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Platelet-fibrin clot formation is a key process in acute arterial thrombosis. The relationship between thrombin-induced platelet-fibrin clot strength (P-FCS) and fibrinogen levels in patients with cardiovascular disease (CVD) and COVID-19 has not been studied. In thhe current study, the contribution of fibrinogen to P-FCS has been explored in healthy subjects (n=157), patients hospitalized with COVID-19 (n=116), and patients with CVD (n=93) using thrombelastography (TEG 6s) with citrate cartridge. We found that thrombin-induced P-FCS, fibrin clot strength (F-CS) and fibrinogen levels (FLEV) were higher among patients with CVD and COVID-19 compared to HS (p<0,05 for all) and highest among patients with COVID-19. P-FCS, an established risk factor for post-PCI ischemic event occurrences, was associated with both F-CS and FLEV (R2=0.67, p<0.001 for both comparisons. These data indicate that fibrinogen levels strongly influence the viscoelastic strength of the platelet-fibrin clot, fibrinogen may be an important driving factor for arterial thrombosis in the presence of potent platelet inhibition and may be as equally important a risk factor as high platelet reactivity. Since P-FCS is significantly associated with fibrinogen levels, the role of fibrinogen as a risk factor for arterial ischemic event occurrences should be further studied to improve antithrombotic therapy personalization., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

A heightened risk for thrombosis is a hallmark of COVID-19. Expansive clinical experience and medical literature have characterized small (micro) and large (macro) vessel involvement of the venous and arterial circulatory systems. Most events occur in patients with serious or critical illness in the hyperacute (first 1-2 weeks) or acute phases (2-4 weeks) of SARS-CoV-2 infection. However, thrombosis involving the venous, arterial, and microcirculatory systems has been reported in the subacute (4-8 weeks), convalescent (> 8-12 weeks) and chronic phases (> 12 weeks) among patients with mild-to-moderate illness. The purpose of the current focused review is to highlight the distinguishing clinical features, pathological components, and potential mechanisms of venous, arterial, and microvascular thrombosis in patients with COVID-19. The overarching objective is to better understand the proclivity for thrombosis, laying a solid foundation for screening and surveillance modalities, preventive strategies, and optimal patient management., (© 2024. The Author(s).)

Genotype based personalized antiplatelet therapy in the setting of percutaneous coronary intervention (PCI) has been studied in clinical trials. Despite the demonstrated risk associated with CYP2C19 loss-of-function (LoF) carriage in clopidogrel-treated PCI patients, real-world implementation of genotyping for PCI has been low. The goal of the current study was to provide CYP2C19 genotype information to the interventionalist prior to the completion of the catheterization to facilitate immediate personalized antiplatelet therapy. Routine personalization of P2Y 12 inhibitor therapy for PCI in a community hospital cardiac catheterization laboratory by POC genotyping with the SpartanRx system was first offered in February 2017. A best practice advisory (BPA) based on the Clinical Pharmacogenetics Implementation Consortium Guideline for CYP2C19 genotype and clopidogrel therapy was placed in the electronic health record prescription medication ordering system. By December 2019, 1,052 patients had CYP2C19 genotype testing, 429 patients underwent PCI with genotype guided antiplatelet therapy, and 250 patients underwent PCI without genotype testing and received antiplatelet therapy at the discretion of the treating physician. BPA compliance was 93. 87% of LoF allele carriers were prescribed ticagrelor or prasugrel whereas 96% of non-LoF allele carriers were prescribed clopidogrel. The genotyping results were available within 1 h and made immediately available for decision making by the interventional cardiologist. POC CYP2C19 genotyping is feasible in a community hospital catheterization laboratory and is associated with high rate of best practice compliance.Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03040622., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Despite decades of investigations, the optimal assessment of the "therapeutic response" to early after loading dose of acetylsalicylic acid (ASA) remains unclear. Limited information is available on the relation between pharmacodynamic (PD) and pharmacokinetic (PK) measurements assessed immediately after ASA administration. Serial PD and PK analyses were performed immediately after a single 162 or 650 mg dose of chewed and swallowed ASA in ten healthy adults. ASA response was defined as > 95% inhibition of serum thromboxane (Tx)B 2,  < 550 aspirin reaction units (ARU) by VerifyNow Aspirin (VN) test, and ≤ 20% arachidonic acid (AA)-induced platelet aggregation (PA). Correlation analyses between PK and PD measurements and receiver operating characteristic (ROC) curve analyses were performed. ASA response measured by VN test and AA-induced PA was achieved within 30 min of ASA administration. A correlation was observed between ARU and AA-induced maximum PA (r = 0.69, p < 0.001), serum TxB 2 (r = 0.74 and p < 0.001), and serum TxB 2 inhibition (r = 0.79, p < 0.001). In ROC curve analyses, ≤ 558 ARU and ≤ 7% AA-induced PA were associated with > 95% inhibition of TxB 2 . 686 ng/ml plasma ASA cut-off point was associated with > 95% inhibition of serum TxB 2 , ≤ 7% 1 mM AA-induced PA, and ≤ 585 ARU. A modest ~ 50% inhibition of TxB 2 inhibition was associated with marked inhibition of 1 mM AA-induced platelet aggregation by LTA. Our analyses demonstrated important relationships between pharmacodynamic, and pharmacokinetic parameters measured immediately following oral ASA and cutoff values for ARU and AA-induced PA that is associated with > 95% inhibition of serum TxB 2 ., (© 2023. The Author(s).)

