Postthrombotic syndrome and quality of life after deep vein thrombosis in patients treated with edoxaban versus warfarin

Background

Postthrombotic syndrome (PTS) is a long-term complication after deep vein thrombosis (DVT) and can affect quality of life (QoL). Pathogenesis is not fully understood but inadequate anticoagulant therapy with vitamin K antagonists is a known risk factor for the development of PTS.

Objectives

To compare the prevalence of PTS after acute DVT and the long-term QoL following DVT between patients treated with edoxaban or warfarin.

Methods

We performed a long-term follow-up study in a subset of patients with DVT who participated in the Hokusai-VTE trial between 2010 and 2012 (NCT00986154). Primary outcome was the prevalence of PTS, defined by the Villalta score. The secondary outcome was QoL, assessed by validated disease-specific (VEINES-QOL) and generic health-related (SF-36) questionnaires.

Results

Between 2017 and 2020, 316 patients were enrolled in 26 centers in eight countries, of which 168 (53%) patients had been assigned to edoxaban and 148 (47%) to warfarin during the Hokusai-VTE trial. Clinical, demographic, and thrombus-specific characteristics were comparable for both groups. Mean (SD) time since randomization in the Hokusai-VTE trial was 7.0 (1.0) years. PTS was diagnosed in 85 (51%) patients treated with edoxaban and 62 (42%) patients treated with warfarin (adjusted odds ratio 1.6, 95% CI 1.0-2.6). Mean differences in QoL scores between treatment groups were not clinically relevant.

Conclusion

Contrary to our hypothesis, the prevalence of PTS tended to be higher in patients treated with edoxaban compared with warfarin. No differences in QoL were observed. Further research is warranted to unravel the role of anticoagulant therapy on development of PTS.

Isolated Distal Deep Vein Thrombosis: Perspectives from the GARFIELD-VTE Registry

Isolated distal deep vein thrombosis (IDDVT) represents up to half of all lower limb DVT. This study investigated treatment patterns and outcomes in 2,145 patients with IDDVT in comparison with those with proximal DVT (PDVT; n = 3,846) and pulmonary embolism (PE; n = 4,097) enrolled in the GARFIELD-VTE registry. IDDVT patients were more likely to have recently undergone surgery (14.6%) or experienced leg trauma (13.2%) than PDVT patients (11.0 and 8.7%, respectively) and PE patients (12.7 and 4.5%, respectively). Compared with IDDVT, patients with PDVT or PE were more likely to have active cancer (7.2% vs. 9.9% and 10.3%). However, influence of provoking factors on risk of recurrence in IDDVT remains controversial. Nearly all patients (IDDVT, PDVT, and PE) were given anticoagulant therapy. In IDDVT, PDVT, and PE groups the proportion of patients receiving anticoagulant therapy was 61.4, 73.9, and 81.1% at 6 months and 45.8, 54.7, and 61.9% at 12 months. Over 12 months, the incidence of all-cause mortality, cancer, and recurrence was significantly lower in IDDVT patients than PDVT patients (hazard ratio [HR], 0.61 [95% confidence interval [CI], 0.48–0.77]; sub-HR [sHR], 0.60 [95% CI, 0.39–0.93]; and sHR, 0.76 [95% CI, 0.60–0.97]). Likewise, risk of death and incident cancer was significantly (both p < 0.05) lower in patients with IDDVT compared with PE. This study reveals a global trend that most IDDVT patients as well as those with PDVT and PE are given anticoagulant therapy, in many cases for at least 12 months.

[The conspicuous leg]

Symptoms of the leg or of both legs, may indicate a need for evaluation and/or treatment, which must be clarified urgently or even as an emergency situation. Among the diseases which must be considered from a vascular viewpoint are critical limb ischemia, suspicion of deep leg vein thrombosis and special forms of venous insufficiency. With respect to infections erysipelas and the syndrome of infected diabetic foot must be considered as well as peripheral and central leg paresis as orthopedic and neurological disorders, respectively. The current review summarizes the main clinical features of these diseases. Criteria are discussed as to which require the particular capabilities of a hospital and which patients can be managed in an outpatient setting.

