Venous thromboembolism prevention in the acutely ill medical patient: a review of the literature and focus on special patient populations

Evaluating thromboprophylaxis in the sickle cell disease population: Navigating the evidence gap

Sickle cell disease (SCD) arises from beta-globin gene mutations, with global estimates indicating around 500 000 affected neonates in 2021. In the United States, it is considered rare, impacting fewer than 200 000 individuals. The key pathogenic flaw lies in mutant haemoglobin S, prone to polymerization under low oxygen conditions, causing erythrocytes to adopt a sickled shape. This leads to complications like vascular occlusion, haemolytic anaemia, inflammation and organ damage. Beyond erythrocyte abnormalities however, there is a body of literature highlighting the hypercoagulable state that is likely a contributor to many of the complications we see in SCD. The persistent activation of the coagulation cascade results in thromboembolic events, notably venous thromboembolism (VTE) which is independently associated with increased mortality in both adults and children with SCD. While the increased risk of VTE in the SCD population seems well established, there is a lack of guidelines for thromboprophylaxis in this population. This Wider Perspective will describe the hypercoagulable state and increased thrombosis risk in the SCD population, as well as advocate for the development of evidence-based guidelines to aid in the prevention of VTE in SCD.

Anticoagulation in Venous Thromboembolism Prophylaxis in Medically Ill Patients: Potential Impact of NOACs

While substantial evidence supports the use of standard-duration injectable anticoagulants for venous thromboembolism (VTE) prophylaxis, consensus is mixed about which agents may be preferred in acutely ill patients with ongoing need of VTE prophylaxis past the first 10-day duration of hospital stay and post-discharge. Non-vitamin K antagonist oral anticoagulants (NOACs) provide Factor Xa inhibition to prevent the thrombin generation essential in thromboembolism development, but evidence for the efficacy and safety of most NOACs is conflicting regarding extended-duration prophylaxis. Enoxaparin, a preferred injectable anticoagulant in standard-duration VTE prophylaxis, has shown an increased risk of major bleeding events when used in extended-duration prophylaxis, which outweighs its benefit. Rivaroxaban has demonstrated efficacy in extended-duration prophylaxis, but both rivaroxaban and apixaban have shown increased risks of major bleeding. Betrixaban remains the only NOAC approved in the USA for extended-duration VTE prophylaxis, and it demonstrates efficacy, with fewer adverse effects than other NOACs. This review evaluates the appropriateness of different NOAC agents compared with current therapies for the extended-duration VTE prophylaxis setting in medically ill populations.

Meta-Analysis Comparing the Efficacy, Safety, and Cost-Benefit of Direct Acting Oral Anticoagulants Versus Enoxaparin Thromboprophylaxis to Prevent Venous Thromboembolism Among Hospitalized Patients

Venous thromboembolism (VTE) is a potentially fatal complication of hospitalization. Thromboprophylaxis using subcutaneous low molecular weight heparin (LMWH) can result in local irritation, pain, and ecchymoses, leading to nonadherence. Direct acting oral anticoagulants (DOACs) are an alternative, but their efficacy and safety for short-term inpatient-only use versus LMWH, in medically hospitalized patients, has not been rigorously assessed. We performed a systematic review with meta-analyses and exploratory cost effectiveness analysis of Phase III randomized controlled trials comparing DOACs to LMWH for VTE prophylaxis to determine the risk and benefit of each. The primary efficacy end point (composite of total VTE and any-cause mortality) occurred in 1,321 of 10,978 (11.4%) of patients receiving DOAC prophylaxis and 1,084 of 10,600 (10.2%) with LMWH (odds ratio [OR] 0.84; 95% confidence interval [CI] 0.63 to 1.13). The primary safety end point (composite of major bleeding and clinically relevant bleeding) occurred in 519 of 16,131 (3.2%) of patients receiving DOACs and 381 of 14,616 (2.6%) with LMWH (OR 1.12; 95%CI 0.83 to 1.53). Subgroup analyses for efficacy (n = 9,233) and safety (n = 12,584) was conducted on patients randomized to Apixaban or LMWH. The primary efficacy end point occurred in 294 of 4618 (6.4%) patients on Apixaban and 383 of 4615 (8.3%) on Enoxaparin (OR 0.82; 95% CI 0.55 to 1.24). Major and clinically relevant bleeding occurred in 157 of 6278 (2.50%) and 185 of 6,306 (2.9%), respectively (OR 0.86; 95% CI 0.58 to 1.26). Exploratory cost effectiveness analysis suggested that Apixaban compared with Enoxaparin thromboprophylaxis could result in long-term cost savings. In conclusion, this systematic review of randomized controlled trials and meta-analysis, stratified by type of patients and drug, indicates noninferiority of DOACs in efficacy, safety, and cost for short-term VTE thromboprophylaxis among patients hospitalized for medical illness.