Background: Circadian fluctuations in thrombogenicity and hemostasis play a role in acute cardiovascular thrombotic events occurring in the early morning hours. There is a lack of data assessing thrombogenicity, platelet function, and hemodynamics to investigate diurnal variations in a high cardiovascular risk population., Methods: This was an exploratory, single-center study conducted in aspirin-treated patients with Type II Diabetes Mellitus (T2DM) (n = 37) with documented vascular disease and/or multiple cardiovascular risk factors. Hemodynamic monitoring and blood sample collection for thromboelastography (TEG) and platelet function testing were done serially at 7-9 AM (morning), 7-9 PM (evening), 11 PM-1 AM (night), and at 5-7 AM (awakening)., Results: R-value measured by TEG was shorter during awakening hours than during the night and day hours (p < 0.05). There were no changes in platelet reactivity in response to arachidonic acid, adenosine diphosphate, and collagen between time points. Pulse pressure (PP) was highest during awakening hours (p < 0.05)., Conclusion: Study findings provide a mechanistic explanation for increased thrombotic events observed in the early waking hours among diabetics with multiple cardiovascular risk factors. The role of chronotherapy in reducing coagulability and PP to improve clinical outcomes should be explored., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Tirofiban is a glycoproteine (GP) IIb/IIIa receptor antagonist, which inhibits platelet-platelet aggregation and is a potential adjunctive antithrombotic treatment in patients with acute coronary syndromes (ACS) or high-risk percutaneous coronary interventions (PCI). It is administered intravenously as a bolus followed by continuous infusion. However, the dosage recommendations in the United States (US) and European Union (EU) differ considerably. Furthermore, in routine clinical practice, deviations from the recommendations may occur. The objective of the present study was to investigate the impact of different alterations on tirofiban plasma concentrations in US and EU administration regimens and to give suggestions for delay management in clinical practice. We therefore mathematically simulated the effects of different bolus-infusion delays and infusion interruptions in different scenarios according to the renal function. Here, we provide a systematic assessment of concentration patterns of tirofiban in the US versus EU dosage regimens. We show that differences between the two regimens have important effects on plasma drug levels. Furthermore, we demonstrate that deviations from the proper administration mode affect the concentration of tirofiban. Additionally, we calculated the optimal dosage of a second bolus to rapidly restore the initial concentration without causing overdosage. In conclusion, differences in tirofiban dosing regimens between the U.S and EU and potential infusion interruptions have important effects on drug levels that may impact on degrees of platelet inhibition and thus antithrombotic effects. Thus, the findings of our modelling studies may help to explain differences in clinical outcomes observed in previous clinical trials on tirofiban., (© 2022. The Author(s).)

