Risk Of Fatal Pulmonary Embolism Research Articles

Extended Post Discharge Prophylaxis for Venous Thromboembolism Prevention After Bariatric Surgery.

The utility of routine post-discharge VTE prophylaxis after bariatric surgery remains a matter of debate. While inpatient chemical prophylaxis decreases the risk of fatal pulmonary embolism, most thromboembolic events occur after discharge and carry high morbidity and mortality. To address this risk, apixaban was introduced as extended prophylaxis for 30days after surgery. The study ranges between 1/2014 and 7/2022. Apixaban was incorporated as routine extended prophylaxis protocol in 05/2017 and is dosed at 2.5mg BID for 30days. There were two study groups: those who received apixaban on discharge (n = 1443; 60%) and those who did not (n = 953; 40%). Patients with concern for postoperative bleeding (hypotension, unexplained tachycardia with hematocrit drop > 6%, hematocrit drop > 9%), or on preoperative anticoagulant/antiplatelet therapy (except aspirin), were not discharged on apixaban. Post-discharge VTE, readmission, transfusion, and reoperation rates were compared between groups. There were 2396 consecutive primary bariatric operations: sleeve gastrectomy (1949; 81%), Roux-en-Y gastric bypass (419; 18%), and duodenal switch (28; 1%). There were no post-discharge VTEs in patients treated with apixaban vs. five (0.5%) VTEs in patients who did not receive treatment; p = 0.02. There was a higher incidence in post-discharge bleeding events in the apixaban group (0.5 vs 0.3%; p = 0.75), mostly requiring readmission for monitoring without intervention or transfusion. In the apixaban group, one patient underwent EGD for bleeding while another required blood transfusion; there were no reoperations for bleeding. There were no post-discharge VTEs in patients who received apixaban. Treatment was associated with a higher risk of self-resolving bleeding events. This study adds to the increasing body of evidence supporting the benefit of routine, extended oral chemoprophylaxis after bariatric surgery.

Two cases of acute pulmonary artery embolism triggered by fresh and chronic mixed‐vein thrombosis with a “Blowfish sign”

Ultrasonography and computed tomography of the lower extremities revealed fresh and chronic mixed-vein thrombosis (FCMVTs) presenting the "Blowfish sign," accompanied by pulmonary embolism. FCMVTs presenting the "Blowfish sign" may increase the risk of fatal pulmonary embolism, and its detection by ultrasonography is important for preventing pulmonary embolism.

Clinical outcomes of AngioJet pharmacomechanical thrombectomy versus catheter-directed thrombolysis for the treatment of filter-related caval thrombosis.

