Rivaroxaban for the Treatment of Pulmonary Embolism

With the advent of new oral anticoagulants (NOACs) for the treatment of deep-vein thrombosis (DVT) and/or pulmonary embolism (PE), a new era of oral anticoagulation for patients with venous thromboembolism (VTE) has begun. Rivaroxaban is the first NOAC to receive regulatory approval for the acute and continued treatment of DVT and PE, and for the secondary prevention of VTE. Here, the clinical trials of rivaroxaban in patients with VTE are reviewed, and the clinical use of rivaroxaban for patients with PE is discussed. Even though rivaroxaban will facilitate the therapeutic management of PE, its use in specific clinical situations needs further study.     

Vena caval filters: a review for intensive care specialists

Venous thromboembolism (VTE) is a common complication among patients in the intensive care unit. While anticoagulation remains standard therapy, vena caval filters are an important alternative when anticoagulation is contraindicated. To determine the safety and efficacy of vena caval filters in the treatment of VTE, a comprehensive review of the English-language medical literature was performed. Except for one randomized controlled trial, the literature supporting the use of vena caval filters consists almost exclusively of case series, which in many instances are limited by incomplete and short follow-up. While case series suggest that filters function effectively in the prevention of pulmonary embolism (2%-4% symptomatic pulmonary embolism [PE], fatal PE < 2%), recent higher quality studies indicate that filters may not provide significant additional protection to that provided by anticoagulation alone. Furthermore, filters are associated with a 2- fold increase in the incidence of recurrent DVT. Until randomized comparative studies are available, the safety and efficacy of all the available devices should be considered to be roughly equivalent. Since filters do not inhibit continued clot formation, all filter patients should receive anticoagulation for durations appropriate for their thrombotic disorder. Although extended anticoagulation may prevent thrombotic complications associated with filter placement, this strategy has yet to be experimentally tested. While many additional indications for vena caval filter use have been proposed (VTE in cancer patients, PE prophylaxis in trauma patients, etc), well-designed clinical trials demonstrating their efficacy in these situations are lacking. Further development of temporary/retrievable filters, which offer the potential to avoid the long-term complications of permanent filters, should be a research priority. Until additional data are available, vena caval filters should generally be restricted to patients with VTE who cannot receive anticoagulation.     

Rivaroxaban plus Percutaneous catheter-directed treatment for a patient with massive pulmonary embolism and colporrhagia

Massive pulmonary embolism (PE) is defined by acute PE with sustained systemic arterial hypotension that is below 90?mm?Hg for at least 15?min or requires inotropic agents (Jaff et al., 2011). For patients with absolute contraindications to thrombolysis, interventional treatment requires the removal of obstructing thrombi from the main pulmonary arteries to facilitate RV recovery and improve symptoms and survival (European Respiratory Society et al., 2014). For patients with acute PE, anticoagulation is recommended, with the objective of preventing both early death and recurrent symptomatic or fatal VTE. Rivaroxaban, an oral factor Xa inhibitor and a new oral anticoagulants, shows effective anticoagulation within hours of administration. It has a fixed-dose regimen, and requires no laboratory monitoring (EINSTEIN-PE Investigators et al., 2012). However, the efficacy and safety of rivaroxaban plus catheter-directed treatment for massive PE and bleeding is unknown. This case demonstrated that a combination of catheter-directed treatment and rivaroxaban was safe and effective in for the treatment of severe PE with vaginal bleeding.     