Diabetes mellitus (DM) is associated with a greater risk of COVID-19 and an increased mortality when the disease is contracted. Metformin use in patients with DM is associated with less COVID-19-related mortality, but the underlying mechanism behind this association remains unclear. Our aim was to explore the effects of metformin on markers of inflammation, oxidative stress, and hypercoagulability, and on clinical outcomes. Patients with DM on metformin (n = 34) and metformin naïve (n = 41), and patients without DM (n = 73) were enrolled within 48 h of hospital admission for COVID-19. Patients on metformin compared to naïve patients had a lower white blood cell count (p = 0.02), d-dimer (p = 0.04), urinary 11-dehydro thromboxane B 2 (p = 0.01) and urinary liver-type fatty acid binding protein (p = 0.03) levels and had lower sequential organ failure assessment score (p = 0.002), and intubation rate (p = 0.03), fewer hospitalized days (p = 0.13), lower in-hospital mortality (p = 0.12) and lower mortality plus nonfatal thrombotic event occurrences (p = 0.10). Patients on metformin had similar clinical outcomes compared to patients without DM. In a multiple regression analysis, metformin use was associated with less days in hospital and lower intubation rate. In conclusion, metformin treatment in COVID-19 patients with DM was associated with lower markers of inflammation, renal ischemia, and thrombosis, and fewer hospitalized days and intubation requirement. Further focused studies are required to support these findings., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

In this prospective, 3-arm, repeated-measure multicenter investigation in 280 patients with cardiovascular risk factors, platelet aggregation was measured with the novel AggreGuide A-100 ADP (A-100 ADP) and VerifyNow (VN)-PRU assays at baseline, and after United States Food and Drug Administration approved loading and 7 days maintenance doses of clopidogrel (n = 94), prasugrel (n = 43) or ticagrelor, (n = 143). Based on the predetermined cutoff values of < 4.7 platelet activity index with A-100 ADP assay to indicate antiplatelet response, more than 91% of patients met the criteria following loading and maintenance doses of prasugrel and more than 84% patients met the criteria following loading and maintenance doses of ticagrelor whereas only 32% and 51% of patients met the criteria following loading and maintenance doses of clopidogrel, respectively. The total percent agreement between the A-100 ADP and VN-PRU assays was 89%. The A-100 ADP assay, which includes whole blood in motion, performs comparably to the VN-PRU assay in a study of patients with cardiovascular risk factors treated with P2Y 12 inhibitors possessing known differences in antiplatelet potencies. Trial registration ClinicalTrials.gov Identifier: NCT3111420., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Arachidonic acid (AA)-induced platelet aggregation (PA) and serum thromboxane B 2 (TxB 2 ) inhibition are widely used to indicate cyclooxygenase-1 activity and the antiplatelet effect of acetylsalicylic acid (ASA). Despite decades of investigations, the relation between these measurements remains unclear. We sought to evaluate the relation between AA-PA and serum TxB 2 inhibition. We serially measured AA-PA (conventional aggregation), serum TxB 2, plasma ASA and salicylic acid (SA) (liquid chromatography-mass spectrometry), and urinary 11-dehydro thromboxane B 2 (u11-dh TxB 2 ) (enzyme-linked immunosorbent assay) levels at 10 times over 24 hours in seventeen healthy volunteers receiving a single dose of 162 mg chewed and swallowed ASA (n = 6), 50 mg inhaled ASA (n = 6), or 100 mg inhaled ASA (n = 5) (ClinicalTrials.gov Identifier: NCT04328883, April 1, 2020). Baseline variability was more pronounced with serum TxB 2 (31-680 ng/mL) as compared to maximal AA-PA (65-81%) and u11-dh TxB 2 (1556-4440 pg/mg creatinine). The relation between serum TxB 2 inhibition and AA-PA was stepwise; after 30-40% inhibition of serum TxB 2 , AA-PA fell to < 5%. By receiver operating characteristic curve analysis using AA-PA < 5% to define aspirin responsiveness, serum TxB2 inhibition > 49% and u11-dh TxB2 < 1520 pg/mg creatinine met the definition. Our study demonstrates a non-linear relation between serum TxB 2 inhibition and AA-PA. Aggregation was nil once TxB 2 inhibition reached > 49%. Moreover, these results suggest that the definition of > 95% inhibition of serum TxB 2 to indicate the level of platelet COX-1 inhibition needed for clinical efficacy may be overestimated and should be re-considered in future translational research investigations that attempt to link the clinical efficacy of ASA with a laboratory measurement cutoff.

