Bayer Pharma AG

Essence of this Article

Medical illness and hospitalization increase the risk of developing venous thromboembolism, which, along with associated complications, leads to poorer patient outcomes and an increased healthcare burden. Thromboprophylaxis significantly reduces the risk of venous thromboembolism in acutely ill medical patients, and current guidelines recommend that unfractionated heparin, low molecular weight heparin or fondaparinux should be administered for the duration of hospitalization or immobilization. Other guidelines advise thromboprophylaxis with these agents for up to 14 days. Despite this guidance, many patients do not receive adequate thromboprophylaxis. Furthermore, the duration of recommended prophylaxis may not be sufficient to ensure protection while patients are at risk of venous thromboembolic events.

Preventable venous thromboembolism in medically ill patients


Medical illness increases the risk of venous thromboembolism (VTE).478

  • Risk factors for VTE are common among hospitalized patients479
  • The risk of developing VTE is eightfold greater in hospitalized patients than in the general population480
  • Risk factors often remain after hospital discharge, and the post-discharge development of VTE can lead to rehospitalization481

Adverse consequences stemming from VTE contribute substantially to poor outcomes.482 These include:

  • Fatal pulmonary embolism – a major cause of sudden death in hospitalized medical patients483
  • Chronic post-thrombotic syndrome, with venous ulceration as the most severe manifestation
  • Chronic thromboembolic pulmonary hypertension
  • Recurrent VTE

In general hospitals, approximately 75% of patients who suffer a fatal pulmonary embolism have a medical illness.484

The treatment of VTE and its long-term sequelae, and the potential for increased duration of hospitalization, result in a significant economic burden to healthcare systems.485

Thromboprophylaxis in medically ill patients

Thromboprophylaxis can reduce the occurrence of venous thromboembolic events in medically ill patients by up to 63%.486-489 Based on the results of placebo-controlled studies,486-489 the following agents are recommended for the prevention of VTE in medically ill patients:

  • Unfractionated heparin486
  • Low molecular weight heparin487, 288, 490
  • Fondaparinux489

Evidence-based clinical practice guidelines have been developed to support physicians in ensuring adequate thromboprophylaxis in at-risk, acutely ill medical patients (Table 1).491-493 However, prophylaxis is recommended only for the duration of hospitalization or immobilization, or, alternatively, for up to 14 days.491-493 This may not be sufficient to protect patients from the risk of post-discharge events, which may persist for weeks to months.491

Despite the availability of clear guidelines, evidence indicates that as few as 16% of at-risk medical patients receive adequate thromboprophylaxis,494 suggesting a need for strategies to improve the utilization of thromboprophylaxis in the acutely ill patient population.478, 495, 496

Table 1. Clinical practice guidelines for venous thromboembolism prophylaxis in medically ill patients

Guidance Recommendation Grade of evidence
ACCP 2012491 For acutely ill, hospitalized medical patients at increased risk of thrombosis, anticoagulant thromboprophylaxis with LMWH, LDUH bid, LDUH tid or fondaparinux is recommended 1B
For acutely ill, hospitalized medical patients at low risk of thrombosis, the use of pharmacological prophylaxis or mechanical prophylaxis is not advised 1B
For acutely ill, hospitalized medical patients experiencing bleeding or who are at high risk of bleeding, anticoagulant thromboprophylaxis is not recommended 1B
For acutely ill, hospitalized medical patients at increased risk of thrombosis who are experiencing bleeding or who are at high risk of major bleeding, the optimal use of mechanical thromboprophylaxis with graduated compression stockings or intermittent pneumatic compression is recommended over no mechanical thromboprophylaxis 2C
When bleeding risk decreases, and if VTE risk persists, pharmacological thromboprophylaxis is recommended to be substituted for mechanical thromboprophylaxis 2B
In acutely ill, hospitalized medical patients who receive an initial course of thromboprophylaxis, extending the duration of thromboprophylaxis beyond the period of patient immobilization or acute hospital stay is not recommended 2B
ACP 2011492 Assessment of the risk for thromboembolism and bleeding in medical (including stroke) patients prior to initiation of prophylaxis of VTE is recommended Moderate
Pharmacological prophylaxis with heparin or a related drug for VTE in medical (including stroke) patients is recommended, unless the assessed risk of bleeding outweighs the likely benefits Moderate
The use of mechanical prophylaxis with graduated compression stockings for prevention of VTE is not recommended Moderate
International Consensus Statement* 2013493 All acutely ill medical patients should be routinely assessed for risk of VTE and considered for thromboprophylaxis N/A
For acutely ill medical patients, prophylaxis with LDUH 5000 IU bid or tid, or LMWH (enoxaparin 40 mg od or dalteparin 5000 IU od) for 6–14 days, is recommended. An alternative option is fondaparinux 2.5 mg od High
In patients with suspected or proven haemorrhagic stroke and in those with ischaemic stroke in whom the risks of prophylactic anticoagulant therapy are perceived to outweigh the benefits, graduated compression stockings combined with intermittent pneumatic compression is recommended Moderate


*Under the auspices of the Cardiovascular Disease Educational and Research Trust, European Venous Forum, North American Thrombosis Forum, International Union of Angiology and Union Internationale du Phlebologie.
ACCP, American College of Chest Physicians; ACP, American College of Physicians; bid, twice daily; IU, international units; LDUH, low-dose unfractionated heparin; LMWH, low molecular weight heparin; N/A, not available; od, once daily; tid, three times daily; VTE, venous thromboembolism.

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