Obesity is associated with postinjury hypercoagulability

Exposure to statin therapy decreases the incidence of venous thromboembolism after trauma

INTRODUCTION

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in trauma patients, despite chemoprophylaxis. Statins have been shown capable of acting upon the endothelium. We hypothesized that statin therapy in the pre- or in-hospital settings leads to a decreased incidence of VTE.

METHODS

We conducted a retrospective cohort study of injured patients who received statin therapy pre- or in-hospital. Adult, highest-level trauma activation patients admitted from January 2018 to June 2022 were included. Patients on prehospital anticoagulants, had history of inherited bleeding disorder, and who died within the first 24 hours were excluded. Statin users were matched to nonusers by statin use indications including age, current heart and cardiovascular conditions and history, hyperlipidemia, injury severity, and body mass index. Time to in-hospital statin initiation and occurrence of VTE and other complications within 60 days were collected. Differences between groups were determined by univariate, multivariable logistic regression, and Cox proportional hazard analyses.

RESULTS

Of 3,062 eligible patients, 79 were statin users, who were matched to 79 nonusers. There were no differences in admission demographics, vital signs, injury pattern, transfusion volumes, lengths of stay, or mortality between groups. The overall VTE incidence was 10.8% (17 of 158). Incidence of VTE in statin users was significantly lower (3%) than nonusers (19%; p = 0.003). Differences between statin users and nonusers were observed for rates of deep vein thrombosis (0% vs. 9%), pulmonary embolism (3% vs. 15%), and sepsis (0% vs. 5%). Exposure to statins was associated with an 82% decreased risk of developing VTE (hazard ratio, 0.18; 95% confidence interval, 0.04-0.86; p = 0.033).

CONCLUSION

Statin exposure was associated with decline in VTE and lower individual rates of deep vein thrombosis, pulmonary embolism, and sepsis. Our findings indicate that statins should be evaluated further as a possible adjunctive therapy for VTE chemoprophylaxis after traumatic injury.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level IV.

Associations of exposure to disinfection by-products with blood coagulation parameters among women: Results from the Tongji reproductive and environmental (TREE) study

BACKGROUND

Experimental studies have shown that disinfection byproducts (DBPs) induce coagulotoxicity, but human evidence is scarce.

OBJECTIVE

This study aimed to explore the relationships of DBP exposures with blood coagulation parameters.

METHODS

Among 858 women from the Tongji Reproductive and Environmental (TREE) study, urinary dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) were detected as internal biomarkers of DBP exposures. We measured activated partial thromboplastin time (APTT), fibrinogen (Fbg), international normalized ratio (INR), prothrombin time (PT), and thrombin time (TT) as blood coagulation parameters. Multivariable linear regression models were utilized to estimate the relationships between urinary DCAA and TCAA and blood coagulation parameters. The effect modifications by demographic and lifestyle characteristics were further explored.

RESULTS

Elevated tertiles of urinary DCAA concentrations were associated with increased PT and INR (11.29%, 95% CI: 1.66%, 20.92% and 0.99%, 95% CI: 0.08%, 1.90% for the third vs. first tertile, respectively; both P for trends < 0.05). Stratification analysis showed that the positive associations were only observed among younger (< 30 years), leaner (body mass index < 24.0 kg/m2), and non-passive smoking women. Moreover, elevated tertiles of urinary TCAA concentrations in positive associations with PT and INR were observed among younger women (17.89%, 95% CI: 2.50%, 33.29% and 1.82%, 95% CI: 0.34%, 3.30% for the third vs. first tertile, respectively; both P for trends < 0.05) but not among older women (both P for interactions < 0.05).

CONCLUSION

Higher levels of urinary DCAA and TCAA are associated with prolonged clotting time among women.

Adiposity and Coagulation: Predicting Postinjury Coagulation With Advanced Imaging Analysis

INTRODUCTION

Anatomic distribution of adipose tissue has demonstrated variable associations with hypercoagulability. Utilizing a retrospective analysis of a previously enrolled prospective cohort, we assessed computed tomography (CT) scan-based anthropometric and volumetric measures of adiposity as predictors of postinjury hypercoagulability.

METHODS

Segmentation analysis of arrival CT scans in significantly injured patients at a single level-I trauma center enrolled from December 2017 to August 2021 were analyzed for anthropometric indices of waist circumference (WC) and sagittal abdominal diameter (SAD), and volumetric parameters of visceral adipose tissue, superficial/deep subcutaneous adipose tissue, psoas/paravertebral muscle volume, and abdominal wall muscle volume. Associations with thromboelastography (TEG) were explored.

RESULTS

Data from 91 patients showed strong correlations between body mass index and standard anthropometric measures of WC and SAD (P < 0.001); calculated volumes of subcutaneous adipose tissue and visceral adipose tissue (P < 0.001); and ratios of subcutaneous adipose:psoas muscle (SP ratio) and visceral adipose:psoas muscle ratio (both with P < 0.001, respectively). Correlation between TEG maximal amplitude (MA) and body mass index and SAD were not significant, with only weak correlation between TEG-MA and WC (r = 0.238, P = 0.041). Moderate but significant correlations existed between SP ratio and TEG-MA (r = 0.340, P = 0.005), but not visceral adipose:psoas muscle ratio (r = 0.159, P = 0.198). The relationship between TEG-MA and SP ratio remained significant when adjusted for injury severity score and lactate level (b = 0.302, P = 0.001).

