miR-19a and miR-20a and Tissue Factor Expression in Activated Human Peripheral Blood Mononuclear Cells

Background and Aims. To investigate the behaviour of miR-19a and miR-20a, two microRNAs involved in posttranscriptional modulation of TF expression in peripheral blood mononuclear cells (PBMCs) exposed to high glucose (HG) and lipopolysaccharide (LPS), and to evaluate the involvement of angiotensin II in that process. Methods. TF Procoagulant Activity (PCA, one-stage clotting assay), antigen (Ag, ELISA), and miR-19a and miR-20a levels (specific TaqMan® MicroRNA Assays) were evaluated in PBMCs exposed to high glucose (HG, 50 mM), LPS (100 ng/mL), and Olmesartan (OLM, 10−6 M), an angiotensin II type 1 receptor antagonist. Results. HG increased TF expression and decreased both miRs as compared to control glucose conditions (11.1 mM). In HG-activated PBMCs, LPS stimulated TF expression and downregulated miR-20a, an effect reverted by OLM (10−6 M); miR-19a expression was unchanged by LPS in both CG and HG conditions. Conclusions. miR-19a and miR-20a are inhibited by inflammatory stimuli active on TF expression and their response differs by the stimulus under investigation; angiotensin II may participate in that mechanism.

Referral Patterns and Diagnostic Yield of Lung Scintigraphy in the Diagnosis of Acute Pulmonary Embolism

Introduction. The purpose of this study is to assess referral patterns and the yield of ventilation-perfusion (V/Q) scintigraphy in patients referred for acute pulmonary embolism (PE). Methods. We retrospectively reviewed the charts of all patients who underwent V/Q studies between April 1, 2008, and March 31, 2010. Patients were subdivided into 4 groups based on their referral source: emergency department (ED), hospital inpatient ward, outpatient thrombosis clinic, and all other outpatient sources. Results. A total of 1008 patients underwent V/Q scintigraphy to exclude acute PE. The number of ED, inpatient, thrombosis clinic, and outpatient studies was 43 (4.3%), 288 (28.6%), 351 (34.8%), and 326 (32.3%). Proportion of patients with contrast contraindication varied significantly among the different groups. Of the 1,008 studies, 331 (32.8%) were interpreted as normal, 408 (40.5%) as low, 158 (15.7%) as intermediate, and 111 (11.0%) as high probability for PE. 68 (6.7%) patients underwent CTPA within 2 weeks following V/Q. Conclusion. The rate of nondiagnostic studies is lower than that reported in previously published data, with a relatively low rate of intermediate probability studies. Only a small fraction of patients undergoing a V/Q scan will require a CTPA.

Pathogenesis of Thromboembolism and Endovascular Management

Venous thromboembolism (VTE), a disease that includes deep venous thrombosis (DVT) and pulmonary embolism (PE), is associated with high mortality, morbidity, and costs. It can result in long-term complications that include postthrombotic syndrome (PTS) adding to its morbidity. VTE affects 1/1000 patients, costs $13.5 billion annually to treat, and claims 100,000 lives annually in the US. The current standard of care for VTE is anticoagulation, though thrombolysis may be performed in patients with PE and threatened limb. This review discusses pathogenesis and medical treatment of VTE and then focuses on endovascular treatment modalities. Mechanical- and catheter-directed thrombolysis (CDT) is discussed, as well as patient selection criteria, and complications. The first prospective study (CaVenT) comparing CDT with anticoagulation alone in acute DVT, despite study shortcomings, corroborates the existing literature indicating improved outcomes with CDT. The potential of the ongoing prospective, multicenter, randomized ATTRACT trial is also highlighted.

The Typical Presentation Spectrum of Deep Vein Thrombosis Associated with Inferior Vena Cava Malformations

Congenital malformations of the inferior vena cava (IVC) are rare and underreported. They can be a risk factor for deep venous thrombosis (DVT) as a result of inadequate venous drainage of the lower extremities through collateral circulation. The significant number of cases reported in the literature highlights their importance, warranting investigating their existence in younger individuals with idiopathic DVT of the lower extremities and pelvic veins. In this systematic review, we depict the typical presentation of IVC malformations, their management, and the management of their associated DVT.

Out of Sight, out of Mind? An Audit Which Proposes a Follow-Up and Management Pathway for Inferior Vena Cava Filters

Insertion of an IVC filter can be a safe and effective way to avoid PE in thrombosis patients who cannot be anticoagulated. If temporary filters are not promptly removed they can become difficult to remove, causing avoidable complications and often requiring lifelong warfarin. In this study, two sequential audits of retrieval of temporary IVC filters were conducted before and after the implementation of a coordinated management strategy for IVC filter follow-up. 33 filter placements were examined over a 15-month period (Group A). Following implementation of the strategy a comparable 15-month period in which 33 IVC filters were placed was audited (Group B). Following implementation, failed retrievals dropped from 15% to 9%. The number successfully retrieved did not change at 45%. The number made permanent from the outset following expert discussion increased from 12% to 39%. The number of filters with no attempted retrieval and no consultation about retrieval decreased from 27% to 9% (these patients were lost to follow-up with multiple contact attempts made). In Group B 100% of placed IVC filters were followed up appropriately. The proposed model is an easily implemented plan to avoid patient morbidity caused by temporary IVC filters made unintentionally permanent by loss to follow-up.