Compared with Caucasian patients, East Asian patients with coronary artery disease (CAD) have demonstrated better clinical outcomes. We sought to compare the viscoelastic properties of clot formation and their impact on clinical outcomes in East Asian vs. Caucasian patients. We analyzed age- and sex-matched East Asian and Caucasian patients with stable CAD (n = 249 each). Viscoelastic properties of clot formation were assessed with thromboelastography (TEG), and 3-year clinical outcomes were recorded. Major adverse cardiovascular events (MACE) were defined as a composite of cardiovascular death, myocardial infarction, or stroke. Compared with Caucasians, East Asians showed lower platelet-fibrin clot strength (PFCS) (maximum amplitude [MA]: 61.8 ± 7.9 vs. 65.4 ± 5.0 mm, p < 0.001). In a multivariate analysis, high PFCS (defined as MA ≥ 68 mm) was significantly associated with MACE occurrence (odds ratio 6.27, 95% CI 2.41 to 16.30, p < 0.001). East Asians vs. Caucasians had lower prevalence of high PFCS (odds ratio 0.50, 95% CI 0.27 to 0.93, p = 0.028). In conclusion, this is the first study to demonstrate different viscoelastic properties of clot between East Asian and Caucasian patients with stable CAD. The platelet-fibrin clot strength was significantly associated with MACE in these patients and was significantly lower in East Asians. Future studies are warranted to further explore the mechanistic explanation and clinical importance of these findings.

Patients with peripheral artery disease (PAD) have shown the increased risk of cardiovascular (CV) morbidity and mortality. This study sought to evaluate the impact of clot strength on prevalence and major adverse CV events (MACE) of PAD in high-risk patients. We enrolled patients undergoing percutaneous coronary intervention (PCI) (n = 1667) with available platelet-fibrin clot strength [thrombin-induced maximal amplitude (MA thrombin ) measured by thromboelastography] and inflammation [high sensitivity C-reactive protein (hs-CRP)]. PAD was defined with abnormal ankle-brachial index (≤ 0.9 or > 1.4). MACE was defined as a composite of CV death, myocardial infarction or stroke. PAD was observed in 201 patients (12.1%). In the multivariate analysis, high clot strength [MA thrombin  ≥ 68 mm: odds ratio (OR) 1.70, 95% confidence interval (CI) 1.20 to 2.41, p = 0.003] and enhanced inflammation (hs-CRP ≥ 3.0 mg/L: OR 2.30, 95% CI 1.56 to 3.41, p < 0.001) were associated with PAD occurrence. During the follow-up post-PCI (median, 25 months), MACE was more frequently occurred in patients with vs. without PAD (18.7% vs. 6.4% at 3 years; hazard ratio 1.72, 95% CI 1.03 to 2.87, p = 0.039). Furthermore, combined presence of PAD and high clot strength significantly increased the risk of MACE. In conclusion, this study is the first to show the impact of clot strength on prevalence and clinical outcomes of PAD in coronary artery disease patients undergoing PCI. Whether antithrombotic strategy according to level of this biomarker can improve clinical outcomes in PAD patients deserves the further study.