Fatal pulmonary embolism and fatal bleeding in cancer patients with venous thromboembolism: findings from the RIETE registry

OBJECTIVES: To examine the clinical characteristics and outcomes of cancer patients with venous thromboembolism (VTE) in order to identify factors that place these patients at an increased risk for fatal pulmonary embolism (PE) or fatal bleeding. PATIENTS AND METHODS: Registro Informatizado de la Enfermedad Trombo Embólica (RIETE) is a prospective registry of consecutive patients with symptomatic, objectively confirmed, acute VTE. RESULTS: Up to January 2006, a total of 14 391 patients with symptomatic acute VTE were enrolled in RIETE, of whom 2945 (20%) had cancer. During the 3-month follow-up period the frequency of fatal PE in cancer patients was 2.6%, and that of fatal bleeding 1.0%. These frequencies were significantly higher than in VTE patients without cancer (1.4% and 0.3%, respectively). In patients with cancer, abnormal renal function, metastatic disease, recent major bleeding and recent immobility for >or= 4 days (42% of the 108 patients who died from PE or bleeding had recent immobility) were factors independently associated with an increased risk for both fatal PE and fatal bleeding. In addition, PE diagnosis on admission was an independent risk factor for fatal PE, while body weight < 60 kg was an independent risk factor for fatal bleeding. CONCLUSIONS: Both fatal PE and fatal bleeding are more common in cancer patients with VTE than in those patients without cancer. In cancer patients, abnormal renal function, metastatic disease, recent major bleeding and recent immobility for >or= 4 days are associated with an increased risk for both fatal PE and fatal bleeding.     

Efficacy of inferior vena cava filters in anticoagulated patients

BACKGROUND AND OBJECTIVES: The benefit of an inferior vena cava (IVC) filter in addition to standard anticoagulation regimens is unknown. METHODS: We examined data for patients who received IVC filters with anticoagulation (AC-Filter) after an episode of venous thromboembolism (VTE) and compared them with data for those who received anticoagulation only (AC-Only). Outcome measures were new pulmonary embolism (PE), recurrent deep vein thrombosis (DVT), and mortality at 90 days and at 5 years. Demographic data included age, gender, and ethnicity/race, prior thromboembolic history, cancer, serum albumin, and time in therapeutic range. In addition, subsets matched for age, gender and race/ethnicity were examined in detail. RESULTS: AC-Filter patients (n = 251), when compared to AC-Only patients (n = 1377), did not differ significantly with regard to gender or cancer status, but white males in general had better outcomes. AC-Filter patients were more likely to have had a previous history of PE or VTE (P < 0.001). In comparison to AC-Only patients, AC-Filter patients had lower mean serum albumin levels (3.1 +/- 0.8 vs. 3.6 +/-0.8 mg dL(-1), P < 0.001) and were older (65 +/- 16.1 years vs. 60 +/- 17.5 years, P < 0.001). After stratification according to previous history of PE or VTE prior to the index VTE event, no differences in the outcome measures of new PE, recurrent DVT or mortality were identified between groups, but patients with a prior history of PE from either group were more likely to have a new PE (hazard ratio 1.9, P < 0.001). CONCLUSIONS: These data suggest that IVC filters may not provide any substantial additional benefit for patients who can tolerate anticoagulant therapy.     

Pulmonary embolism

The underlying disorder of pulmonary embolism (PE) is venous thromboembolism (VTE), comprising deep vein thrombosis, thrombus in transit, acute pulmonary embolism and chronic thromboembolic pulmonary hypertension (CTEPH). PE may recur and cause serious long-term complications, such as post-thrombotic syndrome and CTEPH. This short overview summarizes current concepts on pathophysiology, epidemiology, diagnosis and treatment of this common disorder.     

Cancer-associated thrombosis in Asia

Thrombosis is a common complication in cancer patients. Although the major inherited risk factors for thrombophilia are different between Asians and Caucasians, the main acquired risk factors that are associated with the development of venous thromboembolism (VTE) in Asians appear to be similar to those for Caucasians. Malignancy is the most important acquired risk factor for VTE in Asians. Recent studies have shown that the incidence of VTE is significant in Asian patients with cancer, particularly those in an advanced stage. Cancer associated VTE is more severe and associated with higher morbidity and mortality. Unprovoked VTE is associated with an increased risk of subsequent cancer diagnosis. A number of international and national guidelines are available to provide guidance to healthcare providers to treat and prevent this serious complication based on best-available evidence. Identifying cancer patients at risk for VTE and use of appropriate thromboprophylaxis in these patients can potentially improve morbidity and mortality. Although direct oral anticoagulants (DOACs) may become an attractive treatment for cancer-associated VTE, further clinical trials are needed to evaluate the safety and efficacy of DOACs directly against LMWH in cancer patients.     

