[Heparin-Induced Thrombocytopenia].

The extensive use of therapeutic doses of heparin to prevent thrombosis in critically ill patients with COVID-19 during the pandemic has led to an increased incidence of bleeding and heparin-induced thrombocytopenia (HIT). In addition, the introduction of the AstraZeneca and Johnson&Johnson vaccines against COVID-19 into clinical practice was associated with the development of a rare but very severe, adverse thrombotic complication, vaccine-induced immune thrombotic thrombocytopenia (VITT). Thrombotic complications of VITT turned out to be similar to HIT both clinically and pathophysiologically. HIT is a potentially fatal immune-mediated adverse drug response that results in emergence of antibodies that activate platelets in the presence of heparin. HIT is characterized by a high incidence of venous and arterial thromboses, often with fatal outcomes. Currently, there are clearly defined international guidelines for the diagnosis, treatment and prevention of HIT. In case of thrombotic complications, non-heparin anticoagulants should be used.

Massive arterial and venous thrombosis from smouldering multiple myeloma: further evidence for monoclonal gammopathy of thrombotic significance.

A man in his 40s presented to the emergency department after 2 weeks of abdominal pain and bloating. Radiological investigations revealed multiple unusual sites of thrombosis, including large thrombi in his portal and mesenteric veins, and a left ventricular thrombus with resultant embolic infarcts to his spleen, kidneys, coronary arteries and brain. Standard causes of underlying thrombophilia were excluded. A serum protein electrophoresis and serum-free light chains, with subsequent bone marrow biopsy, lead to the diagnosis of smouldering multiple myeloma (sMM), albeit an unusual presentation with severe clinical sequelae. Although sMM is known to be associated with an increased risk of venous thromboembolism, it is not recognised to cause thrombosis in both venous and arterial vascular beds simultaneously. Physicians encountering patients with multiple thrombi in unusual vascular beds without clear aetiology should consider an underlying monoclonal gammopathy in their list of differentials.

Platelet mass cytometry reveals dysregulation of prothrombotic pathways in essential thrombocythemia.

Thromboembolic events are common in patients with essential thrombocythemia (ET). However, the pathophysiological mechanisms underlying the increased thrombotic risk remain to be determined. Here, we perform the first phenotypical characterization of platelet expression using single-cell mass cytometry in six ET patients and six age- and sex-matched healthy individuals. A large panel of 18 transmembrane regulators of platelet function and activation were analyzed, at baseline and after ex-vivo stimulation with thrombin receptor-activating peptide (TRAP). We detected a significant overexpression of the activation marker CD62P (p-Selectin) (p = .049) and the collagen receptor GPVI (p = .044) in non-stimulated ET platelets. In contrast, ET platelets had a lower expression of the integrin subunits of the fibrinogen receptor GPIIb/IIIa CD41 (p = .036) and CD61 (p = .044) and of the von Willebrand factor receptor CD42b (p = .044). Using the FlowSOM algorithm, we identified 2 subclusters of ET platelets with a prothrombotic expression profile, one of them (cluster 3) significantly overrepresented in ET (22.13% of the total platelets in ET, 2.94% in controls, p = .035). Platelet counts were significantly increased in ET compared to controls (p = .0123). In ET, MPV inversely correlated with platelet count (r=-0.96). These data highlight the prothrombotic phenotype of ET and postulate GPVI as a potential target to prevent thrombosis in these patients.

