DVT and PE, start to finish.
DVT and PE workup and treatment: Wells and D-dimer, the 2026 AHA/ACC PE categories, choosing DOAC vs LMWH vs UFH, US-label doses with renal cutoffs, duration, distal DVT, subsegmental PE and filters.
Reviewed October 2026 · verify against current guidelines
Two tools, one page — score and image suspected PE in the PE pathway. Once VTE is confirmed, the VTE treatment tool returns eligible agents and US-label doses from weight, CrCl, cancer, pregnancy, APS and interacting drugs. Prophylaxis lives in thromboprophylaxis.
DVT and PE · 1 of 6
Suspected DVT: score, D-dimer, ultrasound.
Two-level Wells score for DVT (1 point each unless stated)
| Cancer | Active cancer: treatment ongoing, within 6 months, or palliative. |
|---|---|
| Immobile leg | Paralysis, paresis or recent plaster cast of the leg. |
| Bed or surgery | Bedridden 3 days or more, or major surgery under general or regional anesthesia within 12 weeks. |
| Tenderness | Localized along the deep venous system. |
| Swelling | Entire leg swollen (1). Calf at least 3 cm larger than the other side (1). Pitting edema in the symptomatic leg only (1). |
| Veins | Collateral superficial veins, not varicose. |
| History | Previously documented DVT. |
| Alternative | Another diagnosis at least as likely: minus 2. |
| Read it | 2 or more: DVT likely. 1 or less: DVT unlikely. |
Testing strategy by pretest probability (ASH 2018)
| Unlikely (low, about 10% or less) | Start with a highly sensitive D-dimer (strong). Negative: DVT excluded, no imaging, no anticoagulation. Positive: proximal or whole-leg ultrasound. Negative ultrasound in this group needs no more testing. |
|---|---|
| Intermediate (about 25%) | Whole-leg ultrasound, or proximal ultrasound repeated once at 1 week if negative and nothing else explains the leg. D-dimer first is acceptable when prevalence is about 15% or lower. |
| Likely (high, 50% or more) | Ultrasound first. A negative first scan with no alternative diagnosis gets a repeat. |
| Never | A positive D-dimer alone does not diagnose DVT, at any probability. |
| Recurrent DVT | D-dimer first if unlikely; otherwise proximal ultrasound, compared with prior images. A new segment, or a rise in noncompressibility of more than 4 mm, signals recurrence. |
D-dimer pitfalls — limited value in inpatients, after surgery and in pregnancy, because most results are positive (ASH 2018). It must be a highly sensitive assay. NICE suggests considering an age-adjusted threshold for people over 50. For likelihood-ratio thinking, see likelihood ratios.
DVT deep vein thrombosisPE pulmonary embolismVTE venous thromboembolismPTP pretest probability
DVT and PE · 2 of 6
Suspected PE: route it, then rank it.
Diagnosis, briefly
Low or intermediate probability: D-dimer first, and a negative result ends the workup. High probability or a positive D-dimer: image. ASH 2018 accepts V/Q or CTPA after a positive D-dimer; V/Q may be preferred to limit radiation where it is available and likely to be diagnostic, and CTPA is preferred when it is not (abnormal chest x-ray, lung disease). The 2026 AHA/ACC summary calls CTPA the standard test, with V/Q when CTPA is not an option. Wells, PERC, YEARS, age-adjusted D-dimer and sPESI are scored in the PE pathway; they are not repeated here.
Pregnancy — ASH 2018 (pregnancy rec 30) suggests V/Q over CTPA. The PE pathway applies the 2026 AHA/ACC approach: the pregnancy-adapted YEARS algorithm and low-dose CTPA.
