EBM Series: Outpatient Management of DVT and PE
Objectives
To understand the prevalence and morbidity associated with deep venous thrombosis (DVT) and pulmonary embolism (PE)
To develop a framework for selecting individuals most appropriate for outpatient management of VTE
To describe outpatient options for VTE
Definitions
Pulmonary embolism (PE): blood clot formation within a branch of the pulmonary arterial system
Deep venous thrombosis (DVT): blood clot formation in a deep vein, most commonly within the lower leg, thigh, or pelvis
Venous thromboembolism (VTE): a collective term referring to both DVT and PE
Epidemiology
Approximately 900,000 diagnoses of DVT or PE in the US per year (1)
Estimated incidence of 1 per 1000 adults, although limited by underdiagnosis (2)
About two-thirds manifest as DVT, and one-third as PE (2)
30-day mortality in Medicare beneficiaries is 5.1 and 9.1 percent for DVT and PE respectively (3)
PE is responsible for about 100,000 deaths per year (1)
Who is sent home?
A 2016 study by Singer et al. found that 90% of PE and 52% of DVT patients presenting through the emergency department were hospitalized for initiation of anticoagulation and monitoring. Fifty-one percent of patient with PE in that study were considered low-risk based on sPESI score, many of whom would have been appropriate for discharge with outpatient initiation of anticoagulation (4). Several clinical decision tools exist to help clinicians risk-stratify patients, as discussed below. When utilized appropriately, these tools can be used to reduce hospitalization of otherwise low-risk patients with VTE (4-6).
5 steps to manage DVT and PE as outpatient
Adapted from: A clinical decision framework to guide the outpatient treatment of emergency department patients diagnosed with acute pulmonary embolism or deep vein thrombosis: Results from a multidisciplinary consensus panel (6):
Make the diagnosis of DVT or PE
Stratify your patient’s risk of clinical decompensation
Stratify your patient’s risk of bleeding on anticoagulation
Select and start an appropriate anticoagulant
Ensure your patient has access to medications with timely follow-up and discussion of appropriate return precautions
General inclusion and exclusion criteria
Inclusion criteria:
Age 18 to 80
BMI < 40*
Able to follow-up with PCP within 7 days
Able to comply with home medication regimen
Adequate home support
Exclusion criteria:
Known coagulopathy or currently on anticoagulation
New or active* malignancy
Renal dysfunction (CrCl < 30)
Currently on dual antiplatelet therapy
Active use of strong CYP450 3A4 agents
*relative contraindication
Step 1: Diagnosis of DVT or PE
Diagnosis of DVT
Venous duplex ultrasound
Diagnosis of PE
CT pulmonary angiography (CT-PA or CTPE)
VQ scan
Although not necessary, point-of-care or comprehensive echocardiography can be useful to identify other high-risk features discussed below
Step 2: Stratify your patient’s risk of clinical decompensation
Hemodynamic instability
SBP < 100
HR > 100 to 110
Tachypnea or hypoxia
During prehospital or ED course
INCLUDES pre-syncope and syncope (indicative of transient period of hypotension)
Clinical decision rules
Apply simplified PESI or Hestia clinical decision rule
Hestia clinical decision rule is more specific for identifying patients appropriate for outpatient management, and includes not only physiologic considerations, but social considerations as well (7)
When compared to simplified PESI, Hestia criteria has similar rates of home treatment and adverse effects, but requires less frequent over-ruling by clinician judgment (7)
High-risk imaging findings
Radiographic evidence of right heart strain on CT-PA or bedside echocardiogram
Thrombus located in the main pulmonary artery branches or “saddle” physiology
Clot in transit (visualized within the right heart) on CT or echocardiogram
High-risk lab findings
Troponin level elevation
BNP elevation
Associated high-risk DVT
Includes iliofemoral clots, extensive clot burden, and clots with associated skin changes (further discussed below)
High-risk EKG findings
New right heart strain pattern
New RBBB
Deep T-wave inversions
S1Q3T3 pattern
New-onset arrythmia (e.g. atrial fibrillation or atrial flutter)
Risk stratification of DVT
In the absence of associated PE, risk stratification of DVT is relatively simple, and involves assessing for only a few high-risk features.
Iliofemoral DVT or extensive clot burden
Associated with greater morbidity and mortality (8)
Includes those patients appropriate for mechanical thrombolysis
Phlegmasia cerulea dolens or phlegmasia alba dolens
Reddish or milky-white discoloration of the affected extremity indicative of severe venous outflow obstruction and congestion
Often associated with severe pain and extensive clot burden
Step 3: Stratify your patient’s risk of bleeding on anticoagulation
Stratifying bleeding involves consideration of multiple risk factors listed below. Although frequently used, scores such as VTE-BLEED or HAS-BLED have limited utility in the emergency department, as they are designed to quantify the risk of continued long-term anticoagulation, and not to direct the initiation of anticoagulation in acute VTE.