The inferior vena cava filter is utilized worldwide to intercept thrombi and to reduce the risk of fatal pulmonary embolism (PE). However, filter-related thrombosis is a complication of filter implantation. Endovascular methods such as AngioJet rheolytic thrombectomy (ART) and catheter-directed thrombolysis (CDT) can treat filter-related caval thrombosis, but the clinical outcomes of both treatment modalities have not been determined. To compare the treatment outcomes of AngioJet rheolytic thrombectomy vs catheter-directed thrombolysis in patients with filter-related caval thrombosis. In this single-center retrospective study, 65 patients (34 males and 31 females; mean age: 59.0 ± 13.43 years) with intrafilter and inferior vena cava thrombosis were enrolled between January 2021 and August 2022. These patients were assigned to either the AngioJet group (n = 44) or the CDT group (n = 21). Clinical data and imaging information were collected. Evaluation measures included thrombus clearance rate, periprocedural complications, urokinase dosage, incidence of PE, limb circumference difference, length of stay, and filter removal rate. Technical success rates were 100% in the AngioJet and CDT groups. In the AngioJet group, grade II and grade III thrombus clearance was achieved in 26 (59.09%) and 14 (31.82%) patients, respectively. In the CDT group, grade II and grade III thrombus clearance was accomplished in 11 (52.38%) patients and 8 (38.10%) patients, respectively (P > 0.05).The peridiameter difference of the thigh was significantly reduced in patients from both groups after treatment (P < 0.05). The median dosage of urokinase was 0.08 (0.02, 0.25) million U in the AngioJet group and 1.50 (1.17, 1.83) million U in the CDT group (P < 0.05). Minor bleeding was shown in 4 (19.05%) patients in the CDT group, and when it was compared with that in the AngioJet group, the difference was statistically significant (P < 0.05). No major bleeding occurred. Seven (15.91%) patients in the AngioJet group had hemoglobinuria and 1 (4.76%) patient in the CDT group had bacteremia. There were 8 (18.18%) patients with PE in the AngioJet group and 4 (19.05%) patients in the CDT group before the intervention (P > 0.05). Computed tomography angiopulmonography (CTA) showed that PE was resolved after the intervention. New PE occurred in 4 (9.09%) patients in the AngioJet group and in 2 (9.52%) patients in the CDT group after theintervention (P > 0.05). These cases of PE were asymptomatic. The mean length of stay was longer in the CDT group (11.67 ± 5.34 d) than in the AngioJet group (10.64 ± 3.52 d) (P < 0.05). The filter was successfully retrieved in the first phase in 10 (47.62%) patients in the CDT group and in 15 (34.09%) patients in the AngioJet group (P > 0.05).Cumulative removal was accomplished in 17 (80.95%) out of 21 patients in the CDT group and in 42 (95.45%) out of 44 patients in the ART group (P > 0.05). The median indwelling time for patients with successful retrieval was 16 (13139) d in the CDT group and 59 (12231) d in the ART group (P > 0.05). Compared with catheter-directed thrombolysis, AngioJet rheolytic thrombectomy can achieve similar thrombus clearance effects, improve the filter retrieval rate, reduce the urokinase dosage and lower the risk of bleeding events in patients with filter-related caval thrombosis.

Pulmonary embolism and 529 human blood metabolites: genetic correlation and two-sample Mendelian randomization study

BackgroundThe incidence of pulmonary embolism complications in the literature ranges from 10 to 50%, with a 0.5–10% risk of fatal pulmonary embolism. However, the biological cause of pulmonary embolism is unknown.MethodsThis study used data from the Genome-Wide Association Study (GWAS) of Pulmonary Embolism and Human Blood Metabolites from the UK Biobank, and the data from subjects of European ancestry were analyzed. We explored the relationship between pulmonary embolism and blood metabolites in three ways. We first analyzed the genetic correlation between pulmonary embolism and human blood metabolites using the linkage disequilibrium score regression (LDSC) and then analyzed the causal relationship between pulmonary embolism and meaningful blood metabolites obtained from the LDSC, a procedure for which we used Mendelian randomization analysis. Finally, we obtained transcriptome sequencing data for patients with a pulmonary embolism from the GEO database, analyzed differentially expressed genes (DEGs) in patients with pulmonary embolism versus healthy populations, and compared the DEGs with the resulting blood metabolite genes to further validate the relationship between pulmonary embolism and blood metabolites.ResultWe found six human blood metabolites genetically associated with pulmonary embolism, stearic acid glycerol phosphate ethanolamine (correlation coefficient = 0.2582, P = 0.0493), hydroxytryptophan (correlation coefficient = 0.2894, P = 0.0435), and N1-methyladenosine (correlation coefficient = 0.0439, P = 0.3728), and a significant causal relationship was discovered between hydroxytryptophan and pulmonary embolism. After screening microarray data from the GEO database, we performed differential gene analysis on the GSE19151 dataset and screened a total of 22,216 genes with P values less than 0.05, including 17,361 upregulated genes and 4854 downregulated genes. By comparing the resulting differentially expressed genes with six genes encoding blood metabolites, LIPC and NAT2 were found to be differentially expressed in association with pulmonary embolism.

