Anticoagulation in patients with atrial fibrillation,thrombocytopenia and hematological malignancy

Journal of Thrombosis and Thrombolysis - Managing anticoagulation in hematological malignancy patients with atrial fibrillation and thrombocytopenia is a clinical challenge with limited data. We...     

Thromboembolic Events Following Splenectomy: Risk Factors,Prevention, Management and Outcomes

Background

Thromboembolic events following splenectomy are not uncommon. However, the role of thromboprophylaxis and risk factors for thrombosis, as well as the clinical course and outcomes, are not well characterized.

Methods

A retrospective review of individuals who underwent splenectomy between January 2006 and December 2015 in two university hospitals.

Results

Overall, 297 patients underwent splenectomy [open splenectomy (n = 199), laparoscopic splenectomy (n = 98)]. Mechanical (thigh-length pneumatic compression stockings) and pharmacologic thromboprophylaxis (40 mg enoxaparin daily, starting 12 h after surgery until discharge) was provided for all patients. One hundred and sixteen patients (39%) also received an extended thromboprophylaxis course of enoxaparin for 2–4 weeks after discharge. Twenty-three patients (7.7%) experienced thrombotic complications following splenectomy, including 16 cases (5.4%) of portal-splenic mesenteric venous thrombosis (PSMVT), 5 (1.7%) pulmonary embolism and 2 (0.7%) deep vein thrombosis. Longer operative time (mean operative time of 405 vs. 273 min, P = 0.03) was independently associated with PSMVT. Post-splenectomy thrombocytosis was not associated with thrombosis (P = 0.41). The overall thrombosis rate was significantly lower in patients who received an extended thromboprophylaxis course following splenectomy (3.4 vs. 10.5%, P = 0.02). Complete resolution of thrombosis was observed in most cases (n = 20, 87.0%), with no recurrent thrombosis during a mean follow-up of 38 ± 25 months.

Conclusions

Thromboembolic complications, mainly PSMVT, are common following splenectomy. Longer operative time was associated with thrombosis. Significantly lower rates of thrombosis were found in patients who received an extended thromboprophylaxis course.

     

Prolonged fever of unknown origin and hemophagocytosis evolving into acute lymphoblastic leukemia

Hemophagocytic syndrome (HPS) is an unusual acute syndrome presenting with fever, hepatosplenomegaly, and cytopenias. The hallmark of HPS is the accumulation of activated macrophages that engulf hematopoietic cells in the reticuloendothelial system. Most cases of HPS in adults are secondary to infection or malignancy, and thus investigation of the underlying disease is necessary. We describe a patient with prolonged fever, HPS, and chromosomal abnormalities in the bone marrow who underwent thorough evaluation for the cause of his symptoms. A final diagnosis of acute lymphoblastic leukemia (ALL) was established in a fourth, repeated bone marrow biopsy performed more than 2 months after the first presenting symptom appeared. This unusual case demonstrates the importance of cytogenetic abnormalities found in cases of HPS and the importance of repeated testing when an underlying disease is suspected.     

Bleeding, Obstruction, and Perforation in a Series of Patients With Aggressive Gastric Lymphoma Treated With Primary Chemotherapy

Background The management of patients with gastric lymphoma has evolved, with a shift toward nonsurgical treatment. The rates of surgical complications in patients receiving chemotherapy have been insufficiently studied. The objective of this study was to assess the frequency of bleeding, perforation, and gastric outlet obstruction in patients who received chemotherapy as primary treatment for gastric diffuse large B cell lymphoma (DLBCL).Methods We reviewed files of all patients with gastric DLBCL who were diagnosed and treated primarily with chemotherapy in our hospital between 1990 and 2005.Results Eighteen (25%) of 73 patients experienced surgical complications, of whom 6 (8%) underwent surgery. Eight patients (11%), six with active lymphoma, experienced gastric bleeding; one required gastrectomy. Eight patients (11%) developed gastric outlet obstruction, of whom three were treated conservatively, three required surgery, one stopped treatment, and one received further chemotherapy. Six of the eight patients had no evidence of active lymphoma at the time of obstruction. Two additional patients underwent gastrectomy due to resistant or relapsed disease. Gastric perforation was not observed. Median survival was 90 months for the entire series, 94 months for patients with gastric outlet obstruction, and 11.5 months for patients with gastric bleeding.Conclusions Given the rate of surgical complications, especially gastric bleeding and gastric outlet obstruction, there is still an important role for the surgical consultant in the treatment of patients with gastric DLBCL receiving chemotherapy. Gastric perforation, although frequently cited as a complication, is in fact rarely observed.     

