Prophylaxis for Venous Thrombo-Embolism in Neurocritical Care: A Critical Appraisal

Venous thrombo-embolism (VTE) is frequently encountered in critically ill neurological and neurosurgical patients admitted to intensive care units. This patient population includes those with brain neoplasm, intracranial hemorrhage, ischemic stroke, subarachnoid hemorrhage, pre- and post-operative patients undergoing neurosurgical procedures and those with traumatic brain injury, and acute spinal cord injury (SCI). There is a wide variability in clinical practice for thromboprophylaxis in these patients, in part due to paucity of data based on randomized clinical trials. Here, we review the current literature on the incidence of VTE in the critically ill neurological and neurosurgical patients as well as appraise available data to support particular practice paradigms for specific subsets of these patients. Data synthesis was conducted via search of Medline, Cochrane databases, and manual review of article bibliographies. Critically ill neurological and neurosurgical patients have higher susceptibility to VTE. Intermittent compression devices with or without anti-thrombotics is generally the method of choice for thromboprophylaxis. Low molecular weight heparin is the method of choice in certain patient subgroups such as those with SCI and ischemic stroke. Inferior vena cava filters may play a role in thromboprophylaxis in selected cases. Without clear guidelines that can be universally applied to this diverse group of patients, prophylaxis for VTE should be tailored to the individual patient with cautious assessment of benefits versus risks. There is a need for higher level evidence to guide VTE prophylaxis in certain subgroups of this patient population.     

Initial treatment of venous thromboembolism

Immediate anticoagulant treatment is essential to reduce morbidity and mortality in patients with acute venous thromboembolism (VTE). Currently, rapid anticoagulation can only be achieved with parenteral anticoagulants, such as heparin or low-molecular-weight heparin (LMWH). Weight-adjusted LMWH is the treatment of choice, because it produces predictable anticoagulation and does not require coagulation monitoring. If heparin is used, the activated partial thromboplastin time must be monitored and the heparin dose adjusted to ensure a therapeutic level of anticoagulation. Heparin is recommended for patients with renal impairment and for those at high risk of bleeding. The selective factor Xa inhibitor fondaparinux is a recently introduced alternative to heparin or LMWH for initial VTE treatment. Heparin, LMWH, or fondaparinux should be given for at least five to seven days. Vitamin K antagonists should be initiated on the first day, or as soon as possible, in patients who are candidates for an oral anticoagulant. An oral anticoagulant agent to be used without laboratory monitoring for both acute and long-term treatment of VTE remains an unsolved clinical need in the treatment of VTE.     

Prevention of venous thromboembolism in immobilized neurological patients: Guidelines of the Italian Society for Haemostasis and Thrombosis (SISET)

Neurological disorders are often associated with immobilization, thus placing patients at increased risk for venous thromboembolism (VTE). This risk is very high in patients with acute ischemic stroke and spinal cord injuries, and it remains poorly defined in patients with peripheral nervous disorders or degenerative disorders of the central nervous system. The benefit of prophylactic strategies remains often unclear. The Italian Society for Studies on Haemostasis and Thrombosis promoted the development of evidence- and consensus-based guidelines to help physicians involved in the management of neurological patients. After a comprehensive and systematic review of the literature, a panel of experts formulated recommendations for the prevention of VTE in adolescent or adult patients presenting with different neurological disorders. Patients with acute ischemic stroke should routinely receive pharmacological prophylaxis to be started within 48 hours and continued for approximately 14 days; patients with acute hemorrhagic stroke should routinely receive mechanical prophylaxis, pharmacological prophylaxis should be considered once the patient is stable; patients with neuro-muscular degenerative diseases and with other major risk factors for venous thrombosis should be considered for the administration of pharmacological or mechanical prophylaxis; patients with peripheral nerve diseases should receive mechanical prophylaxis while immobilized and in the presence of additional risk factors for VTE, patients with Guillain Barrè should be considered for pharmacological prophylaxis with low molecular weight heparin; patients with spinal cord injury should receive combined mechanical and pharmacological prophylaxis; patients with non traumatic spinal cord diseases should be considered for pharmacological prophylaxis.     