Screening for venous thrombotic events in patients presenting with pelvis and acetabular fractures: A new practice based on a prospective study

IntroductionPelvic fractures are complex fractures associated with a high risk of venous thromboembolic complications (VTE) and up to a 10% risk of fatal pulmonary embolism. We aimed to reduce perioperative morbidity and mortality using a systematic screening protocol and secondly to evaluate this protocol and identify VTE risk factors. MethodsThis was a prospective monocentric study involving 100 consecutively enrolled patients. The protocol included a venous ultrasound examination of the inferior vena cava and lower limbs and abdominopelvic CT venography within 48 h prior to surgery. The evaluation criteria were the mortality and complication rates. Secondary endpoints were the rate of VTE events and the identification of risk factors. ResultsOne patient died on D1 postoperatively of a massive pulmonary embolism. Migration of a vena cava filter was reported for another. No thrombotic recurrence or hemorrhagic complications were reported. The rate of VTE events was 21%, of which 90% were pre-operative asymptomatic events. CT venography did not show superiority over ultrasound. Patients with greater fracture displacement, preoperative infection, higher platelet counts, or having had a preoperative transfusion were at a higher risk of developing deep vein thrombosis (DVT). ConclusionsThe rate of asymptomatic VTE events in pelvic fractures is extremely high and leads to propose the following recommendations: (1) they should be preoperatively investigated by ultrasound and (2) a vena cava filter must be placed in cases of proximal DVT and the surgery postponed to allow anticoagulation treatment for at least 48 h, regardless of the type of thrombosis. Level of evidenceLevel II. Study typeDiagnostic test.

Incidence of DVT following medial open wedge high tibial osteotomy (MOW-HTO): Prospective study

Background: High tibial osteotomy (HTO) is an established procedure for the treatment of medial compartment osteoarthritis of knee with varus deformity and it has become a popular procedure. In elective knee surgeries such as total knee arthroplasty (TKA) and HTO, it is well recognized that those are associated with a substantial risk of developing deep vein thrombosis (DVT) which carries a risk of fatal pulmonary embolism. Materials and Methods: In this prospective study, we analysed 110 patients, operated with MOW-HTO, for medial compartment osteoarthritis, for evidence of DVT, after dividing the patients into a trial group which received chemoprophylaxis in the form of Fondaparinux and a control group which did not receive any DVT prophylaxis. Results: At postoperative day 6, overall DVT was diagnosed in 6 (15.78%) patients in control group and in 5 (7.1%) patients in fondapariux group (P &gt; 0.05). All patients with DVT were asymptomatic clinically. Proximal DVT was diagnosed in only 1 patient (2.5%) in control group, however none of the patient in fondapariux group had proximal DVT (P&gt;0.05). There was no case of symptomatic DVT and symptomatic PE in either group during the entire study period. Among demographic characteristic, age and body mass index (BMI) showed association (P&lt;0.5) with postoperative incidences of DVT in univariate analysis, however multivariate analysis showed patients with age more than 55 years had significant correlation with post- operative DVT. Incidences of overall DVT diagnosed by Doppler USG and CT venography were not different statistically. Conclusion: Our data demonstrates that the incidences of DVT following MOW-HTO were lower than incidences following TKA in Asian patients. therefore it would not be advisable to use routine chemoprophylaxis following MOW-HTO in a low DVT incidence population

Pulmonary Embolism Secondary to Catheter-Related Thrombosis

A central venous catheter is a device used for chemotherapy. Catheters are at high risk for local venous thrombosis. Once a catheter-related thrombosis is formed, the risk of concomitant pulmonary embolism is regularly underestimated. A 58-year-old man with a non-metastatic pulmonary cancer reported a right-side cervical pain and episodes of hemoptysis. A thrombosis of the right internal vein was detected with compressive ultrasound imaging. Because of the presence of abnormal respiratory signs, a CT scan was performed that confirmed a pulmonary embolism. A catheter related thrombosis is associated with a number of clinically relevant complications, including catheter dysfunction, recurrent deep venous thrombosis, post thrombotic syndrome, anticoagulation-associated bleeding and pulmonary embolism. The risk of fatal pulmonary embolism should not be missed.

