secondary prevention in this high-risk population.

Risk assessment of venous thromboembolism in inflammatory bowel disease by inherited risk in a population-based incident cohort.

BACKGROUND: Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammatory disease of the digestive tract with increasing prevalence globally. Although venous thromboembolism (VTE) is a major complication in IBD patients, it is often underappreciated with limited tools for risk stratification. AIM: To estimate the proportion of VTE among IBD patients and assess genetic risk factors (monogenic and polygenic) for VTE. METHODS: Incident VTE was followed for 8465 IBD patients in the UK Biobank (UKB). The associations of VTE with F5 factor V leiden (FVL) mutation, F2 G20210A prothrombin gene mutation (PGM), and polygenic score (PGS003332) were tested using Cox hazards regression analysis, adjusting for age at IBD diagnosis, gender, and genetic background (top 10 principal components). The performance of genetic risk factors for discriminating VTE diagnosis was estimated using the area under the receiver operating characteristic curve (AUC). RESULTS: The overall proportion of incident VTE was 4.70% in IBD patients and was similar for CD (4.46%), UC (4.49%), and unclassified (6.42%), and comparable to that of cancer patients (4.66%) who are well-known at increased risk for VTE. Mutation carriers of F5/F2 had a significantly increased risk for VTE compared to non-mutation carriers, hazard ratio (HR) was 1.94, 95% confidence interval (CI): 1.42-2.65. In contrast, patients with the top PGS decile had a considerably higher risk for VTE compared to those with intermediate scores (middle 8 deciles), HR was 2.06 (95%CI: 1.57-2.71). The AUC for differentiating VTE diagnosis was 0.64 (95%CI: 0.61-0.67), 0.68 (95%CI: 0.66-0.71), and 0.69 (95%CI: 0.66-0.71), respectively, for F5/F2 mutation carriers, PGS, and combined. CONCLUSION: Similar to cancer patients, VTE complications are common in IBD patients. PGS provides more informative risk information than F5/F2 mutations (FVL and PGM) for personalized thromboprophylaxis.

A Patient with Recurrent Strokes: Approach to Coagulopathy.

Despite anticoagulation recommendations, patients may present with recurrent events. While medication adherence is always a concern, assessment of anticoagulation failure demands a systematic approach, taking into account the potential limitations of anticoagulants and a review of differential diagnoses for comorbidities. We illustrate our approach in a case presentation.

Defining heparin resistance: communication from the ISTH SSC Subcommittee of Perioperative and Critical Care Thrombosis and Hemostasis.

The term heparin resistance (HR) is used by clinicians without specific criteria. We performed a literature search and surveyed our SSC membership to better define the term when applied to medical and intensive care unit patients. The most common heparin dosing strategy reported in the literature (53%) and by survey respondents (80.4%) was the use of weight-based dosing. Heparin monitoring results were similar based on the proportion of publications and respondents that reported the use of anti-Xa and activated partial thromboplastin time. The most common literature definition of HR was >35 000 U/d, but no consensus was reported among survey respondents regarding weight-based and the total dose of heparin when determining resistance. Respondent consensus on treating HR included antithrombin supplementation, direct thrombin inhibitors, or administering more heparin as the strategies available for treating HR. A range of definitions for HR exist. Given the common use of heparin weight-based dosing, future publications employing the term HR should include weight-based definitions, monitoring assay, and target level used. Further work is needed to develop a consensus for defining HR.

Cancer-associated thrombosis by cancer sites and inherited factors in a prospective population-based cohort.