An open-label randomized controlled trial of low molecular weight heparin for the prevention of central venous line-related thrombotic complications in children: the PROTEKT trial

OBJECTIVE(S): Central venous lines (CVLs) are major risk factors for venous thromboembolism (VTE) in children. The objective of PROTEKT was to determine if a low molecular weight heparin (reviparin-sodium) safely prevents CVL-related VTE. STUDY DESIGN: This multi-center, open-label study, with blinded central outcome adjudication, randomized patients with new CVLs to twice-daily reviparin-sodium or standard care. The efficacy outcome was based on an exit venogram at Day 30 (+14 days), or earlier in case of CVL removal, or confirmed symptomatic VTE. The safety outcomes were major bleeding and death. Due to slow and restricted patient accrual, PROTEKT was closed prematurely. RESULTS: With reviparin-sodium, 14.1% (11:78) of patients had VTE compared to 12.5% (10:80) of control patients (odds ratio=1.15; 95% confidence interval 0.42, 3.23); 2P=0.82). One patient had a major bleed and there were two deaths, all three events occurring in the standard care group. CONCLUSIONS: The use of reviparin-sodium for short-term prophylaxis of CVL-related VTE in children was safe but its efficacy remains unclear. Although underpowered, PROTEKT provided valuable information on event rates and predictors of CVL-related VTE.     

Venous thromboembolism prophylaxis in medical inpatients: a retrospective chart review

BACKGROUND: Venous thromboembolic disease (VTE) is a major cause of morbidity and mortality in hospitalized patients. Most hospitalized patients with a fatal pulmonary embolism are medical patients who do not have a history of recent surgery [BMJ 302 (1991) 709; J. R. Soc. Med. 82 (1989) 198]. There is evidence suggesting that VTE prophylaxis is indicated in many high risk medical patients [Chest 119 (2001) 132S; NEJM 341 (1999) 793]. However, previous studies have shown that only about one third of high risk medical patients receive VTE prophylaxis [Ann. Intern. Med. 115 (1991) 591; Chest 106 (1994) 13; Chest 107 (1995) 296]. The objective of this study was to determine the frequency of use of VTE prophylaxis in medical inpatients at two teaching hospitals in Hamilton, Ontario. METHODS: A retrospective chart review of consecutive patients admitted to medical wards at two acute care sites of McMaster University affiliated teaching hospitals between October 10, 2001 and December 11, 2001 was performed. For each patient, demographic data, risk factors for VTE, method of VTE prophylaxis and contraindications to VTE prophylaxis were recorded. RESULTS: 756 patient charts were reviewed and 310 (41%) were excluded because the primary diagnosis required anticoagulation, the patients were being treated with anticoagulation (warfarin or heparin) before admission or the patient was admitted to the intensive care unit. Of the remaining 446 patients, 146 (33%) received some form of VTE prophylaxis. Of the patients receiving prophylaxis, 4% had early ambulation, 9% wore anti-embolic stockings (AES), 1% used intermittent pneumatic compression, 23% used unfractionated heparin and 3% used low molecular weight heparin. Two hundred five (46%) patients had one identifiable VTE risk factor and 63 (14%) had two or more risk factors. Patients with more VTE risk factors were more likely to receive prophylaxis. INTERPRETATION: One third of medical inpatients at two teaching hospitals in Hamilton received some form of VTE prophylaxis.     

Prevention of deep venous thrombosis and pulmonary embolism following stroke: a systematic review of published articles

We performed a systematic review of the literature on venous thromboembolism (VTE) prophylaxis following cerebral infarct (CI) and haemorrhagic stroke. MEDLINE, Cochrane, LILACS and SciELO databases were scanned, and the Abstracts from Brazilian, American and European Neurology and Stroke Congresses were scrutinized for clinical trials. Moreover, the reference lists of articles and reviews were searched. A pooled analysis of two large studies with aspirin was made. Both unfractionated heparin and low molecular weight heparins/heparinoids (LMWH) are partially effective for VTE prophylaxis after CI, and should be routinely used in patients with motor deficit and reduced mobility and no contraindications. Reduction of deep venous thrombosis is better established than the effect over pulmonary embolism or mortality. Some evidence points to a greater efficacy of LMWH. The available evidence does not support the use of mechanical methods or dextran. Aspirin may have a mild protective effect. Low-dose Warfarin might be useful in the rehabilitation setting. Strict recommendations cannot be made in patients with haemorrhagic stroke but intermittent pneumatic compression merits further study. There are important limitations of current VTE preventive strategies following stroke. Additional studies on the combination of methods after CI and of low doses of anticoagulants following cerebral haemorrhage are urgently needed.     