Essential thrombocythemia (ET) is a rare disease characterized by an increased number of platelets in the blood. As a complication, many of these patients develop a blood clot, which can be life-threatening. So far, the reason behind the higher risk of blood clots is unclear. In this study, we analyzed platelet surface markers that play a critical role in platelet function and platelet activation using a modern technology called mass cytometry. For this purpose, blood samples from 6 patients with ET and 6 healthy control individuals were analyzed. We found significant differences between ET platelets and healthy platelets. ET platelets had higher expression levels of p-Selectin (CD62P), a key marker of platelet activation, and of the collagen receptor GPVI, which is important for clot formation. These results may be driven by a specific platelet subcluster overrepresented in ET. Other surface markers, such as the fibrinogen receptor GPIIb/IIIa CD41, CD61, and the von Willebrand factor receptor CD42b, were lower expressed in ET platelets. When ET platelets were treated with the clotting factor thrombin (thrombin receptor-activating peptide, TRAP), we found a differential response in platelet activation compared to healthy platelets. In conclusion, our results show an increased activation and clotting potential of ET platelets. The platelet surface protein GPVI may be a potential drug target to prevent abnormal blood clotting in ET patients.

Daytime plasma cortisol and cortisol response to dexamethasone suppression are associated with a prothrombotic state in hypertension.

Background and aims: A prothrombotic state was demonstrated in patients with Cushing's syndrome and is involved in the development and progression of cardiovascular and renal damage in hypertensive patients. This study was designed to examine the relationships between cortisol secretion and the hemostatic and fibrinolytic systems in hypertension. Methods: In 149 middle-aged, nondiabetic, essential hypertensive patients free of cardiovascular and renal complications, we measured hemostatic markers that express the spontaneous activation of the coagulation and fibrinolytic systems and assessed daily cortisol levels (8 AM, 3 PM, 12 AM; area under the curve, AUC-cortisol) together with the cortisol response to dexamethasone overnight suppression (DST-cortisol). Results: Plasma levels of D-dimer (D-dim), prothrombin fragment 1 + 2 (F1 + 2), and von Willebrand factor (vWF) were progressively and significantly higher across tertiles of AUC-cortisol and DST-cortisol, whereas no differences were observed in fibrinogen, tissue plasminogen activator, plasminogen activator inhibitor-1, antithrombin III, protein C, and protein S. D-dim, F1 + 2, and vWF were significantly and directly correlated with age and both AUC-cortisol and DST-cortisol. Multivariate regression analysis showed that both AUC-cortisol and DST-cortisol were related to plasma D-dim, F1 + 2, and vWF independently of age, body mass index, blood pressure, and renal function. Conclusion: Greater daily cortisol profile and cortisol response to overnight suppression are independently associated with a prothrombotic state in hypertensive patients and might contribute to the development of organ damage and higher risk of cardiovascular complications.

Antiphospholipid antibodies and antiphospholipid syndrome.

Individuals with antiphospholipid syndrome (APS) have antibodies directed against phospholipid-binding proteins (aPL). The condition is most associated with an increased risk of thromboembolism and obstetric complications. The 2023 classification criteria for APS include six clinical domains (venous thromboembolism, arterial thrombosis, microvascular events, obstetric events, cardiac valve, thrombocytopaenia) and two laboratory domains (lupus anticoagulant, and anti-cardiolipin or anti-ß2-glycoprotein-I antibodies). Diagnosis and treatment of APS are specialist tasks and are summarised in this review.

Delayed Diagnosis of Pulmonary Artery Thrombosis in a Patient Undergoing Mitral Valve Replacement.

ABSTRACT: The occurrence of pulmonary artery thrombus in association with rheumatic mitral stenosis is a rare complication. Pulmonary artery thrombus formation may worsen pulmonary artery pressures, and this may precipitate acute right heart failure. The possible mechanisms behind pulmonary artery thrombus formation during mitral valve replacement surgery could be acute coagulopathy following surgery, the presence of chronic pulmonary thromboembolism, or chronic atrial fibrillation. We report an unusual case of pulmonary artery thrombus in a patient with rheumatic MS which was diagnosed with transoesophageal echocardiography after MVR.

Recurrent intra-cardiac thrombosis: A rare manifestation of Behçet's disease.

Behçet's disease is a systemic vasculitis characterized by recurrent bipolar aphtosis and ophthalmic disorders. Cardiac involvement is rarely reported and could be associated to poor prognosis. Intracardiac thrombosis is exceptional and represents a therapeutic issue. We report the case of a young man admitted in internal medicine department for management of prolonged fever and recurrent mouth ulcers.