Tinzaparin in outpatients with pulmonary embolism or deep vein thrombosis

BACKGROUND: The low-molecular-weight heparins (LMWHs) have been shown to be effective in the outpatient treatment of deep vein thrombosis (DVT). Data regarding outpatient use of any LMWH in pulmonary embolism (PE) or tinzaparin in DVT while transitioning therapy to a vitamin K antagonist are limited. OBJECTIVE: To determine the safety and efficacy of tinzaparin in patients with either DVT or PE being transitioned to warfarin during LMWH therapy in the outpatient setting. METHODS: All patients who were treated with at least one outpatient dose of tinzaparin for venous thromboembolism (VTE) were identified. Charts of all patients followed within the University of California Davis healthcare system were reviewed. The incidence of bleeding and recurrent thromboembolism over a minimum of the first 4 weeks to a maximum of 12 weeks after initiating anticoagulation was assessed. RESULTS: A total of 178 patients with acute VTE were treated with tinzaparin, and outcomes could be determined in 140 cases. Forty-seven percent of these patients had objectively documented PE. Only one (0.7%) case of recurrent VTE was observed. Major bleeding was documented in 5 (3.6%) and minor bleeding in 8 (5.8%) patients. Two bleeding events, both major, occurred during tinzaparin therapy. CONCLUSIONS: Outpatient use of tinzaparin during transition to warfarin therapy in the treatment of VTE, including PE, appears to be feasible in patients who are judged candidates for home therapy.     

Symptomatic subsegmental pulmonary embolism: what is the next step?

Summary. The introduction of computed tomography pulmonary angiography (CTPA) has led to an increase in the incidence of pulmonary embolism (PE) diagnosis. However, the case fatality rate is lower and the mortality rates of PE have remained unchanged, suggesting a lower severity of illness. Specifically, the multiple‐detector CTPA increased the rate of subsegmental filling defect reported in patients with suspected PE. Whether these filling defects reported on CTPA would correlate with true subsegmental PE (SSPE) on pulmonary angiography or are actually artifacts is unknown. The inter‐observer agreement for SSPE diagnosis among radiologists with varied levels of experience is low (κ of 0.38; 95% CI, 0.0–0.89). Furthermore, the clinical importance of a symptomatic SSPE diagnosed by CTPA is unclear. SSPE are frequent on pulmonary angiography in patients with a low probability ventilation‐perfusion (V/Q) scan for suspected PE. Several prospective management cohort studies have demonstrated that patients with low or intermediate V/Q scan results can be safely managed without anticoagulation by combining the scan results with the pretest probability (PTP) of PE and compression ultrasonography. Although clinical equipoise exists, the majority of patients diagnosed with SSPE on CTPA are currently treated with anticoagulant therapy. Only a small number of patients with SSPE diagnosed by CTPA and without DVT who did not receive anticoagulation treatment have been reported in the literature. None of these patients suffered recurrent symptomatic VTE (PE or DVT) during the 3‐month follow‐up period (0%; 95% CI, 0–7.4%), suggesting that SSPE might be clinically unimportant. These conclusions are only hypothesis generating and need to be confirmed in prospective clinical management studies before changing clinical practice.     