Trends in post-discharge prophylactic anticoagulant use among stroke patients in the United States between 2006 and 2019

BackgroundStroke is an independent risk factor for venous thromboembolism (VTE). Although the risk of VTE persists after hospital discharge, information on the utilization of anticoagulants among stroke patients after discharge remains limited.ObjectiveTo evaluate changes in post-discharge thromboprophylaxis among stroke patients between 2006 and 2019.MethodsWe conducted a retrospective repeated cross-sectional analysis using a commercial healthcare insurance database in the United States. We included patients aged ≥ 18 years with incident stroke diagnosis and assessed prophylactic use of anticoagulants in the 30 days following hospital discharge including low-molecular-weight heparin (enoxaparin ≤40 mg/day, dalteparin ≤5000 IU/day), unfractionated heparin ≤5000 IU/ twice daily or 3 times a day, apixaban 2.5 mg twice daily, and rivaroxaban 10 mg/day. Patients with atrial fibrillation, VTE, mechanical heart valves, cancer, antiphospholipid antibody syndrome, and users of therapeutic doses of anticoagulants were excluded. We used the Cochrane-Armitage test to assess changes in the use of anticoagulants across the study period.ResultsThere was a small increase in the overall use of post-discharge prophylactic anticoagulants among stroke patients between 2006 and 2019 from 0.5% to 1.9%. The use of heparin decreased from 0.5% in 2006 to 0.3% in 2019 (P-value for trend = 0.001). In contrast, the use of apixaban or rivaroxaban increased from 0.1% in 2013 to 1.6% in 2019 (P-value for trend < 0.001). Apixaban was more commonly used than rivaroxaban.ConclusionsIn this population-based study of stroke patients, we found that post-discharge anticoagulant use remains low through 2019. Prophylactic use of heparin or rivaroxaban was relatively low but the use of apixaban increased over the study period. Further research is needed to determine if these agents are safe and effective for VTE prevention in stroke patients.     

The relative contributions of antithrombin III during heparin treatment, and of clinically recognisable risk factors, to early recurrence of venous thromboembolism

The influence of antithrombin III (ATIII) level and ATIII activity, measured during intravenous heparin treatment for venous thromboembolism (VTE), on 'heparin requirement' (the heparin dose required to prolong the activated partial thromboplastin time (APTT) into its designated therapeutic range), and on the likelihood of recurrent VTE during the first month of anticoagulant therapy, were examined in a prospective study of 232 patients with VTE treated according to a standard protocol. 15 patients with recurrent VTE (6.5%) had a lower mean APTT during heparin treatment than patients without recurrence; a finding due partly to their heparin requirement. However, there was no measurable relationship between ATIII level or ATIII activity and either heparin requirement or recurrence of VTE. By contrast, both the presence of disseminated malignancy and the development of heparin induced thrombocytopenia were powerful, clinically recognisable, risk factors for recurrence during or soon after heparin therapy.     

Risk factors for symptomatic venous thromboembolism in Thai hospitalised medical patients

Thromboprophylaxis for venous thromboembolism (VTE) failed to reduce overall mortality in hospitalised medical patients. As a VTE prediction model for Asians is still lacking, this study aimed to identify very high risk patients who would be the main target for prevention. In 2009, medical patients admitted to King Chulalongkorn Memorial hospital, a tertiary care centre, were prospectively evaluated for risk factors. The high-risk cohort was monitored for symptomatic VTE until six weeks after discharge. No heparin prophylaxis was given. Of 1,290 high-risk patients, 27 (2.1%, 95% confidence interval [CI] 1.3-2.9) developed proven VTE, 25.9% of which were diagnosed after discharge. Cases with VTE stayed longer in the hospital (median 18 vs. 11 days, p < 0.001). The significant risk factors in a multivariate analysis were autoimmune disease, solid tumours, family history of VTE, varicose vein and oestrogen with the relative risks of 11.8, 4.7, 120.3, 40.1 and 17.1 (p < 0.001, 0.001, 0.001, 0.002 and 0.038), respectively. Either autoimmune disease or solid tumours were found in 63% of VTE with the relative risk of 4.5 (95% CI 2.1-9.7, p < 0.001). In contrast, previously reported VTE scores in western patients could not stratify the VTE risks, but all the scores predicted higher mortality. In conclusion, VTE is common in Asian hospitalised medical patients. Patients with autoimmune disease and those with solid tumours are highly susceptible to VTE. A prophylactic strategy in these groups is required.     

