[Recommendations for the use of thromboprophylaxis in hospitalized patients with COVID-19 in Argentina]. / Recomendaciones para el uso de tromboprofilaxis en pacientes hospitalizados por COVID-19 en la Argentina.

Although the incidence is uncertain, some case reports suggest that COVID 19 infection is associated with an increased risk of venous thromboembolism. We suggest starting prophylactic anticoagulant therapy for all patients hospitalized with a symptomatic infection with COVID-19, unless contraindicated, with enoxaparin 40 mg SC daily if creatinine clearance is greater than 30 ml/min.

Si bien la incidencia es incierta, algunos reportes de caso sugieren que la infección por COVID 19 se asocia con un aumento del riesgo de tromboembolismo venoso. Sugerimos iniciar tromboprofilaxis a todos los pacientes hospitalizados por síntomas asociados con una infección por COVID-19, a menos que esté contraindicado, con enoxaparina 40 mg SC diariamente si el clearance de creatinina es mayor a 30 ml/min.

Recomendaciones para el uso de tromboprofilaxis en pacientes hospitalizados por COVID-19 en la Argentina / Recommendations for the use of thromboprophylaxis in hospitalized patients with COVID-19 in Argentina

Si bien la incidencia es incierta, algunos reportes de caso sugieren que la infección por COVID 19 se asocia con un aumento del riesgo de tromboembolismo venoso. Sugerimos iniciar tromboprofilaxis a todos los pacientes hospitalizados por síntomas asociados con una infección por COVID-19, a menos que esté contraindicado, con enoxaparina 40 mg SC diariamente si el clearance de creatinina es mayor a 30 ml/min.

Although the incidence is uncertain, some case reports suggest that COVID 19 infection is associated with an increased risk of venous thromboembolism. We suggest starting prophylactic anticoagulant therapy for all patients hospitalized with a symptomatic infection with COVID-19, unless contraindicated, with enoxaparin 40 mg SC daily if creatinine clearance is greater than 30 ml/min.

[Updated recommendations for venous thromboembolic prophylaxis in Argentina]. / Recomendaciones actualizadas para profilaxis de la enfermedad tromboembólica venosa en Argentina.

Venous thromboembolic disease (VTE) in hospitalized adults has high morbidity and mortality, is the origin of chronic complications and increased cost for the health system. Since the publication of recommendations for thromboprophylaxis in hospitalized patients in 2013, new alternatives and strategies have emerged, which motivated us to update our recommendations. Although there are different consensus and clinical practice guidelines, adherence to them is suboptimal. The different therapeutic alternatives for hospitalized adult patients (non-surgical, surgical non-orthopedic, with and without cancer, orthopedic an d pregnant) have been updated, paying particular attention to the drugs available in Argentina.

La enfermedad tromboembólica venosa (ETV) en adultos hospitalizados posee elevada morbimortalidad, es origen de complicaciones crónicas y determina incrementos de costos para el sistema de salud. Desde la publicación de recomendaciones de tromboprofilaxis en pacientes internados en 2013, han surgido nuevas alternativas y estrategias, que nos motivaron a actualizar nuestras recomendaciones. A pesar de que existen diferentes consensos y guías de práctica clínica la adherencia a las mismas es subóptima. Se han actualizado las diferentes alternativas terapéuticas para los adultos hospitalizados (clínicos no quirúrgicos, quirúrgicos no ortopédicos, con y sin cáncer, ortopédicos y embarazadas), poniendo particular atención en los fármacos disponibles en Argentina.

Recomendaciones actualizadas para profilaxis de la enfermedad tromboembólica venosa en Argentina / Updated recommendations for venous thromboembolic prophylaxis in Argentina

La enfermedad tromboembólica venosa (ETV) en adultos hospitalizados posee elevada morbimortalidad, es origen de complicaciones crónicas y determina incrementos de costos para el sistema de salud. Desde la publicación de recomendaciones de tromboprofilaxis en pacientes internados en 2013, han surgido nuevas alternativas y estrategias, que nos motivaron a actualizar nuestras recomendaciones. A pesar de que existen diferentes consensos y guías de práctica clínica la adherencia a las mismas es subóptima. Se han actualizado las diferentes alternativas terapéuticas para los adultos hospitalizados (clínicos no quirúrgicos, quirúrgicos no ortopédicos, con y sin cáncer, ortopédicos y embarazadas), poniendo particular atención en los fármacos disponibles en Argentina.