Evaluating the safety and effectiveness of venous thromboembolism prophylaxis in patients with sickle cell disease

Nearly every component of hemostasis is altered in sickle cell disease (SCD), yet little evidence exists to guide utilization of venous thromboembolism prophylaxis (VTEP) in this population. This retrospective cohort study included 135 adult patients admitted with a diagnosis of SCD vaso-occlusive crisis to the general medicine service at a tertiary care academic medical center from August 1, 2011 to August 1, 2013. If VTEP was discontinued, the medical record was reviewed for suspicion of VTE, hemorrhage, heparin-induced thrombocytopenia (HIT), or other adverse events. The primary objective was to characterize the safety and effectiveness of VTEP in SCD. The secondary objective was to assess the correlation of VTE with risk factors documented in the general medical population. Most patients (116/135, 85.9%) were prescribed VTEP upon admission, with early discontinuation in 23 patients (19.8%). Reasons for discontinuation included suspicion of VTE (10/116, 8.6%), hemorrhage (5/116, 4.3%), and/or HIT (4/116, 3.4%). Since patients with SCD receiving standard VTEP regimens appear to have similar outcomes compared to medically ill patients in prospective studies, using these regimens appears to be safe when indicated in the opinion of the provider. Once daily injections may be preferred in order to optimize adherence.

Incidence of venous thromboembolism in France: a retrospective analysis of a national insurance claims database

Background

Data estimating the annual incidence of venous thromboembolism (VTE) in France, taking into account both hospital and community settings, are very lacking.

This study aimed to estimate the annual incidence of VTE (pulmonary embolism (PE) and deep vein thrombosis (DVT)) in France in 2011 in “real world” population.

Methods

This was a longitudinal insurance claims study of the incidence of VTE in France over 2 years (2010 and 2011). The data analysis was performed using the EGB (Echantillon Généraliste des Bénéficiaires) database, a randomly selected sample of the French national insurance database (CNAMTS) which covers 77 % of the population. All adult patients experiencing a VTE event during the study period were analysed. Recurrence rate of VTE and all-cause mortality rate were also estimated over a 12-month follow-up period.

Results

The estimated annual incidence of VTE in France was 184.0 per 100 000 subjects, corresponding to a total of 119 670 events countrywide. The estimated incidence of DVT and PE were respectively 119.8 and 64.2 per 100 000 subjects. Annual recurrence of VTE was reported in 5.5 % (n = 99) patients, with a significantly higher recurrence rate in patients with PE than those with DVT (p = 0.02). Overall, 6.2 % (n = 112) of patients had died over the 12-month follow-up (respectively 10.2 and 7.7 % of patients with DVT and PE).

Discussion

To our knowledge, this analysis is the first to estimate the annual incidence of VTE in France using exhaustive data from the EGB database. This has allowed the incidence of DVT in the community to be documented, which to date has not been characterised. Previous studies in France have been limited to the hospital setting and have yielded incidence rates comparable to ours.

Conclusions

This analysis is the first to estimate the annual incidence of VTE in France using exhaustive data from the EGB database. This study showed that the incidence and the burden of the disease remains elevated.

The effect of chronic liver disease on venous thromboembolism among medically managed patients in Singapore General Hospital

BACKGROUND

Chronic liver disease (CLD) has been suggested to be associated with venous thromboembolism (VTE) in western populations. However, little is known about the risk effects of CLD on VTE among Asians.

OBJECTIVE

To compute the prevalence of VTE among hospitalised Asian patients, and to evaluate the pattern and scale of risk effects of CLD on VTE occurrence.