Treatment of patients with acute deep vein thrombosis and/or pulmonary embolism: Efficacy and safety of non-VKA oral anticoagulants in selected populations

Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT) and pulmonary embolism (PE), presents a large clinical burden. Prompt, effective and sustained anticoagulation is vital because of the risk of recurrent events, including life-threatening PE, and complications such as post-thrombotic syndrome and chronic thromboembolic pulmonary hypertension. Dual-drug standard therapy is effective; however, parenteral low molecular weight heparin, coupled with routine coagulation monitoring and dose adjustment of vitamin K antagonists (VKAs), presents challenges for patients and healthcare providers. Non-VKA oral anticoagulants provide a simplified option for VTE treatment. Phase III studies have investigated rivaroxaban and apixaban as single-drug approaches, and edoxaban and dabigatran in conjunction with initial heparin therapy. These agents demonstrated non-inferiority to standard therapy, and most showed significant reductions in major bleeding. However, clinical information is limited in patient subgroups, e.g. fragile patients or patients with renal impairment or cancer, who may be at higher risk of bleeding and/or VTE. A prespecified pooled analysis of the EINSTEIN DVT and EINSTEIN PE studies (8281 patients), undertaken to evaluate clinical outcomes with rivaroxaban versus standard therapy, confirmed the non-inferiority of rivaroxaban, with significant reductions in major bleeding and fewer intracranial and retroperitoneal bleeding events. Consistent efficacy and safety were observed with rivaroxaban, irrespective of fragility, cancer or clot severity. The introduction of the non-VKA oral anticoagulants and approval of rivaroxaban in the EU, US and Canada for the treatment and secondary prevention of DVT and PE offer the potential for improvements in effective care across a broad spectrum of patients with VTE.     

Deep vein thrombosis in patients with stroke

A frequent condition affecting patients with stroke is venous thromboembolism (VTE), which consists of two components: deep vein thrombosis, and pulmonary embolism as its complication The main risk factors of VTE are: age over 65 years, motor deficit with immobilisation, heart failure, infection, obesity and coagulopathy Typical symptoms of deep vein thrombosis (pain, tenderness, swelling of calf and increased skin temperature) can be masked by sensory and autonomic deficits following brain ischaemia Diagnosis of VTE is based on clinical symptoms confirmed by biochemical and radiological findings The treatment of VTE consists of anticoagulation; prevention of VTE in stroke patients is based on use of low-molecular heparins and non-pharmacological methods.     

Dermatan sulphate for the prevention of postoperative venous thromboembolism in patients with cancer. DOS (Dermatan sulphate in Oncologic Surgery) Study Group.

BACKGROUND: Patients undergoing surgery for cancer are at high risk for venous thromboembolism (VTE). Agents that selectively inhibit thrombin, such as dermatan sulphate, have potential for a favourable benefit-risk ratio in the prevention of this complication. METHODS: Patients scheduled for elective abdominal, thoracic, gynecologic or urologic surgery for cancer resection, were randomised to dermatan sulphate (600 mg intramuscularly on the second day before surgery, then 300 mg once daily), or calcium heparin (5,000 IU subcutaneously t.i.d., starting 2 hours before operation). Both treatments were continued until postoperative day 7 or until adequate mobilisation was achieved. Bilateral venography was scheduled at the end of treatment. Venograms were centrally assessed in blind conditions. The study outcomes were VTE (venographically proven deep vein thrombosis IDVT] or symptomatic, objectively confirmed pulmonary embolism) and bleeding complications. RESULTS: At 27 centres, 842 patients were randomised and underwent surgery (418 dermatan sulphate, 424 heparin). Efficacy was assessed in 521 patients with adequate venography and/or confirmed pulmonary embolism. DVT was observed in a total of 96 patients; symptomatic non-fatal pulmonary embolism developed in 2 patients (one per group), who also had DVT at venography. Postoperative VTE occurred in 40 of 267 patients on dermatan sulphate, 15.0%, versus 56 of 254 patients on heparin. 22.0% (p = 0.033). Relative risk reduction was 32.7% (95% confidence interval, 3.1 to 53.2%). The rate of bleeding complications in all operated patients was 6.9% with dermatan sulphate and 7.5% with heparin (confidence interval for the absolute risk difference, -4.1 to 2.9%). The inhospital mortality rate was 1.2% and 1.4%, respectively. CONCLUSIONS: In oncologic surgery, dermatan sulphate prevents VTE more effectively than heparin without increasing bleeding complications.     

