Duration of venous thromboembolism risk across a continuum in medically ill hospitalized patients

Extended Thromboprophylaxis with Betrixaban in Acutely Ill Medical Patients

BACKGROUND

Patients with acute medical illnesses are at prolonged risk for venous thrombosis. However, the appropriate duration of thromboprophylaxis remains unknown.

METHODS

Patients who were hospitalized for acute medical illnesses were randomly assigned to receive subcutaneous enoxaparin (at a dose of 40 mg once daily) for 10±4 days plus oral betrixaban placebo for 35 to 42 days or subcutaneous enoxaparin placebo for 10±4 days plus oral betrixaban (at a dose of 80 mg once daily) for 35 to 42 days. We performed sequential analyses in three prespecified, progressively inclusive cohorts: patients with an elevated d-dimer level (cohort 1), patients with an elevated d-dimer level or an age of at least 75 years (cohort 2), and all the enrolled patients (overall population cohort). The statistical analysis plan specified that if the between-group difference in any analysis in this sequence was not significant, the other analyses would be considered exploratory. The primary efficacy outcome was a composite of asymptomatic proximal deep-vein thrombosis and symptomatic venous thromboembolism. The principal safety outcome was major bleeding.

RESULTS

A total of 7513 patients underwent randomization. In cohort 1, the primary efficacy outcome occurred in 6.9% of patients receiving betrixaban and 8.5% receiving enoxaparin (relative risk in the betrixaban group, 0.81; 95% confidence interval [CI], 0.65 to 1.00; P=0.054). The rates were 5.6% and 7.1%, respectively (relative risk, 0.80; 95% CI, 0.66 to 0.98; P=0.03) in cohort 2 and 5.3% and 7.0% (relative risk, 0.76; 95% CI, 0.63 to 0.92; P=0.006) in the overall population. (The last two analyses were considered to be exploratory owing to the result in cohort 1.) In the overall population, major bleeding occurred in 0.7% of the betrixaban group and 0.6% of the enoxaparin group (relative risk, 1.19; 95% CI, 0.67 to 2.12; P=0.55).

CONCLUSIONS

Among acutely ill medical patients with an elevated d-dimer level, there was no significant difference between extended-duration betrixaban and a standard regimen of enoxaparin in the prespecified primary efficacy outcome. However, prespecified exploratory analyses provided evidence suggesting a benefit for betrixaban in the two larger cohorts. (Funded by Portola Pharmaceuticals; APEX ClinicalTrials.gov number, NCT01583218.).

Heart failure and risk of venous thromboembolism: a systematic review and meta-analysis

BACKGROUND

Venous thromboembolism is a major global health problem that is often secondary to other clinical situations. Many studies have investigated the association between venous thromboembolism and heart failure, but have yielded inconsistent findings. We aimed to quantify the absolute and relative risks (RR) for venous thromboembolism in patients with heart failure after hospital admission. We also assessed rates of venous thromboembolism in patients in different settings.

METHODS

In this systematic review and meta-analysis, we searched for studies investigating the risk of venous thromboembolism in patients in hospital with heart failure. We searched for studies published between Jan 1, 1955, and March 31, 2015, in PubMed, Embase, Evidence-Based Medicine Reviews, Allied and Complementary Medicine Database, Ovid HealthSTAR, Global Health, Ovid Nursing Database, Web of Science, CINAHL Plus, ProQuest Central, Conference Papers Index, BIOSIS Previews, and ClinicalTrials.gov. All cohort studies and subgroup analyses of randomised controlled trials (RCTs) were eligible for inclusion if they reported venous thromboembolism rates (number of events per follow-up period) or RR estimates. We extracted data from published reports and contacted the corresponding authors of records with insufficient quantitative data. RRs and 95% CIs were pooled using a random-effects model. This study is registered with PROSPERO, number CRD42014015504.

FINDINGS

Of 8673 records identified, we included 71 studies with data from 88 cohorts in our analysis, with 59 cohorts included in the assessment of venous thromboembolism rates and 46 cohorts included in the meta-analysis of heart failure and risk of venous thromboembolism. Venous thromboembolism rates varied widely in patients in hospital with heart failure from different settings. The overall median symptomatic venous thromboembolism rate was 2·48% (IQR 0·84-5·61); rates was were 3·73% (1·05-7·31) for patients who did not receive thromboprophylaxis and 1·47% (0·64-3·54) for those who did. Overall, patients with heart failure in hospital had an RR of 1·51 (1·36-1·68) for venous thromboembolism. The overall I(2) statistic was 96·1% and there was no evidence of publication bias (Egger's test, p=0·46).

INTERPRETATION

Heart failure is a common independent risk factor for venous thromboembolism. Thromoboprophylaxis should be considered in clinical practice for high-risk patients.

FUNDING

National Natural Science Foundation.