2026 AHA/ACC acute PE clinical categories (AHA Top Things to Know)
| A | Asymptomatic, found incidentally. Can be discharged home from the ED without admission. |
|---|---|
| B | Symptomatic with a low clinical severity score. Early discharge is generally recommended. |
| C | Symptomatic with an elevated severity score, plus elevated biomarkers and/or RV dysfunction. Hospitalize. |
| D | Incipient cardiopulmonary failure. Hospitalize; advanced therapy can be considered (D1 to D2). |
| E | Cardiopulmonary failure with persistent hypotension. Advanced therapy is reasonable in E1. |
| Subcategories | B1 to E2 and the respiratory modifier are assigned in the PE pathway. |
Home treatment for PE: two validated gates
| Hestia (all must be no) | Unstable; needs lysis or embolectomy; active bleeding or high bleeding risk; oxygen over 24 h to keep SpO2 above 90%; PE on anticoagulation; IV pain medicine over 24 h; medical or social reason to stay over 24 h; CrCl under 30; severe liver impairment; pregnancy; history of HIT. |
|---|---|
| sPESI 0 (1 point each) | Age over 80; cancer; chronic cardiopulmonary disease; SBP under 100; heart rate 110 or more; SaO2 under 90%. sPESI alone does not screen for social reasons to admit. |
| Evidence | HOME-PE (1,975 randomized): 30-day recurrence, major bleeding or death 3.82% (34/891) with Hestia vs 3.57% (32/896) with sPESI, per protocol; noninferior. Treated at home (intention to treat): 38.4% with Hestia and 36.6% with sPESI. |
| Guidelines | CHEST 2021 recommends outpatient treatment for low-risk PE when home circumstances are adequate (strong). ASH 2020 suggests home over hospital (conditional). 2026 AHA/ACC: categories A and B can usually go home. |
CTPA CT pulmonary angiographyV/Q ventilation-perfusion scansPESI simplified Pulmonary Embolism Severity IndexRV right ventricleHIT heparin-induced thrombocytopenia
DVT and PE · 3 of 6
Choose the drug before the dose.
Default choices
- A DOAC over a VKA for the first 3 months: CHEST 2021 (strong) and 2026 AHA/ACC; ASH 2020 suggests the same.
- No DOAC is preferred over another (ASH 2020). Choose on lead-in need, once- vs twice-daily dosing, kidney function, interacting drugs, cancer and cost.
- Apixaban and rivaroxaban start orally. Dabigatran and edoxaban need 5 to 10 days of parenteral anticoagulation first (labels).
- When parenteral therapy is needed, LMWH over UFH (2026 AHA/ACC). Exception: unstable PE or possible thrombolysis or embolectomy, where continuous UFH comes first (NICE NG158 1.3.12; apixaban and rivaroxaban labels).
- Suspend aspirin taken for stable cardiovascular disease while anticoagulated, unless there is a recent ACS or stent (ASH 2020).
Situations that change the drug
| Cancer | Apixaban, edoxaban or rivaroxaban over LMWH (CHEST 2021, strong). ASH 2021: apixaban, rivaroxaban or LMWH to start (#20), LMWH over UFH (#21, strong), and a DOAC (apixaban, edoxaban or rivaroxaban) over LMWH for the first 3 to 6 months (#23). With luminal GI cancer, edoxaban and rivaroxaban caused more GI major bleeding than LMWH; apixaban or LMWH may be preferred. Dabigatran is in neither list. |
|---|---|
| Pregnancy | LMWH over UFH (ASH 2018, strong). DOACs and VKAs are avoided because of fetal risk. Once- or twice-daily dosing; no routine anti-Xa monitoring. Exception: a mechanical valve needs a specialist regimen (see below). |
| APS | Any confirmed APS: VKA preferred over a DOAC — CHEST 2021 #17 (adjusted-dose VKA, target INR 2.5, weak, with parenteral overlap) and EULAR 2019 #4A (VKA, INR 2 to 3; a DOAC only if the INR target cannot be reached or a VKA is contraindicated). Triple-positive (lupus anticoagulant, anticardiolipin and anti-β2-glycoprotein I): all four DOAC labels say not recommended, and EULAR says no rivaroxaban. |
| CrCl under 30 | Dabigatran has no label dose at 30 or less. Rivaroxaban: limited data at 15 to 29, avoid under 15. Edoxaban: not recommended under 15. Apixaban: no label adjustment, including dialysis, based on pharmacokinetic data. Enoxaparin: 1 mg/kg once daily. UFH is an option (NICE 2020; ASH 2018). |
| Obesity | Enoxaparin by actual body weight, not a capped dose, without routine anti-Xa monitoring (ASH 2018). The labels give no weight-based dose for apixaban, rivaroxaban or dabigatran. NICE suggests considering drug-level monitoring under 50 kg or over 120 kg. |
| Interacting drugs | With a P-gp or strong CYP3A4 inhibitor or inducer, ASH 2018 suggests a VKA or LMWH over a DOAC. Label specifics are in the tool and section 4. |
| Breastfeeding | UFH, LMWH and warfarin are safe options; ASH 2018 recommends against DOACs. |
Liver and valves (US labels)
| Liver | Rivaroxaban and edoxaban: avoid in Child-Pugh B or C. Apixaban: no dose for Child-Pugh B; not recommended in C. Dabigatran: no hepatic dosing statement; ASH 2020 says the DOAC preference may not apply in moderate to severe liver disease. |
|---|---|
| Mechanical valve | DOACs are contraindicated (2020 ACC/AHA, class 3; dabigatran label: contraindicated). Use warfarin, with the INR target set by cardiology (2020 ACC/AHA: mitral 3.0; aortic 2.5, or 3.0 with risk factors such as a hypercoagulable state). APS is a hypercoagulable state, so with APS an aortic valve also takes 3.0; confirm with cardiology. In pregnancy, the regimen is set with cardiology and maternal-fetal medicine: 2020 ACC/AHA calls warfarin through pregnancy reasonable when the dose needed is 5 mg/day or less (2a); if more is needed, dose-adjusted LMWH (at least twice daily, anti-Xa 0.8 to 1.2 U/mL 4 to 6 hours after the dose) in the first trimester, then warfarin (2a), or LMWH throughout (2b). Ideally switch to LMWH or IV UFH at least 1 week before planned delivery, then to UFH at least 36 hours before; stop UFH at least 6 hours before a planned vaginal delivery (class 1). |
| Bioprosthetic valve or TAVR | Apixaban and rivaroxaban labels: not recommended with prosthetic valves (rivaroxaban names TAVR). Dabigatran: not recommended in AF with a bioprosthetic valve; not studied for VTE. Edoxaban: not addressed. |
| Mitral stenosis | Edoxaban: not recommended in moderate to severe mitral stenosis. The other DOAC labels do not address it. |
DVT and PE · 4 of 6
Doses, from the US labels.
