The venous thrombotic risk in nonsurgical patients

Betrixaban: Safely Reducing Venous Thromboembolic Events with Extended Prophylaxis

Although venous thromboembolism prophylaxis of acute medically ill patients is commonly employed, a percentage of high-risk patients still have venous thromboembolic events within 30 days of discharge. Research over the last several years has attempted to identify characteristics of these high-risk patients to facilitate provision of extended prophylaxis and venous thromboembolic event reduction; however, extended prophylaxis has been associated with a significant increase in the risk for major bleeding until recently. Betrixaban, a new oral direct Xa inhibitor with once-daily dosing and limited renal elimination, significantly reduces the risk of venous thromboembolism without increasing the risk for major bleeding. Consequently, betrixaban is the only anticoagulant approved by the Food and Drug Administration for preventing venous thromboembolism with extended prophylaxis in acute medically ill patients.

The profile and frequency of known risk factors or comorbidities for deep vein thrombosis in an urban district hospital in KwaZulu-Natal

Background

Although deep vein thrombosis (DVT) is a preventable disease, it increases the morbidity and mortality in hospitalised, patients, resulting in considerable economic health impact. The identification and primary prevention of risk factors using risk assessment and stratification with subsequent anti-thrombotic prophylaxis in moderate- to severe-risk categories is the most rational means of reducing morbidity and mortality.

Aim and setting

The aim of the study was to describe the profile and frequency of known risk factors or comorbidities of hospitalised medical patients with ultrasound-diagnosed DVT in an urban district hospital in KwaZulu-Natal.

Methods

A retrospective review of clinical notes of all medical patients (age ≥ 13 years) admitted to the hospital with ultrasound-diagnosed DVT between July and December 2013.

Results

The median age was 40 years (interquartile range 32–60 years) and female preponderance was 72.84%. HIV and tuberculosis emerged as the prevalent risk factors, accounting for 51.85% and 35.80%, respectively. Other risk factors observed were recent hospitalisation (34.57%), smoking (25.93%), previous DVT (19.75%) and congestive cardiac failure (18.52%).

Conclusion

DVT in our study occurred predominantly in young female patients unlike previous studies where patients were generally older. Furthermore, HIV and tuberculosis were the two most common known risk factors or comorbidities observed. Clinicians should have a heightened awareness of venous thromboembolism in patients with either condition or where both conditions occur together and appropriate thromboprophylaxis should be administered.

The use of an exclusion-based risk-assessment model for venous thrombosis improves uptake of appropriate thromboprophylaxis in hospitalized medical patients

BACKGROUND

Venous thromboembolism is a common condition in hospitalized medical patients. Numerous studies have demonstrated that low molecular weight heparin significantly reduces this risk but, despite this, the use of thromboprophylaxis remains poor.

AIM

To evaluate the use of an exclusion based risk-assessment model (RAM) for venous thrombosis in improving the uptake of appropriate thromboprophylaxis in hospitalized medical patients.

DESIGN

A survey with a subsequent audit cycle of three separate audits over 36 months.

METHODS

497 hospitalized patients with acute medical conditions on general medical wards were audited at a secondary care centre in London, UK. The survey and subsequent audits were performed by reviewing the notes and medication charts of medical patients, prior to the launch of the RAM and at 12, 28 and 36 months following its introduction.

RESULTS

Prior to launching the RAM, 49% of hospitalized medical patients received appropriate thromboprophylaxis. This did not change 12 months after the RAM was introduced but increased significantly to 71% following formal education of the health care professionals involved in thromboprophylaxis prescription. This improvement was maintained as demonstrated by a subsequent audit 8 months later (75.9%).

CONCLUSION

The introduction of a simple exclusion-based RAM for venous thrombosis in medical patients significantly improved delivery of thromboprophylaxis. The successful uptake of the RAM appears to have been dependent on direct education of those health carers involved in its use. A similar exclusion-based model used nationally could have a significant impact on the burden of VTE currently experienced in the UK.