Bleeding and Thrombosis in Patients With Out-of-Hospital Ventricular Tachycardia/Ventricular Fibrillation Arrest Treated With Extracorporeal Cardiopulmonary Resuscitation.

BACKGROUND: Extracorporeal cardiopulmonary resuscitation improves outcomes after out-of-hospital cardiac arrest. However, bleeding and thrombosis are common complications. We aimed to describe the incidence and predictors of bleeding and thrombosis and their association with in-hospital mortality. METHODS AND RESULTS: Consecutive patients presenting with refractory ventricular tachycardia/ventricular fibrillation out-of-hospital cardiac arrest between December 2015 and March 2022 who met the criteria for extracorporeal cardiopulmonary resuscitation initiation at our center were included. Major bleeding was defined by the Extracorporeal Life Support Organization's criteria. Adjusted analyses were done to seek out risk factors for bleeding and thrombosis and evaluate their association with mortality. Major bleeding occurred in 135 of 200 patients (67.5%), with traumatic bleeding from cardiopulmonary resuscitation in 73 (36.5%). Baseline demographics and arrest characteristics were similar between groups. In multivariable analysis, decreasing levels of fibrinogen were independently associated with bleeding (adjusted hazard ratio [aHR], 0.98 per every 10 mg/dL rise [95% CI, 0.96-0.99]). Patients who died had a higher rate of bleeds per day (0.21 versus 0.03, P<0.001) though bleeding was not significantly associated with in-hospital death (aHR, 0.81 [95% CI. 0.55-1.19]). A thrombotic event occurred in 23.5% (47/200) of patients. Venous thromboembolism occurred in 11% (22/200) and arterial thrombi in 15.5% (31/200). Clinical characteristics were comparable between groups. In adjusted analyses, no risk factors for thrombosis were identified. Thrombosis was not associated with in-hospital death (aHR, 0.65 [95% CI, 0.42-1.03]). CONCLUSIONS: Bleeding is a frequent complication of extracorporeal cardiopulmonary resuscitation that is associated with decreased fibrinogen levels on admission whereas thrombosis is less common. Neither bleeding nor thrombosis was significantly associated with in-hospital mortality.

Evaluation of the position of the central venous catheter tip of implantable venous access devices in the occurrence of postoperative thrombotic and non-thrombotic complications.

BACKGROUND: The position of the catheter tip of totally implantable venous access devices (TIVAD) is a risk factor for postoperative complications. The study aim was to assess the early and late complications (EC and LC) associated with the position of the catheter tip in cancer patients. METHODS: We reviewed cancer patients who had a TIVAD placed in 2020. EC (≤ 90 days), LC (> 90 days) and risk factors for TIVAD-associated complications were assessed. The vertical mismatch of the catheter tip was compared to an "ideal position" (> 10 mm below the carina and ≥ 20 mm below the right main bronchus (RMB)) using chest x-ray, post-implantation. RESULTS: 301 patients were included. Median follow-up after TIVAD implantation was 9.4 months. All TIVAD catheters were inserted via the internal jugular vein (IJV). The mean distance between the catheter tip and the carina and the RMB was 21.3 mm and 6.63 mm respectively. In total, 11.3% patients developed EC and 5.6% had LC. An association was found between the position of the catheter tip from the carina (≤ 10 mm vs. > 10 mm) and the occurrence of EC (18.3% vs. 8.6%, p = 0.01) and for the catheter insertion side (left IJV vs. right IJV) (19.1% vs. 9.0% p = 0.02). Multivariate analysis showed that left IJV catheter insertion (OR 2.76), and a catheter tip located ≤ 10 mm below the carina (OR 2.71) are significant independent risk factors of EC. CONCLUSIONS: TIVAD catheter tip located at ≤ 10 mm below the carina, and a left-side inserted catheter, are higher risk of EC.