Extended-Duration Thromboprophylaxis Among Acute Medically Ill Patients

Acute medical illnesses are associated with a prolonged elevation in inflammatory markers that predisposes patients to thrombosis beyond the duration of their hospital stay. In parallel, both observational and randomized data have demonstrated a rate of postdischarge venous thromboembolic events that often exceeds that observed in the hospital setting. Despite this significant residual risk of venous thromboembolic events following discharge among acute medically ill patients, no therapeutic strategies have been recommended to address this unmet need. Available randomized trials have demonstrated the efficacy of extending the duration of thromboprophylaxis with available anticoagulants; however, the efficacy is offset, at least in part, by an increase in bleeding events. Identification of the optimal therapeutic strategies, treatment duration, and risk assessment tools that reconcile both efficacy and safety of extended-duration thromboprophylaxis among acute medically ill patients is an area of ongoing investigation.

Implementation of a mandated venous thromboembolism clinical order set improves venous thromboembolism core measures

BACKGROUND

Venous thromboembolism (VTE), including pulmonary embolism and deep vein thrombosis, is a major cause of morbidity and mortality. It results in approximately 300 000 deaths in the United States each year, and two thirds of VTE events are hospital acquired. However, VTE prophylaxis for hospitalized patients remains suboptimal.

OBJECTIVES

Assess the effect of a physician-mandated VTE prophylaxis computerized order set on the rates of hospital acquired VTE.

METHODS

A retrospective prevalence study of hospitalized patients pre- and postimplementation of a mandatory VTE order set. Additionally, the Joint Commission VTE Core Measures data was tracked for improvements postimplementation.

RESULTS

At baseline, 73% of patients received appropriate prophylaxis (n = 148) compared with 90% (n = 192) postintervention (P = 0.015). The percentage of patients who received VTE prophylaxis within 24 hours of arrival at the hospital increased from a baseline of 73% to 93% postimplementation (P = 0.0004). Hospital-acquired VTE prevalence rates decreased from 2% (4 cases) to 0.05% (1 case; P = 0.37) post intervention. The incidence of potentially preventable VTE cases (the Joint Commission's core measure 6) decreased from 3.9% to 0% (P = 0.39). These differences were not statistically significant, but they are clinically significant. These results were also sustained over time.

CONCLUSION

This study demonstrates that a mandated physician VTE order set ensures that nearly all patients will be stratified for VTE risk and provided with prophylaxis based on their risk category. Adhering to the evidence-based clinical practice guidelines from the American College of Chest Physicians is effective in improving prophylaxis and decreasing the rate of hospital-acquired VTE in hospitalized patients, and in decreasing the rate of preventable VTE cases based on the Joint Commission's core measure 6.

Pattern of frequent but nontargeted pharmacologic thromboprophylaxis for hospitalized patients with cancer at academic medical centers: a prospective, cross-sectional, multicenter study

PURPOSE

Hospitalized patients with cancer are considered to be at high risk for venous thromboembolism (VTE). Despite strong recommendations in numerous clinical practice guidelines, retrospective studies have shown that pharmacologic thromboprophylaxis is underutilized in hospitalized patients with cancer.

PATIENTS AND METHODS

We conducted a prospective, cross-sectional study of hospitalized patients with cancer at five academic hospitals to determine prescription rates of thromboprophylaxis and factors influencing its use during hospitalization.

RESULTS

A total of 775 patients with cancer were enrolled across five academic medical centers. Two hundred forty-seven patients (31.9%) had relative contraindications to pharmacologic prophylaxis. Accounting for contraindications to anticoagulation, the overall rate of pharmacologic thromboprophylaxis was 74.2% (95% CI, 70.4% to 78.0%; 392 of 528 patients). Among the patients with cancer without contraindications for anticoagulation, individuals hospitalized with nonhematologic malignancies were significantly more likely to receive pharmacologic thromboprophylaxis than those with hematologic malignancies (odds ratio [OR], 2.34; 95% CI, 1.43 to 3.82; P=.007). Patients with cancer admitted for cancer therapy were significantly less likely to receive pharmacologic thromboprophylaxis than those admitted for other reasons (OR, 0.37; 95% CI, 0.22 to 0.61; P<.001). Sixty-three percent of patients with cancer classified as low risk, as determined by the Padua Scoring System, received anticoagulant thromboprophylaxis. Among the 136 patients who did not receive anticoagulation, 58.8% were considered to be high risk by the Padua Scoring System.

CONCLUSION

We conclude that pharmacologic thromboprophylaxis is frequently administered to hospitalized patients with cancer but that nearly one third of patients are considered to have relative contraindications for prophylactic anticoagulation. Pharmacologic thromboprophylaxis in hospitalized patients with cancer is commonly prescribed without regard to the presence or absence of concomitant risk factors for VTE.

Risk of venous thromboembolism in patients treated for bacterial infection in the community with outpatient parenteral antimicrobial therapy

BACKGROUND

It is recommended that venous thromboembolism (VTE) prophylaxis be considered for patients receiving outpatient parenteral antimicrobial therapy (OPAT), but there is no published data to quantify VTE risk in this patient group.