Epidemiology of thrombotic risk factors: the difficulty in using clinical trials to develop a risk assessment model

There is a paucity of data assessing the risks and prevention of venous thromboembolism in critical care settings. Consequently, it is difficult to estimate the risk of venous thromboembolism for a typical patient, on an individual basis, and this difficulty leads to underuse of thromboprophylaxis, especially in intensive care unit patients. Thrombosis is a multifactorial disease and patients may present multiple risk factors simultaneously. The problem in quantifying risk factors is to combine these risk factors even when they are not detected in the same multivariate analysis. A model for predicting the risk of venous thromboembolism in hospitalized medical patients has yet to be developed and validated. Meanwhile, other approaches have been proposed to replace the ideal study utilizing a large prospective cohort of hospitalized medical patients. In this context, several scoring systems based on risk assessment models have been proposed, some including the use of computerized electronic prompts, to help physicians prescribe appropriate prophylaxis. This article reviews evidence on the risk of venous thromboembolism associated with different medical conditions and risk factors, and presents a tentative risk-assessment model for risk stratification in hospitalized medical patients.

[Prophylaxis of venous thromboembolism]

The recommendations on venous thromboprophylaxis have been updated on the basis of current evidence reviewed by a multidisciplinary team. The problem has been approached with regard to its relevance in both surgical and nonsurgical patients. It should be noted that these recommendations were drawn up for use in Spain and, therefore, should be implemented with the drugs and therapeutic practices authorized and generally accepted in this country.

Thromboembolic Therapies in Dogs and Cats: An Evidence-Based Approach

In veterinary medicine, we are forced to make use of less than ideal "evidence," such as extrapolation from experimental studies in dogs and cats without naturally occurring diseases and from clinical trials in other species (particularly human clinical trials), as well as limited information gained from veterinary clinical experience, small clinical trials, case studies, and anecdotal reports. In this article, specific treatment recommendations are made for each of the common thromboembolic conditions seen in dogs and cats. These recommendations are made with the important caveat that, to date, such suggested therapeutic approaches are based on limited evidence.

[Use of low molecular weight heparin for medical prophylaxis by European geriatricians]

PURPOSE

Many hospitalised elderly patients are at increased risk of venous thromboembolism (VTE). The aim of this study was to assess the rate and duration of medical utilization of low molecular weight heparin (LMWH) for VTE prevention by European geriatricians.

METHOD

A questionnaire was sent to 94 geriatricians of the European Academy for Medicine of Ageing (EAMA), to be filled out for each patient older than 65 years of their institutions who received LMWH during 1 day of December 2000.

RESULTS

In the 37 centers that participated (representing 11 different European countries) 2912 patients were present on the day of the study: 857 patients in acute care, 367 in rehabilitation care, 1568 in long-term care and 141 in day hospital. Prophylaxis by LMWH was given to 284 medical patients (9.75%, mean age 82.2 years). Use of LMWH was more frequent in acute and rehabilitation care (22.4% and 9.8%) than in long-term care (3.1%). The main risk factors in patients with LMWH prophylaxis were: bedridden (53%), infectious disease (18%), heart failure (17.6%), venous insufficiency (17.6%), paralysis of lower limbs (16.6%), recent stroke (15%) and malignancy (10%). The duration of the treatment for VTE prophylaxis exceeded 30 days in 51 patients (12%) and one year in 15 patients (3.3%).

CONCLUSION

In Europe, VTE prophylaxis by LMWH is widely used in elderly medical patients without specific guidelines in this population. Further studies are necessary to evaluate the appropriate duration of prophylaxis in very prolonged immobilization.

[What kind of treatment are available in deep vein thrombosis prevention?]

In order to propose new recommendations concerning deep vein thrombosis prevention in surgery and obstetrics, we identified all the available tools. We performed a Medline search for ten years to review all the studies published in this field. This preliminary stage is mandatory in assessing guidelines able to work out strategies considering each patient in each particular surgical situation. There are no formal guidelines and we outlined a practical approach for the prevention of deep vein thrombosis. Data concerning all available treatment were not classified in an evidence-based strategy.