Comparison of apixaban versus aspirin for the prevention of latent bioprosthetic aortic valve thrombosis: study protocol for a prospective randomized trial.

BACKGROUND: The optimal antithrombotic strategy early after aortic valve replacement surgery with a biological valve remains controversial due to lack of high-quality evidence. Either oral anticoagulants or acetylsalicylic acid should be considered for the first 3 months. Hypo-attenuated leaflet thickening on cardiac computed tomography has been associated with latent bioprosthetic valve thrombosis and may be prevented with anticoagulation. We hypothesize that anticoagulation with apixaban is superior to single antiplatelet therapy with acetylsalicylic acid in reducing hypo-attenuated leaflet thickening of bioprosthetic aortic valve prostheses. METHODS: In this prospective, open-label, randomized trial, patients undergoing isolated aortic valve replacement surgery with rapid deployment bioprosthetic valves will be randomized. The treatment group will receive 5 mg of apixaban twice a day for the first 3 months and 100 mg of acetylsalicylic acid thereafter. The control group will be administered 100 mg of acetylsalicylic acid once a day, indefinitely. After the 3-month treatment period, a contrast-enhanced electrocardiogram-gated cardiac computed tomography will be performed to identify hypo-attenuated leaflet thickening of the bioprosthetic valve. The primary objective of the study is to assess the impact of apixaban on the prevention of hypo-attenuated leaflet thickening at 3 months. The secondary and exploratory endpoints will be clinical outcomes and safety profiles of the two strategies. DISCUSSION: Antithrombotic therapy after aortic valve replacement is used to prevent valve thrombosis and systemic thromboembolism. Latent bioprosthetic valve thrombosis is a precursor of clinically significant prosthetic valve dysfunction or thromboembolic events. The hallmark feature of latent bioprosthetic valve thrombosis is hypo-attenuated leaflet thickening on cardiac computed tomography. Subclinical leaflet thrombosis occurs frequently in bioprosthetic aortic valves, more commonly in transcatheter than in surgical valves. There is no evidence on the effect of direct oral anticoagulants on the incidence of hypo-attenuated leaflet thickening after surgical aortic valve replacement with rapid deployment bioprostheses. TRIAL REGISTRATION: ClinicalTrials.gov NCT06184113. Registered on December 28, 2023.

The incidence of thrombosis with co-occurring thrombocytopenia prior to the SARS-CoV2 pandemic: A population-based study.

BACKGROUND: Thrombosis with thrombocytopenia syndrome (TTS) is a very rare prothrombotic disorder that is a safety concern for some COVID-19 vaccines. We aimed to devise a case definition to estimate the incidence of thrombosis with thrombocytopenia as a proxy for TTS in a national insurance claims database. METHODS: We conducted a retrospective observational study using the National Health Insurance Research Database (NHIRD) in Taiwan over the three-year period prior to the SARS-COV-2 pandemic (2017-2019). Our case definition was all patients with newly diagnosed thrombosis co-occurring with a diagnosis of thrombocytopenia within seven days before or after the thrombosis diagnosis. Cases were identified using International Classification of Disease-10 codes. FINDINGS: We identified 2010 patients with newly diagnosed thrombosis co-occurring with thrombocytopenia during the study period. The mean age was 64.71 years; female:male ratio 1:1.45. The most frequent thrombotic events were coronary artery disease (18.81%), cerebral infarction (16.87%), and disseminated intravascular coagulation (13.13%). Cerebral venous sinus thrombosis was rare (<0.1%). The average annual incidence rate of co-occurring new diagnoses of thrombosis and thrombocytopenia was 2.84 per 100 000 population. Incidence rates were higher in men than women, except in 20-39 year-olds (higher in females). 20.6% of patients died within the first month after diagnosis. INTERPRETATION: We observed that the demographic and clinical characteristics of thrombosis with co-occurring thrombocytopenia using our case definition is different from that of TTS. Further research is needed to refine the case definition of TTS in the post-COVID-19 vaccination period.