Treatment of DVT or PE (adults)
| Apixaban | 10 mg twice daily for 7 days, then 5 mg twice daily. Extended phase after at least 6 months: 2.5 mg twice daily. Kidney: no label adjustment. Combined P-gp and strong CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir): cut the dose by 50%, and avoid them at 2.5 mg. Avoid rifampin, carbamazepine, phenytoin and St John’s wort. |
|---|---|
| Rivaroxaban | 15 mg twice daily with food for 21 days, then 20 mg daily with food. Extended phase after at least 6 months: 10 mg daily. Kidney: CrCl 15 or more (on actual weight); avoid under 15. Avoid ketoconazole, ritonavir and the same inducers. Erythromycin with CrCl 15 to under 80: only if the benefit justifies the risk. |
| Dabigatran | Parenteral for 5 to 10 days, then 150 mg twice daily; same dose to reduce recurrence. Kidney: CrCl over 30 only. For DVT and PE, avoid P-gp inhibitors when CrCl is under 50. Avoid rifampin. |
| Edoxaban | Parenteral for 5 to 10 days, then 60 mg daily. Use 30 mg for CrCl 15 to 50, weight 60 kg or less, or verapamil, quinidine, or a short course of azithromycin, clarithromycin, erythromycin, oral itraconazole or ketoconazole. Not recommended under CrCl 15. No reduced-dose extended regimen. |
| Enoxaparin | 1 mg/kg subcutaneously every 12 hours; inpatients may get 1.5 mg/kg once daily. Outpatient label use is DVT without PE. CrCl under 30: 1 mg/kg once daily. Actual body weight; the label sets no maximum. With warfarin: at least 5 days and until the INR is 2 to 3. |
| UFH | Weight-based: 80 units/kg bolus, then 18 units/kg/h (Raschke 1993). Label alternative: 5,000 units IV, then 20,000 to 40,000 units per 24 h. Adjust to an aPTT 1.5 to 2 times normal or your lab’s anti-Xa target. No renal adjustment in the label. Contraindicated with a history of HIT. |
Run it for your patient — the VTE treatment tool refuses to show a dose until weight, CrCl and every safety screen are answered. For CrCl from Cockcroft–Gault with ideal or adjusted weight, use kidney function.
DOAC direct oral anticoagulantLMWH / UFH low-molecular-weight / unfractionated heparinVKA vitamin K antagonistP-gp P-glycoproteinCrCl creatinine clearance (Cockcroft–Gault)APS antiphospholipid syndrome
DVT and PE · 5 of 6
How long, and at what dose.
