BACKGROUND: Non-factor replacement therapies are emerging as prophylactic treatment options in haemophilia A or B (HA/HB) with and without inhibitors. Concizumab is an anti-tissue factor pathway inhibitor (TFPI) monoclonal antibody preventing factor (F)Xa inhibition and enhancing thrombin generation. Based on experience with other non-factor therapies and extended half-life products, there is a focus on potential interference with common clinical coagulation assays used to monitor patients treated with concizumab.
OBJECTIVE: To evaluate the impact of concizumab on standard clinical coagulation assays.
METHODS: Plasma samples (normal, HA/HB with/without inhibitors) in the presence/absence of added concizumab (250-16,000 ng/mL) were analysed in clinical assays including activated partial thromboplastin time (aPTT), prothrombin time (PT), FVIII and FIX one-stage clot and chromogenic substrate assay, assays for detecting FVIII or FIX inhibitors and other assays for coagulation factors.
RESULTS: Concizumab did not impact PT assays, but resulted in a small shortening of aPTT (up to 5 s in haemophilia plasma and 0.4 s in normal plasma). Concizumab had no, or only a minor impact on FVIII and FIX activity assays or Bethesda inhibitor assays. FXI and FXII activity in normal plasma, as measured by single factor aPTT-based assay, was significantly increased in the presence of concizumab (+11% each). This was also the case for FVII and FX measured by PT-based assays using plasma with 25% of FVII or FX (+64% and +22%, respectively).
CONCLUSIONS: The presence of concizumab did not, or only slightly, influence the outcome of standard clinical coagulation assays relevant for HA and HB.

Coagulopathy development in traumatic brain injury (TBI) is among the significant complications that can negatively affect the clinical course and outcome of TBI patients. Timely identification of this complication is of utmost importance in the acute clinical setting. We reviewed TBI patients admitted to our trauma center from 2015 to 2021. Demographic data, mechanism of injury, findings on admission, imaging studies, procedures during hospitalization, and functional outcomes were gathered. INR with a cutoff of 1.3, platelet count less than 100 × 10⁹/L, or partial thromboplastin time greater than 40s were utilized as the markers of coagulopathy. A total of 4002 patients were included. Coagulopathy occurred in 38.1% of the patients. Age of the patients (Odds Ratio (OR) = 0.993, 95% Confidence Interval (CI) = 0.986-0.999, p = 0.028), systolic blood pressure (OR = 0.993, 95% CI = 0.989-0.998, p = 0.005), fibrinogen level (OR = 0.998, 95% CI = 0.996-0.999, p < 0.001), and hemoglobin level (OR = 0.886, 95% CI = 0.839-0.936, p < 0.001) were independently associated with coagulopathy. Furthermore, coagulopathy was independently associated with higher mortality rates and longer ICU stays. Coagulopathy had the most substantial effect on mortality of TBI patients (OR = 2.6, 95% CI = 2.1-3.3, p < 0.001), compared to other admission clinical characteristics independently associated with mortality such as fixed pupillary light reflex (OR = 1.8, 95% CI = 1.5-2.4, p < 0.001), GCS (OR = 0.91, 95% CI = 0.88-0.94, p < 0.001), and hemoglobin level (OR = 0.93, 95% CI = 0.88-0.98, p = 0.004). Early coagulopathy in TBI patients can lead to higher mortality rates. Future studies are needed to prove that early detection and correction of coagulopathy and modifiable risk factors may help improve outcomes of TBI patients.

Data on the pathophysiological mechanisms of hemostatic alterations in the thrombotic events that occur during Ramadan intermittent fasting (RIF), particularly in the natural coagulation inhibitors, are very limited. Thus, our objective was to evaluate the effect of RIF on the natural anticoagulants level, antithrombin, protein C, and total and free protein S (PS) in healthy participants. Participants were divided into two groups. Group I consisted of 29 healthy fasting participants whose blood samples were taken after 20 days of fasting. Group II included 40 healthy non-fasting participants whose blood samples were taken 2-4 weeks before the month of Ramadan. Coagulation screening tests including prothrombin time (PT), activated partial thromboplastin time (APTT) and plasma fibrinogen level, natural anticoagulants; antithrombin, protein C, free and total PS and C4 binding protein (C4BP) levels were evaluated in the two groups. High levels of total and free PS without change in antithrombin, protein C, and C4BP levels were noted in the fasting group as compared with non-fasting ones (p < 0.05). PT and APTT showed no difference between the two groups. However, the fibrinogen level was higher in the fasting group. In conclusion, RIF was found to be associated with improved anticoagulant activity in healthy participants, which may provide temporal physiological protection against the development of thrombosis in healthy fasting people.