A retrospective review of antiphospholipid syndrome: a single tertiary centre experience.

INTRODUCTION: Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterised by thrombosis and pregnancy morbidity in the presence of antiphospholipid antibodies (aPL). Our study aims to study the clinical and laboratory characteristics, treatment strategies and outcomes of APS patients retrospectively. MATERIALS AND METHODS: A retrospective review of all APS patients treated in Rheumatology Unit, Hospital Pulau Pinang between October 2021 and October 2022 was conducted. RESULTS: A total of 53 APS patients (age 42.4±13.9 years) including 22 (41.5%) primary and 31 (58.5%) secondary APS patients were identified. Thrombosis was the most common clinical manifestation (51/53; 96.2%) followed by pregnancy morbidity (15/45; 33.3%). For other clinical manifestations, aPL-associated thrombocytopenia was the most frequently observed manifestation (26.4%) followed by autoimmune haemolytic anaemia (18.9%). Lupus anticoagulant (LA) (88.7%) was the most commonly found aPL followed by anticardiolipin antibody (aCL) (50.9%) and anti-beta 2 glycoprotein 1 antibody (B2GP1) (30.2%). 10 (18.9%) patients tested positive for all three aPL. The majority of our patients (86.8%) receive warfarin as anticoagulation therapy while the remaining receive aspirin or direct oral anticoagulants. CONCLUSION: Our population cohort demonstrated a high incidence of pregnancy morbidities and a similar incidence of thrombotic events compared to other population cohorts in both Asian and the European countries.

Repeated acute coronary syndrome caused by a mind-bending mural thrombus in ascending aorta: a case report and review of the literature.

BACKGROUND: Acute coronary syndrome due to coronary artery embolism in the setting of ascending aortic thrombus is an uncommon condition, even rarer when there is no aortic pathology such as aneurysm, severe atherosclerosis, aortic dissection, or thrombophilia (whether inherited or acquired). CASE PRESENTATION: We report a case of a 58-year-old male presented with acute chest pain, electrocardiogram showing non-ST-elevation acute coronary syndrome. The computed tomography angiography of coronary artery revealed a mural thrombus in the proximal part of ascending aorta, located above the left coronary artery ostium, without any aortic pathologies. With the exception of hypertension and cigarette smoking, no other risk factors were identified in this patient that may increase the risk of thrombosis. Given the life-threatening risk of interventional therapy and surgery, the patient determinedly opted for anticoagulant and dual antiplatelet therapy. Then he experienced the reoccurrence of chest pain after 6-day treatment, progressed to anterior and inferior ST-segment elevation myocardial infarction. Coronary artery embolism originating from the ascending aortic thrombus was suspected. Considering the hemodynamic instability of the patient, the medical treatment was continued and bridged to warfarin and aspirin after discharge. Follow-up computed tomography angiography at 6 months showed no obstruction in coronary artery and complete resolution of the thrombus. No thromboembolic events occurred henceforward. CONCLUSIONS: Acute coronary syndrome could be a manifestation of secondary coronary embolism due to ascending aortic thrombus. Currently, there is no standardized guideline for the treatment of aortic mural thrombus, individualized treatment is recommended. When surgical therapy is not applicable for the patient, anticoagulation and dual antiplatelet treatment are alternative treatments that may successfully lead to the resolution of the aortic thrombus.

Factors predicting resolution of left ventricular thrombus in different time windows after myocardial infarction.