Care of patients with acute pulmonary emboli: a clinical review with cardiovascular focus

Acute pulmonary embolism (PE) is a common, multidisciplinary disease with substantial associated morbidity, mortality and healthcare expense. In this article we present a succinct review of diagnostic tools, risk stratification and medical therapies for cardiovascular care of patients with acute PE. While pulmonary angiography remains the 'gold standard' for diagnosis, a host of diagnostic modalities, interpreted in the setting of clinical probability, are available for patient assessment, including ECG, chest radiography, D-dimer, lower-extremity venous ultrasound, ventilation-perfusion scans, computed tomography and magnetic resonance angiography, and echocardiography, each with associated value. Diagnostic algorithms incorporate multiple tools in order to obtain a more comprehensive evaluation. Therapeutic anticoagulation remains the mainstay of therapy in PE. In massive PE, utilization of thrombolysis is reasonable in the absence of contraindications. Submassive PE, characterized by right ventricular dysfunction as assessed by echocardiography and ECG, is associated with higher mortality. Use of thrombolysis in submassive PE remains controversial. Catheter-directed therapies are emerging as an added approach to acute PE and have the potential to improve outcomes in PE. Use of inferior vena cava filters should be pursued in a select patient population as they serve to reduce recurrent acute PE; however, they are associated with more frequent deep venous thrombosis and provide no mortality benefit. In risk-stratified hemodynamically stable patients, an outpatient management strategy inclusive of therapeutic anticoagulation and careful clinical follow-up may be appropriate.     

Patients with a first symptomatic unprovoked deep vein thrombosis are at higher risk of recurrent venous thromboembolism than patients with a first unprovoked pulmonary embolism

Summary. Background: Previous studies are mixed as to whether patients with unprovoked pulmonary embolism (PE) have a higher rate of venous thromboembolism (VTE) recurrence after anticoagulation is discontinued than patients with unprovoked deep vein thrombosis (DVT). Objectives: To determine whether patients with unprovoked PE have a higher rate of VTE recurrence than patients with unprovoked DVT in a prospective multicenter cohort study. Patients/Methods: Six hundred and forty‐six patients with a first episode of symptomatic unprovoked VTE were treated with heparin and subsequent oral anticoagulation for 5–7 months, and were followed every 6 months for recurrent VTE after their anticoagulant therapy was discontinued. Results: Of 646 patients, 194 had isolated PE, 339 had isolated DVT, and 113 had both DVT and PE. After a mean of 18 months of follow‐up, there were 91 recurrent VTE events (9.5% annualized risk of recurrent VTE in the total population). The crude recurrent VTE rate for the isolated PE, isolated DVT and DVT and PE groups were 7.7%, 16.5% and 17.7%, respectively. The relative risk of recurrent VTE for isolated DVT vs. isolated PE was 2.1 (95% confidence interval 1.2–3.7). Conclusions: This study has demonstrated that patients with a first episode of unprovoked isolated DVT are 2.1 times more likely to have a recurrent VTE episode than patients with a first episode of unprovoked isolated PE. These findings need to be considered when determining the optimal duration of anticoagulant therapy for patients with unprovoked VTE.     

Guidelines and the use of inferior vena cava filters: a review of an institutional experience

Summary.  Background and objectives:  Based on the American College of Chest Physicians 2004 antithrombotic therapy for venous thromboembolism (VTE) and the Eastern Association for the Surgery of Trauma 2002 guidelines, placement of an inferior vena cava (IVC) filter is indicated in patients who either have, or are at high risk for, VTE, but have a contraindication or failure of anticoagulation. Our aim is to compare clinical characteristics and outcomes of patients receiving IVC filters within-guidelines (WG) and outside-of-guidelines (OOG). Methods:  The 558 patients who received an IVC filter were divided into two groups called WG or OOG. The WG group met the criteria described above and the OOG group did not have a contraindication to or a failure of anticoagulation. Results:  The WG group had 362 patients and the OOG group had 196 patients. The OOG group had one (0.5%) patient with post-filter pulmonary embolism (PE), two (1%) with IVC thrombosis, and seven (3.6%) with deep vein thrombosis (DVT). The WG group had five (1.4%) patients with post-filter PE, 13 (3.6%) with IVC thrombosis, and 34 (9.4%) with DVT. All patients who developed post-filter PE had a DVT before filter placement, and patients who did not have a prior VTE event were at a significantly lower risk of developing post-filter IVC thrombosis and PE. Conclusion:  Our data do not support the use of an IVC filter outside of guidelines in patients without prior VTE who can tolerate anticoagulation because of the low risk of developing PE.     