The relation of device related thrombosis (DRT) and major bleeding after left atrial appendage closure (LAAC) to laboratory thrombosis and hemostasis markers has not been studied. We performed a prospective case control study to identify clinical characteristics and laboratory markers in patients who developed DRT and major bleeding following WATCHMAN LAAC. Thromboelastography, platelet aggregation (PA), urinary 11-dehydrothromboxane B 2 (UTX), fibrinogen, D-dimer, thrombin time and von Willebrand factor activity were determined at baseline, immediately following, and at 45 and 180 days post-LAAC (n = 32) and outcomes were followed for 1 year. Baseline characteristics and thrombogenic profiles of patients with and without DRT and/or BARC bleeding were compared. Mean age was 76 ± 8 years and CHADS2 VASc score was 4.4 ± 1.4. There were 3 DRTs (2 within 6 months, and 1 at 12 months), 4 Type 3A BARC bleeds, and 2 non-cardiac deaths. Patients with DRT had higher baseline thrombin-induced platelet-fibrin clot strength (68.0 ± 1.8 vs. 62.7 ± 4.7 mm, p = 0.06); FCS (35.6 ± 6.0 vs. 24.4 ± 6.6 mm, p = 0.009); and D-dimer (1712 ± 2330 vs. 283 ± 213 ng/mL, p = 0.001). At baseline, 5 patients had all 3 factors associated with high thrombotic risk and 2 experienced a DRT within 6 months. Patients with Type 3A BARC bleeding had lower baseline collagen-induced and 45-day ADP-induced PA (p < 0.01 for both). DRT following LAAC was associated with a baseline prothrombogenic profile whereas bleeding was associated with low platelet reactivity. These preliminary findings warrant further validation and have future implications on patient selection and adjunctive antithrombotic therapy following LAAC.Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03040622 .

Early assessment of thrombogenicity and antithrombotic drug effects may be important for therapeutic decision making in patients presenting with acute stroke. In this prospective, single center, pilot study, a bedside thrombelastography assay (TEG6s) was used to measure thrombogenicity and antithrombotic drug response in serial patients presenting emergently with symptoms of acute stroke (n = 90). TEG6s measures were compared against diagnosis obtained by NIH Stroke Scale/Score and imaging. Acute ischemic stroke (AIS) was diagnosed in 30 patients, intracerebral hemorrhage (ICH) in 19, transient ischemic attack (TIA) in 10 and stroke mimic (SM) in 31. Patients with AIS had a higher prevalence of A-Fib (33.3% vs. 11.6%, p = 0.01), and ACE inhibitor use (56.3% vs. 21.6%, p < 0.001) compared to combined non-AIS group. Time to initial clot formation (R) was shorter in AIS vs. TIA, ICH, and SM (p < 0.05). Comparing patients with AIS and combined non-AIS group the AUC for R was 0.83 (cut point of ≤ 4.8, sensitivity = 67%; specificity = 84%, p < 0.001). In AIS patients, 46% had suboptimal response (< 30% MA AA inhibition) to aspirin and 80% of patients on P2Y 12 therapy had high platelet reactivity (> 50% ADP-induced platelet aggregation). Patients receiving tissue plasminogen activator had significant reduction in clot strength and near complete lysis at 30 min which normalized within 2 h after treatment (p < 0.001 for both). The rapid bedside measurement of thrombogenicity and antithrombotic drug effects is feasible in patients presenting with symptoms of acute stroke. Our preliminary data suggest that AIS is associated with faster ex-vivo clot formation, and poor antiplatelet response. Future study of the TEG6s to "blueprint" hemostasis is warranted in the stroke population.

