Aims

The aim of the authors of the guidelines for the prevention of venous thromboembolism (VTE) in medical patients is to spread knowledge and raise awareness of the prevention of deep vein thrombosis (DVT) and pulmonary embolism (PE), thereby improving patient safety.

Patient populations to which the recommendations apply

The recommendations for prophylaxis apply to various populations of patients, that is, those treated medically, those with malignancies, and others at an increased VTE risk. The recommendations below do not apply to children.

Target users of the guidelines

The guidelines target physicians and other medical professionals participating in the care of the patient populations mentioned above—at the level of both specialized and primary health care.

Methodology for updating the Polish guidelines for venous thromboembolism prevention

In recent years, numerous guidelines for the prevention and treatment of VTE have been published by European, American, and international scientific societies.^1-49 The current guidelines are an adaptation of the existing reliable recommendations. This document is based on the 2025 updated Polish guidelines.⁵⁰

Introduction

1. Venous thromboembolism (VTE) comprises deep vein thrombosis (DVT) and pulmonary embolism (PE).

2. VTE is the third most common cardiovascular disease, after myocardial infarction and stroke. The annual incidence of 1 per 1000 in middle‑aged people increases to nearly 1% in people over 80 years

   old.⁵¹

3. PE causes about 10% of deaths in hospitalized patients and is the most common preventable cause of death.

4. Proper VTE prevention is considered the most important intervention that increases patient safety by reducing the risk of VTE. However, it does not fully prevent VTE.

5. The rationale for thromboprophylaxis is:

   1. Frequent occurrence of VTE in hospitalized patients and after hospital discharge;

   2. Long‑term complications, such as post‑thrombotic syndrome, recurrent VTE, and chronic pulmonary hypertension in 1%–4% of patients;

   3. Treatment of VTE complications is far more expensive than VTE prevention;

   4. The benefits of prophylactic doses of anticoagulants far outweigh the risk of clinically significant bleeding.

Individual characteristics and clinical conditions that increase the risk of venous thromboembolism

1. Age above 40 years (risk increases with age);

2. Obesity (body mass index [BMI] ≥30 kg/m

   ²

   . Note: The BMI cutoff varies for different VTE risk assessment scales);

3. Family history of VTE;

4. Trauma (especially multiorgan injuries or fractures of the pelvis or hip);

5. Stroke;

6. Paresis of the lower limbs, long‑term immobilization;

7. Malignancies;

8. History of VTE;

9. Congenital or acquired thrombophilia;

10. Sepsis;

11. Conservative treatment of immobilized patients;

12. Heart failure of the New York Heart Association class III and IV;

13. Respiratory failure;

14. Autoimmune diseases;

15. Nephrotic syndrome;

16. Myeloproliferative neoplasms;

17. Nocturnal paroxysmal hemoglobinuria;

18. Pressure on the venous vessels (eg, tumor, hematoma, aneurysm);

19. Pregnancy and puerperium;

20. Prolonged immobilization in a seated position (eg, airplane flight, prolonged computer‑related seated immobility syndrome, e‑thrombosis);

21. Varicose veins of the lower extremities;

22. Acute infection;

23. Other rare diseases (eg, idiopathic pulmonary fibrosis, sarcoidosis).

Diagnostic and therapeutic interventions that increase the risk of venous thromboembolism

1. Major surgical procedures, especially of the lower extremities, pelvis, and abdomen;

2. Catheters in large veins;

3. Anticancer treatment: chemotherapy, hormonal treatment, and use of angiogenesis inhibitors;

4. Use of oral contraceptives, hormone replacement therapy, or selective estrogen receptor modulators;

5. Use of erythropoiesis‑stimulating drugs.

Acutely ill medical patients

Acutely ill hospitalized medical patients

R‑9. In hospitalized acutely ill medical patients, we suggest using LMWH, UFH, or fondaparinux (W/++– –), with the use of LMWH (W/++– –) or fondaparinux (W/+– – –) rather than UFH.²

Note: This recommendation does not apply to patients taking DOACs for other indications.

