Research and Practice in Thrombosis and Haemostasis最新文献

Background

Polyphenols have been shown to decrease oxidative stress and modulate glycemic response. Nevertheless, their effect on platelet bioenergetics and clot structure in diabetes and hyperglycemia is unknown.

Objectives

To investigate the effect of polyphenols on human platelet bioenergetics and its subsequent effect on clot structure in normoglycemia vs acute hyperglycemia in vitro.

Methods

Four polyphenols (resveratrol, hesperetin, epigallocatechin gallate [EGCG], and quercetin) were selected for initial analysis. Healthy volunteers’ isolated platelets/platelet-rich plasma were treated with 5 or 25 mM glucose to represent normoglycemia and acute hyperglycemia, respectively. Platelet-derived reactive oxygen species (ROS), citrate synthase activity (mitochondrial density), mitochondrial calcium flux, and mitochondrial respiration were performed following exposure to polyphenols (20 µM, 1 hour) to determine their effects on platelet bioenergetics. Procoagulant platelets (annexin V) and fibrin fiber density (Alexa Fluor-488 fibrinogen; Invitrogen) were analyzed by laser scanning confocal microscopy, while clot porosity was determined using platelet-rich plasma following exposure to polyphenols (20 µM, 20 minutes).

Results

Acute hyperglycemia increased ROS, mitochondrial calcium flux, maximal respiration, and procoagulant platelet number. Resveratrol, quercetin, and EGCG reduced platelet ROS in normoglycemic and acute hyperglycemic conditions. Mitochondrial density was decreased by quercetin and EGCG in normoglycemia. Resveratrol and EGCG reduced mitochondrial calcium flux in acute hyperglycemia. Resveratrol also decreased procoagulant platelet number and attenuated oxygen consumption rate in normoglycemia and acute hyperglycemia. No effect of hyperglycemia or polyphenols was observed on fibrin fiber density or clot pore size.

Conclusion

Our results suggest polyphenols attenuate increased platelet activity stemming from hyperglycemia and may benefit thrombosis-preventative strategies in patients with diabetes.

Background

Testing for lupus anticoagulant (LA) is not recommended in case of inflammation as C-reactive protein (CRP) can interfere in vitro with the phospholipids present in the activated partial thromboplastin time test used to detect an LA. However, the potential interference of an acute phase protein (ie, CRP) in LA testing using the dilute Russell’s viper venom (DRVV) test is poorly studied.

Objectives

To study the effect of inflammation, as evidenced by increased CRP levels, on DRVV tests.

Methods

First, a retrospective analysis (2013-2023) was performed: data on all LA workups were retrieved, and the association between CRP levels and DRVV screen, mix, and confirm clotting times was studied. Second, data on DRVV panels and CRP levels were extracted from 2 prospective studies involving intensive care unit patients to study the association between both variables. Third, CRP was added to normal pooled plasma at 6 relevant concentrations (up to 416 mg/L) to study the association between CRP itself and DRVV coagulation times.

Results

In the retrospective analysis, DRVV screen and confirm clotting times significantly increased as CRP increased (increase of 0.11 seconds and 0.03 seconds per 1 mg/L increase of CRP level, respectively). In the prospective analysis, only DRVV screen was prolonged with high CRP levels (increase of 0.06 seconds for a 1 mg/L increase in CRP level); DRVV screen/confirm ratio was also increased with high CRP levels. In vitro, the addition of CRP did not significantly increase any DRVV clotting times.

Conclusion

LA testing should be performed with much caution in the presence of inflammation as it may be associated with prolongation of both activated partial thromboplastin time and DRVV clotting times.

Background

Clinical evidence suggests that anemia exacerbates traumatic bleeding and worsens outcomes.

Objectives

To study the influence of iron deficiency anemia on traumatic bleeding, coagulopathy, and mortality.

Methods

C57BL/6J mice received an iron-deficient diet (8 weeks; ±1 mg intraperitoneal iron dextran 2 weeks before trauma). Control mice received a normal diet. Iron deficiency anemia was confirmed by hematocrit, red cell indices, and liver iron. Mice received saline or tranexamic acid (TXA; 10 mg/kg) just before liver laceration. Blood loss, coagulopathy (activated partial thromboplastin time, factor [F]II, FV, FVIII, FX, and fibrinogen), D-dimer, thrombin-antithrombin complexes, and plasmin-alpha-2-antiplasmin complexes were analyzed at 15 and 60 minutes, and a cytokine panel was performed at 60 minutes and 6 hours after trauma. Survival was monitored for 7 days.

Results

Compared with nonanemic mice, anemic mice had lower hematocrit and hepatic iron content. Anemic mice experienced higher blood loss compared with nonanemic mice, which was reduced by TXA. Both groups developed traumatic coagulopathy characterized by activated partial thromboplastin time prolongation, thrombin-antithrombin complex formation, and depletion of FV, FVIII, and fibrinogen. TXA corrected the coagulopathy. However, plasmin-alpha-2-antiplasmin complex formation and D-dimers, markers of fibrinolysis, were higher in anemic mice and were not corrected by TXA. Seven-day survival was low in anemic mice, and rescued by TXA, but high in nonanemic mice without additional improvement by TXA. Among cytokines, only interleukin-6 increased, which was prevented by TXA most notably in anemic mice.