CSL112 (Apolipoprotein A-I [Human]), an infusible, plasma-derived apolipoprotein A-I, is being developed to reduce cardiovascular events following acute myocardial infarction (AMI). A predecessor compound (CSL111) demonstrated a potential antiplatelet effect. A phase 2a multicentre, randomised, single-ascending dose study in patients with stable atherosclerotic disease receiving dual antiplatelet therapy (DAPT) assessed the potential additive effects of CSL112 administration on platelet function and increase bleeding risk in the subacute period after AMI. Patients (n = 44) on aspirin (75-325 mg/day) and either clopidogrel (75 mg/day, n = 37) or prasugrel (10 mg/day, n = 7) for > 30 days alongside standard-of-care therapy were randomised to a single dose of placebo or CSL112: 1.7, 3.4, or 6.8 g. Light transmission aggregometry was used to assess platelet aggregation in response to 2 mM arachidonic acid, 5 and 20 µM adenosine diphosphate, and 4 µg/mL collagen, pre-dose (baseline) and up to 48 h post-dosing. Compared to placebo, CSL112 had no clinically meaningful time- or dose-dependent effects on maximum platelet aggregation in response to any agonist, by either dose or renal function subgroup (p > 0.05). Coagulation parameters showed little variation over time or between treatment groups (p > 0.05). CSL112, when co-administered with standard DAPT, did not significantly influence platelet aggregation in response to agonists and is, therefore, not expected to significantly increase bleeding risk when administered with antiplatelet therapies.

Aspirin is the dominant antiplatelet therapy for cardiovascular disease. Naproxen is frequently used in aspirin-treated patients and may influence the antiplatelet effect of aspirin. We evaluated the pharmacodynamic interaction (lower bound of the one-sided 95% CI for serum TxB 2 inhibition < 95%) between 220 mg immediate-release naproxen sodium (once or twice daily) and 81 mg daily immediate release aspirin at various dosing intervals. There was no interaction during the first day of concurrent treatment. After 10 days, irrespective of the timing and dose of naproxen in relation to aspirin dosing, a pharmacodynamic interaction occurred which persisted after discontinuing naproxen. In the control group (aspirin alone), the lower bound for serum TxB 2 inhibition was > 98% at all time points. The clinical relevance of these observations remains unknown and merits further investigation since over-the-counter naproxen is widely used to relieve pain by individuals taking low dose aspirin for cardioprotection., Clinical Trial Registration: NCT02229461.

High central aortic pulse pressure (CPP) and thrombin-induced platelet-fibrin clot strength (TIP-FCS) have been associated with ischemic outcomes in patients with coronary artery disease in separate studies. But, the ischemic risk associated with these factors has never been analyzed in a single study and their interrelation is unknown. The primary aim of the study was to establish cut points for CPP and TIP-FCS measured at the time of catheterization associated with long term major adverse cardiovascular events. We enrolled 334 consecutive patients undergoing cardiac catheterization and assessed thrombogenicity by thrombelastography. Patients were followed up to 3 years. The primary endpoint was a composite of cardiovascular death, myocardial infarction, and ischemic stroke and the secondary endpoint was occurrence of the primary endpoint or recurrent ischemic events requiring hospitalization. Patients with primary and secondary endpoint occurrence had higher CPP (83 ± 20 vs. 60 ± 18 mmHg, p < 0.0001; 70 ± 21 vs. 59 ± 18 mmHg, p < 0.0001, respectively) and TIP-FCS (68.5 ± 5.8 vs. 65.5 ± 5.0 mm, p = 0.008; 67.4 ± 5.9 vs. 65.2 ± 4.8 mm, p = 0.001, respectively). CPP >60 mmHg and TIP-FCS >69 mm were both independent predictors of primary endpoint occurrence (p = 0.0001 and p = 0.02, respectively). ROC analysis for CPP and TIP-FCS showed a C-statistic of 0.81 (p < 0.0001) and 0.68 (p = 0.007) for the primary endpoint, respectively. Patients with CPP >60 mmHg had higher TIP-FCS (66.8 ± 5.1 vs. 64.8 ± 5.0 mm, p < 0.001) and primary and secondary endpoint occurrence (13 vs. 1.1%, p < 0.0001 and 31.8 vs. 14.4%, p = 0.0002, respectively). CPP >60 mmHg + TIP-FCS > 69 mm was associated with a markedly increased risk of primary endpoint occurrence [HR (95% CI) 5.4(2.3-12.5), p = 0.0001]. High CPP and thrombogenicity are interrelated; each are independently associated with increased cardiovascular risk; and simultaneous presence markedly enhances risk. The mechanistic link between CPP and thrombogenicity deserves further study.