Venous thromboembolism in the ICU: main characteristics,diagnosis and thromboprophylaxis

Venous thromboembolism (VTE), including pulmonary embolism (PE) and deep venous thrombosis (DVT), is a common and severe complication of critical illness. Although well documented in the general population, the prevalence of PE is less known in the ICU, where it is more difficult to diagnose and to treat. Critically ill patients are at high risk of VTE because they combine both general risk factors together with specific ICU risk factors of VTE, like sedation, immobilization, vasopressors or central venous catheter. Compression ultrasonography and computed tomography (CT) scan are the primary tools to diagnose DVT and PE, respectively, in the ICU. CT scan, as well as transesophageal echography, are good for evaluating the severity of PE. Thromboprophylaxis is needed in all ICU patients, mainly with low molecular weight heparin, such as fragmine, which can be used even in cases of non-severe renal failure. Mechanical thromboprophylaxis has to be used if anticoagulation is not possible. Nevertheless, VTE can occur despite well-conducted thromboprophylaxis.     

The outcome after treatment of venous thromboembolism is different in surgical and acutely ill medical patients. Findings from the RIETE registry

BACKGROUND: The history of venous thromboembolism (VTE), and the rationale for thromboprophylaxis in surgical patients are well understood. The situation is less clear for acutely ill medical patients. OBJECTIVES: To compare the clinical presentation of VTE and clinical outcomes of immobile acutely ill medical patients with surgical patients. PATIENTS: RIETE (Registro Informatizado de la Enfermedad TromboEmbolica) is a Spanish registry of consecutively enrolled patients with objectively confirmed, symptomatic acute VTE. In this analysis, clinical characteristics of patients, details of anticoagulant therapy, and outcomes of all enrolled acutely ill medical patients with immobility >/= 4 days, and surgical patients are included. RESULTS: Of 6160 patients enrolled up to December 2003, 756 (12%) were acutely ill medical patients with immobility >/= 4 days, and 884 (14%) were surgical patients who developed VTE within 2 months of surgical intervention. Only 28% of acutely ill medical patients had received thromboprophylaxis, compared with 67% of surgical patients. During the 3-month follow-up period, both fatal pulmonary embolism (PE) and fatal bleeding occurred more frequently in acutely ill medical patients. Immobility in acutely ill medical patients, cancer, and PE were associated with a significantly higher risk of fatal PE or bleeding. CONCLUSIONS: In patients treated for VTE, the incidences of fatal PE, fatal bleeding, and major bleeding were significantly higher in acutely ill medical patients compared with surgical patients. Given the low percentage of acutely ill medical patients who had received thromboprophylaxis, increasing its use appropriately may reduce the incidence of VTE and associated complications.     

The management of venous thromboembolism in cancer patients

Venous thromboembolism (VTE), encompassing deep venous thrombosis and pulmonary embolism (PE), is a common complication of cancer and an important cause of preventable mortality in people with cancer. Because VTE can be clinically silent, fatal PE generally occurs without warning, and preventive measures are, therefore, necessary in high-risk patients. Clinical guidelines recommend the use of low-molecular-weight heparins in the treatment and prevention of VTE in patients with cancer, in addition to non-pharmacological interventions aimed at reducing thrombotic risk. Nurses have an important role in helping to identify patients at risk of developing VTE, and in the implementation of preventive or therapeutic regimens, and monitoring the development of complications. Furthermore, nurses are in an ideal position to educate patients on the importance of preventive measures and to help ensure compliance with thromboprophylactic interventions.     