After the 3-month treatment phase
| Everyone | 3-month treatment phase (CHEST 2021, strong). ASH 2020 suggests 3 to 6 months over 6 to 12. 2026 AHA/ACC frames the initial phase as 3 to 6 months. |
|---|---|
| Major transient trigger | Stop. CHEST 2021 recommends against extended therapy. Example: surgery under general anesthesia over 30 minutes, within 3 months. |
| Minor transient trigger | CHEST 2021 suggests against extended therapy. |
| Persistent risk factor | Offer extended-phase anticoagulation, preferably a DOAC (CHEST 2021, strong). ASH 2020 suggests indefinite therapy. |
| Unprovoked | Offer extended-phase anticoagulation (CHEST 2021, strong; ASH 2020 suggests indefinite) unless bleeding risk is high. A second unprovoked event: indefinite (ASH 2020, strong). |
| Cancer | ASH 2021 suggests long-term anticoagulation beyond 6 months (#32) and continuing indefinitely over stopping (#33), with a DOAC or LMWH (#34). CHEST 2021 (#24) offers extended therapy for a persistent risk factor. NICE (UK): 3 to 6 months, then review. |
Extended phase in practice
- Reduced-dose apixaban 2.5 mg twice daily or rivaroxaban 10 mg daily is suggested over full dose (CHEST 2021); ASH 2020 accepts either. Those trials did not study active cancer; there, only apixaban has trial evidence: after at least 6 months of treatment, 2.5 mg twice daily was noninferior to 5 mg for recurrent VTE (2.1% vs 2.8%) with less clinically relevant bleeding (12.1% vs 15.6%) (API-CAT, NEJM 2025).
- A reduced-dose DOAC is recommended over aspirin or nothing (CHEST 2021, strong). Aspirin is only for patients who choose to stop anticoagulation.
- Reassess at least yearly and with any major change in health (CHEST 2021).
- ASH 2020 suggests against routine prognostic scores, D-dimer or residual-thrombus ultrasound to set duration after unprovoked VTE.
- 2026 AHA/ACC: review within 1 week of discharge and by 3 months, and ask about dyspnea and exercise limitation at every visit for at least a year to find chronic thromboembolic disease.
DVT and PE · 6 of 6
Small clots, big clots, no anticoagulation.
Edge cases
| Isolated distal DVT | Without severe symptoms or risk factors for extension, CHEST 2021 suggests weekly ultrasound for 2 weeks over anticoagulation. No extension: no anticoagulation (strong). Extends but stays distal: anticoagulation suggested. Extends into proximal veins: anticoagulate (strong). Favor treatment from the start with a positive D-dimer, thrombus over 5 cm or over 7 mm, multiple veins, nearness to the proximal veins, no reversible provoking factor, active cancer, prior VTE or inpatient status. |
|---|---|
| Subsegmental PE | No proximal DVT and low recurrence risk: clinical surveillance over anticoagulation (CHEST 2021). High recurrence risk (hospitalized, cancer, no reversible trigger, pregnancy): anticoagulate. Confirm the clot is real: good opacification, multiple defects, seen on more than one image. |
| Incidental PE | Treat like comparable symptomatic PE (CHEST 2021). |
| Superficial vein thrombosis | Suspected SVT above the knee: ultrasound to exclude proximal DVT first; DVT is treated as DVT. The trial evidence (CALISTO) enrolled SVT at least 5 cm long. At increased risk of progression: anticoagulate for 45 days, fondaparinux 2.5 mg daily preferred (CHEST 2021). Rivaroxaban 10 mg daily is the oral alternative. Risk markers: extensive, above the knee near the saphenofemoral junction, great saphenous vein, severe symptoms, prior VTE, cancer, recent surgery. |
| IVC filter | Not with anticoagulation for leg DVT (CHEST 2021, strong) or for PE with hemodynamic compromise (ASH 2020). Use one for acute proximal DVT when anticoagulation is contraindicated (CHEST 2021, strong). Make it retrievable and remove it once anticoagulation is running (ASH 2020; NICE 2020). |
Thrombolysis and catheter therapy, briefly
| Hypotension or shock | Systemic thrombolysis plus anticoagulation (ASH 2020, strong; CHEST 2021 suggests it if bleeding risk is acceptable). Start with UFH: the apixaban and rivaroxaban labels say they are not an alternative to UFH in unstable PE or when lysis or embolectomy may follow. Alteplase label for massive PE: 100 mg IV over 2 hours, then heparin once the aPTT is twice normal or less. |
|---|---|
| No hypotension | CHEST 2021 recommends against systemic thrombolysis for most patients (strong). Consider it for those who deteriorate on anticoagulation with acceptable bleeding risk. |
| Catheter therapy | When lysis is chosen, systemic over catheter-directed (ASH 2020; CHEST 2021). Catheter-assisted removal for shock with high bleeding risk, failed lysis, or too little time (CHEST 2021). 2026 AHA/ACC: advanced therapies are reasonable in E1 and can be considered in D1 to D2. |
| Proximal DVT | Anticoagulation alone for most (ASH 2020; CHEST 2021). Thrombolysis is reasonable for limb-threatening DVT; prefer catheter-directed when lysis is used. |
Common errors
- Treating a positive D-dimer as a diagnosis.
- Starting dabigatran or edoxaban on day 1 without the parenteral lead-in.