Évaluation des complications thromboemboliques veineuses chez les patients opérés de fractures du bassin

IntroductionFractures of the pelvis (acetabulum and pelvic ring) are complex in both radiological diagnosis and therapeutic management. They show high risk of thrombosis, with variable rates of venous thromboembolic complications in the literature, ranging from 10% to 50%, with 0.5–10% risk of fatal pulmonary embolism. The objective of the present study was to determine the rate of venous thromboembolic events in a consecutive cohort of pelvic fracture and to attempt to identify thromboembolic risk factors in this population. Material and methodThe study was based on a continuous retrospective series of 120 patients operated on between January 2015 and January 2017. Standard demographic data, clinical and diagnostic data for the fracture and the surgical approach were collected. Risk factors for venous thrombotic episodes were identified on Greenfield Risk Assessment Profile items (age, BMI, cancer, history of venous thromboembolism, surgery time, transfusion, femoral venous catheter, associated fracture) to define groups with high or low thrombotic risk. ResultsThere was a 5% rate of venous thromboembolic events, and 2.5% of pulmonary embolism including 1 causing intraoperative death. The Greenfield score usually applied in surgery to assess venous thromboembolism risk did not seem relevant in this population already at high risk of venous thromboembolism. No additional independent risk factors were identified. ConclusionThis is the largest cohort focusing on thromboembolic risk in pelvic fracture. The results refine rates reported in the literature. A prospective study, currently underway, should highlight risk factors so as better to prevent these complications.

Evaluation of venous thromboembolic complications in patients operated on for pelvic fracture.

Fractures of the pelvis (acetabulum and pelvic ring) are complex in both radiological diagnosis and therapeutic management. They show high-risk of thrombosis, with variable rates of venous thromboembolic complications in the literature, ranging from 10% to 50%, with 0.5-10% risk of fatal pulmonary embolism. The objective of the present study was to determine the rate of venous thromboembolic events in a consecutive cohort of pelvic fracture and to attempt to identify thromboembolic risk factors in this population. The study was based on a continuous retrospective series of 120 patients operated on between January 2015 and January 2017. Standard demographic data, clinical and diagnostic data for the fracture and the surgical approach were collected. Risk factors for venous thrombotic episodes were identified on Greenfield Risk Assessment Profile items (age, BMI, cancer, history of venous thromboembolism, surgery time, transfusion, femoral venous catheter, associated fracture) to define groups with high or low thrombotic risk. There was a 5% rate of venous thromboembolic events, and 2.5% of pulmonary embolism including 1 causing intraoperative death. The Greenfield score usually applied in surgery to assess venous thromboembolic risk did not seem relevant in this population already at high-risk of venous thromboembolism. No additional independent risk factors were identified. This is the largest cohort focusing on thromboembolic risk in pelvic fracture. The results refine rates reported in the literature. A prospective study, currently underway, should highlight risk factors so as better to prevent these complications.

Is a normal computed tomography pulmonary angiography safe to rule out acute pulmonary embolism in patients with a likely clinical probability? A patient-level meta-analysis.

A normal computed tomography pulmonary angiography (CTPA) remains a controversial criterion for ruling out acute pulmonary embolism (PE) in patients with a likely clinical probability. We set out to determine the risk of VTE and fatal PE after a normal CTPA in this patient category and compare these risk to those after a normal pulmonary angiogram of 1.7 % (95 %CI 1.0-2.7 %) and 0.3 % (95 %CI 0.02-0.7 %). A patient-level meta-analysis from 4 prospective diagnostic management studies that sequentially applied the Wells rule, D-dimer tests and CTPA to consecutive patients with clinically suspected acute PE. The primary outcome was the 3-month VTE incidence after a normal CTPA. A total of 6,148 patients were included with an overall PE prevalence of 24 %. The 3-month VTE incidence in all 4,421 patients in whom PE was excluded at baseline was 1.2 % (95 %CI 0.48-2.6) and the risk of fatal PE was 0.11 % (95 %CI 0.02-0.70). In patients with a likely clinical probability the 3-month incidences of VTE and fatal PE were 2.0 % (95 %CI 1.0-4.1 %) and 0.48 % (95 %CI 0.20-1.1 %) after a normal CTPA. The 3-month incidence of VTE was 6.3 % (95 %CI 3.0-12) in patients with a Wells rule >6 points. In conclusion, this study suggests that a normal CTPA may be considered as a valid diagnostic criterion to rule out PE in the majority of patients with a likely clinical probability, although the risk of VTE is higher in subgroups such as patients with a Wells rule >6 points for which a closer follow-up should be considered.

