Prevention and treatment of venous thromboembolism with low-molecular-weight heparins: Clinical implications of the recent European guidelines

Venous Thromboembolism Prophylaxis: Need for Continuous Assessment Due to Changes in Risk During the Same Hospitalization

Objective

To explore the role of venous thromboembolism (VTE) risk reassessment in hospitalized medically ill patients without a change in level of care.

Patients and Methods

In this exploratory retrospective study, the medical records of 171 consecutive adult patients (≥18 years) hospitalized under the medicine service for more than 3 days without a change in the level of care from January 1, 2015, to March 1, 2015, were reviewed. The primary outcome was a change in the risk score between day 1 and day 3 of hospital stay (using the Padua Prediction Score). The secondary outcomes were changes in risk stratification class (low vs high) and cost-benefit analysis.

Results

The risk score was significantly different between day 1 and day 3 (4.7±1.7 vs 4.2±1.8; P=.008). All the patients with low risk on day 1 remained at low risk on day 3. However, 25 of 136 patients (18.4%) with high risk on day 1 were reclassified as low risk on day 3 (P<.001). No patients changed from low risk to high risk at day 3. The reclassification could have saved $35 per patient-day of inappropriate pharmacological prophylaxis in addition to patient discomfort, bleeding risk, and heparin-induced thrombocytopenia.

Conclusion

This is the first study to suggest the need for regular assessment for VTE risk on medicine wards because of changing patient risk. Regular reassessment could reduce health care waste and patient discomfort.

Venous Thromboembolism Prophylaxis: Inadequate and Overprophylaxis When Comparing Perceived Versus Calculated Risk

Guidelines for venous thromboembolism (VTE) prophylaxis recommend appropriate risk stratification using risk estimation models as high risk or low risk followed by initiation of chemical or mechanical prophylaxis, respectively. We explored adherence to guidelines on the basis of the documentation of VTE prophylaxis. A retrospective medical record review of 437 consecutive adult patients (≥18 years) admitted to general medical wards under medicine service between January 1, 2015, and March 1, 2015, was performed. The primary outcome was appropriateness of risk stratification using the Padua Prediction Score. Secondary outcomes were appropriateness of type of prophylaxis (chemical vs mechanical) and cost-benefit analysis. We observed appropriate stratification based on the documented risk (compared with the calculated risk) in 54.9% of the patients (40.8% with low risk vs 72.1% with high risk; P<.001). Overall, 182 of 240 low-risk patients received unnecessary chemical prophylaxis, whereas 23 of 197 high-risk patients without contraindications for chemical prophylaxis received mechanical or no prophylaxis. No clinical VTE events were noted in the patients inappropriately assigned to mechanical or no prophylaxis. Also, 67.3% of patients with both low documented and low calculated risk and 74.5% of patients with low documented and high calculated risk received chemical prophylaxis, consistent with a tendency toward overtreatment. A total of 4068 annualized patient-days ($77,652/y) of inappropriate chemical prophylaxis were administered. In conclusion, estimation of the risk of VTE based on clinical impression was not congruent with the risk calculated using risk prediction models and was associated with a tendency toward overtreatment. These data support the inclusion of VTE risk calculators in electronic health record systems.

Direct Oral Anticoagulants for the Management of Thromboembolic Disorders

Anticoagulation therapy is central to the management of thromboembolic disorders, and the use of direct oral anticoagulants offers several advantages over standard therapy with parenteral heparins and vitamin K antagonists. In phase III clinical trials, the direct oral anticoagulants (given once or twice daily) all demonstrated favorable benefit–risk profiles compared with conventional standard therapy for the treatment and secondary prevention of venous thromboembolism and for stroke prevention in patients with nonvalvular atrial fibrillation. In clinical practice, many factors may influence overall clinical outcomes in patients receiving anticoagulant therapy, including adherence and persistence to the prescribed therapy, which becomes particularly important during long-term therapy. When choosing an anticoagulant for an individual patient, the pharmacological and clinical profile of the anticoagulant, its dosing regimen, and the patient’s clinical characteristics (eg, renal function and comorbidities) and preferences should be considered. This review examines the rationale for and clinical evidence of the selected dosing regimens of the direct oral anticoagulants for the treatment of venous thromboembolism and stroke prevention in nonvalvular atrial fibrillation. The potential influence of dosing strategies (eg, once- or twice-daily dosing) and other factors on patient adherence and therapy persistence are also discussed.