BACKGROUND: Left ventricular thrombus (LVT) is a serious complication after myocardial infarction. However, due to its asymptomatic nature, early detection is challenging. We aimed to explore the differences in clinical correlates of LVT found in acute to subacute and chronic phases of myocardial infarction. METHODS: We collected data from 153 patients who were diagnosed with LVT after myocardial infarction at the Affiliated Hospital of Qingdao University from January 2013 to December 2022. Baseline information, inflammatory markers, transthoracic echocardiograph (TTE) data and other clinical correlates were collected. Patients were categorized into acute to subacute phase group (< 30 days) and chronic phase group (30 days and after) according to the time at which echocardiograph was performed. The resolution of thrombus within 90 days is regarded as the primary endpoint event. We fitted logistic regression models to relating clinical correlates with phase-specific thrombus resolution. RESULTS: For acute to subacute phase thrombus patients: C-reactive protein levels (OR: 0.95, 95% CI: 0.918-0.983, p = 0.003) were significantly associated with thrombus resolution. For chronic phase thrombus patients: anticoagulant treatment was associated with 5.717-fold odds of thrombus resolution (OR: 5.717, 95% CI: 1.543-21.18, p = 0.009). CONCLUSIONS: Higher levels of CRP were associated with lower likelihood of LVT resolution in acute phase myocardial infarction; Anticoagulant therapy is still needed for thrombus in the chronic stage of myocardial infarction.

The Etiology of the Thrombotic Phenomena Involved in the Process of Coronary Artery Disease-What Is the Role of Thrombophilic Genes in the Development of This Pathology?

Cardiovascular diseases, among which includes coronary artery disease, represent one of the most important causes of mortality and morbidity worldwide. Research aimed at determining the risk factors involved recognizes a group of "traditional" risk factors, but also more recent studies identified over 100 "novel" ones which may have a role in the disease. Among the latter is the thrombophilia profile of a patient, a pathology well-established for its involvement in venous thromboembolism, but with less studied implications in arterial thrombosis. This paper reviews the literature, explaining the pathophysiology of the thrombophilia causes associated most with coronary thrombosis events. Results of several studies on the subject, including a meta-analysis with over 60,000 subjects, determined the significant involvement of factor V Leiden, prothrombin G20210A mutation, plasminogen activator inhibitor-1 and antiphospholipid syndrome in the development of coronary artery disease. The mechanisms involved are currently at different stages of research, with some already established and used as therapeutic targets.

The impact of small movements with dual lumen cannulae during venovenous extracorporeal membrane oxygenation: A computational fluid dynamics analysis.

BACKGROUND AND OBJECTIVES: Venovenous Extracorporeal Membrane Oxygenation (VV ECMO) provides respiratory support to patients with severe lung disease failing conventional medical therapy. An essential component of the ECMO circuit are the cannulas, which drain and return blood into the body. Despite being anchored to the patient to prevent accidental removal, minor cannula movements are common during ECMO. The clinical and haemodynamic consequences of these small movements are currently unclear. This study investigated the risk of thrombosis and recirculation caused by small movements of a dual lumen cannula (DLC) in an adult using computational fluid dynamics. METHODS: The 3D model of an AVALON Elite DLC (27 Fr) and a patient-specific vena cava and right atrium were generated for an adult patient on ECMO. The baseline cannula position was generated where the return jet enters the tricuspid valve. Alternative cannula positions were obtained by shifting the cannula 5 and 15 mm towards inferior (IVC) and superior (SVC) vena cava, respectively. ECMO settings of 4 L/min blood flow and pulsatile flow at SVC and IVC were applied. Recirculation was defined as a scalar value indicating the infused oxygenated blood inside the drainage lumen, while thrombosis risk was evaluated by shear stress, stagnation volume, washout, and turbulent kinetic energy. RESULTS: Recirculation for all models was less than 3.1 %. DLC movements between -5 to 15 mm increased shear stress and turbulence kinetic energy up to 24.7 % and 11.8 %, respectively, compared to the baseline cannula position leading to a higher predicted thrombosis risk. All models obtained a complete washout after nine seconds except for when the cannula migrated 15 mm into the SVC, indicating persisting stasis and circulating zones. CONCLUSION: In conclusion, small DLC movements were not associated with an increased risk of recirculation. However, they may increase the risk of thrombosis due to increased shear rate, turbulence, and slower washout of blood. Developing effective cannula securement devices may reduce this risk.