Prevalence and Clinical Outcome of Free-Floating Thrombus Formation in Lower Extremity Deep Veins.

Most published guidelines for treatment of acute and subacute deep venous thrombosis (DVT) recommend early ambulation over initial bed rest. However, formation of free-floating thrombus in the lower extremity deep veins carries a high risk of fatal pulmonary embolism (PE) during ambulation. Furthermore, the natural history of free-floating thrombus in this patient population is not known. The purpose of this study was to identify the prevalence and outcome of free-floating thrombus among patients with acute DVT. Between January 2013 and December 2013, 427 patients were diagnosed as having DVT by compression ultrasound. The anatomic distributions of the thrombi were divided into iliofemoral, femoropopliteal, and calf DVT. The ultrasound features of the thrombi were classified as firmly or loosely attached and free-floating. PE was confirmed with computed tomography angiography. Among 427 patients with DVT, seven (1.7%) were found to have free-floating thrombus. The risk factors for DVT included recent knee surgery in two (28.5%), recent hip surgery in one (14.3%), immobilization in one (14.3%), malignant neoplasm in one (14.3%), hormone replacement therapy in one (14.3%), and stroke in one (14.3%). Initial treatment of these patients included bed rest and anticoagulation therapy. Two of these patients underwent temporary insertion of an inferior vena cava filter. The thrombus was located predominantly in the femoropopliteal segment (five patients, 71.4%), and the prevalence of femoropopliteal DVT was significantly higher in patients with free-floating thrombus than in those without (P = .0002). PE was found in three patients (42.9%), and the incidence of PE was significantly higher in patients who had free-floating thrombus than in those who did not (P = .0001). The free-floating thrombus resolved spontaneously in four patients (57.1%) within a mean period of 19 days. On the other hand, the thrombus became firmly attached to the vein wall in the remaining three patients (42.9%) within a mean period of 9 days, leading to secondary thrombus recanalization. No further thromboembolic complications were encountered in these patients. Although the prevalence of free-floating thrombus formation is low among patients with DVT, it can be detected by compression ultrasound in daily practice. Our data show that the natural history of free-floating thrombus treated by anticoagulation can be largely classified into two patterns: early spontaneous thrombus resolution and initial adhesion to the vein wall with secondary thrombus recanalization. Insertion of an inferior vena cava filter can be reserved for patients in whom anticoagulation is contraindicated.

Long‐Term Outcomes in Individuals Aged 75 and Older with Pulmonary Embolism

Long‐Term Outcomes in Individuals Aged 75 and Older with Pulmonary Embolism

Thromboembolism during neoadjuvant therapy for rectal cancer: a systematic review

Thromboembolism (TE) is a common, costly and morbid complication that is also associated with decreased survival in cancer patients. However, the risk of cancer-associated TE varies because of the multitude of patient-, cancer- and treatment-related influences. Thromboprophylaxis (TP) is currently not widely adopted in the ambulant population. A review of the literature was undertaken to determine the rate of TE and the benefit of TP in patients with rectal cancer during neoadjuvant therapy (nT). A systematic literature search of electronic databases, including PubMed and Embase, was performed (1995-2012) for all studies assessing nT in rectal cancer. Data were extracted and used to assess study design, patient demographic and clinical characteristics, treatment protocols and TE incidence. A systematic review was conducted to identify the rates of TE. The search strategy included text terms and MeSH headings for TP, rectal cancer and nT. Twelve of 86 studies met quality criteria for reporting TE complications and described 10 pulmonary emboli and three deep-vein thromboses in 3375 patients (overall TE rate = 0.38%). Ninety per cent of pulmonary emboli reported were fatal, suggesting significant under-reporting of TE events, even in high-quality studies. The risk of fatal pulmonary embolism in studies examining nT in rectal cancer that reported complications systematically was one in 375 (0.27%; 95% CI: 0.09-0.44%). The overall TE rate, as well as the effectiveness of TP during nT, remains unknown. TE events should be systematically reported using common terminology frameworks in cancer studies.