AIM AND METHOD

The aim of this retrospective cohort study was to establish VTE incidence in patients managed through an OPAT service and assess utility of a common VTE prediction score normally used for inpatients. Consecutive episodes of OPAT between May 2009 and May 2012 were included. Patients on long-term anti-coagulants, those with an established indication for extended, outpatient VTE prophylaxis (i.e. patients referred to OPAT following hip or knee arthroplasty) were excluded. The Padua VTE Prediction Score was retrospectively applied to the cohort. The primary outcome was incidence of symptomatic VTE during or up to 90 days after completion of OPAT treatment.

RESULTS

There were 780 included patient episodes; 105 (13.5%) patients had a Padua VTE risk score >3; no patients received pharmacological VTE prophylaxis during OPAT treatment. During or up to 90 days following OPAT, two proximal lower limb DVTs were diagnosed, giving VTE incidence of 2/780 (0.26%, 95% CI: 0.03-0.92%), and there were eight deaths of which none were suspected to be related to VTE. There was one intracranial haemorrhage associated death.

CONCLUSION

This retrospective cohort study found a low incidence of VTE in OPAT patients, and does not support routine application of inpatient VTE prophylaxis algorithms to patients treated for infection in the community.

The design and rationale for the Acute Medically Ill Venous Thromboembolism Prevention with Extended Duration Betrixaban (APEX) study

Randomized clinical trials have identified a population of acute medically ill patients who remain at risk for venous thromboembolism (VTE) beyond the standard duration of therapy and hospital discharge. The aim of the APEX study is to determine whether extended administration of oral betrixaban (35-42 days) is superior to a standard short course of prophylaxis with subcutaneous enoxaparin (10 ± 4 days followed by placebo) in patients with known risk factors for post-discharge VTE. Patients initially are randomized to receive either betrixaban or enoxaparin (and matching placebo) in a double dummy design. Following a standard duration period of enoxaparin treatment (with placebo tablets) or betrixaban (with placebo injections), patients receive only betrixaban (or alternative matching placebo). Patients are considered for enrollment if they are older than 40 years, have a specified medical illness, and restricted mobility. They must also meet the APEX criteria for increased VTE risk (aged ≥75 years, baseline D-Dimer ≥2× upper the limit of "normal", or 2 additional ancillary risk factors for VTE). The primary efficacy end point is the composite of asymptomatic proximal deep venous thrombosis, symptomatic deep venous thrombosis, non-fatal (pulmonary embolus) pulmonary embolism, or VTE-related death through day 35. The primary safety outcome is the occurrence of major bleeding. We hypothesize that extended duration betrixaban VTE prophylaxis will be safe and more effective than standard short duration enoxaparin in preventing VTE in acute medically ill patients with known risk factors for post hospital discharge VTE.

Antithrombotic medication use and bleeding risk in medically ill patients after hospitalization

BACKGROUND

Hospitalized medically ill patients receiving antithrombotic medications experience increased risk of bleeding. We examined antithrombotic use, bleeding rates, and associated risk factors at 30 days post discharge.

METHODS

This retrospective database analysis included nonsurgical patients aged ≥40 years hospitalized for ≥2 days during 2005 to 2009. Previously cited, validated International Classification of Diseases, Ninth Revision, Clinical Modification codes for major bleeding were used to define clinically relevant bleeding.

RESULTS

Of the 327,578 patients, 9.1% received antithrombotic medications, of which 3.7% were anticoagulants. Rates of major and minor bleeding were 1.8% and 7.1%, respectively. Preindex gastroduodenal ulcer, thromboembolic stroke, blood dyscrasias, liver disease, and rehospitalization were the strongest predictors of major bleeding. Other risk factors included increasing age, male gender, and hospital stay of ≥3 days.

CONCLUSIONS

Careful consideration of these demonstrated bleed-associated comorbidities before initiating anticoagulation or combining antithrombotic medications in medically ill patients may improve strategies for prevention of postdischarge thromboembolism.

The effects of obesity on venous thromboembolism: A review

Obesity has emerged as a global health issue that is associated with wide spectrum of disorders, including coronary artery disease, diabetes mellitus, hypertension, stroke, and venous thromboembolism (VTE). VTE is one of the most common vascular disorders in the United States and Europe and is associated with significant mortality. Although the association between obesity and VTE appears to be moderate, obesity can interact with other environmental or genetic factors and pose a significantly greater risk of VTE among individuals who are obese and who are exposed simultaneously to several other risk factors for VTE. Therefore, identification of potential interactions between obesity and certain VTE risk factors might offer some critical points for VTE interventions and thus minimize VTE morbidity and mortality among patients who are obese. However, current obesity measurements have limitations and can introduce contradictory results in the outcome of obesity. To overcome these limitations, this review proposes several future directions and suggests some avenues for prevention of VTE associated with obesity as well.