Venous thromboembolic disease (VTE) in hospitalized adults has high morbidity and mortality, is the origin of chronic complications and increased cost for the health system. Since the publication of recommendations for thromboprophylaxis in hospitalized patients in 2013, new alternatives and strategies have emerged, which motivated us to update our recommendations. Although there are different consensus and clinical practice guidelines, adherence to them is suboptimal. The different therapeutic alternatives for hospitalized adult patients (non-surgical, surgical non-orthopedic, with and without cancer, orthopedic an d pregnant) have been updated, paying particular attention to the drugs available in Argentina.

Prevalence of Deep Vein Thrombosis in Hospitalized Patients With Suspected Pulmonary Embolism Ruled Out by Multislice CT Angiography.

Current evidence suggests that for outpatients with suspected pulmonary embolism (PE), multislice computed tomographic angiography (CTPA) is sufficient to rule out PE. However, the accuracy of CTPA alone has not been established for hospitalized patients. Our goal was to determine the prevalence of deep vein thrombosis (DVT) in hospitalized patients who had PE ruled out by CTPA. We conducted a prospective cohort study of patients who developed symptoms indicative of PE, after being admitted to the hospital for any reason other than PE and were evaluated with multislice CTPA. The main outcome was proximal DVT. Between November 2011 and December 2014, 191 hospitalized patients were screened. A total of 99 patients satisfied our inclusion criteria. The average length of hospitalization for this group was 14 days (range: 2-127 days). While hospitalized, 54 (28%) patients underwent a major surgical procedure and 80 (79%) were receiving thromboprophylaxis. Of the 99 patients included, 7 (7.07%; 95% confidence intervals [CIs]: 3.4-13.8) were diagnosed with a proximal DVT. The likelihood of developing a proximal DVT was higher for those with subtle and nonspontaneously reported symptoms of DVT, odds ratio [OR] was 50.93 (95% CI: 5.35-2572) and for those classified as PE likely OR was 37.54 (95% CI: 4.05-186.1). Given the prevalence of DVT in hospitalized patients with suspected PE ruled out by a negative multislice CTPA, our study suggests that compression ultrasonography would, in fact, be justified for patients with these characteristics.

The importance of post thrombotic syndrome as an outcome after deep venous thrombosis: A survey of Canadian thrombosis clinicians.

OBJECTIVES: The development of post thrombotic syndrome (PTS) is a major source of morbidity and reduced quality of life. We sought to determine the value assigned by clinicians to post thrombotic syndrome and whether clinicians believe that any post thrombotic syndrome or severe post thrombotic syndrome are important outcomes to assess after deep vein thrombosis (DVT) as compared to other outcomes. DESIGN: The design of the study was a self-responded electronic survey. Questions for the online survey were designed by two authors (R.I. and E.G.). METHODS: The survey was distributed to 233 members of Thrombosis Canada and the Canadian Society for Vascular Surgery between August 2014 and October 2014. RESULTS: There were 84 responses to the survey with complete responses were obtained from 71 respondents for a response rate of 36%. PTS was ranked as a significantly less important outcome after DVT than recurrent DVT, pulmonary embolism during treatment, major bleeding, death, quality of life, venous ulceration and severe post thrombotic syndrome (all comparisons p<0.05 by two sample t-test). CONCLUSIONS: Our survey determined that "any post thrombotic syndrome" is perceived by physicians as less important than other DVT outcomes. Thus, "Severe PTS" and not "Any PTS" should be included as an outcome measure in studies investigating acute DVT.

A new prognostic strategy for adult patients with acute pulmonary embolism eligible for outpatient therapy.

We sought to derive a parsimonious predictive model to identify a subgroup of patients that will experience a low number of adverse events within 14 days of the diagnosis of pulmonary embolism. Retrospective cohort study of adult patients with acute pulmonary embolism at the Ottawa Hospital between 2007 and 2012. Primary outcome was defined as the composite of all-cause mortality, recurrent venous thromboembolism and major bleeding within 14 days. Multivariate logistic regression models were fit to model the occurrence of the primary outcome so as to guide either outpatient therapy or early discharge after initial admission. Calibration and discrimination were assessed in both the derivation and internal validation cohorts. 1143 patients were included, of whom 42% were treated as outpatients. At pulmonary embolism diagnosis, final score to predict the primary outcome included age, malignancy, intravenous drug or oxygen requirement and systolic blood pressure <90 mmHg, with an area under the curve (AUC) of 0.79 (95% CI 0.73-0.84) and 0.82 (95% CI 0.75-0.89) in the derivation and validation cohorts respectively. Conversely, final score to predict primary outcome after initial admission included age, malignancy, intravenous drug requirement and systolic blood pressure <90 mmHg (AUC: 0.70 (95% CI 0.64-0.76) and 0.72 (95% CI 0.66-0.79) in the derivation and validation cohorts). We have developed two simple clinical scores that may identify patients with pulmonary embolism at low risk of clinically meaningful outcomes during the first 14 days of follow up.