Do medical patients need to receive pharmacologic prophylaxis for the prevention of venous thromboembolism?

Acutely ill medical patients with reduced mobility are at increased risk of venous thromboembolism, which can occur during hospitalization or after discharge. A number of clinical trials and meta-analyses have shown that pharmacologic prophylaxis with anticoagulant drugs in these patients significantly reduces the risk of fatal pulmonary embolism as compared to placebo or no treatment, without significant increase in the risk of major bleeding. Thus, the use of anticoagulant prophylaxis is recommended for all high risk medical patients during hospitalization. To identify these high risk patients, clinicians may use the inclusion criteria applied in the trials, with a selection that is mostly qualitative, or risk assessment models, with a selection that is both qualitative and quantitative. With both approaches, about 40 % of medical patients would be at increased risk of venous thrombosis. Because in the real world medical patients tend to be much older and with more comorbidities than in clinical trials, patient selection needs to also take into account risk factors for bleeding. Among others, estimation of creatinine clearance appears to be particularly important to prevent excessive exposure to anticoagulant drugs. Finally, although the risk of venous thrombosis may persist in some patients after hospital discharge, clinical trials assessing extended prophylaxis in this setting have failed to show a convincing clinical benefit with this approach.

Thirty-day mortality rate in women with cancer and venous thromboembolism. Findings from the Registro Informatizado de la Enfermedad Trombo Embólica Registry

Cancer patients with venous thromboembolism (VTE) are at increased risk of mortality. Estimating the risks for specific causes of death may help to weigh the risks and benefits of different therapeutic strategies in an individual patient. In the Registro Informatizado de la Enfermedad Trombo Embólica Registry of 15 520 consecutive patients with VTE, cancer was present in 20% and was associated with a two-fold increase in the risk of fatal pulmonary embolism. In a subsequent study including 2474 women with cancer, 329 (13%) died during the first month. The incidence of fatal pulmonary embolism (n = 71) exceeded that of fatal bleeding (n = 22), except in women with cancer of the bladder or vulva. Then, we compared the mortality rate according to initial presentation in 3978 women with cancer and VTE, of whom 438 (11%) died during the first month. The risk of fatal bleeding was twice as high as the risk of fatal pulmonary embolism (12 vs. 5 deaths) in those with deep-vein thrombosis alone. The higher risk of dying from bleeding than from pulmonary embolism in some women with cancer and VTE suggests that a less aggressive anticoagulant strategy might reduce fatal bleeding more than it would increase fatal pulmonary embolism during this period.

The Future of Deep Venous Thrombosis and Post-thrombotic Syndrome in 2020

This manuscript addresses six major issues involving deep venous thrombosis (DVT) and post-thrombotic syndrome. Prevention will likely see modest advances in pharmacological therapy, mainly by extending prophylaxis in high-risk patients. More notable advances will be observed in mechanical means of prophylaxis, focusing on sustained application of devices that can move larger volumes of blood. Silent, large-vein thrombi continue to place patients at risk for fatal pulmonary embolism. Improved imaging techniques will permit us to identify these patients over the next eight years. In many of those patients, vena caval interruption will be required. Elimination of high-risk filters and the production of improved filters placed through low-profile systems with antithrombotic agents bound to their surface will improve the short- and long-term results for inferior vena cava filters. The long-term management of DVT will focus on establishing appropriate duration for the individual patient and will see the evolution towards direct Xa and IIa inhibitors. Patients with extensive DVT will more commonly receive treatment strategies designed to eliminate thrombus and restore patency. This will substantially reduce post-thrombotic morbidity and reduce recurrence. Post-thrombotic syndrome will see greater attention towards treating the intraluminal fibrosis, thereby eliminating post-thrombotic venous obstruction. Unfortunately, neovalves will still be searching for the appropriate application.