Platelet adhesion defect in type I Gaucher Disease is associated with a risk of mucosal bleeding

Patients with type I Gaucher Disease (GD) may have a clinically significant bleeding tendency that is disproportionate to their platelet count. We hypothesized that impaired platelet adhesion might contribute to bleeding tendency. Adult patients with type I GD with platelet counts ≥130×10(9) /l and haematocrit ≥30% (n=48), obligatory carriers (n=52), and healthy controls (n=19) were studied. Platelet adhesion, using the IMPACT-R (Cone and Plate(let) Analyser), and platelet aggregation were determined. Type I GD patients had significantly lower platelet adhesion [surface coverage %, median (interquartile range)] 4·6 (3·2-7·5), compared to controls, 8·7 (7·6-10·3), or carriers, 8·1 (6·5-9·4; P=0·001). Platelet adhesion was not affected by the use of disease-specific enzyme replacement therapy but was improved in patients after splenectomy, 7·2 (5·8-9·3). Mixing tests showed that the reduced adhesion was an intrinsic platelet defect. Mucosal bleeding was reported in 17 (35·4%) patients and was associated with abnormal adhesion [P=0·037, with an Odds Ratio (95% confidence interval) of 5·73 (1·1-29·6)]. Five patients (22%) had reduced platelet aggregation, all of whom had reduced platelet adhesion. Platelet aggregation defect was not associated with mucosal bleeding. In conclusion, platelet adhesion defect is a major thrombocytopathy in type I GD patients and can explain part of the increased tendency to bleeding.     

Platelets selectively enhance lymphocyte adhesion on subendothelial matrix under arterial flow conditions

Developing novel anti-platelet therapies is an important clinical strategy for the prevention of arterial thromboses which cause heart attacks and most strokes. Thrombin activates platelets via protease-activated receptors (PARs), and PAR antagonists are currently under investigation as antithrombotics. Yet despite these clinical advances, the importance of PARs to platelet activation during thromboses formed under pathological conditions has not been investigated. To this end, we examined the role of PAR-dependent platelet activation in thrombus formation in the presence of elevated blood shear rates. We used two in vivo thrombosis models and an ex vivo whole blood flow approach in PAR4(-/-) mice, whose platelets are unresponsive to thrombin, to show that the contribution of PAR-mediated platelet activation to thrombosis is diminished at pathological blood shear rates as a direct result of decreased incorporation of thrombin-activated platelets into growing thrombi. Our ex vivo observations were replicated in human whole blood treated with a PAR1 antagonist. These results define a novel, shear-regulated role for thrombin/PAR-dependent platelet activation during thrombosis and provide important insights into the conditions under which PAR antagonists may best be used for the prevention of acute coronary syndromes.     

Clinical and prognostic implications of the initial response to aspirin in patients with acute coronary syndrome

Increased platelet reactivity and decreased response to antiplatelet drugs may result in recurrent ischemic events after acute coronary syndrome (ACS). We evaluated laboratory response to aspirin in patients with ACS before and after percutaneous coronary intervention (PCI) and assessed its effect on major adverse clinical events. Sixty-three consecutive patients with ACS were tested for response to aspirin by light transmittance aggregometry (LTA) and the IMPACT-R test (with arachidonic acid) before and 2 to 4 days after PCI and clopidogrel loading. Patients were followed for clinical events up to 15 months from PCI. Response to aspirin improved significantly after PCI and clopidogrel treatment (mean arachidonic acid-induced LTA decreased from 34.9 ± 3.35% before PCI to 15.2 ± 2.2% and surface coverage increased from 2.2 ± 0.27% to 6.2 ± 0.6%, p <0.0001 for the 2 methods). Improved response to aspirin after PCI correlated with response to clopidogrel (LTA and IMPACT-R, p <0.01). Patients with good laboratory response to aspirin before but not after PCI had a significantly lower major cardiovascular event rate during 15-month follow-up in multivariate analysis. In conclusion, laboratory response to aspirin is highly dynamic in patients with ACS. Improved response to aspirin after PCI may result from stabilization of coronary artery disease and/or clopidogrel treatment. Laboratory response to aspirin before PCI and clopidogrel loading is a sensitive marker for platelet reactivity that correlates with clinical outcome in patients with ACS.