R‑10. In hospitalized acutely ill or critically ill medical patients, we suggest the use of pharmacological prophylaxis rather than mechanical prophylaxis (W/+– – –), while in those who do not receive pharmacological prophylaxis, the use of mechanical prophylaxis (W/+++–).² We recommend using intravenous prophylaxis only during hospitalization, without further extension (S/+++–).² If mechanical prophylaxis is used, we suggest using IPC devices (preferred) or GCSs for this purpose (W/+– – –).² We suggest using either pharmacological prophylaxis alone or mechanical prophylaxis alone rather than combining both methods (W/+– – –).²

R‑11. In medical patients admitted to a hospital and at a low risk of VTE (Table 4), we recommend not using pharmacological or mechanical prophylaxis (S/+++–).⁹

R‑12. In acutely ill medical patients admitted to a hospital with bleeding or at a high risk of bleeding (see note below), we recommend not using pharmacological prophylaxis (S/+++–).⁹ In such patients, we suggest using mechanical prophylaxis, optimally IPC.

Note: The risk of bleeding increases the most in the case of active gastric or duodenal ulcer disease, major bleeding in the last 3 months, platelet count below 50 000/µl, or liver failure (international normalized ratio [INR] >1.5).⁹ Other risk factors for bleeding include age of at least 85 years (vs <⁠40 years), severe renal failure (glomerular filtration rate <⁠30 ml/min/1.73 m²), admission to an intensive care unit (ICU), insertion of a central venous catheter, chronic inflammatory arthritis, active malignancy, and male sex. The presence of several of these factors significantly increases the risk of bleeding.⁹

Prophylaxis in chronically immobilized patients

R‑21. In chronically immobilized patients, including nursing home residents, we suggest that VTE prophylaxis should not be routinely used (W/+– – –).²

Note: If such patients develop an acute illness treated medically or surgically, follow other appropriate recommendations.

R‑22. In medical outpatients with less significant risk factors for VTE (eg, immobilization, minor trauma, illness, infection), we suggest not administering VTE prophylaxis routinely (W/+– – –).²

Long‑distance air travelers

R‑23. In people who are at a significantly increased VTE risk (eg, recent surgery, history of VTE, puerperium, active cancer, or ≥2 risk factors, including a combination of the above with hormone replacement therapy, obesity, or pregnancy), we suggest using GCS and LMWH at a prophylactic dose during long‑distance travel (>4 h) (W/+– – –).²

R‑24. In long‑distance (>4 h) travelers without VTE risk factors, we suggest not using GCS, LMWH, or acetylsalicylic acid (ASA) for VTE prophylaxis (W/+– – –).²

Note: Patients without VTE risk factors who place a high value on VTE prevention may choose to use GCS (which reduces the severity of symptoms associated with chronic venous disease, as well as prevents the onset of edema). The use of DOACs at reduced doses in patients planning long air travel has not yet been studied, and this strategy may increase the risk of bleeding in comparison with LMWH.

Prophylaxis of venous thromboembolism in patients with asymptomatic thrombophilia

R‑25. In patients with asymptomatic thrombophilia (with no history of VTE), we recommend that daily long‑term VTE prophylaxis (mechanical or pharmacological) should not be used (S/++– –).⁹

Prophylaxis in cancer patients

1. Patients with cancer have an average 5‑fold higher risk of VTE than the general population, and VTE is the second most common cause of death in this

   population.²⁵

2. Risk factors for VTE in cancer

   patients²⁵:

   1. Disease‑related factors: as in the general population;

   2. Cancer associated factors: type of cancer, genetic characteristics (JAK2 or K‑ras mutations), histology (adenocarcinoma, multiple myeloma), initial period after diagnosis, primary location (pancreas, stomach, ovaries, brain, lung), stage (advanced, metastasis);

   3. Treatment‑related factors: cancer therapy (chemotherapy [cisplatin, carboplatin, cyclophosphamide, anthracyclines, antimetabolites, irinotecan], taxanes, tasonermin [recombinant tumor necrosis factor α], angiogenesis inhibitors [bevacizumab, axitinib, lenvatinib, pazopanib, sorafenib, sunitinib], immunomodulatory drugs [thalidomide, lenalidomide], proteasome inhibitors [carfilzomib], hormonal treatment, erythropoiesis‑stimulating agents), central venous catheters, hospitalization, extensive surgery;