Indicators of outcome quality in peripheral arterial disease revascularisations – a Delphi expert consensus

Abstract. Introduction: Peripheral arterial disease (PAD) affects a continuously increasing number of people worldwide leading to more invasive treatments. Indication to perform invasive revascularisations usually arises from consensus-based recommendations of practice guidelines and from few randomized controlled trials where outcome measures focus mainly on risk factors associated with mortality and morbidity. To date, no broad consensual agreement of experts on valid indicators of outcome quality exists for PAD. Methods: A literature review was conducted to collect indicators of outcome quality from studies of PAD. The Delphi technique was used to achieve a consensual agreement on a set of core indicators. The expert panel of the two-round Delphi approach was formed by leading vascular specialists joining the IDOMENEO study, physician assistants, wound nurses, and patient representatives. Items were scored via a web-based anonymised electronic questionnaire using a five-point Likert-scale. Results: Out of 40 invited experts 30 joined the panel and completed round one. Twenty-four experts completed the second and final round. Forty-three indicators of outcome quality were initially identified and validated by the panel. After two Delphi rounds, 12 indicators (27.9 %) achieved the limit of agreement for relevance and four (9.3 %) for practicability. Major adverse limb events (MALE), major amputation, and major re-intervention (or re-operation) were consented as both highly relevant and practicable. Additionally, major adverse cardiovascular events (MACE), myocardial infarction, stroke or transient ischaemic attack, all-cause death, all re-intervention (or re-operation), wound infection, vascular access-related major complication, walking distance, and Rutherford-classification were consented as highly relevant. Ankle-brachial-index was consented as highly practicable. Conclusions: This Delphi approach of vascular experts identified three indicators as highly relevant and clinically practicable to be recommended as indicators of outcome quality in invasive PAD treatment. Among others, these consented items may help in harmonising future studies and quality benchmarking increasing their comparability, validity, and efficiency.

Efficacy of telemedical interventional management in patients with heart failure (TIM-HF2): a randomised, controlled, parallel-group, unmasked trial

BACKGROUND

Remote patient management in patients with heart failure might help to detect early signs and symptoms of cardiac decompensation, thus enabling a prompt initiation of the appropriate treatment and care before a full manifestation of a heart failure decompensation. We aimed to investigate the efficacy of our remote patient management intervention on mortality and morbidity in a well defined heart failure population.

METHODS

The Telemedical Interventional Management in Heart Failure II (TIM-HF2) trial was a prospective, randomised, controlled, parallel-group, unmasked (with randomisation concealment), multicentre trial with pragmatic elements introduced for data collection. The trial was done in Germany, and patients were recruited from hospitals and cardiology practices. Eligible patients had heart failure, were in New York Heart Association class II or III, had been admitted to hospital for heart failure within 12 months before randomisation, and had a left ventricular ejection fraction (LVEF) of 45% or lower (or if higher than 45%, oral diuretics were being prescribed). Patients with major depression were excluded. Patients were randomly assigned (1:1) using a secure web-based system to either remote patient management plus usual care or to usual care only and were followed up for a maximum of 393 days. The primary outcome was percentage of days lost due to unplanned cardiovascular hospital admissions or all-cause death, analysed in the full analysis set. Key secondary outcomes were all-cause and cardiovascular mortality. This study is registered with ClinicalTrials.gov, number NCT01878630, and has now been completed.