OBJECTIVE: To assess the effect of gestational age-based dosing of unfractionated heparin (UFH) compared with standard dosing of UFH for thromboprophylaxis on an elevated serum activated partial thromboplastin time (aPTT) during prolonged antepartum hospitalizations.
METHODS: This was a randomized trial of pregnant persons who were admitted in the antepartum period for at least 72 hours. Participants were randomly allocated to the standard dose of UFH (5,000 units subcutaneously every 12 hours) or the gestational age-based dose of UFH (first trimester [less than 14 weeks]: 5,000 units subcutaneously every 12 hours; second trimester [14-27 6/7 weeks]: 7,500 units subcutaneously every 12 hours; third trimester (28 weeks or more): 10,000 units subcutaneously every 12 hours). The primary outcome was the proportion of antepartum patients who had an elevated serum aPTT value above the normal range (more than 36.2 seconds) 6 hours after an UFH dose. Secondary outcomes included the development of venous thromboembolism (VTE) and reported side effects of heparin administration.
RESULTS: Between December 15, 2020, and April 1, 2022, 97 patients with antepartum hospitalizations were screened and 46 were randomized: 22 allocated to standard dosing and 24 allocated to gestational age-based dosing of UFH. A significantly greater proportion of antepartum patients who received gestational age-based dosing had an abnormal elevation in aPTT compared with those who received standard dosing (33.3% vs 4.8%, P =.02). Gestational age-based dosing resulted in higher maximum [interquartile range] aPTT (30.4 [27.4, 37.5] vs 26.6 [23.0, 29.6], P =.01) and anti-Xa levels (0.09 [0.09, 0.11] vs 0.09 [0.09, 0.09], P =.04). There was no significant difference in VTE between groups ( P =.47).
CONCLUSIONS: Gestational age-based dosing of UFH for thromboprophylaxis of antepartum hospitalizations was associated with significantly increased rates of elevated coagulation parameters compared with standard fixed dosing. This study suggests a need for close monitoring if higher doses of UFH during pregnancy are used later in gestation. The efficacy of gestational age-based dosing compared with standard dosing for UFH to prevent thromboembolic events remains an area for future investigation.
BACKGROUND: ClinicalTrials.gov , NCT04635839.

BACKGROUND: Bleeding and thrombotic complications are common in extracorporeal membrane oxygenation (ECMO) patients and are associated with increased mortality and morbidity. The optimal anticoagulation monitoring protocol in these patients is unknown. This study aims to compare the incidence of thrombotic and hemorrhagic complications before and after a protocol change. In addition, the association between hemostatic complications, coagulation tests and risk factors is evaluated.
METHODS: This is a retrospective single center cohort study of adult ECMO patients. We collected demographics, ECMO parameters and coagulation test results. Outcomes of the aPTT guided and multimodal protocol, including aPTT, anti-Xa assay and rotational thromboelastometry were compared and the association between coagulation tests, risk factors and hemostatic complications was determined using a logistic regression analysis for repeated measurements.
RESULTS: In total, 250 patients were included, 138 in the aPTT protocol and 112 in the multimodal protocol. The incidence of thrombosis (aPTT: 14%; multimodal: 12%) and bleeding (aPTT: 36%; multimodal: 40%), did not significantly differ between protocols. In the aPTT guided protocol, the aPTT was associated with thrombosis (Odds Ratio [OR] 1.015; 95% confidence interval [CI] 1.004-1.027). In both protocols, surgical interventions were risk factors for bleeding and thrombotic complications (aPTT: OR 93.2, CI 39.9-217.6; multimodal OR 17.5, CI 6.5-46.9).
CONCLUSIONS: The incidence of hemostatic complications was similar between both protocols and surgical interventions were a risk factor for hemostatic complications. Results from this study help to elucidate the role of coagulation tests and risk factors in predicting hemostatic complications in patients undergoing ECMO support.

The direct-acting oral anticoagulant dabigatran etexilate (DE) targets thrombin and is used widely to prevent thromboembolism. A 79-year-old man was admitted to the Emergency Department due to anuria for 2 days. An urgent laboratory examination revealed a serum creatinine concentration of 888 µmol/L. He was diagnosed with acute exacerbation of chronic renal insufficiency. During continuous renal replacement therapy (CRRT), the coagulation test showed a severe reduction in the fibrinogen level as well as a significantly prolonged prothrombin time (PT) and activated partial thromboplastin time (APTT). The patient had been taking DE (110 mg twice daily) for a long time and had not suspended the medication or reduced the dose during the worsening of anuria. Therefore, it should be evaluated before considering plasma replacement therapy for the patient, whether the abnormal coagulation parameters were induced by interference of excessive DE. Tentatively, we used activated charcoal to treat the plasma and then retested the fibrinogen, PT, and APTT. Results showed that the coagulation indices nearly returned to normal. The present case indicated that activated charcoal could adsorb DE in plasma effectively and eliminate its interference with coagulation test results, thereby providing support for clinical diagnosis and treatment.