Management and adherence to VTE treatment guidelines in a national prospective cohort study in the Canadian outpatient setting. The Recovery Study

Documenting patterns and outcomes of venous thromboembolism (VTE) management and degree of adherence by clinicians to treatment guidelines could help identify remediable gaps in patient care. Prospective, clinical practice-based data from Canadian outpatient settings on management of VTE, degree of adherence with treatment guidelines and frequency of recurrent VTE and bleeding during follow-up was obtained in a multicentre, prospective observational study. From 12 Canadian centres, we assessed 868 outpatients with acute symptomatic VTE who received the low-molecular-weight heparin (LMWH) enoxaparin alone or with vitamin K antagonists (VKA), at baseline and at six months (or at the end of treatment, whichever came first). Index VTE was limb deep venous thrombosis (DVT) in 583 (67.2%) patients, pulmonary embolism (PE) with or without DVT in 262 (30.2%) patients, and unusual site DVT in 23 (2.6%) patients. VTE was unprovoked in 399 (46.0%) patients, associated with cancer in 74 (8.5%) patients, transient risk factors in 327 (37.7%) patients and hormonal factors in 68 (7.8%) patients.With regard to guideline adherence, 58 (7.3%) patients received <5 days LMWH and 114 (14.5%) had overlap <1 day. Among patients with cancer-related VTE, 59.5% were prescribed LMWH monotherapy and 43.2% received such treatment for >3 months. Only 38.1% of patients with transient VTE risk factors had received thromboprophylaxis. Our study provides useful information on clinical presentation, management and related outcomes in Canadian outpatients with VTE. Our results suggest there may be important gaps in use of thromboprophylaxis to prevent VTE and use of LMWH monotherapy to treat cancer-related VTE.     

Risk factors for failure of heparin thromboprophylaxis in patients with acute traumatic spinal cord injury

Venous thromboembolism (VTE) is a well-recognized complication of Acute Traumatic Spinal Cord Injury (ATSCI). Despite prophylaxis by heparins, VTE occurs in a substantial number of ATSCI patients without an obvious explanation. In this matched case-control study we examined whether thrombophilia and other risk factors are associated with failure of thromboprophylaxis.Cases and controls receiving heparin thromboprophylaxis were selected from consecutively admitted ATSCI patients. Patients who developed a new, objectively confirmed, symptomatic VTE despite prophylaxis at hospital were matched by gender, age, level and mechanism of ATSCI with 2-3 controls without VTE. Patients were interviewed about VTE risk factors and tested for factor V Leiden (FVL), prothrombin G20210A (PT), methylenetetrahydrofolate reductase C677T homozygosity (MTHFR), lupus anticoagulant, homocysteine (Hcy) and plasma factor VIII (FVIII) levels.Twenty-two patients with new VTE episodes and 64 controls were ascertained. The total number of gene alterations for MTHFR, FVL and PT or elevated levels of Hcy or FVIII was significantly more common in patients compared to controls (82% vs. 48%, p = 0.006). Multiple logistic regression proved the PT mutation, a positive family history of thrombosis and elevated levels of either FVIII or Hcy to be predictors of thrombosis.

Conclusion

A positive family history of VTE, carriership of the prothrombin mutation and elevated FVIII or Hcy levels were significantly associated with failure to prevent VTE by heparin therapy following ATSCI. Testing for thrombophilia in patients with ATSCI and possibly a more intense thromboprophylactic regimen seem desirable but need to be verified by a prospective study.     