CONCLUSIONS

SP ratio is more strongly correlated with TEG-MA than standard obesity measures, and independently predicts increasing clot strength/stability after injury. Coagulation-relevant measures of sarcopenic obesity can be measured on CT scan, and may be used to optimize thromboprophylaxis strategies for obese injured patients.

The association between body mass index and postpartum hemorrhage after cesarean delivery

We aimed to evaluate the association between obesity and postpartum hemorrhage (PPH) after cesarean delivery (CD). This was a retrospective cohort study using a multicenter database of 20 hospitals in the United States. We analyzed 27,708 patients undergoing CD from 2015 to 2019. The exposure of interest was BMI, and the primary outcome was PPH (estimated blood loss [EBL] ≥ 1000 mL). Simple logistic regression was used to evaluate the relationship between obesity and intrapartum complications. Multivariable logistic regression was used to adjust for any confounding demographic variables. Hosmer and Lemeshow's purposeful selection algorithm was adapted to develop a multivariable logistic regression model of PPH. Analyses were conducted using STATA 16.1 (College Station, Texas) with p ≤ 0.05 considered significant. BMI exerted a significant effect on the frequency of PPH (p = 0.004). Compared to patients with BMI 18.5-24.9 kg/m2, patients with BMI between 25 and 59.9 kg/m2 had an increased odds of PPH. The odds of PPH in patients with BMI > 60 kg/m2 was not increased compared to patients with BMI 18.5-24.9 kg/m2. Obesity was associated with a decreased odds of blood transfusion (aOR 0.73, 95% CI 0.55-0.97). In conclusion, higher BMI was associated with PPH yet a lower odds of transfusion after CD.

Factor VIII: A Dynamic Modulator of Hemostasis and Thrombosis in Trauma

A trace amount of thrombin cleaves factor VIII (FVIII) into an active form (FVIIIa), which catalyzes FIXa-mediated activation of FX on the activated platelet surface. FVIII rapidly binds to von Willebrand factor (VWF) after secretion and becomes highly concentrated via VWF-platelet interaction at a site of endothelial inflammation or injury. Circulating levels of FVIII and VWF are influenced by age, blood type (nontype O > type O), and metabolic syndromes. In the latter, hypercoagulability is associated with chronic inflammation (known as thrombo-inflammation). In acute stress including trauma, releasable pools of FVIII/VWF are secreted from the Weibel-Palade bodies in the endothelium and then augment local platelet accumulation, thrombin generation, and leukocyte recruitment. Early systemic increases of FVIII/VWF (>200% of normal) levels in trauma result in a lower sensitivity of contact-activated clotting time (activated partial thromboplastin time [aPTT] or viscoelastic coagulation test [VCT]). However, in severely injured patients, multiple serine proteases (FXa plasmin and activated protein C [APC]) are locally activated and may be systemically released. Severity of traumatic injury correlates with prolonged aPTT and elevated activation markers of FXa, plasmin, and APC, culminating in a poor prognosis. In a subset of acute trauma patients, cryoprecipitate that contains fibrinogen, FVIII/VWF, and FXIII is theoretically advantageous over purified fibrinogen concentrate to promote stable clot formation, but comparative efficacy data are lacking. In chronic inflammation or subacute phase of trauma, elevated FVIII/VWF contributes to the pathogenesis of venous thrombosis by enhancing not only thrombin generation but also augmenting inflammatory functions. Future developments in coagulation monitoring specific to trauma patients, and targeted to enhancement or inhibition of FVIII/VWF, are likely to help clinicians gain better control of hemostasis and thromboprophylaxis. The main goal of this narrative is to review the physiological functions and regulations of FVIII and implications of FVIII in coagulation monitoring and thromboembolic complications in major trauma patients.

The risk of thromboembolic events with early intravenous 2- and 4-g bolus dosing of tranexamic acid compared to placebo in patients with severe traumatic bleeding: A secondary analysis of a randomized, double-blind, placebo-controlled, single-center trial

BACKGROUND

Screening for the risk of thromboembolism (TE) due to tranexamic acid (TXA) in patients with severe traumatic injury has not been performed in randomized clinical trials. Our objective was to determine if TXA dose was independently-associated with thromboembolism.

STUDY DESIGN AND METHODS

This is a secondary analysis of a single-center, double-blinded, randomized controlled trial comparing placebo to a 2-g or 4-g intravenous TXA bolus dose in trauma patients with severe injury. We used multivariable discrete-time Cox regression models to identify associations with risk for thromboembolic events within 30 days post-enrollment. Event curves were created using discrete-time Cox regression.