Non vitamin K oral anticoagulants (NOACs) do not require regular monitoring but information about their pharmacodynamic effect may be importantin situations like trauma, stroke oremergent surgery. Currently, no standardized point-of-care test is available to evaluate the anticoagulant effects of NOACs. We evaluated the anticoagulant effect of NOACs with the next generation point-of-care TEG assay (TEG® 6S) based on a fully-automated thrombelastography system. We used two TEG® 6S assays, the DTI assay and Anti-Factor Xa (AFXa) assay, to detect anticoagulant effects and classify NOACs. Blood from healthy volunteers (n = 26) was used to obtain a baseline reference range. Data derived from patients on factor Xa inhibitors (FXi) (rivaroxaban and apixaban) (n = 39), and direct thrombin inhibitors (DTIs) (dabigatran) (n = 25) were compared against the reference range for detection of drug effect and drug classification. TEG®6s R-time highly correlated to each NOAC. Presence of NOACs caused elongation of R-time on the AFXa assay compared to the reference range (4.3 ± 1.7 vs. 1.3 ± 0.3 min. for FXi, p < 0.001 and 3.5 ± 1.2 vs. 1.3 ± 0.3 min. for DTI, p < 0.001). R-time on the DTI assay was elongated only in presence of a DTI (3.4 ± 1.0 vs. 1.5 ± 0.2 min, p < 0.001). The cutoff for detection of a DTI effect was an R time of 1.9 min and for anti-Xa effect was 1.95 min. For detection of NOAC therapy, there was ≥92% sensitivity and ≥95% specificity. The automated TEG®6s NOAC assay may be an effective tool to identify an anticoagulant effect from NOAC therapy and facilitate care of patients with bleeding or at risk of bleeding in the event of needing emergency surgery.

Obese individuals, despite having increased cardiovascular (CV) risk factors experience adverse CV outcomes less frequently than non-obese. Little is known about association of long-term weight gain to development of coronary artery disease (CAD), inflammation and thrombogenicity. 418 consecutive patients with suspected CAD undergoing elective cardiac catheterization were included in a sub-analysis of the multi analyte, thrombogenic, and genetic markers of atherosclerosis study. Maximum weight gain (MWG) was defined as percentage increase in weight since age 17 years to year of heaviest weight and categorized as: minor (<30 %), moderate (30-47 %), severe (>47-69 %), and extreme (>69 %). Lipid profiling was determined by vertical density gradient ultracentrifugation, thrombin-induced platelet fibrin clot strength (TIP-FCS) by thrombelastography, and urinary 11-dehydrothromboxane B2 (11-dhTxB2) by ELISA. CAD severity was defined as minimal (<20 %), moderate (20-75 %), and severe (>75 %) luminal diameter obstruction of any major coronary vessel. The mean MWG was 53 ± 33 %. Extreme MWG group had a higher incidence of diabetes mellitus (48 %), hypertension (81 %), depression (25 %), and were most often female (60 %) (p < 0.05 for all). In women, CAD severity was inversely associated to MWG (p = 0.05), whereas in men no such association was observed (p = 0.18). TIP-FCS increased in a stepwise fashion with MWG (p = 0.001). 11-dTxB2 levels were higher in the extreme MWG group, regardless of lipid lowering therapy (p < 0.05). Our data suggest that maximal weight gain since age 17 years is associated with heightened thrombogenicity, inflammation and a poorer lipid profile but not an increased risk for severe CAD development.