Medicinal Herbals with Antiplatelet Properties Benefit in Coronary Atherothrombotic Diseases

Coronary atherothrombotic diseases such as coronary artery disease, peripheral vascular disease, cerebrovascular disease, and heart failure are the serious concerns of the thrombus formed in blood vessels. Anticoagulant and antiplatelet drugs are the cornerstones of the management of these diseases. To prevent the recurrence of these diseases, double antiplatelet drugs such as aspirin and clopidogrel has been the standard management in most hospitals. However, aspirin resistance and clopidogrel inefficient effects due to noncompliance with double drugs regimen can cause a sinister effect on patients. Medicinal plants serve as a greater resource for new medication and their potential currently became a topic of interest to the researchers all over the world. Traditionally, certain herbs have been used as a treatment for heart diseases but have been investigated for their antiplatelet properties. This current review explained few traditional antithrombotic herbals and their antiplatelet properties in vitro and in vivo and this is to be deeply discussed in further research.

The Incidence of Peripheral Catheter-Related Thrombosis in Surgical Patients

Background. Central venous catheters and peripherally inserted central catheters are well established risk factors for upper limb deep vein thrombosis. There is limited literature on the thrombosis rates in patients with peripheral catheters. A prospective observational study was conducted to determine the incidence of peripheral catheter-related thrombosis in surgical patients. Methods. Patients deemed high risk for venous thrombosis with a peripheral catheter were considered eligible for the study. An ultrasound was performed on enrolment into the study and at discharge from hospital. Participants were reviewed twice a day for clinical features of upper limb deep vein thrombosis during their admission and followed up at 30 days. Results. 54 patients were included in the study. The incidence of deep vein thrombosis and superficial venous thrombosis was 1.8% and 9.2%, respectively. All cases of venous thrombosis were asymptomatic. Risk factor analysis was limited by the low incidence of thrombosis. Conclusion. This study revealed a low incidence of deep vein thrombosis in surgical patients with peripheral catheters (1.8%). The study was underpowered; therefore the association between peripheral catheters and thrombosis is unable to be established. Future studies with larger sample sizes are required to determine the association between peripheral catheters and thrombosis.

Length of Stay Comparison between Rivaroxaban and Warfarin in the Treatment of Pulmonary Embolism: Results from a Real-World Observational Cohort Study

Background. Trials have shown that novel oral anticoagulants may decrease length of stay versus warfarin. A comparison of length of stay in the treatment of pulmonary embolism (PE) has not been performed outside post hoc analysis of a large clinical trial. Objective. To evaluate if rivaroxaban decreases length of stay compared to warfarin plus enoxaparin in the treatment of PE. Methods. This was a multicenter, retrospective, observational cohort study. Patients were identified based on discharge diagnosis of PE and were excluded if they received anticoagulants prior to admission and had additional indications for anticoagulation or reduced creatinine clearance. The primary endpoint was length of stay. Secondary endpoints included time from initial dose of oral anticoagulant to discharge and length of stay comparison between subgroups. Results. Inclusion criterion was met by 158 patients (82 warfarin, 76 rivaroxaban). The median length of stay was 4.5 days (interquartile range [IQR], 2.7, 5.9) in the warfarin group and 1.8 days (IQR, 1.2, 3.7) in the rivaroxaban group (P<0.001). Time interval from first dose of oral anticoagulant to discharge was shorter with rivaroxaban (P<0.001). Conclusions. Patients given rivaroxaban had decreased length of stay versus those given warfarin plus enoxaparin for the treatment of PE.

Rapid Progression of Coronary Atherosclerosis: A Review

Atherosclerosis is chronic disease, the prevalence of which has increased steadily as the population ages. Vascular injury is believed to be critical initiating event in pathogenesis of spontaneous atherosclerosis. Syndrome of accelerated atherosclerosis has been classically described in patients undergoing heart transplantation, coronary artery bypass graft, and percutaneous transluminal coronary angioplasty. In contrast to spontaneous atherosclerosis, denuding endothelial injury followed by thrombus formation and initial predominant smooth muscle cell proliferation is believed to be playing a significant role in accelerated atherosclerosis. There is no universal definition of rapid progression of atherosclerosis. However most studies describing the phenomenon have used the following definition: (i) > or = 10% diameter reduction of at least one preexisting stenosis > or = 50%, (ii) > or = 30% diameter reduction of a preexisting stenosis <50%, and (iii) progression of a lesion to total occlusion within few months. Recent studies have described the role of coronary vasospasm, human immunodeficiency virus, various inflammatory markers, and some genetic mutations as predictors of rapid progression of atherosclerosis. As research in the field of vascular biology continues, more factors are likely to be implicated in the pathogenesis of rapid progression of atherosclerosis.

Comparison of Chemical and Mechanical Prophylaxis of Venous Thromboembolism in Nonsurgical Mechanically Ventilated Patients

Background. Thromboembolic events are major causes of morbidity, and prevention is important. We aimed to compare chemical prophylaxis (CP) and mechanical prophylaxis (MP) as methods of prevention in nonsurgical patients on mechanical ventilation. Methods. We performed a retrospective study of adult patients admitted to the Cooper University Hospital ICU between 2002 and 2010. Patients on one modality of prophylaxis throughout their stay were included. The CP group comprised 329 patients and the MP group 419 patients. The primary outcome was incidence of thromboembolic events. Results. Acuity measured by APACHE II score was comparable between the two groups (p=0.215). Univariate analysis showed 1 DVT/no PEs in the CP group and 12 DVTs/1 PE in the MP group (p=0.005). Overall mortality was 34.3% and 50.6%, respectively. ICU LOS was similar. Hospital LOS was shorter in the MP group. Multivariate analysis showed a significantly higher incidence of events in the MP prophylaxis group (odds ratio 9.9). After excluding patients admitted for bleeding in both groups, repeat analysis showed again increased events in the MP group (odds ratio 2.9) but this result did not reach statistical significance. Conclusion. Chemical methods for DVT/PE prophylaxis seem superior to mechanical prophylaxis in nonsurgical patients on mechanical ventilation and should be used when possible.