Venous thromboembolism in immobilized patients with dementia. Findings from the RIETE registry

BackgroundThe natural history of venous thromboembolism (VTE) in patients with dementia has not been thoroughly studied. MethodsWe used the RIETE Registry data to assess the clinical characteristics, treatment strategies and outcome during the first 3months after acute VTE in all immobilized patients with dementia. ResultsAs of August 2011, 37988 patients had been enrolled, of whom 1316 (3.5%) had dementia. Most patients in both subgroups were initially treated with low-molecular-weight heparin (LMWH). Then, 48% of patients with dementia and 25% of those without dementia received LMWH as long-term therapy. During the first 3months of anticoagulant therapy, patients with dementia had a higher incidence of fatal pulmonary embolism (PE): 4.0% vs. 1.2% (odds ratio: 3.3; 95% CI: 2.5-4.4) and fatal bleeding: 1.4% vs. 0.5% (odds ratio: 2.9; 95% CI: 1.8-4.6) than those without dementia. In demented patients initially presenting with PE, the incidence of fatal PE during the first week outweighed that of fatal bleeding (42 vs. 4 deaths), but from Day 8, the incidence of fatal PE was similar to the incidence of fatal bleeding. In patients initially presenting with deep vein thrombosis (DVT), there were 4 fatal PE and 8 fatal bleeding events. ConclusionsVTE patients with dementia had a high incidence of fatal PE and fatal bleeding. In those initially presenting with PE, the risk of dying of PE far outweighed that of fatal bleeding. In patients presenting with DVT alone, the risk of fatal PE was lower than that of fatal bleeding.

Prophylaxis against venous thromboembolism in hospitalized medical patients: an evidence‑based and practical approach

To discuss the evidence regarding the efficacy and safety of anticoagulant prophylaxis against deep vein thrombosis (DVT) in hospitalized medical patients; to understand barriers to implementation of prophylaxis and how they can be overcome; and to have a practical approach as to which patients should and should not receive anticoagulant prophylaxis. The frequency of DVT in hospitalized medical patients, in the absence of prophylaxis varies from 10-15%. Autopsy studies have shown that pulmonary embolism (PE) is associated with 5-10% of deaths in hospitalized patients. With appropriate use of anticoagulant prophylaxis, there is a 57% reduction in the risk for symptomatic PE (relative risk [RR] 0.43, 95% CI 0.26-0.71), a 62% reduction in the risk for fatal PE (RR 0.38, 95% CI 0.21-0.69), and a 53% reduction in the risk for symptomatic DVT (RR 0.47, 95% CI 0.22-1.00). Anticoagulant prophylaxis is also associated with a non-significant increased risk for major bleeding (RR 1.32, 95% CI 0.73-2.37). Risk factors for DVT and bleeding in medical patients may help to identify patients in whom anticoagulant prophylaxis is indicated or contraindicated but validated risk stratifications schemes are lacking. Among hospitalized medical patients, randomized trials have established an acceptable therapeutic benefit-to-risk ratio of anticoagulant prophylaxis to reduce the incidence of clinically silent and symptomatic venous thromboembolism, including a reduction in the incidence of fatal PE. Additional research is needed to develop a validated risk stratification model for hospitalized medical patients that can help identify patients who would benefit most from anticoagulant prophylaxis.

The Efficacy and Safety of Pharmacological Prophylaxis of VTE Following Elective Knee or Hip Replacement: Systematic Review and Network Meta-Analysis