Adverse effects of glucocorticoids: coagulopathy

Hypercortisolism is associated with various systemic manifestations, including central obesity, arterial hypertension, glucose intolerance/diabetes mellitus, dyslipidemia, nephrolithiasis, osteoporosis, gonadal dysfunction, susceptibility to infections, psychiatric disorders, and hypercoagulability. The activation of the hemostatic system contributes to the development of atherosclerosis and subsequent cardiovascular morbidity and mortality. Previous studies have identified an increased risk of both unprovoked and postoperative thromboembolic events in patients with endogenous and exogenous Cushing's syndrome (CS). The risk for postoperative venous thromboembolism in endogenous CS is comparable to the risk after total hip or knee replacement under short-term prophylaxis. The mechanisms that are involved in the thromboembolic complications in hypercortisolism include endothelial dysfunction, hypercoagulability, and stasis (Virchow's triad). It seems that at least two factors from Virchow's triad must be present for the occurrence of a thrombotic event in these patients. Most studies have demonstrated that this hypercoagulable state is explained by increased levels of procoagulant factors, mainly factors VIII, IX, and von Willebrand factor, and also by an impaired fibrinolytic capacity, which mainly results from an elevation in plasminogen activator inhibitor 1. Consequently, there is a shortening of activated partial thromboplastin time and increased thrombin generation. For these reasons, anticoagulant prophylaxis might be considered in patients with CS whenever they have concomitant prothrombotic risk factors. However, multicenter studies are needed to determine which patients will benefit from anticoagulant therapy and the dose and time of anticoagulation.

Perioperative thromboprophylaxis in Cushing's disease: What we did and what we are doing?

PURPOSE

Cushing's disease (CD) is associated with an increased risk of thrombotic events, particularly after surgery. No guidelines are available on the management of patients with CD undergoing pituitary transsphenoidal surgery (TSS). We aimed to compare the effectiveness of different prophylactic procedures on the prevention of thrombotic events after surgery in CD.

METHODS

We retrospectively collected data on 78 consecutive patients who underwent TSS for CD between 2001 and 2012 at Padova's Neurosurgical Unit, recording their hemostatic, hormonal and anthropometric parameters. Patients were divided into two groups according to their perioperative management. Group A (34 patients) received fractionated heparin for a maximum of 14 days after surgery. Patients in group B (44 patients) were given no early glucocorticoid replacement therapy, and treated with subcutaneous enoxaparin 4,000-8,000 U/daily (depending on their weight) for 30 days plus graduated elastic stockings until mobilization, and early ambulation.

RESULTS

The whole cohort of patients had clotting and anticoagulant factors significantly higher than the normal range. The two groups were comparable for age, BMI, ACTH, urinary free cortisol levels, outcome of surgery, and main clotting parameters. The surgical procedure did not change during the study period. Three venous thrombotic events [venous thromboembolic events (VTE), 2 associated with pulmonary embolism] were recorded in group A, none in group B (p = 0.079). No hemorrhagic events were reported.

CONCLUSIONS

Provoked thrombotic events pose a major problem in the management of CD patients after surgery, regardless of the procedure's outcome. The prophylactic regimen proposed in this paper afforded an efficacy prophylaxis against postoperative VTE in patients with CD. Due to the rarity of CD, a multicenter study on a larger sample of cases would be warranted in order to collect more thrombotic events.

The potential of target-specific oral anticoagulants for the acute and long-term treatment of venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) comprises both deep vein thrombosis and pulmonary embolism. VTE is a leading cause of morbidity and mortality worldwide and its increasing incidence and prevalence are a major health concern. The primary medical objective during the acute phase of VTE treatment is to prevent thrombus extension and embolization. Extended treatment aims to prevent or minimize long-term complications, such as recurrent VTE, post-thrombotic syndrome and chronic thromboembolic pulmonary hypertension.

SCOPE

Anticoagulant therapy has been the mainstay of treatment for VTE and traditionally involves initial therapy with heparin, overlapping with and followed by a vitamin K antagonist. Although effective, standard heparin/vitamin K antagonist therapy has several limitations that can be overcome by more recently developed target-specific oral anticoagulants (TSOACs). These agents have predictable pharmacokinetics, a rapid onset of action and few drug-drug or drug-food interactions. Furthermore, TSOACs offer convenient anticoagulation without the need for routine coagulation monitoring and dose adjustment.

FINDINGS

The efficacy and safety data from phase III clinical trials support the use of TSOACs for VTE treatment, including in special patient populations. Risk-stratification tools and strategies have been developed to assist physicians in managing anticoagulation treatment.

CONCLUSIONS

Rivaroxaban is the first TSOAC to gain widespread approval for the treatment of acute deep vein thrombosis and pulmonary embolism and the long-term prevention of recurrent VTE as monotherapy. Dabigatran has also been approved for this indication recently. TSOACs, especially as monotherapy, represent a paradigm shift in clinical practice for the management of patients with VTE.

80-kV pulmonary CT angiography with 40 mL of iodinated contrast material in lean patients: comparison of vascular enhancement with iodixanol (320 mg I/mL)and iomeprol (400 mg I/mL)

OBJECTIVE

The purpose of this article is to compare the vascular enhancement obtained with a low-kilovoltage pulmonary CT angiography (CTA) protocol in lean patients, using 40 mL of a moderate-concentration isoosmolar (iodixanol, 320 mg I/mL) and a high-concentration low-osmolar (iomeprol, 400 mg I/mL) iodinated contrast medium injected at the same iodine delivery rate.