METHOD

Retrospective study of hospital discharge database from 2004 to 2011 to identify patients with VTE and CLD using International Statistical Classification of Diseases and Related Health Problems, 9th Revision, Australian Modification (ICD-9-AM) codes.

RESULTS

Of 199904 medically managed inpatients during the 8years, 1744 (0.9%) patients had VTE. Patients with CLD had significant higher prevalence of VTE (non-cirrhosis CLD 1.5%, cirrhosis 2.0%) than patients without CLD (0.8%, p<0.001). In the logistic regression analyses, non-cirrhosis CLD (odds ratio, OR 1.4, 95% CI 1.2-1.7, p<0.001) and cirrhosis (OR 1.5, 95% CI 1.2-2.0, p=0.002) were significant predictors of VTE after adjustment for age, gender, ethnicity, hospital long stayer, cancer, infectious disease, and other comorbid conditions such as diabetic mellitus, anaemia, and cardiovascular, cerebrovascular, renal and pulmonary diseases.

CONCLUSION

CLD, particular liver cirrhosis, increases the risks of VTE in hospitalised Asian patients. As CLD patients are perceived to be at risks of bleeding due to the prolonged clotting times and thrombocytopenia, the results of this study brings attention to opposite end of the haemostatic pendulum in patients with chronic liver disease.

Cirrhosis is Associated with an Increased 30-Day Mortality After Venous Thromboembolism

Objectives:

Patients with cirrhosis are at increased risk of venous thromboembolism (VTE), but the impact of cirrhosis on the clinical course following VTE is unclear. In a nationwide cohort study, we examined 30-day mortality among patients with cirrhosis and VTE.

Methods:

We used Danish population-based health-care databases (1994–2011) to identify patients with incident VTE, i.e., deep venous thrombosis (DVT), pulmonary embolism (PE), and portal vein thrombosis (PVT). Among these, we identified 745 patients with cirrhosis and 3647 patients without cirrhosis (matched on gender, year of birth, calendar year of VTE diagnosis and VTE type). We assessed the 30-day mortality risk among VTE patients with and without cirrhosis, and the mortality rate ratios (MRRs), using an adjusted Cox model with 95% confidence interval. We obtained information on immediate cause of death for patients who died within 30 days after VTE.

Results:

The 30-day mortality risk for DVT was 7% for patients with cirrhosis and 3% for patients without cirrhosis. Corresponding PE-related mortality risks were 35% and 16%, and PVT-related mortality risks were 19% and 15%, respectively. The adjusted 30-day MRRs were 2.17 (1.24–3.79) for DVT, 1.83 (1.30–2.56) for PE, and 1.30 (0.80–2.13) for PVT. Though overall mortality was higher in patients with cirrhosis than patients without cirrhosis, the proportions of deaths due to PE were similar among patients (25% and 24%, respectively).

Conclusions:

Cirrhosis is a predictor for increased short-term mortality following VTE, with PE as the most frequent cause of death.

Prophylaxis Against Venous Thromboembolism in Hospitalized Medically Ill Patients

Background—

Many hospitalized medically ill patients are at risk of venous thromboembolism (VTE). Risk factors include prior VTE, older age, immobility, obesity, cardiac or respiratory failure, and cancer (at-risk patients). Although guidelines recommend use of VTE prophylaxis for at-risk patients, many may not receive it.

Methods and Results—

Using a database linking admission records from >150 US hospitals to health insurance claims, we identified people ≥40 years of age, hospitalized from 2003 to 2008. We excluded patients who: (1) were treated for VTE or hospitalized in the previous 30 days; (2) were admitted for traumatic injury or surgery; (3) had hypercoagulability at admission; or (4) received therapeutic dosages of low-molecular weight heparin, unfractionated heparin, or fondaparinux at admission. We examined the use of VTE prophylaxis (both pharmacological and nonpharmacological) on day 1 or 2 in hospital among at-risk patients; predictors of receipt of prophylaxis were examined using multivariate logistic regression. The study population consisted of 49 948 patients, of whom 34 374 (69%) were at risk. Only 18% of at-risk patients received VTE prophylaxis on day 1 or 2 in hospital, typically with low-molecular weight heparin (56% of patients receiving prophylaxis), intermittent pneumatic compression (25%), warfarin (16%), or graduated compression stockings (11%). Use of prophylaxis exceeded 25% only in patients admitted from nursing homes and those with prior VTE. Although there were several significant predictors of receipt of VTE prophylaxis, model discrimination was relatively poor (C-statistic=0.61).