Thromboprophylaxis in medical patients: the role of low-molecular-weight heparin

Many hospitalised medical patients are at increased risk of venous thromboembolism (VTE). Consensus statements recommend that such patients be assessed for risk of VTE on admission to hospital and receive thromboprophylaxis where appropriate. However, VTE prophylaxis is not widely used in medical patients. One explanation is that assessing medical patients' risk of VTE is complicated. The risk depends not only on the current illness but also on multiple intrinsic factors, and a variety of strategies for identifying patients who should receive thromboprophylaxis have been suggested. Thromboprophylaxis with unfractionated heparin (UFH) has proved to be effective in reducing the incidence of deep-vein thrombosis and overall mortality in medical patients. Clinical trial evidence, including a meta-analysis, suggests that thromboprophylaxis with low-molecular-weight heparin (LMWH) is at least as effective as with UFH, and also has the advantage of fewer bleeding complications. In particular, two large, randomised clinical trials--Prophylaxis in Medical Patients with Enoxaparin (MEDENOX) and Prospective Evaluation of Dalteparin Efficacy for Prevention of VTE in Immobilized Patients Trial (PREVENT)--showed that thromboprophylaxis with the LMWHs enoxaparin (40 mg s.c. once daily) or dalteparin (5,000 IU once daily) is more effective than placebo and well tolerated in medical patients. In addition, the Thromboembolism-Prevention in Cardiopulmonary Diseases with Enoxaparin (THE-PRINCE) trial showed that enoxaparin treatment was as effective as UFH. These studies provide solid evidence for the widespread use of thromboprophylaxis in medical patients.     

Predictors of acute hospital costs for treatment of ischemic stroke in an academic center

BACKGROUND AND PURPOSE: We sought to determine predictors of acute hospital costs in patients presenting with acute ischemic stroke to an academic center using a stroke management team to coordinate care. METHODS: Demographic and clinical data were prospectively collected on 191 patients consecutively admitted with acute ischemic stroke. Patients were classified by insurance status, premorbid modified Rankin scale, stroke location, stroke severity (National Institutes of Health Stroke Scale score), and presence of comorbidities. Detailed hospital charge data were converted to cost by application of department-specific cost-to-charge ratios. Physician's fees were not included. A stepwise multiple regression analysis was computed to determine the predictors of total hospital cost. RESULTS: Median length of stay was 6 days (range, 1 to 63 days), and mortality was 3%. Median hospital cost per discharge was $4408 (range, $1199 to $59 799). Fifty percent of costs were for room charges, 19% for stroke evaluation, 21% for medical management, and 7% for acute rehabilitation therapies. Sixteen percent were admitted to an intensive care unit. Length of stay accounted for 43% of the variance in total cost. Other independent predictors of cost included stroke severity, heparin treatment, atrial fibrillation, male sex, ischemic cardiac disease, and premorbid functional status. CONCLUSIONS: We conclude that the major predictors of acute hospital costs of stroke in this environment are length of stay, stroke severity, cardiac disease, male sex, and use of heparin. Room charges accounted for the majority of costs, and attempts to reduce the cost of stroke evaluation would be of marginal value. Efforts to reduce acute costs should be monitored for potential cost shifting or a negative impact on quality of care.     

Long-term death and recurrence in patients with acute venous thromboembolism: The MASTER registry

BACKGROUND: The long-term clinical outcome of VTE has been essentially assessed in cohorts of selected patients. The aim of this multicenter registry was to prospectively assess the long-term clinical outcome in a cohort of unselected patients with objectively confirmed acute VTE. MATERIALS AND METHODS: Death and VTE recurrence at 24months were the main study outcomes. Univariate and multivariate survival analyses were performed according to the Kaplan-Meyer and Cox proportional hazard model, respectively. RESULTS: 2119 patients with acute VTE were included in the registry: 1541 (72.7%) with deep vein thrombosis, 206 (9.7%) with pulmonary embolism and 372 (17.6%) with both. Information about death was available in 2021 patients (95.4%) and about recurrence in 1988 patients (93.8%). 167 patients (4.55% patient-year) died during follow-up. After adjusting for age, cancer (Hazard ratio [HR]: 7.2; 95%CI 4.8-10.8), long-term heparin treatment (HR: 2.5; 95%CI 1.8-3.5), in-hospital management of VTE (HR: 2.0; 95%CI 1.3-3.0), and ileo-caval thrombosis (HR: 1.7; 95%CI 1.2-2.4) were found to be independent predictors of death. 124 (3.63% patient-year) patients had a VTE recurrence during follow-up. In-hospital management of VTE (HR: 1.8; 95%CI 1.2-2.9), male gender (HR: 1.7; 95%CI 1.2-2.4) were independent risk factors for recurrent VTE. Cancer (HR: 1.6; 95%CI 1.0-2.8) showed a trend for increased risk of VTE recurrence (p=0.056). The reported rate of major bleeding was 2.5%. CONCLUSIONS: In a large cohort of unselected VTE patients, cancer, ileo-caval thrombosis, long-term heparin treatment and in-hospital management were associated with increased mortality during long-term follow-up. In-hospital management, male gender were associated with an increased risk of VTE recurrence.     