BACKGROUND: The aim of this study was to determine the serum biochemical markers that can predict the risk of haemorrhagic transformation (HT) before and after endovascular treatment (EVT).
METHODS: This study included patients with anterior circulation large vessel occlusion (ACLVO) who underwent EVT within six hours of symptom onset between September 2017 and September 2022. These patients were retrospectively categorised into two groups: an HT group and a No-HT group.
RESULTS: A total of 180 patients were included in the study, of whom 55 (30.6%) had HT. The monocyte count before EVT (p = = 0.005, OR = 0.694, 95% CI 0.536-0.898), the activated partial thromboplastin time before EVT (p = 0.009, OR = 0.186, 95% CI 0.699-0.952), and the eosinophil count after EVT (p = 0.038, OR = 0.001, 95% CI 0.000-0.018) were all found to be independent predictors of HT, with warning values of 6.65%, 22.95 seconds, and 0.035*10^9/L, respectively. When compared to prediction using only demographic data [AUC = 0.662,95% CI (0.545, 0.780)], adding biochemical indices before EVT [AUC = 0.719,95% CI (0.617, 0.821)], adding biochemical indices after EVT [AUC = 0.670,95% CI (0.566, 0.773)], and adding both [AUC = 0.778,95% CI (0.686, 0.870)], the prediction efficiency of HT was improved among all three combinations, with no statistical significance.
CONCLUSIONS: The levels of serum biochemical markers were found to show significant changes before and after EVT in ACLVO patients. A combination of demographic data and serum biochemical markers proved to be effective in predicting the occurrence of HT in patients with ACLVO who underwent EVT.

The purpose of this study was to evaluate the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of frunexian (formerly known as EP-7041 and HSK36273) injection, a small molecule inhibitor of activated coagulation factor XI (FXIa), in healthy Chinese adult volunteers. This study was a randomized, placebo- and positive-controlled, sequential, ascending-dose (0.3/0.6/1.0/1.5/2.25 mg/kg/h) study of 5-day continuous intravenous infusions of frunexian. Frunexian administration exhibited an acceptable safety profile with no bleeding events. Steady state was rapidly reached with a median time ranging from 1.02 to 1.50 h. The mean half-life ranged from 1.15 to 1.43 h. Frunexian plasma concentration at a steady state and area under the concentration-time curve exhibited dose-proportional increases. The dose-escalation study of frunexian demonstrated its progressively enhanced capacities to prolong activated partial thromboplastin time (aPTT) and inhibit FXIa activity. The correlations between PK and PD biomarkers (aPTT/baseline and FXI clotting activity/baseline) were described by the two Emax models, with the EC50 values of 8940 and 1300 ng/mL, respectively. Frunexian exhibits good safety and PK/PD properties, suggesting it is a promising candidate for anticoagulant drug.

To investigate the effect of reduced early-pregnancy activated partial thrombin time (APTT), prothrombin time (PT), and international standardized ratio (INR) on the risk of preeclampsia. A total of 8549 pregnant women with singleton births were included. Early pregnancy APTT, PT, and INR levels, with age, birth, prepregnancy body mass index, fibrinogen (FBG), thrombin time (TT), D-dimer (DD2), antithrombin III (ATIII), fibrin degradation products (FDP) as confounders, generalized linear model of APTT, the relative risk of PT and INR when INR reduction. After adequate adjustment for confounders, the relative risk of preeclampsia was 0.703 for every 1 s increase in plasma PT results in early pregnancy, and for every 0.1 increase in plasma INR results, the relative risk of preeclampsia was 0.767. With a PT less than the P25 quantile (<11 s), the relative risk of preeclampsia was 1.328. The relative risk of preeclampsia at an INR less than the P25 quantile (<0.92) was 1.24. There was no statistical association between APTT on the risk of preeclampsia. The relative risk of preeclampsia is strongly associated with a decrease in PT and INR in early pregnancy. PT and INR in early pregnancy were a potential marker in the risk stratification of preeclampsia. Focusing on reduced PT and INR levels in early pregnancy can help to identify early pregnancies at risk for preeclampsia.

BACKGROUND: Chamomile administration may have desirable effects in the perioperative setting. Current practice, however, discourages perioperative chamomile use due to a theoretical increase in bleeding. Therefore, we evaluated if chamomile acutely (within 4 h of ingestion) prolongs coagulation assays.
METHODS: Eight healthy volunteers were randomized to receive 2 interventions in a crossover design: (a) single dose of chamomile extract capsule (500 mg) and (b) single dose of chamomile tea (3 g in 150 mL water). Interventions were separated at least 3 days apart from each other. Blood was sampled pre-ingestion, 2 h post-ingestion, and 4 h post-ingestion for each intervention. The primary outcome was the maximal change in prothrombin time (PT) before vs after each intervention. Secondary outcomes included changes in international normalized ratio, activated partial thromboplastin time, thrombin time, reptilase time, and fibrinogen levels.
RESULTS: All 8 subjects completed the study. The average pre-ingestion PT values for tea and capsules were 11.9 (1.1) s and 12.0 (0.9) s, respectively. Tea significantly increased the average maximum PT by 0.7 (0.2) s (P = 0.0078). Extract capsules increased the maximum PT by 0.3 (0.2) s (P = 0.06). Neither PT prolongation met the predefined 10% threshold for clinical significance. No significant changes in secondary outcomes were observed.
CONCLUSIONS: Chamomile tea ingestion prolongs PT. However, the clinical significance of this is unclear at this time and warrants further investigation. ClinicalTrials.gov Registration Number: NCT05272475.