FINDINGS

Between Aug 13, 2013, and May 12, 2017, 1571 patients were randomly assigned to remote patient management (n=796) or usual care (n=775). Of these 1571 patients, 765 in the remote patient management group and 773 in the usual care group started their assigned care, and were included in the full analysis set. The percentage of days lost due to unplanned cardiovascular hospital admissions and all-cause death was 4·88% (95% CI 4·55-5·23) in the remote patient management group and 6·64% (6·19-7·13) in the usual care group (ratio 0·80, 95% CI 0·65-1·00; p=0·0460). Patients assigned to remote patient management lost a mean of 17·8 days (95% CI 16·6-19·1) per year compared with 24·2 days (22·6-26·0) per year for patients assigned to usual care. The all-cause death rate was 7·86 (95% CI 6·14-10·10) per 100 person-years of follow-up in the remote patient management group compared with 11·34 (9·21-13·95) per 100 person-years of follow-up in the usual care group (hazard ratio [HR] 0·70, 95% CI 0·50-0·96; p=0·0280). Cardiovascular mortality was not significantly different between the two groups (HR 0·671, 95% CI 0·45-1·01; p=0·0560).

INTERPRETATION

The TIM-HF2 trial suggests that a structured remote patient management intervention, when used in a well defined heart failure population, could reduce the percentage of days lost due to unplanned cardiovascular hospital admissions and all-cause mortality.

FUNDING

German Federal Ministry of Education and Research.

[Bridging anticoagulation in patients receiving vitamin K antagonists : Current status]

Approximately 30% of patients receiving oral anticoagulation using vitamin K antagonists (VKA) require surgery within 2 years. In this context, a clinical decision on the need and the mode of a peri-interventional bridging with heparin is needed. While a few years ago, bridging was almost considered a standard of care, recent study results triggered a discussion on which patients will need bridging at all. Revisiting the currently available recommendations and study results the conclusion can be drawn that the indications for bridging with heparin must nowadays be taken more narrowly and considering the individual patient risk of bleeding and thromboembolism. Bridging with heparin is only needed in patients with a very high risk of thromboembolism. This overview aims to give guidance for a risk-adapted peri-interventional approach to management of patients with a need for long-term anticoagulation using VKA.

Bed Rest in Deep Vein Thrombosis and the Incidence of Scintigraphic Pulmonary Embolism

In several countries of central Europe, patients with acute proximal deep vein thrombosis (DVT) are treated not only by anticoagulation and compression therapy but additionally by strict bed rest for 6-8 days. Until now the theoretical assumption that bed rest substantially reduces the incidence of pulmonary embolism has not been subjected to empirical verification. Patients with acute proximal DVT proven by ultrasonography were randomly assigned to strict bed rest for 8 days (treatment group) or to stay mobilised (control group). In both groups, basic treatment consisted in anticoagulation by subcutaneous low molecular weight heparin/vitamin-K-antagonist and compression therapy. The incidence of pulmonary embolism was assessed by serial ventilation/perfusion SPECT on day 1 and days 8-10. Of the 309 patients with proximal DVT considered for inclusion, 180 were excluded according to the study protocol, and 3 did not give informed consent. One hundred and twenty-six patients were randomly assigned to observe bed rest (n = 62) or to keep mobilised (n = 64). Four patients refused follow-up lung scan.A new lung perfusion defect was detected in 10/59 patients in the treatment group compared to 14/63 patients in the control group (one-sided p-value = 0.25; power 0.8). Bed rest as an additional measure in the treatment of DVT is not able to substantially reduce the incidence of scintigraphically detectable pulmonary embolism. The discomfort and costs associated with the prescription of bed rest in DVT are obviously inappropriate.

Impact of age on the efficacy and safety of extended-duration thromboprophylaxis in medical patients