The utility of routine head CT for hemorrhage surveillance in post-craniotomy patients undergoing anticoagulation for venous thromboembolism

Anticoagulation for postoperative venous thromboembolism (VTE) may infer a higher risk of intracranial hemorrhage. We treat patients with VTE using slowly titrating intravenous heparin drip without bolus. When PTT is greater than 60 s, a head CT is obtained to monitor for the development of a intracranial hemorrhage before transition to oral anticoagulation. We evaluated the utility of routine surveillance head CT to monitor for intracranial hemorrhage during anticoagulation. This is a case series of neurosurgical patients in an academic quaternary hospital who developed a VTE after cranial procedures between 2007 and 2017. Over 11,000 patients were screened for the study. Patients’ demographics data, surgical indication, PTT at the time of surveillance CT head, surveillance CT head findings, and patient’s clinical course were reviewed. A total of 83 patients were included. Three patients (3.6%) developed a new subclinical hemorrhage on CT head imaging while on heparin drip. Interval CT head showed stable hemorrhage in all patients. Heparin drip was stopped in two patients and they both progressed from DVT to pulmonary embolism: one patient died due to cardiac arrest, the other patient was transitioned to oral anticoagulation. In the third patient heparin drip was continued uneventfully and transitioned to oral anticoagulation with no further clinical sequalae. Surveillance CT while on heparin drip for VTE management detected subclinical intracranial hemorrhage in a small subset of patients. Patients whose anticoagulation was stopped had progression of VTE. Undertreatment of VTE in the presence of subclinical hemorrhage may lead to significant morbidity and mortality.     

The pregnant antithrombin III deficient patient: management without antithrombin III concentrate.

Pregnant patients with antithrombin III (AT III) deficiency have an unacceptably high risk of venous thromboembolism (VTE). Antithrombotic therapy is therefore recommended. The reported clinical experience of such prophylaxis is limited. Some authors have recommended the use of AT III concentrate in addition to heparin in the management of these patients. We report successful management with heparin alone during pregnancy and the postpartum period in two patients with AT III deficiency. Both patients had experienced VTE during a prior pregnancy; one also experienced VTE during the reported pregnancy. Both patients were therefore at particularly high risk of further VTE. Based on the good results in these two patients, and a review of previously reported cases, we propose that heparin alone, in a dose to maintain the APTT in a therapeutic range, provides adequate prophylaxis and treatment for VTE during pregnancy and delivery in many AT III deficient subjects.     

An open-label randomized controlled trial of low molecular weight heparin compared to heparin and coumadin for the treatment of venous thromboembolic events in children: the REVIVE trial

OBJECTIVE(S): Venous thromboembolic events (VTE) are serious complications in children and for which the standard of care, unfractionated heparin followed by oral anticoagulation (UFH/OA), is problematic. The objective of REVIVE was to compare the efficacy and safety of a low molecular weight heparin (reviparin-sodium) to UFH/OA for the treatment of VTE in children. STUDY DESIGN: This multicenter, open-label study, with blinded central outcome adjudication, randomized patients with objectively confirmed VTE to receive either reviparin-sodium or UFH/OA. Dose adjustments were made using nomograms. The efficacy outcome was based on recurrent VTE and death due to VTE during the 3-month treatment period. The safety outcomes were major bleeding, minor bleeding and death. Due to slow patient accrual, REVIVE was closed prematurely. RESULTS: At 3 months, with reviparin-sodium, 2/36 patients (5.6%) had recurrent VTE or death compared to 4/40 patients (10.0%) receiving UFH/OA (odds ratio=0.53; 95% CI=(0.05, 4.00); Fisher's exact test: 2P=0.677). There were 7 major bleeds, 2/36 (5.6%) in the reviparin-sodium group and 5/40 (12.5%) in UFH/OA group (odds ratio=0.41; 95% confidence interval 0.04, 2.76); Fisher's exact test: P=0.435). There were 5 deaths during the study period, 1 (2.8%) in the reviparin-sodium group and 4 (10.0%) in the UFH/OA group. All five deaths were unrelated to VTE but one was due to an intracranial hemorrhage in the UFH/OA group. CONCLUSIONS: Although limited by small sample size, REVIVE provides valuable information on the incidence of recurrent VTE, major bleeding and problematic issues associated with therapy of VTE in children.