Abstract 2314Venous thromboembolism (VTE) collectively describes the debilitating, painful and potentially fatal conditions of deep vein thrombosis (DVT) and pulmonary embolism (PE). High-risk surgical procedures can lead to VTE, and patients undergoing major orthopaedic surgery, such as total hip or knee replacement (THR and TKR, respectively), are in the highest risk category for VTE. In the absence of anticoagulant prophylaxis the estimated incidence of DVT following orthopaedic surgery ranges from 40–60%, and the overall risk of fatal PE has been estimated to be between 0.2 and 0.9%. Thromboprophylaxis, both mechanical and pharmacological, is current standard practice for the prevention of VTE in patients undergoing orthopaedic surgery.Currently available anticoagulant therapies such as low molecular weight heparins (LMWHs), which are most commonly used, fondaparinux, and warfarin have demonstrated efficacy but have a number of limitations. LMWHs and fondaparinux require parenteral administration and warfarin has a narrow therapeutic window which is difficult to attain.Apixaban, rivaroxaban and dabigatran are new anti-coagulants for thromboprophylaxis after orthopaedic surgery and have the advantages of oral administration and no requirement for routine laboratory monitoring. We compared the efficacy and safety of apixaban versus other anti-coagulants for the prevention of VTE following total hip replacement and total knee replacement surgery.We systematically searched MEDLINE, EMBASE, the Cochrane library and CINAHL up to July 2010 for randomised controlled trials (RCTs) evaluating apixaban, rivaroxaban, dabigatran, fondaparinux and low molecular weight heparins at European licensed doses. A series of direct and indirect comparisons and a network meta-analysis (NMA) were performed where there were sufficient data for analysis, using enoxaparin as the common control.Indirect comparisons found that dabigatran 220mg od was significantly less efficacious than apixaban 2.5mg bd for the prevention of all VTE and all-cause death in THR patients (OR 2.51; 95% CI 1.50–4.21), and in TKR patients (OR 1.72; 95% CI 1.22–2.42). Rivaroxaban 10mg odwas slightly more effective than apixaban 2.5mg bd in both THR and TKR patients (OR 0.69; 95% CI 0.38–1.25, and OR 0.83; 95% CI 0.57–1.19, respectively), but the differences were not statistically significant. For the incidence of major bleeding the adjusted indirect comparison found that dabigatran 220mg od and rivaroxaban 10mg od had higher, but not statistically significant, bleeding rates compared with apixaban 2.5mg bd. Dabigatran versus apixaban: for THR patients OR 1.13; 95% CI 0.50–2.54 and for TKR patients OR 1.75; 95% CI 0.51–5.99. Rivaroxaban versus apixaban: for THR patients OR 2.48; 95%CI 0.44–13.8 and for TKR patients OR 1.86; 95% CI0.47–7.30. Trials comparing fondaparinux with enoxaparin were only available in THR patients, and for the outcomes any DVT and major bleeding. The adjusted indirect comparison found that fondaparinux 2.5mg od had higher but non-significant rates of any DVT (OR 1.29; 95% CI 0.69–2.43) and major bleeding (OR 1.22; 95% CI 0.56–2.67) compared with apixaban 2.5mg bd. The NMA showedno significant differences between the treatments for the outcomes evaluated.Apixaban, rivaroxaban and dabigatran have demonstrated similar or improved efficacy and similar safety compared with current therapies for the prevention of VTE in patients undergoing orthopaedic surgery. Apixaban may be more effective than dabigatran and similar to rivaroxaban, whilst all three have a comparable safety profile. Considering practical and economic advantages, such as the ease of oral dosing and the substantial reduction in costs related to this, these new anti-coagulants represent an appealing alternative to conventional thromboprophylaxis regimens in patients undergoing THR and TKR surgery and may improve patient compliance and standard of care. [Display omitted] Disclosures:Cohen:Pfizer Ltd: Consultancy. Pieter:Pfizer/BMS: Employment. Marchant:Pfizer Ltd: Employment. Mitchell:Pfizer Ltd: Consultancy. Orme:Pfizer Ltd: Consultancy. Simon:BMS: Employment. Sutton:Pfizer Ltd: Consultancy. Rublee:Pfizer Ltd: Employment.

Venous Thromboembolism

Therefore, it is notastonishing that, although VTE is seen throughout the world,the rate of its clinical manifestations, deep venous thrombosis(DVT) and pulmonary embolism (PE), varies. Thus, Asianand Native American individuals have been reported to havea significantly lower rate of VTE than whites and blacks; thelatter present with the highest rate