Cancer-associated thrombosis (CAT) is common and associated with mortality. We estimated CAT rate by cancer sites and inherited factors among cancer patients from the UK Biobank (N =70,406). The 12-month CAT rate after cancer diagnosis was 2.37% overall but varied considerably among cancer sites. Among the 10 cancer sites classified as 'high-risk' of CAT by the National Comprehensive Cancer Network guidelines, 6 had CAT rate <5%. In contrast, 5 cancer sites classified as 'average-risk' by the guidelines had CAT rate >5%. For inherited risk factors, both known mutation carriers in two genes (F5/F2) and polygenic score for venous thromboembolism (VTE) (PGSVTE) were independently associated with increased CAT risk. While F5/F2 identified 6% patients with high genetic-risk for CAT, adding PGSVTE identified 13 % patients at equivalent/higher genetic-risk to CAT than that of F5/F2 mutations. Findings from this large prospective study, if confirmed, provide critical data to update guidelines for CAT risk assessment.

Personalized Postacute Hospitalization Recovery: A Novel Intervention to Improve Patient Experience and Reduce Cost.

GOAL: Readmissions are a significant financial burden for payers. Cardiovascular-related discharges are particularly prone to readmission. Posthospital discharge support can impact patient recovery and probably reduce patient readmissions. This study aimed to address the underlying behavioral and psychosocial factors that can negatively affect patients after discharge. METHODS: The study population was adult patients admitted to the hospital with a cardiovascular diagnosis who had a plan to discharge home. Those who consented to participate were randomized to intervention or control groups on a 1:1 basis. The intervention group received behavioral and emotional support, whereas the control group received usual care. Interventions included motivational interviewing, patient activation, empathetic communication, addressing mental health and substance use, and mindfulness. PRINCIPAL FINDINGS: Observed total readmission costs were significantly lower in the intervention group than in the control group ($1.1 million vs. $2.0 million) as was the observed mean cost per readmitted patient ($44,052 vs. $91,278). The mean expected cost of readmission after adjustment for confounding variables was lower in the intervention group than in the control group ($8,094 vs. $9,882, p = .011). PRACTICAL APPLICATIONS: Readmissions are a costly spend category. In this study, posthospital discharge support addressing the psychosocial factors contributing to patients' readmissions resulted in a lower total cost of care for those with a cardiovascular diagnosis. We describe an intervention that is reproducible and can be scaled broadly through technology to reduce readmission costs.

Cost-effectiveness analysis of extended thromboprophylaxis with rivaroxaban versus no prophylaxis in high-risk patients after hospitalisation for COVID-19: an economic modelling study.

Background: In patients at high risk of thromboembolism who were discharged after hospitalisation due to COVID-19, thromboprophylaxis with rivaroxaban 10 mg/day for 35 days significantly improved clinical outcomes, reducing thrombotic events compared with no post-discharge anticoagulation. The present study aimed to estimate the cost-effectiveness of this anticoagulation strategy. Methods: Using the database of the MICHELLE trial, we developed a decision tree to estimate the cost-effectiveness of thromboprophylaxis with rivaroxaban 10 mg/day for 35 days versus no thromboprophylaxis in high-risk post-discharge patients for COVID-19 through an incremental cost-effectiveness analysis. Findings: 318 patients in 14 centres in Brazil were enrolled in the primary MICHELLE trial. The mean age was 57.1 years (SD 15.2), 127 (40%) were women, 191 (60%) were men, and the mean body-mass index was 29.7 kg/m2 (SD 5.6). Rivaroxaban 10 mg per day orally for 35 days after discharge decreased the risk of events defined by the primary efficacy outcome by 67% (relative risk 0.33, 95% CI 0.12-0.90; p = 0.03). The mean cost for thromboprophylaxis with rivaroxaban was $53.37/patient, and no prophylaxis was $34.22/patient, with an incremental cost difference of $19.15. The effectiveness means obtained in the intervention group was 0.1457, while in the control group was 0.1421, determining an incremental QALY difference of 0.0036. The estimated incremental cost-effectiveness ratio (ICER) was $5385.52/QALY. Interpretation: Extended treatment with Rivaroxaban as thromboprophylaxis after hospital discharge for high-risk patients with COVID-19 is a cost-effective treatment option. Funding: Modest funding was provided by Science Valley Research Institute, São Paulo, Brazil.