Venous Thromboembolism: Exploring Incidence and Utility of Screening in Individuals With Brain Injury

ObjectiveTo determine the incidence of VTE in the population with brain injuries (BIs) using ultrasonography, and to assess the risk of pulmonary embolism (PE) development and/or bleeding complications related to anticoagulation.DesignRetrospective study.SettingAcute rehabilitation hospital.Participants238 individuals with moderate to severe BI who were routinely screened for VTE with ultrasonography on admission to rehabilitation (N=238).InterventionsNot applicable.Main Outcome MeasuresRetrospective chart review was performed to identify individuals who were diagnosed with VTE at the following 3 time points: in acute care prior to admission to rehabilitation, at the time of admission diagnosed via screening examination, and after admission to rehabilitation. Additionally, risk factors for VTE, PE, and incidence of bleeding complications related to therapeutic anticoagulation were assessed.Results123 deep vein thromboses (DVTs) were identified with 38.2% in acute care (n=47), 69.1% on admission to rehabilitation (n=85), and 7.3% during the course of rehabilitation stay (n=9). Risk factors for development of VTE included age at injury, body mass index, injury etiology, history of neurosurgical procedure, and surgery during inpatient rehabilitation. Of those who were placed on therapeutic anticoagulation due to admission diagnosis of VTE (n=50), 2% developed recurrent DVT and 2% had bleeding complications. There was zero incidence of PE.ConclusionWe demonstrated a high prevalence of VTEs identified on screening ultrasonography on admission to inpatient rehabilitation among individuals with moderate to severe BIs, and low complications related to anticoagulation. Given the findings of this study, prospective research in ultrasonography screening for VTE in moderate to severe BI is needed.     

Safety of outpatient treatment in acute pulmonary embolism

See also Baglin T. Fifty per cent of patients with pulmonary embolism can be treated as outpatients. This issue, pp 2404–5; Kovacs MJ, Hawel JD, Rekman JF, Lazo‐Langner A. Ambulatory management of pulmonary embolism: a pragmatic evaluation. This issue, pp 2406–11. Summary. Introduction: Data regarding outpatient treatment of pulmonary embolism (PE) is scarce. This study evaluates the safety of outpatient management of acute PE. Methods: This is a retrospective cohort study of consecutive patients presenting at the Ottawa Hospital with acute PE diagnosed between 1 January 2007 and 31 December 2008. PE was defined as an arterial filling defect on CTPA or a high probability V/Q scan. Patients were managed as outpatients if they were hemodynamically stable, did not require supplemental oxygenation and did not have contraindications to low‐molecular‐weight heparin therapy. Results: In this cohort of 473 patients with acute PE, 260 (55.0%) were treated as outpatients and 213 (45.0%) were admitted to the hospital. The majority of the patients were admitted because of severe comorbidities (45.5%) or hypoxia (22.1%). No outpatient died of fatal PE during the 3‐month follow‐up period. At the end of follow‐up, the overall mortality was 5.0% (95% CI, 2.7–8.4%). The rates of recurrent venous thromboembolism (VTE) in outpatients were 0.4% (95% CI, 0.0–2.1%) and 3.8% (95% CI, 1.9–7.0%) within 14 days and 3 months, respectively. The rates of major bleeding episodes were 0% (95% CI, 0–1.4%) and 1.5% (95% CI, 0.4–3.9%) within 14 days and 3 months, respectively. Four (1.5%) outpatients were admitted to the hospital within 14 days. Conclusions: A majority of patients with acute PE can be managed as outpatients with a low risk of mortality, recurrent VTE and major bleeding episodes.     