Conclusion

These observations provide first and critical proof-of-principle evidence that anemia accelerates traumatic bleeding and increases mortality, which could be rescued by anemia correction (parenteral iron) or periprocedural TXA.

Severe congenital protein C deficiency (SCPCD) is a rare disorder associated with life-threatening purpura fulminans and disseminated intravascular coagulation that typically present within hours after birth. Treatment options for patients with SCPCD include replacement therapy with a plasma-derived protein C concentrate. In this targeted literature review, we summarize information on the use of protein C concentrate as long-term prophylaxis (>1 week of treatment) for patients with SCPCD. In total, 18 publications were included in the review, of which 15 were case studies. Treatment with protein C concentrate (Ceprotin; Baxalta US Inc, a Takeda company; Takeda Manufacturing Austria AG) was reported in 11 publications, and treatment with protein C concentrate (Protexel; LFB Biomedicaments) was reported in 2 publications. One publication reported on both Ceprotin and Protexel. Details of protein C concentrate treatment regimens, including the dose, administration frequency, and route of administration, were reported in 11 publications. Dosing regimens varied across all 11 publications, possibly due to different protein C trough levels among patients or the administration of concomitant medications. Seven of the 11 publications reported on patients who initially received intravenous protein C concentrate and subsequently switched to subcutaneous administration. Treatment outcomes with protein C concentrate were generally favorable, including the prevention of coagulopathy and thrombosis and the healing of cutaneous lesions. Three adverse events in 1 publication were identified as being possibly related to Ceprotin administration. Although published data are limited, this review provides valuable insights into the treatment of patients with SCPCD in clinical practice, including protein C concentrate dosing regimens, administration routes, and associated clinical outcomes.

Background

Pulmonary embolism (PE) is a potentially life-threatening condition. Admission and treatment in the intensive care unit (ICU) is an important element in critically ill PE patients.

Objectives

We aimed to identify risk factors for ICU admission and differences in patient profiles regarding risk factors and comorbidities between PE patients who had to be admitted to an ICU and those who were treated in a normal ward without ICU.

Methods

We used the German nationwide inpatient sample to analyze all hospitalizations of PE patients in Germany from 2016 to 2020 stratified for ICU admission.

Results

Overall, 484,859 hospitalized PE patients were treated in German hospitals from 2016 to 2020. Among these, 92,313 (19.0%) were admitted to ICU. Patients treated in ICU were younger (69.0 [IQR, 58.0-78.0] vs 72.0 [IQR, 60.0-80.0] years; P < .001) and had higher prevalence of cardiovascular risk factors and comorbidities. In-hospital case fatality rate was elevated in PE patients treated in ICU (22.7% vs 10.7%; P < .001), and ICU admission was independently associated with increased in-hospital case fatality (odds ratio [OR], 2.54; 95% CI, 2.49-2.59; P < .001). Independent risk factors for ICU admission comprised PE with imminent or present decompensation (OR, 3.30; 95% CI, 3.25-3.35; P < .001), hemodynamic instability (OR, 4.49; 95% CI, 4.39-4.59; P < .001), arterial hypertension (OR, 1.20; 95% CI, 1.18-1.22; P < .001), diabetes mellitus (OR, 1.16; 95% CI, 1.14-1.18; P < .001), obesity (OR, 1.300; 95% CI, 1.27-1.33; P < .001), surgery (OR, 2.55; 95% CI, 2.50-2.59; P < .001), stroke (OR, 2.86; 95% CI, 2.76-2.96; P < .001), pregnancy (OR, 1.45; 95% CI, 1.21-1.74; P < .001), heart failure (OR, 1.74; 95% CI, 1.71-1.77; P < .001), atrial fibrillation/flutter (OR, 1.69; 95% CI, 1.66-1.73; P < .001), chronic obstructive pulmonary disease (OR, 1.21; 95% CI, 1.18-1.24; P < .001), and renal failure (OR, 1.92; 95% CI, 1.88-1.95; P < .001).

Conclusion

ICU treatment is an important element in the treatment of PE patients. Besides hemodynamic compromise, cardiovascular risk factors, stroke, pregnancy, and cardiopulmonary as well as renal comorbidities were independent predictors of ICU admission. Necessity of ICU admission was afflicted by increased case fatality.

Cardiovascular diseases (CVDs) are the leading cause of mortality globally while also contributing to excess health system costs. Significant advancements have been made in the understanding and prevention of deaths from CVD. In addition to risk factor modifications, one of the key developments in this area is the appropriate prescribing of antiplatelet medications for secondary prevention of CVD. With the advent of vascular devices, there has been an increased use of potent antiplatelet agents to mitigate thrombosis risk. A well-recognized, albeit rare complication of antiplatelet drugs is the heightened risk of bleeding. This adverse effect is particularly relevant when a patient receiving these medications may require an urgent surgery. In addition, for elective surgeries, although these drugs can be withheld, there may be some situations when interruption of antiplatelet agents, even for short duration, may lead to thrombotic events. There are no robust guidelines on how to manage these clinical scenarios, although there have been some important studies published recently in this area. In this review, we provide our approach to patients on antiplatelet drugs who may require urgent surgeries or surgical interventions.