Direct oral factor Xa inhibitors for the prevention of non-central nervous systemic embolism patients with non-valvular atrial fibrillation - a systematic review and meta-analysis.

BACKGROUND: The aim of this systematic review and meta-analysis was to evaluate the efficacy of direct oral factor Xa inhibitors for preventing non-central nervous systemic embolism in patients with non-valvular atrial fibrillation. METHODS: We conducted a systematic review of the following databases: Ovid MEDLINE, EUROPUBMED, EMBASE, and the Cochrane Central Register of Controlled Trials, from July 1st 1990 to April 1st, 2015. Randomised controlled trials were included if they reported the outcomes of patients with non-valvular atrial fibrillation treated with a direct oral factor Xa inhibitors compared to a vitamin K antagonist. The primary outcome was objectively confirmed as non-central nervous systemic embolism and ischaemic stroke was the secondary outcome. The random-effects model odds ratio was used as the outcome measure. RESULTS: Our initial search identified 987 relevant articles, of which three satisfied our inclusion criteria and were included. Compared to vitamin K antagonists targeting an INR between 2 and 3, direct oral factor Xa inhibitors alone did not reduce the incidence of non-central nervous systemic embolism [OR 0.63 (95 % CI 0.30 - 1.35)] or ischaemic stroke [OR 1.06 (95 % CI 0.86 - 1.32)]. CONCLUSIONS: As a drug class, direct oral factor Xa inhibitors do not reduce the incidence of non-central nervous systemic embolism (or ischaemic stroke) in patients with non-valvular atrial fibrillation. Selecting drugs for the prevention of non-central nervous systemic embolism in patients with non-valvular atrial fibrillation should be based on individual drug efficacy data, rather than class data.

Antiphospholipid antibodies and lower extremity peripheral arterial disease - a systematic review and meta-analysis.

BACKGROUND: Despite being an important risk factor for venous thromboembolism and ischaemic stroke, the role of antiphospholipid antibodies in patients with peripheral arterial disease remains a matter of debate. The aim of this study was to evaluate the association of persistently elevated antiphospholipid antibodies and lower extremity peripheral arterial disease. METHODS: We conducted a systematic review of electronic databases including MEDLINE, EUROPUBMED and EMBASE to assess the prevalence of antiphospholipid antibodies in patients with lower extremity peripheral arterial disease. Case-control studies were included if they reported the prevalence of antiphospholipid antibodies in patients with lower extremity peripheral arterial disease. Two reviewers (FV and EG) independently assessed the eligibility of all articles. The primary outcome measure was the odds ratio (OR) for the prevalence of antiphospholipid antibodies patients with lower extremity peripheral arterial disease, along with the corresponding 95 % confidence intervals (CIs). RESULTS: Our initial electronic search identified 128 relevant abstracts, of which two studies were included. Antiphospholipid antibodies were found in 50/571 patients with lower extremity peripheral arterial disease and 13/490 of the controls, OR 3.32 (95 % CI = 1.49 to 7.4). In those with critical limb ischaemia, the prevalence of antiphospholipid antibodies was elevated compared to controls, pooled OR 4.78 (95 % CI = 2.37 to 9.65). CONCLUSIONS: Our systematic review and meta-analysis suggests that the prevalence of persistently elevated levels of antiphospholipid antibodies is increased in patients with lower extremity peripheral diseases when compared to healthy controls, especially in those with critical limb ischaemia.

Timing of vitamin K antagonist re-initiation following intracranial hemorrhage in mechanical heart valves: Systematic review and meta-analysis.