Clinical trials of deep vein thrombosis prophylaxis in medical patients

Autopsies and clinical studies have shown that venous thromboembolism (VTE) is a common cause of morbidity and mortality in medical patients. Prophylaxis of VTE has been less extensively studied in medical patients than in surgical patients, and the results of recent practice audits indicate that the use of thromboprophylaxis is uncommon in medical patients. In the past few years, 3 large randomized clinical trials have demonstrated the efficacy and safety of prophylaxis of VTE in the medical setting. The prophylaxis in MEDical patients with ENOXaparin (MEDENOX), Prospective Evaluation of Dalteparin Efficacy for PREVENTion of VTE in Immobilized Patients Trial (PREVENT), and ARixta for ThromboEmbolism Prevention in a Medical Indications Study (ARTEMIS) studies have compared the low-molecular-weight heparins enoxaparin and dalteparin, and the specific factor Xa inhibitor fondaparinux, respectively, with placebo in acutely ill medical patients hospitalized with heart failure, respiratory failure, infectious disease, or inflammatory disease. All studies showed both a statistically significant reduction in the rate of venous thromboembolic events (as assessed by venography or compression ultrasonography) and a rate of major bleeding events that were comparable to placebo. The results of these studies support the evidence-based recommendations for systematic use of thromboprophylaxis in this setting.

Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy

This article discusses the prevention of venous thromboembolism (VTE) and is part of the Seventh American College of Chest Physicians Conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following. We recommend against the use of aspirin alone as thromboprophylaxis for any patient group (Grade 1A). For moderate-risk general surgery patients, we recommend prophylaxis with low-dose unfractionated heparin (LDUH) (5,000 U bid) or low-molecular-weight heparin (LMWH) [< or = 3,400 U once daily] (both Grade 1A). For higher risk general surgery patients, we recommend thromboprophylaxis with LDUH (5,000 U tid) or LMWH (> 3,400 U daily) [both Grade 1A]. For high-risk general surgery patients with multiple risk factors, we recommend combining pharmacologic methods (LDUH three times daily or LMWH, > 3,400 U daily) with the use of graduated compression stockings and/or intermittent pneumatic compression devices (Grade 1C+). We recommend that thromboprophylaxis be used in all patients undergoing major gynecologic surgery (Grade 1A) or major, open urologic procedures, and we recommend prophylaxis with LDUH two times or three times daily (Grade 1A). For patients undergoing elective total hip or knee arthroplasty, we recommend one of the following three anticoagulant agents: LMWH, fondaparinux, or adjusted-dose vitamin K antagonist (VKA) [international normalized ratio (INR) target, 2.5; range, 2.0 to 3.0] (all Grade 1A). For patients undergoing hip fracture surgery (HFS), we recommend the routine use of fondaparinux (Grade 1A), LMWH (Grade 1C+), VKA (target INR, 2.5; range, 2.0 to 3.0) [Grade 2B], or LDUH (Grade 1B). We recommend that patients undergoing hip or knee arthroplasty, or HFS receive thromboprophylaxis for at least 10 days (Grade 1A). We recommend that all trauma patients with at least one risk factor for VTE receive thromboprophylaxis (Grade 1A). In acutely ill medical patients who have been admitted to the hospital with congestive heart failure or severe respiratory disease, or who are confined to bed and have one or more additional risk factors, we recommend prophylaxis with LDUH (Grade 1A) or LMWH (Grade 1A). We recommend, on admission to the intensive care unit, all patients be assessed for their risk of VTE. Accordingly, most patients should receive thromboprophylaxis (Grade 1A).

Venous thromboembolism in intensive care patients

Venous thromboembolism frequently complicates the management of patients with severe medical and surgical illnesses. Because the diagnosis of VTE is especially challenging in critically ill patients, the focus of intensivists should be on characterization of risk factors and the appropriate choice of VTE prophylaxis. LDUH or LMHW is the preferred choice for VTE prophylaxis in ICU patients. Mechanical methods of prophylaxis should be reserved for patients with a high risk for bleeding. The effectiveness of mechanical methods and of combined strategies of prevention and the clinically important outcomes of therapy need to be explored further in critically ill patients. Few diagnostic strategies have been assessed in ICU patients with suspected PE. Ventilation-perfusion lung scans remain a pivotal diagnostic test but retain the same limitations in critically ill patients as seen in other patient populations. Newer noninvasive techniques, such as spiral CT associated with imaging of the extremities, are gaining more wide-spread use, but, thus far, pulmonary angiography remains the most reliable technique to confirm or exclude PE in patients with respiratory failure. A consensus must be reached regarding the most appropriate combination of tests for adequate and cost-effective diagnosis of VTE. Further investigation of diagnostic strategies that include adequate consideration of clinical diagnosis using standardized models and noninvasive imaging are warranted.