Conclusion—

The majority of at-risk hospitalized medically ill patients do not receive VTE prophylaxis.

Incidence of Deep Vein Thrombosis in Hospitalized Chinese Medical Patients and the Impact of DVT Prophylaxis

Objective. To evaluate the incidence of deep vein thrombosis in hospitalized Chinese medical patients and the impact of DVT prophylaxis. Methods. All cases of confirmed proximal DVT from 1 January 2005 to 31 December 2008 were reviewed retrospectively to determine the presence of risk factors and whether DVT developed: during hospitalization in medical wards or in case of readmission with a diagnosis of DVT within 14 days of discharge from a recent admission to medical wards. The impact of prophylaxis will be estimated by comparing the annual incidence of proximal DVT among medical patients hospitalized from 2005 to 2007 with that of 2008 (DVT prophylaxis commonly used). Results. From 1 January 2005 to 31 December 2008, 3938 Doppler ultrasound studies were performed for suspected DVT. Proximal DVT was diagnosed in 687 patients. The calculated incidence of proximal DVT among medical patients hospitalized for at least two days was 1.8%, 2%, and 1.7% for the year 2005, 2006, and 2007, respectively. The incidence was 1.1% for 2008 (P < .001). Conclusion. Proximal DVT was substantial in Chinese medical patients, and DVT prophylaxis might reduce such risk.

The incidence of venous thromboembolism and practice of deep venous thrombosis prophylaxis in hospitalized cirrhotic patients

Background

Cirrhotic patients are characterized by a decreased synthesis of coagulation and anticoagulation factors. The coagulopathy of cirrhotic patients is considered to be auto-anticoagulation. Our aim was to determine the incidence and predictors of venous thromboembolism (VTE) and examine the practice of deep venous thrombosis (DVT) prophylaxis among hospitalized cirrhotic patients.

Methods

A retrospective cohort study was performed in a tertiary teaching hospital. We included all adult patients admitted to the hospital with a diagnosis of liver cirrhosis from January 1, 2009 to December 31, 2009. We grouped our cohort patients in two groups, cirrhotic patients without VTE and cirrhotic with VTE.

Results

Over one year, we included 226 cirrhotic patients, and the characteristics of both groups were similar regarding their clinical and laboratory parameters and their outcomes. Six patients (2.7%) developed VTE, and all of the VTEs were DVT. Hepatitis C was the most common (51%) underlying cause of liver cirrhosis, followed by hepatitis B (22%); 76% of the cirrhotic patients received neither pharmacological nor mechanical DVT prophylaxis.

Conclusion

Cirrhotic patients are at risk for developing VTE. The utilization of DVT prophylaxis was suboptimal.

Risk of venous thromboembolism in patients with liver disease: a nationwide population-based case-control study

OBJECTIVES

It is known that liver disease can cause an imbalance in the coagulation system, but available data on liver disease and risk of venous thromboembolism are conflicting. We examined the risk of venous thromboembolism in patients hospitalized with liver diseases.

METHODS

We conducted a nationwide Danish case-control study of incident cases of venous thromboembolism from 1980 to 2005 using population-based data from the National Registry of Patients, and from the Civil Registration System. We used conditional logistic regression to compute the relative risk of venous thromboembolism in patients with liver disease compared to population controls. We then excluded patients with known malignancy (diagnosed either before or up to 3 months after the venous thromboembolism) or fractures, trauma, surgery, or pregnancy within 90 days before the venous thromboembolism to estimate the risk associated with unprovoked venous thromboembolism.