BACKGROUND: While evidence supports resumption of vitamin K antagonists (VKAs) among mechanical heart valve (MHV) patients presenting with anticoagulant-associated intracranial hemorrhage (ICH), ideal timing of resumption is uncertain. OBJECTIVE: To determine the optimal timing of VKA re-initiation and its associated clinical outcomes. METHODS: We performed a systematic review and a meta-analysis of studies published from January 1950 to August 2015. We extracted data on the location of initial ICH, use of cranial surgery, presence of atrial fibrillation, MHV type and position, number of MHVs, and timing of VKA resumption. Outcomes including valve thrombosis, thromboembolic events or ICH recurrence were recorded. Meta-regression analysis was conducting with controlling for covariates. We calculated absolute risks, and assessed the effect of anticoagulant resumption timing on ICH recurrence. RESULTS: 23 case-series and case-reports were identified. Overall ICH recurrence was 13% (95% confidence interval [CI], 7%-25%), while valve thrombosis and ischemic strokes occurred at 7% (95% CI, 3%-17%) and 12% (95% CI, 5%-23%) respectively. A trend towards lower ICH recurrence was observed with delayed VKA resumption (slope estimate -0.2154, p=0.10). Recurrence rate ranged from 50% with VKA resumption at 3days to 0% with resumption at 16days. CONCLUSION: Among patients with MHV, there is inadequate data to suggest an optimal timing of VKA re-initiation following an ICH, though delayed restart appears to be protective against recurrence but is associated with higher risk of thrombosis. Our analysis suggests 4-7days might be an ideal time with least risk of thrombosis or ICH recurrence.

Long-term risk of venous thrombosis after stopping anticoagulants for a first unprovoked event: A multi-national cohort.

BACKGROUND: Choosing short-term (3-6 months) or indefinite anticoagulation after a first unprovoked venous thromboembolic event (VTE) is a common and difficult clinical decision. The long-term absolute risk of recurrent VTE after a first unprovoked VTE, in all patients and sub-groups, is not well established, hindering decision making. METHODS: We conducted a multi-center multi-national prospective cohort study in first unprovoked VTE patients to establish the long-term risk of recurrent VTE after short-term anticoagulation in first unprovoked VTE patients (and sub-groups).We followed patients for symptomatic suspected VTE off of OAT. Suspected recurrent VTE was investigated with reference to baseline imaging and then independently and blindly adjudicated. FINDINGS: We recruited 663 participants between October, 2001 and March 2006 with the last follow-up in April 2014. During a mean 5.0 years of follow-up, 165/663 suspected VTE (in 408 patients) were adjudicated as recurrent VTE resulting in an annualized risk of recurrent VTE of 5.0% (95% CI: 4.2-5.8%) with a cumulative risk of 29.6% at 8 years. Men had a 7.6% (95% CI: 6.3-9.2%) annual risk of recurrent VTE. High risk women (2 or more HERDOO2 points; see text) had an annual risk of recurrent VTE of 5.9% (95% CI: 4.2-8.1%). Low risk women (1 or 0 HERDOO2 points) had 1.1% (95% CI: 0.6-2.0%) annual risk of recurrent VTE with a cumulative risk of 8.7% at 8 years. INTERPRETATION: Men and high risk women with unprovoked VTE should be considered for long-term anticoagulant therapy given a high risk of recurrent VTE after long-term follow-up. Women with a low HERDOO2 score may be able to safely discontinue anticoagulants. FUNDING: This study was funded by the Canadian Institutes of Health Research (Grant # MOP 64319) and Heart and Stroke Foundation of Ontario (Grant # NA 6771). Registered at www.clinicaltrials.gov identifier: NCT00261014.

Prevalence and Geographical Variation of Prothrombin G20210A Mutation in Patients with Cerebral Vein Thrombosis: A Systematic Review and Meta-Analysis.

OBJECTIVES: To compare the prevalence of prothrombin G20210A in patients with objectively confirmed cerebral vein or cortical vein thrombosis against healthy controls, and evaluate geographical variations. DESIGN: Systematic review and meta-analysis of case control studies. METHODS: We conducted a systematic review of electronic databases including MEDLINE and EMBASE. The main outcome was the prevalence of prothrombin G20210A in patients with objectively confirmed cerebral vein or cortical vein thrombosis; we also analyzed individual country variations in the prevalence. The random-effects model OR was used as the primary outcome measure. RESULTS: In total 19 studies evaluated 868 cases of cerebral venous thrombosis and 3981 controls. Prothrombin G20210A was found in 103/868 of the patients with cerebral venous thrombosis and 105/3999 of the healthy controls [random effects pooled OR 5.838, 95% CI 3.96 to 8.58; I217.9%]. The prevalence of prothrombin G20210A was significantly elevated in Italian studies (OR 9.69), in Brazilian studies (OR 7.02), and in German studies (OR 3.77), but not in Iranian studies (OR 0.98). CONCLUSION: Prothrombin G20210A is significantly associated with cerebral venous thrombosis when compared to healthy controls, although this association is highly dependent on the country of origin.