- Forgetting to step down: apixaban after day 7, rivaroxaban after day 21.
- Capping enoxaparin in obesity, or dosing it on ideal weight.
- A DOAC in triple-positive APS, pregnancy or breastfeeding.
- A filter left in after anticoagulation is established.
- Routine compression stockings to prevent post-thrombotic syndrome: ASH 2020 and CHEST 2021 suggest against them.
IVC inferior vena cavaaPTT activated partial thromboplastin timeACS acute coronary syndromeED emergency department
Educational reference only — not medical advice. Verify against local protocol.
Sources
Verify against current guidelines and local protocol before acting.
- Lim W, Le Gal G, Bates SM, et al. American Society of Hematology 2018 guidelines for management of venous thromboembolism: diagnosis of venous thromboembolism. Blood Adv 2018;2(22):3226-3256. doi:10.1182/bloodadvances.2018024828
- Ortel TL, Neumann I, Ageno W, et al. American Society of Hematology 2020 guidelines for management of venous thromboembolism: treatment of deep vein thrombosis and pulmonary embolism. Blood Adv 2020;4(19):4693-4738. doi:10.1182/bloodadvances.2020001830
- Stevens SM, Woller SC, Baumann Kreuziger L, et al. Antithrombotic therapy for VTE disease: second update of the CHEST guideline and expert panel report. Chest 2021;160(6):e545-e608. doi:10.1016/j.chest.2021.07.055
- Creager MA, Barnes GD, Giri J, et al. 2026 AHA/ACC/ACCP/ACEP/CHEST/SCAI/SHM/SIR/SVM/SVN guideline for the evaluation and management of acute pulmonary embolism in adults. Circulation 2026;153(12):e977-e1051; J Am Coll Cardiol 2026;87(13):1626-1710. doi:10.1161/CIR.0000000000001415. Correction: Circulation 2026;154(2):e24. Category definitions and key recommendations taken from the AHA Top Things to Know summary and the ACC press release (Feb 19, 2026).
- Witt DM, Nieuwlaat R, Clark NP, et al. American Society of Hematology 2018 guidelines for management of venous thromboembolism: optimal management of anticoagulation therapy. Blood Adv 2018;2(22):3257-3291. doi:10.1182/bloodadvances.2018024893
- 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;2(22):3317-3359. doi:10.1182/bloodadvances.2018024802
- Lyman GH, Carrier M, Ay C, et al. American Society of Hematology 2021 guidelines for management of venous thromboembolism: prevention and treatment in patients with cancer. Blood Adv 2021;5(4):927-974. doi:10.1182/bloodadvances.2020003442
- Tektonidou MG, Andreoli L, Limper M, et al. EULAR recommendations for the management of antiphospholipid syndrome in adults. Ann Rheum Dis 2019;78:1296-1304. doi:10.1136/annrheumdis-2019-215213
- 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;42:3146-3157. doi:10.1093/eurheartj/ehab373
- National Institute for Health and Care Excellence. Venous thromboembolic diseases: diagnosis, management and thrombophilia testing (NG158). 2020, updated 2023. Two-level DVT Wells score adapted from Wells PS et al., N Engl J Med 2003;349:1227-35.
- Otto CM, Nishimura RA, Bonow RO, et al. 2020 ACC/AHA guideline for the management of patients with valvular heart disease (pregnancy and prosthetic valves), as summarized in ACC Ten Points to Remember, Dec 2020. Circulation 2021;143(5):e72-e227. doi:10.1161/CIR.0000000000000923.
- Raschke RA, Reilly BM, Guidry JR, et al. The weight-based heparin dosing nomogram compared with a standard care nomogram. Ann Intern Med 1993;119:874-881. doi:10.7326/0003-4819-119-9-199311010-00002
- US prescribing information (DailyMed): ELIQUIS (apixaban) rev 04/2025; XARELTO (rivaroxaban) rev 09/2026; PRADAXA (dabigatran) capsules rev 06/2025; SAVAYSA (edoxaban) rev 07/2025; LOVENOX (enoxaparin) rev 05/2026; Heparin Sodium Injection (Pfizer) rev 10/2025; ACTIVASE (alteplase) rev 01/2026.
- American Heart Association. Top Things to Know: 2026 Guideline for the Evaluation and Management of Acute Pulmonary Embolism in Adults. professional.heart.org. American College of Cardiology press release, February 19, 2026.
- Mahé I, Carrier M, Mayeur D, et al. Extended reduced-dose apixaban for cancer-associated venous thromboembolism (API-CAT). N Engl J Med 2025;392(14):1363-1373. doi:10.1056/NEJMoa2416112