RESULTS

There were 50 patients in the placebo group, 49 in the 2-g, and 50 in the 4-g TXA group. In adjusted analyses for thromboembolism, a 2-g dose of TXA had an hazard ratio (HR, 95% confidence interval [CI]) of 3.20 (1.12-9.11) (p = .029), and a 4-g dose of TXA had an HR (95% CI) of 5.33 (1.94-14.63) (p = .001). Event curves demonstrated a higher probability of thromboembolism for both doses of TXA compared to placebo. Other parameters independently associated with thromboembolism include time from injury to TXA administration, body mass index, and total blood products transfused.

DISCUSSION

In patients with severe traumatic injury, there was a dose-dependent increase in the risk of at least one thromboembolic event with TXA. TXA should not be withheld, but thromboembolism screening should be considered for patients receiving a dose of at least 2-g TXA intravenously for traumatic hemorrhage.

Thromboelastography in obese horses with insulin dysregulation compared to healthy controls

BACKGROUND

Both obesity and metabolic syndrome are associated with hypercoagulability in people, increasing the risk of cardiovascular disease and thromboembolic events. Whether hypercoagulability exists in obese, insulin-dysregulated horses is unknown.

HYPOTHESIS/OBJECTIVES

To determine if coagulation profiles differ between healthy horses and those with obesity and insulin dysregulation.

ANIMALS

Fifteen healthy horses (CON) and 15 obese, insulin-dysregulated horses (OBID). Individuals were university or client owned.

METHODS

Case-control study. Obesity was defined as a body condition score (BCS) ≥7.5/9 (modified Henneke scale). Insulin dysregulation status was assessed by an oral sugar test (OST). Kaolin-thromboelastography and traditional coagulation variables were compared between groups. The direction and strength of the association between coagulation variables and BCS and OST results were determined using Spearman's correlation.

RESULTS

Thromboelastography variables MA (OBID: 69.5 ± 4.5 mm; CON: 64.8 ± 4.3 mm; P = .007) and G-value (OBID: 11749 ± 2536 dyn/m2 ; CON: 9319 ± 1650 dyn/m2 ; P = .004) were higher in OBID compared to CON. Positive correlations between MA and BCS (R = 0.45, P = .01) and serum insulin (T0 : R = 0.45, P = .01; T60 : R = 0.39, P = .03), and G-value and BCS (R = 0.46, P = .01), and serum insulin (T0 : R = 0.48, P = .007; T60 : R = 0.43, P = .02; T90 : R = 0.38, P = .04) were present.

CONCLUSIONS AND CLINICAL IMPORTANCE

Obese, insulin-dysregulated horses are hypercoagulable compared to healthy controls.

Thromboelastography-Based Profiling of Coagulation Status in Patients Undergoing Bariatric Surgery: Analysis of 422 Patients

INTRODUCTION/PURPOSE

Some clinical indicators suggest hypercoagulability/hyperaggregability in patients with morbid obesity. Thromboelastography (TEG®) has been used to profile coagulation status in surgical patients. We aimed to assess coagulation profiles in patients with morbid obesity undergoing bariatric surgery by correlating demographic and patient characteristics to pre-operative TEG® values.

MATERIALS AND METHODS

Pre-operative TEG® values from 422 patients undergoing bariatric surgery were evaluated. TEG® results were analyzed by gender, use of medications known to alter the coagulation profile, and body mass index (BMI).

RESULTS

Patients have a mean of 45.03 ± 11.8 years, female (76.3%), and with a mean BMI of 42 kg/m ¹. The overall coagulation profile of female patients was significantly different from males, even in the sub-cohort without use of medications known to alter coagulation. The majority of patients (94%) with a G value > 15 dynes/cm ¹ (clot strength) were female. In females, there was no association between BMI and TEG® values; however, in men, there was a statistically significant difference in TEG® values for those with BMI < 40 kg/m ¹ compared to those with BMI > 50 kg/m².

CONCLUSIONS

TEG®-based analysis of coagulation profiles offers unique insights. Compared to laboratory normal values (R time, angle, maximal amplitude, and G values), patients with morbid obesity may have a tendency for hypercoagulability/hyperaggregability, with mean values at the higher limit. A significant hypercoagulable difference in TEG® values was identified in female as compared to male patients. Male patients with a BMI greater than 50 kg/m² were also found to be increasingly hypercoagulable.

Chinese expert consensus on diagnosis and treatment of trauma-induced hypercoagulopathy

Trauma-induced coagulopathy (TIC) is caused by post-traumatic tissue injury and manifests as hypercoagulability that leads to thromboembolism or hypocoagulability that leads to uncontrollable massive hemorrhage. Previous studies on TIC have mainly focused on hemorrhagic coagulopathy caused by the hypocoagulable phenotype of TIC, while recent studies have found that trauma-induced hypercoagulopathy can occur in as many as 22.2-85.1% of trauma patients, in whom it can increase the risk of thrombotic events and mortality by 2- to 4-fold. Therefore, the Chinese People's Liberation Army Professional Committee of Critical Care Medicine and the Chinese Society of Thrombosis, Hemostasis and Critical Care, Chinese Medicine Education Association jointly formulated this Chinese Expert Consensus comprising 15 recommendations for the definition, pathophysiological mechanism, assessment, prevention, and treatment of trauma-induced hypercoagulopathy.