Risk factors:
Active bleeding or recent (< 1 month) major bleeding*
Thrombocytopenia (< 100×10^3 / µL)
Recent major surgery, trauma, or stroke
Recent epidural, neurosurgical, or cerebrospinal procedure
Active malignancy of critical site intolerant of bleeding
Intracranial, spinal, ocular, oropharyngeal, or retroperitoneal
Cirrhosis or severe liver dysfunction
Severe renal dysfunction (CrCl < 30) or ESRD on dialysis
*clinician judgment
Step 4: Select and start an appropriate anticoagulant
DOACs are the preferred agent for most patients seen in the emergency department. Pregnant patients should be started on low-molecular-weight heparin after discussion with OB/GYN or maternal-fetal medicine. Patients requiring anticoagulation with warfarin due to co-morbid conditions are not appropriate for discharge from the emergency department, as they are considered high-risk due to their co-morbidities. These patients should be started on heparin and admitted for observation and bridge to warfarin.
DOACs (e.g. apixaban and rivaroxaban)
Preferred agent for most patients
Ask about timing of other medications and ease of taking medications
Apixaban is twice daily dosing, but has lowest rate of adverse bleeding
Rivaroxaban is once daily dosing, but has higher rates of bleeding, especially GI bleeds (9)
Low molecular weight heparin (e.g. lovenox)
Preferred in pregnancy (10)
Consult OB or MFM prior to discharging a patient with VTE
Warfarin (coumadin)
Preferred in patients with severe liver dysfunction, prosthetic valves, antiphospholipid syndrome, or high-risk of bleeding requiring reversal (7, 11)
These patients should be admitted for initiation of anticoagulation with heparin bridge therapy
Step 5: Ensure your patient has access to medications with timely follow-up and discussion of appropriate return precautions
Give the first dose of anticoagulant in the emergency department, and instruct patients to return to the emergency department if they are unable to fill their prescription
Ensure patients have short-term follow-up with primary care, ideally within 7 to 10 days
Discuss signs of adverse bleeding and worsening thromboembolic disease requiring prompt return to the emergency department
AUTHORED BY : BEJAN KANGA, MD
FACULTY EDITING BY: NIK SEKOULOPOULOS, MD
References
Data and Statistics on Venous Thromboembolism. Centers for Disease Control and Prevention. Updated May 15, 2024. Retrieved from: https://www.cdc.gov/blood-clots/data-research/facts-stats/index.html.
Cushman M. Epidemiology and risk factors for venous thrombosis. Semin Hematol. 2007 Apr; 44(2):62-9.
Lutsey PL, Zakai NA. Epidemiology and prevention of venous thromboembolism. Nat Rev Cardiol. 2023 Apr; 20(4):248-262.
Singer AJ, Thode HC Jr, Peacock WF 4th. Admission rates for emergency department patients with venous thromboembolism and estimation of the proportion of low risk pulmonary embolism patients: a US perspective. Clin Exp Emerg Med. 2016 Sep; 3(3):126-131.
Bledsoe JR, Woller SC, Stevens SM, et al. Management of Low-Risk Pulmonary Embolism Patients Without Hospitalization: The Low-Risk Pulmonary Embolism Prospective Management Study. Chest. 2018 Aug; 154(2):249-256.
Kabrhel C, Vinson DR, Mitchell AM, et al. A clinical decision framework to guide the outpatient treatment of emergency department patients diagnosed with acute pulmonary embolism or deep vein thrombosis: Results from a multidisciplinary consensus panel. J Am Coll Emerg Physicians Open. 2021 Dec; 2(6):e12588.
Roy PM, Penaloza A, Hugli O, et al. Triaging acute pulmonary embolism for home treatment by Hestia or simplified PESI criteria: the HOME-PE randomized trial. Eur Heart J. 2021 Aug; 42(33):3146-3157.
Jiménez D, Aujesky D, Díaz G, et al. Prognostic significance of deep vein thrombosis in patients presenting with acute symptomatic pulmonary embolism. Am J Respir Crit Care Med. 2010 May; 181(9):983-91.
Adeboyeje G, Sylwestrzak G, Barron JJ, ET AL. Major Bleeding Risk During Anticoagulation with Warfarin, Dabigatran, Apixaban, or Rivaroxaban in Patients with Nonvalvular Atrial Fibrillation. J Manag Care Spec Pharm. 2017 Sep; 23(9):968-978.
Bates SM, Rajasekhar A, Middeldorp S, et al. American Society of Hematology 2018 guidelines for management of venous thromboembolism: venous thromboembolism in the context of pregnancy. Blood Adv. 2018 Nov 27; 2(22):3317-3359.
Pengo V, Denas G, Zoppellaro G, et al. Rivaroxaban vs warfarin in high-risk patients with antiphospholipid syndrome. Blood. 2018 Sep; 132(13):1365-1371.