SUBJECTS AND METHODS

Forty-two lean patients (31 men and 11 women; body mass index, ≤ 23 kg/m(2)) with suspected pulmonary embolism and non-small cell lung carcinoma underwent pulmonary CTA with a 64-MDCT scanner using a tube voltage of 80 kV. Twenty-three patients (54.8%) received 40 mL of iodixanol (320 mg I/mL) injected at a rate of 5 mL/s, and the remaining 19 patients (45.2%) were administered an equal volume of iomeprol (400 mg I/mL) at a flow rate of 4 mL/s. Intraarterial density was measured in the common pulmonary artery trunk, the main right and left pulmonary arteries, lobar arteries, and at the segmental level, for a total of 15 regions of interest per patient. Intravascular enhancement homogeneity from central to subsegmental level was also assessed visually using a semiquantitative score (1 = poor, 2 = good, and 3 = excellent).

RESULTS

The overall vascular density of pulmonary arteries down to the segmental level was significantly higher with iodixanol (320 mg I/mL) than with iomeprol (400 mg I/mL) (p = 0.036). Enhancement homogeneity was good with both contrast agents, with no statistically significant difference between them (p = 0.8966).

CONCLUSION

In 80-kV pulmonary CTA of lean patients, higher intravascular enhancement can be achieved with 40 mL of iodixanol (320 mg I/mL) than with the same volume of iomeprol (400 mg I/mL), with good vessel conspicuity down to the subsegmental level.

Prevention of venous thromboembolism in pregnancy: a review of guidelines, 2000-2011

INTRODUCTION

Pregnant women are four to five times more likely than nonpregnant women to develop venous thromboembolism (VTE). The aim of this review is to provide an overview of guidelines in the literature on VTE risk assessment, screening for thrombophilias, and thromboprophylaxis dissemination among pregnant women.

METHODS

We performed a review of the published literature to identify evidence-based guidelines published between the years 2000 and 2011. We searched for guidelines from U.S. and international organizations that identified clinically based practice recommendations to healthcare providers on how VTE risk should be assessed, thrombophilias screened, and thromboprophylaxis disseminated among pregnant women.

RESULTS

We found nine guidelines that met our requirements for assessing VTE risk and found seven guidelines addressing thrombophilia screening. Seven of the nine agreed that all women should undergo a risk factor assessment for VTE either in early pregnancy or in the preconception period. Seven of the nine agreed that pregnant women with more than one additional VTE risk factor be considered for thromboprophylaxis, and five of the seven groups addressing thrombophilia screening agreed that selected at-risk populations should be considered for thrombophilia screening.

CONCLUSIONS

There is some agreement between U.S. and international guidelines that women should be assessed for VTE risk during preconception and again in pregnancy. Although there is agreement that the general population of women should not be screened for thrombophilias, no agreement exists as to the clinical subgroups for which screening should be done.

Prospective analysis of risk factors and distribution of venous thromboembolism in the population-based Malmö Thrombophilia Study (MATS)

BACKGROUND

Despite venous thromboembolism (VTE) being a major cause of morbidity and mortality, there is still limited information on its prevalence and incidence in the general population.

OBJECTIVE

To evaluate risk factors, distribution and epidemiology of VTE in the Malmö area with 280,000 inhabitants.

METHODS

Patients diagnosed with VTE at Malmö University Hospital in 1998-2006 were invited to a prospective population-based study. Blood sampling and a questionnaire study could be performed in 70% of patients. Remaining 30% were excluded due to language problems, dementia, other severe disease, or unwillingness to participate.

RESULTS

During 1998-2006 1140 VTE patients (559 men [49%, age 62+/-16 years] and 581 women [51%, age 61+/-20 years]) were included. Deep venous thrombosis (DVT) occurred in 882 (77%), pulmonary embolism (PE) in 330 (29%), and both DVT and PE in 72 (6%). The most common acquired risk factors among VTE patients were hormone therapy (24% of female DVT patients and 19% of female PE patients), immobilisation (17% of DVT patients and 18% of PE patients), previous surgery (13% of DVT patients and 19% of PE patients), and concomitant malignant disease (12% of DVT patients and 11% of PE patients). A positive family history for VTE was obtained from 25% of DVT patients and 22% of PE patients. Yearly incidences of VTE, DVT and PE in Malmö were 66, 51, and 19/100.000, respectively.

CONCLUSION

Hormone therapy, immobilisation, previous surgery and concomitant malignancy were the most common acquired risk factors among VTE patients in this population-based study. The VTE-incidence was lower than in earlier epidemiological studies.