RESULTS

A total of 99,444 patients with venous thromboembolism and 496,872 population controls were included in the study. Patients with liver disease had a clearly increased relative risk of venous thromboembolism, varying from 1.74 (95% CI, 1.54-1.95) for liver cirrhosis to 1.87 (95% CI, 1.73-2.03) for non-cirrhotic liver disease. The risks were higher for deep venous thrombosis compared with pulmonary embolism. In the analysis, restricted to 67,519 patients with unprovoked venous thromboembolism and 308,614 population controls, we found slightly higher relative risks: 2.06 (95% CI, 1.79-2.38) for liver cirrhosis and 2.10 (95% CI, 1.91-2.31) for non-cirrhotic liver disease.

CONCLUSIONS

Patients with liver disease have a substantially increased risk of venous thromboembolism.

Evaluating the appropriateness of thromboprophylaxis in an acute care setting using a computerised reminder, through order-entry system

AIMS

Evidence suggests that thromboprophylaxis is still significantly underutilised across the United States despite its relationship with morbidity, mortality and resource expenditure. Previous randomised trials that have incorporated computerised reminders, through order-entry systems, have resulted in increased rates of thromboprophylaxis and lower incidences of clinically diagnosed deep-vein thrombosis or pulmonary embolism. The primary purpose of this prospective, observational study is to evaluate the use and appropriateness of preset computerized thromboprophylaxis regimens for patients in a major county metropolitan hospital over a 1-month period by evaluating the proportion of patients actually receiving recommended thromboprophylaxis according to established hospital guidelines.

METHODS

This prospective, observational study was conducted in a large county hospital that recently established an evidence-based routine computerised policy to decrease risk of venous thromboembolism. Physicians, residents, medical interns, medical students, pharmacy students, and nurses were the targets of the investigation. Data were randomly collected between 10 internal medicine teams from 10 October 2006 to 10 November 2006. Investigators completed one DVT/PE risk assessment form for each patient reviewed and compared this to actual prescribed therapy to determine appropriateness of therapy.

RESULTS

Pharmacological or non-pharmacological thromboprophylaxis was administered to 100% of patients evaluated. Eighty-six patients received recommended DVT/PE prophylaxis based on established hospital guidelines.

DISCUSSION

Reported values seem to indicate that computerized reminders are capable of providing venous thromboprophylaxis for medically ill (non-surgical) patients relative to published norms.

CONCLUSION

Results of this observational study reinforces the evidence that computerized, reminders, through order-entry systems might increase the delivery of thromboprophylaxis for hospitalized patients.

High risk for venous thromboembolism in diabetics with hyperosmolar state: comparison with other acute medical illnesses

BACKGROUND

Diabetes mellitus is generally not recognized as an important risk factor for venous thromboembolism (VTE). However, clinical observations and case reports have suggested that patients with diabetes and hyperosmolarity may be at increased risk for VTE.

OBJECTIVES

To determine the risk of VTE in patients hospitalized for diabetes with hyperosmolar state compared to patients with other acute medical illnesses.

PATIENTS/METHODS

The California Patient Discharge Data Set was used to determine the incidence of first-time VTE in all patients admitted between 1995 and 2000 for diabetes with hyperosmolarity and 11 other acute medical conditions. Proportional hazard modeling was used to adjust for age, race, gender, and prior hospitalization within 3 months.

RESULTS

Among 2859 patients with diabetes and hyperosmolarity, 34 (1.2%) developed VTE during the hospitalization and 14 (0.5%) developed VTE within 91 days after discharge. In an adjusted multivariate model comparing the risk of VTE to cases with depression, patients with hyperosmolarity had a significantly higher risk of VTE [hazard ratio (HR) = 16.3; 95% confidence interval (CI): 10-25] comparable to the risk associated with sepsis (HR = 19.3; 95% CI: 13-29) or acute connective tissue disease (HR = 21; 95% CI: 15-31). Compared to uncomplicated diabetes, patients with hyperosmolarity had a significantly higher risk of VTE (HR = 3.0; 95% CI: 2.1-4.5) whereas patients with ketoacidosis were not at higher risk (HR = 1.2; 95% CI: 0.8-1.7).

CONCLUSIONS

Patients hospitalized for diabetes with hyperosmolarity are at increased risk for developing VTE both during their inpatient stay and in the 3 months after discharge. Thromboprophylaxis in these patients appears warranted, and extended prophylaxis for after hospital discharge should be studied.