Risk of major bleeding in patients receiving vitamin K antagonists or low doses of aspirin. A systematic review and meta-analysis.

UNLABELLED: Prior meta-analysis and observational studies have suggested that the bleeding risks associated with anticoagulation using vitamin K antagonists (VKA) or aspirin (ASA) are similar. OBJECTIVE: The aim of this systematic review was to provide the odds ratios (ORs) of major bleeding, intracranial bleeding or major extra-cranial bleeding of anticoagulation with VKA compared to low doses of ASA. METHODS: We conducted a systematic review of Ovid MEDLINE, Embase and the Cochrane Central Register of Controlled Trials (RCT). Randomized controlled trials reporting bleeding rates in adult patients randomized to a VKA (INR 2-3) or to ASA alone (<325mg daily). Random effects OR were calculated. RESULTS: Fifteen trials reporting the outcome of 2511 participants treated with VKA alone and 2471 treated with ASA alone were included; most common conditions evaluated were non-valvular atrial fibrillation (five trials) and heart failure (three trials). Overall, the use of VKA was associated with an increased risk of major bleeding (OR 1.76 (95% CI 1.33-2.33) when compared to ASA. The OR associated with VKA use for intracranial bleeding and extra-cranial bleeding were 1.74 (95% CI 0.83-3.62) and 1.66 (95% CI 0.94-2.92), respectively. In trials achieving good control of anticoagulation [time in therapeutic range (TTR) >65%], the risk of bleeding with VKA was similar to that of ASA [OR 1.16 (95% CI 0.79-1.71)]. CONCLUSION: Contrary to prior reports our results suggest that the risk of major bleeding with the use VKA is higher compared to those of patients treated with ASA alone. However, in patients achieving a good TTR, the risk of major bleeding with VKA or ASA is similar.

Aspirin Compared to Low Intensity Anticoagulation in Patients with Non-Valvular Atrial Fibrillation. A Systematic Review and Meta-Analysis.

BACKGROUND: Despite its lack of efficacy, aspirin is commonly used for stroke prevention in atrial fibrillation. Since prior studies have suggested a benefit of low-intensity anticoagulation over aspirin in the prevention of vascular events, the aim of this systematic review was to compare the outcomes of patients with non-valvular atrial fibrillation treated with low-intensity anticoagulation with Vitamin K antagonists or aspirin. METHODS: We conducted a systematic review searching Ovid MEDLINE, Embase and the Cochrane Central Register of Controlled Trials, from 1946 to October 14th, 2015. Randomized controlled trials were included if they reported the outcomes of patients with non-valvular atrial fibrillation treated with a low-intensity anticoagulation compared to patients treated with aspirin. The primary outcome was a combination of ischemic stroke or systemic embolism. The random-effects model odds ratio was used as the outcome measure. RESULTS: Our initial search identified 6309relevant articles of which three satisfied our inclusion criteria and were included. Compared to low-intensity anticoagulation, aspirin alone did not reduce the incidence of ischemic stroke or systemic embolism OR 0.94 (95% CI 0.57-1.56), major bleeding OR 1.06 (95% CI 0.42-2.62) or vascular death OR 1.04 (95% CI 0.61-1.75). The use of aspirin was associated with a significant increase in all-cause mortality OR 1.66 (95% CI 1.12-2.48). CONCLUSION: In patients with non-valvular atrial fibrillation, aspirin provides no benefits over low-intensity anticoagulation. Furthermore, the use of aspirin appears to be associated with an increased risk in all-cause mortality. Our study provides more evidence against the use aspirin in patients with non-valvular atrial fibrillation.

Haematological problems in obstetrics.

Physiologic changes occur during pregnancy, which influence normal haematologic values and impact the diagnosis and management of haematologic disease in pregnancy. Physiologic changes of pregnancy also commonly lead to mimicking symptoms of haematologic disease that may prompt investigations for haematologic disease. The toxicity and radiation associated with the diagnostic imaging and pharmacologic management of both benign and malignant haematological conditions during pregnancy present unique challenges. Strategies for diagnosis and treatment must weigh the benefits and risks to the mother while also taking foetal outcome into consideration. In this review, we highlight the common haematologic diseases encountered by obstetricians and try to provide guidance for the most prevalent diagnostic and therapeutic questions. At the other end of the spectrum, we also comment on less common but very challenging haematologic diseases in pregnancy that require multidisciplinary effort to arrive at difficult individual diagnostic and treatment decisions.