Comparative Effectiveness and Safety of Direct-acting Oral Anticoagulants and Warfarin in Patients with Venous Thromboembolism and Active Cancer: An Observational Analysis

PurposeThere is limited evidence to support the use of direct-acting oral anticoagulants (DOACs) in patients with venous thromboembolism (VTE) and active cancer. This study aimed to assess the effectiveness of DOACs versus warfarin for the prevention of recurrent VTE and major bleeding events in patients with VTE and active cancer.MethodsWe identified patients with incident VTE and active cancer who newly initiated treatment with DOACs or warfarin from Truven Health MarketScan Commercial Claims and Medicare supplemental databases. Patients were followed up from treatment initiation (index date) until the occurrence of >7-day gap in treatment, the start of the study comparator, an outcome of interest (recurrent VTE or major bleeding), inpatient death, disenrollment, or end of the study period, whichever occurred first. We controlled for confounders via propensity score matching and estimated the hazard ratios (HRs) using Cox proportional hazards regression models.FindingsA total of 9952 patients were included in the matched cohort (4976 DOACs users and 4976 warfarin users). Patient characteristics were well balanced after matching. We observed a lower incidence of recurrent VTE (3 vs 5 per 100 person-years) and major bleeding events (2 vs 3 per 100 person-years) in the DOAC group compared to warfarin group, respectively. In Cox regression models, use of DOACs (vs warfarin) was associated with a lower risk of recurrent VTE (hazard ratio (HR), 0.59; 95% CI, 0.42–0.82) and major bleeding events (HR, 0.64; 95% CI, 0.44–0.94).ImplicationsOn the basis of our findings, among patients with VTE and active cancer, DOACs offer superior effectiveness with a lower risk of bleeding when compared with warfarin for the secondary prevention of VTE.     

Vena cava filter options: what’s on the horizon?

Inferior vena cava (IVC) filters are the mainstay for pulmonary embolic prophylaxis in patients with high venous thromboembolic (VTE) risk—in particular, patients with acute VTE (deep venous thrombosis and/or pulmonary embolism) who have contraindication to therapeutic anticoagulation. Technology continues to evolve regarding IVC filters, with the most exciting changes over the past several decades including techniques of percutaneous insertion from laparotomy and retrieval of these devices. This paper will review current IVC filter designs and concepts and will discuss developments on the horizon.     

Use of Direct Oral Anticoagulants Versus Traditional Therapies for Acute Venous Thromboembolism After Direct Discharge From the Emergency Department or After Hospitalization: An Audit of 16 Canadian Hospitals

PurposeThis study compares and describes the use of direct oral anticoagulants (DOACs) versus traditional therapies (parenteral anticoagulant with or without warfarin) for acute venous thromboembolism (VTE) between individuals discharged directly from the emergency department (ED) versus those hospitalized. This study also reports patterns based on discharge from an academic, community, or rural-based site.MethodsThis retrospective medical records study included patients discharged with acute VTE (2015–2016) from 16 institutions across 4 provinces. Patients with atypical clots, other indications for anticoagulants, or an anticipated lifespan <3 months or those who were pregnant or breastfeeding were excluded.FindingsOverall, 590 individuals (30.0%) discharged from the ED and 809 (53.8%) discharged after hospitalization were studied. Hospitalized patients were significantly older, had more comorbidities (cancer, pulmonary disease, and heart failure), and were more likely to have pulmonary embolism than deep vein thrombosis. DOAC use was significantly higher in the ED cohort versus the hospitalized cohort (51.4% vs 44.3%; P < 0.004) and more common for those having lower risk of pulmonary embolisms (simplified Pulmonary Embolism Severity Index score of 0 compared with ≥1) in the ED (58.0% and 26.5%; P < 0.0001) and hospitalized cohorts (57.1% and 35.7%; P < 0.0001). Use of DOACs was lowest in academic settings (46.2%) and highest in rural sites (56.7%). Follow-up patterns were different, with specialists and VTE clinics being most common in academic sites and family physicians being most common in rural practices.ImplicationsDOACs were used in less than half of all patients, with more use in EDs and rural sites. Follow-up patterns (VTE clinic or specialist vs family physician) varied and likely contributed to therapy selection. Over time, use of DOACs is likely to increase, and patient factors (eg, those younger with fewer comorbidities) and health care contact (eg, place of discharge or availability of an ambulatory VTE clinic) will likely continue to influence practice patterns.