DVT prophylaxis and anticoagulation in the surgical patient

One of the most common postoperative complications is venous thromboembolism, a term encompassing deep vein thrombosis and pulmonary embolism. This article reviews the epidemiology, natural history, difficulties in diagnosis, and strategies for the prevention of postoperative venous thromboembolism. We thoroughly review the currently available methods for thromboprophylaxis including: early ambulation, elastic compression stockings, pneumatic compression devices, inferior vena cava filters, and a variety of pharmacologic agents such as unfractionated heparin, warfarin, aspirin, low molecular weight heparin, and pentasaccharides. Finally, we review the perioperative management of patients on long-term oral anticoagulation.

Enoxaparin vs heparin for prevention of deep-vein thrombosis in acute ischaemic stroke: a randomized, double-blind study

OBJECTIVES

To compare the efficacy, safety, and overall risk-benefit profile of enoxaparin and unfractionated heparin (UFH) prophylaxis of venous thromboembolic complications in patients with acute ischaemic stroke.

METHODS

Patients with ischaemic stroke resulting in lower-limb paralysis lasting for at least 24 h and necessitating bedrest, were randomized within 48 h of the onset of stroke, and treated with enoxaparin (40 mg subcutaneously once daily) or UFH (5000 IU subcutaneously thrice daily) for 10 +/- 2 days. Main outcome measures were deep-vein thrombosis, pulmonary embolism (PE), death from any cause, intracranial haemorrhage including haemorrhagic infarction, or any other major bleeding.

RESULTS

Outcome events occurred within 3 months of stroke in 40/106 patients treated with enoxaparin (37.7%) and 52/106 patients treated with UFH (49.1%, P=0.127). Fewer patients treated with enoxaparin (14, 13.2%) than with UFH (20, 18.9%) had evidence of haemorrhagic transformation of ischaemic stroke.

CONCLUSIONS

Enoxaparin administered subcutaneously once daily was as safe and effective as subcutaneous UFH given thrice daily in the prevention of thromboembolic events in patients with lower limb paralysis caused by acute ischaemic stroke.

[Thromboembolism prevention in acute myocardial infarction]

The objectives were to identify risk factors for vein thromboembolic disease (VTD) among patients with acute myocardial infarction (AMI) and to analyse both quantitatively and qualitatively the performed thromboembolic prophylaxis. A cross-sectional study was carried out with all inpatients at the Coronary Unit at our hospital during 1998. The risk factors for thromboembolism included: inmobilization (79.2%), heart failure (33.2%) and age over 70 years (31%). VTD prophylaxis was performed in 86.9% of the time. Non-fractioned heparin (NFH) and low molecular weight heparins (LMWH), mostly nadroparine, were the most commonly used drugs at admission and at discharge, respectively. Overdosage and underdosage for NFH and LMWH, respectively, were observed. That patients received or not VTD prophylaxis was not influenced by thromboembolic risk factors.

Venous thromboembolism in medical inpatients: prophylaxis with low-weight heparin in a university hospital and prevalence of thromboembolic events

The aim of this study was to determine the prevalence of venous thromboembolism (VT) in current prophylactic practice with low-molecular-weight heparin (LMWH) among medical inpatients and to analyze associated risk factors for VT. A cross-sectional survey on five given days was conducted in the medical departments of a university hospital. The prevalence of prophylaxis and confirmed VT was measured. Risk markers for receiving high doses of LMWH and for VT under prophylaxis were assessed by logistic regression models. Of 1,194 inpatients, 1.4% suffered VT. The mean proportion of patients with LMWH prophylaxis was 24% (range: 4-64%). The prevalence of VT was higher among inpatients receiving prophylaxis than among those patients not receiving prophylaxis (3.5% vs. 0.7%, p = 0.002). Under prophylaxis, independent risk markers for thrombosis were history of vein thrombosis (odds ratio [OR]: 4.03; confidence interval [95%CI]: 1.04-15.62) and age (OR: 1.08; 95%CI: 1.01-1.15). Two factors were independently associated with the prescription of high doses of LMWH: obesity was positively associated (OR: 7.50; 95%CI: 2.97-18.92; p < 0.0001) and respiratory insufficiency was negatively associated. In medical departments, current prophylaxis practice leads to many patients being given LMWH. LMWH doses and other preventive measures should be adapted in high-risk inpatients.