   4. The presence of a catheter in the central vein in cancer patients predisposes to upper limb

      VTE.⁹

Primary prophylaxis in cancer outpatients receiving systemic therapy

R‑26. We suggest considering primary VTE prevention in cancer outpatients if their estimated risk of VTE within 6 months exceeds 8%–10% (≥2 points on the Khorana scale (Table 5); or such a risk on other scales, eg, Vienna‑CATS or COMPASS‑CAT) (W/+– – –).²⁶

R‑27. In outpatients starting systemic anticancer therapy who are at a high risk of VTE, we suggest considering LMWH, apixaban (2.5 mg twice daily) or rivaroxaban (10 mg once a day) for primary prevention of VTE (W/+++-).²⁶

Note: The summary of product characteristics of rivaroxaban and apixaban currently has no indication for use in the prophylaxis of VTE in patients with cancer. The duration of anticoagulant prophylaxis depends on the clinical situation: in adjuvant treatment usually for 6 months, in metastatic disease mostly longer.

R‑28. In cancer outpatients undergoing systemic therapy, we recommend no thromboprophylaxis over oral thromboprophylaxis with vitamin K antagonist (S/+– – – for benefit data, /++++ for adverse events).⁸

Primary prophylaxis in cancer patients with a central venous catheter

R‑29. In cancer patients with a central venous catheter, we suggest that parenteral or oral anticoagulants should not be used for the prevention of VTE (W/++– –).⁸

Primary prophylaxis in medical hospitalized patients with malignant tumors

R‑30. In hospitalized, conservatively treated cancer patients without a diagnosis of VTE:

1. We suggest that routine thromboprophylaxis should not be used if the hospital admission is related solely to diagnostic procedures or infusion of anticancer

   drugs.²⁷

2. We suggest thromboprophylaxis if additional risk factors are present, if there are no bleeding episodes or other contraindications

   (W/+– – –).^8,27

3. We recommend the use of LMWH for prolonged bed immobilization (>72 h) or reduced mobility if there are no bleeding episodes or other contraindications

   (S/+++–).²⁵

4. We suggest using pharmacological rather than mechanical thromboprophylaxis

   (W/+– – –).⁸

5. We suggest using pharmacological thromboprophylaxis alone instead of a combination of pharmacological and mechanical prophylaxis

   (W/+– – –).⁸

6. As part of pharmacological thromboprophylaxis, we suggest using LMWH instead of UFH

   (W/++– –).⁸

7. We suggest discontinuing thromboprophylaxis at the time of hospital discharge rather than continuing it after hospitalization

   (W/+– – –).⁸

Prophylaxis in patients with multiple myeloma

1. Patients with multiple myeloma have a 9‑fold increased risk of VTE, as compared with the general population. The use of immunomodulatory drugs (thalidomide, lenalidomide, or pomalidomide) in combination with glucocorticosteroids or as a part of combination chemotherapy significantly increases this risk, especially within 6 months of therapy

   initiation.²⁸

2. Risk stratification for deciding on the type of prophylaxis (antiplatelet or anticoagulant treatment) is based on the IMPEDE or SAVED score (

   Table 6

   ).²⁸

R‑31. In multiple myeloma patients at a lower thrombotic risk (≤3 points on the IMPEDE scale or <⁠2 points on the SAVED scale), we suggest ASA at a dose of 75–325 mg/d.²⁸

R‑32. In multiple myeloma patients at a higher thrombotic risk (≥4 points on the IMPEDE scale or ≥2 points on the SAVED scale), we suggest using one of the following drugs:

1. LMWH at a prophylactic dose (equivalent to 40 mg enoxaparin once a day);

2. Rivaroxaban 10 mg once a day;

3. Apixaban 2.5 mg twice a day;

4. Fondaparinu × 2.5 mg once a day;

5. Warfarin (with a target INR of

   2–3).²⁶

We suggest that anticoagulant treatment should be used for the entire duration of specific multiple myeloma treatment or for 3–6 months, and followed by ASA treatment (longer anticoagulation may be considered when additional patient- or treatment‑related risk factors or other transient risk factors are present).