Clinical and safety outcomes associated with treatment of acute venous thromboembolism: a systematic review and meta-analysis.

IMPORTANCE: Many anticoagulant strategies are available for the treatment of acute venous thromboembolism, yet little guidance exists regarding which drug is most effective and safe. OBJECTIVE: To summarize and compare the efficacy and safety outcomes associated with 8 anticoagulation options (unfractionated heparin [UFH], low-molecular-weight heparin [LMWH], or fondaparinux in combination with vitamin K antagonists); LMWH with dabigatran or edoxaban; rivaroxaban; apixaban; and LMWH alone) for treatment of venous thromboembolism. DATA SOURCES: A systematic literature search was conducted using MEDLINE, EMBASE, and the evidence-based medicine reviews from inception through February 28, 2014. STUDY SELECTION: Eligible studies were randomized trials reporting rates of recurrent venous thromboembolism and major bleeding in patients with acute venous thromboembolism. Of the 1197 studies identified, 45 trials including 44,989 patients were included in the analyses. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently extracted trial-level data including number of patients, duration of follow-up, and outcomes. The data were pooled using network meta-analysis. MAIN OUTCOMES AND MEASURES: The primary clinical and safety outcomes were recurrent venous thromboembolism and major bleeding, respectively. RESULTS: Compared with the LMWH-vitamin K antagonist combination, a treatment strategy using the UFH-vitamin K antagonist combination was associated with an increased risk of recurrent venous thromboembolism (hazard ratio [HR], 1.42; 95% credible interval [CrI], 1.15-1.79). The proportion of patients experiencing recurrent venous thromboembolism during 3 months of treatment were 1.84% (95% CrI, 1.33%-2.51%) for the UFH-vitamin K antagonist combination and 1.30% (95% CrI, 1.02%-1.62%) for the LMWH-vitamin K antagonist combination. Rivaroxaban (HR, 0.55; 95% CrI, 0.35-0.89) and apixaban (HR, 0.31; 95% CrI, 0.15-0.62) were associated with a lower risk of bleeding than was the LMWH-vitamin K antagonist combination, with a lower proportion of patients experiencing a major bleeding event during 3 months of anticoagulation: 0.49% (95% CrI, 0.29%-0.85%) for rivaroxaban, 0.28% (95% CrI, 0.14%-0.50%) for apixaban, and 0.89% (95% CrI, 0.66%-1.16%) for the LMWH-vitamin K antagonist combination. CONCLUSIONS AND RELEVANCE: Using meta-analytic pooling, there were no statistically significant differences for efficacy and safety associated with most treatment strategies used to treat acute venous thromboembolism compared with the LMWH-vitamin K antagonist combination. However, findings suggest that the UFH-vitamin K antagonist combination is associated with the least effective strategy and that rivaroxaban and apixaban may be associated with the lowest risk for bleeding.

Management of pregnancy associated venous-thromboembolism: a survey of practices.

INTRODUCTION: Low-molecular-weight heparin (LMWH) is frequently recommended for the treatment of pregnancy associated venous thromboembolism (PAVTE). Given that prior reports have suggested a wide variation in dosing of LMWH in pregnancy and the use of anti-Xa monitoring in pregnancy, the principal aim of this survey was to assess current practices for the management of PAVTE. METHODS: An electronic survey was conducted. The target sample was members of the North American Society of Obstetric Medicine and Thrombosis Interest Group of Canada. RESULTS: The final sample consisted of 27/69 hematologists (39.1%), 30/69 internists (43.5%), 8/69 obstetricians (11.6%), and 4/69 from other specialties (5.7%). For the acute treatment of patients pregnant patients with deep vein thrombosis 42/69 (60.8%) preferred LMWH given twice a day 42/69 (60.8%), whereas 25/69 (36.2%) preferred once daily. These results were similar for patients with pulmonary embolism (PE). For long-term treatment more than 70% of the respondents favoured treatment with full doses of LMWH given once a day or twice a day and 16/69 (23.2%) intermediate doses for patients diagnosed with DVT. These results were similar for patients with PE. Fourteen physicians out of 69 (20.3%) did not measure anti-Xa monitoring during acute treatment period and 24/69 (34.8%) never used anti-Xa levels during the long term treatment period. Management during the peri-partum period varied widely according to the time of the diagnosis of PAVTE. DISCUSSION: In conclusion, our survey shows wide variation in practice regarding LMWH dosing and anti-Xa monitoring in pregnancy associated VTE and calls for trials comparing different long term strategies using LMWH in patients with PAVTE.