Tissue factor activated thromboelastography correlates to clinical signs of bleeding in dogs

The Small Animal Hospital, Department of Small Animal Clinical Sciences, Faculty of Life Sciences, University of Copenhagen, Frederiksberg DK-1870, Denmark
The Veterinary Journal (Impact Factor: 2.17). 01/2009; DOI: 10.1016/j.tvjl.2007.08.022

ABSTRACT The ability of a laboratory assay to correlate to clinical phenotype is crucial for the accurate diagnosis and monitoring of haemostasis and is therefore challenging with currently used routine haemostasis assays. Thromboelastography (TEG) is increasingly used to evaluate haemostasis in humans and may well be of value in the workup of dogs suspected of having a haemostatic disorder. This study was undertaken to evaluate prospectively how tissue factor (TF) activated TEG correlated to clinical signs of bleeding in dogs, compared to a routine coagulation profile. A prospective case-control study was performed over a 2 year period from 2004–2006. Eligible dogs were those where the primary clinician requested a coagulation profile to evaluate haemostasis. The dogs were simultaneously evaluated with a TF-activated TEG assay. Twenty-seven dogs, characterised as hypo-coagulable based on the TEG parameter G (<3.2K dyn/cm2), were included in the study as cases. Size matched control groups of TEG normo- (G = 3.2K–7.2K dyn/cm2) and hyper-coagulable (G > 7.2K dyn/cm2) dogs were selected retrospectively from the eligible dogs. For all dogs, clinical signs of bleeding were noted at time of analysis.There were statistically significant differences between all TEG values of hypo- and normo- and hyper-coagulable dogs. Thromboelastography correctly identified dogs with clinical signs of bleeding with a positive predictive value (PPV) of 89% and a negative predictive value (NPV) of 98% based on G alone. In comparison, the coagulation profile had a PPV between 50–81% and a NPV between 92–93% for detection of bleeding, depending on the observer. In conclusion, a TF-activated TEG G value < 3.2K dyn/cm2 correctly identified dogs with clinical signs of bleeding with very high PPV and NPV, irrespective of observer. The findings strongly suggest that TF- activated TEG may be of value in the workup of dogs suspected of having a haemostatic disorder.

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    • "The inflammatory response to infection can activate the coagulation system via complex interactions and can result in a consumptive coagulopathy (Esmon et al., 1999; Laforcade et al., 2003; Weiss and Rashid, 1998). Coagulation derangement, specifically hypercoagulability, is considered likely in a number of systemic diseases affecting small animals (Donahue and Otto, 2005; Kristensen et al., 2008; Otto et al., 2000; Wiinberg et al., 2008, 2009). If uncontrolled, the hypercoagulable state may lead to DIC, which has been identified as a major risk factor for poor outcome in both human and canine medicine (Laforcade et al., 2003; Weiss and Rashid, 1998). "
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    ABSTRACT: The inflammatory response to infection can activate the coagulation system via complex interactions. If uncontrolled, this may lead to a consumptive coagulopathy, a major risk factor for a poor clinical outcome. This prospective observational study was conducted to determine whether consumptive coagulopathy in dogs with Babesia rossi infection is related to mortality. Seventy-two client-owned dogs diagnosed with canine babesiosis were included. Diagnosis was confirmed by polymerase chain reaction and reverse line blot and dogs co-infected with Babesia vogeli or Ehrlichia canis were excluded. Blood samples were collected at admission. Coagulation factor-, antithrombin (AT)-, and protein C (PC)-activity, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and D-dimer concentrations were measured. The mortality rate was 18% (13/72 dogs) and the median activities of all the coagulation factors were significantly lower in the non-survivors compared to the survivors. Median PT and aPTT were significantly longer in the non-survivors compared to the survivors. Median AT activity was not significantly different but median PC activity was significantly decreased in the non-survivors. Median D-dimer concentrations were significantly higher in non-survivors compared to survivors. This study showed that dogs that died from B. rossi infection had a more severe consumptive coagulopathy compared to survivors, characterized by procoagulant activation, inhibitor consumption, and increased fibrinolytic activity.
    The Veterinary Journal 10/2012; DOI:10.1016/j.tvjl.2012.09.009 · 2.17 Impact Factor
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    • "Because of its ability to evaluate cell-to-protein interaction during clot formation, TEG has been proposed as a useful tool to detect hypercoagulability in dogs (Otto et al., 2000; Donahue and Otto, 2005). TEG is a sensitive tool closely correlated with the clinical phenotype in selected hemostatic disorders (Wiinberg et al., 2009). We propose recalcified ⇑ Corresponding author at: Department of Small Animal Clinical Sciences and Veterinary Teaching Hospital, Michigan State University, East Lansing, MI 48824, USA. "
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    ABSTRACT: Hemostatic abnormalities were investigated in 32 dogs with carcinoma and 19 age-matched healthy dogs. Thromboelastography, hemostasis profile (i.e. prothrombin time [PT], activated partial thromboplastin time [aPTT], fibrinogen concentration), platelet count (PLT), thrombin-antithrombin complexes (TAT), and plasminogen activator inhibitor-1 (PAI-1) activity were evaluated. Dogs with carcinomas had faster thrombus generation (TEG(TG), a mathematic value obtained from the first derivate of the thromboelastographic tracing; 834.8±91.1 vs. 707.8±75.8mm/min; mean±SD), increased fibrinogen concentration (276 vs. 151mg/dL), and PLT (425 vs. 324U×10(9)/L), but had decreased PAI-1 activity (15.7 vs. 26.2IU/mL).The most common hemostatic abnormalities found in carcinoma dogs were hypercoagulability (TEG(TG)>mean+2 SD of healthy dogs) and thrombocytosis (PLT>424×10(9)U/L) in 46% of cases, and hyperfibrinogenemia (fibrinogen >384mg/dL) in 32% of cases. Disseminated intravascular coagulation was uncommon and the extent of disease was not correlated with hypercoagulability. TEG(TG) showed good correlation with fibrinogen (r=0.80) and hyperfibrinogenemia seems to be a main factor of the hypercoagulable state in carcinoma dogs. In conclusion, TEG(TG) is a valid parameter to diagnose hypercoagulability.
    The Veterinary Journal 03/2011; 190(2):e78-83. DOI:10.1016/j.tvjl.2011.02.025 · 2.17 Impact Factor
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    • "Thromboelastometry (TEM) investigates the coagulation process by evaluating the viscoelastic properties of the blood clot from its formation to fibrinolysis [5]. It is widely employed in human medicine, and recently it has been validated in many species including equine [6] [7] [8] [9]. TEM could thus be a useful and noninvasive tool to obtain early information about the haemostatic profile in horses affected by EIPH. "
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    ABSTRACT: Exercise-induced pulmonary hemorrhage (EIPH) commonly occurs in race horses. Thromboelastometry (TEM) investigates the whole hemostatic process by evaluating the viscoelastic properties of the blood clot from its formation to fibrinolysis. The aim of this study was to assess whether horses with EIPH have abnormal thromboelastometric profiles. Intrinsic and extrinsic pathways, fibrinogen activity and fibrinolysis were investigated by TEM before and after the race in negative controls and in horses on which EIPH was confirmed by bronchoscopy. Compared with controls, horses with EIPH had an increased coagulability in both pre- and postrace samplings, especially for the intrinsic pathway and for the fibinrolytic activity. These results suggest that coagulation is preactivated in horses prone to develop EIPH, possibly due to recent or recurrent hemorrhage.
    09/2010; 2010. DOI:10.4061/2010/945789
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