The EXCLAIM study enrolled hospitalised acutely ill medical patients with age >40 years and recently-reduced mobility into a trial of extended-duration anticoagulant thromboprophylaxis. This post-hoc analysis evaluated the impact of age on patient outcomes. After completion of open-label therapy with enoxaparin 40 mg once-daily (10 ± 4 days), eligible patients underwent randomisation to receive double-blind therapy of enoxaparin (n=2,975) or placebo (n=2,988) for 28 ± 4 days. During follow-up, the venous thromboembolism (VTE) risk increased with age in both treatment groups. In patients with age >75 years, those who received extended-duration enoxaparin had lower incidence of VTE (2.5% vs 6.7%; absolute difference [AD] [95% confidence interval]: −4.2% [−6.5, −2.0]), proximal deep-vein thrombosis (2.5% vs 6.6%; AD −4.1 % [−6.2, −2.0]), and symptomatic VTE (0.3% vs 1.5%; AD −1.2% [−2.2, −0.3]), in comparison to those who received placebo. In patients with age ≤75 years, those who received enoxaparin had reduced VTE (2.4% vs 2.8%; AD −0.4% [−1.5, 0.7]) and symptomatic VTE (0.2% vs 0.7%; AD −0.6% [−1.0, −0.1]) in comparison to those who received placebo. In both age subgroups, patients who received enoxaparin had increased rates of major bleeding versus those who received placebo: age >75 years (0.6% vs 0.2%; AD +0.3% [−0.2, 0.9], respectively); age ≤75 years (0.7% vs 0.2%; AD +0.5% [0.1, 0.9]). Patients in both age subgroups that received enoxaparin had similar low bleeding rates (0.6% and 0.7%, respectively). VTE risk increased with age, though the bleeding risk did not. Patients with age >75 years had a more favourable benefit-to-harm profile than younger patients.

Continuation of venous thromboembolism prophylaxis after hospital discharge into the outpatient setting: the ACCEPT study

Transition from the hospital into the outpatient setting is a critical event for the appropriate provision of VTE prophylaxis. Data for this transition for the situation in Germany is scant. This was a retrospective, observational study in patients receiving in-hospital thromboprophylaxis and discharged with or without a recommendation to continue. Patient with previous thromboembolism were excluded. A total of 3,211 patients were identified by 518 physicians of which 2,853 had all data available for the present analysis; mean patient's age was 57.4 ± 17.5 (SD) years, 48.2% were male and bodyweight was 79.8 ± 16.1 kg. During hospitalization 95.5% of surgical and 84.0% of medical patients received any thromboprophylaxis, the mean hospital duration being 12.7 ± 20.3 days. Surgical patients had high, medium and low risk in 53.8, 37.1 and 9.1%, respectively. Medical patients had high, medium and low risk in 78.8, 19.8 and 1.4%. A hospital recommendation to continue thromboprophylaxis was given to 84.6% (95% CI 83.1-85.9%) of surgical and 64.9% (95% CI 59.1-70.6%) of medical patients and implemented in 96.6 and 94.3%, respectively. On the other hand, in patients without a respective hospital recommendation (15.4% of surgical and 35.1% of medical patients), thromboprophylaxis was continued in 65.3% of surgical and 73.1% of medical patients because of high risk. Our data illustrate acceptable rates of prophylaxis in surgical and medical patients in Germany. As the results show, it is essential that not only hospital physicians are aware of the actual risk at discharge, but office based physicians assess thromboembolic risk.

Prevalence of deep vein thrombosis in acutely admitted ambulatory non-surgical intensive care unit patients

Background

Data on prevalence rates of venous thromboembolism (VTE) in different patient populations are scarce. Most studies on this topic focus on older patients or patients with malignancies, immobilization or thrombophilia. Less is known about the VTE risk profile of non-surgical patients presenting with a variety of medical diseases of differing severity. Aim of the present study was to investigate VTE prevalence in a pospective cohort study of ambulatory medical intensive care unit patients within 24 h after acute admission.

Methods

Prospective cohort study of 102 consecutive patients after acute admission to medical intensive care unit. Ultrasound compression sonography, APACHE-II-Scoring and laboratory examination was performed within 24 hours after admission.Possible determinants of a high risk of VTE were examined. In all patients with a confirmed diagnosis of DVT or suspicion of PE thoracic computer tomography (CT) was performed.

Results

VTE was found in 7.8% out of 102 of patients, mean APACHE-II-Score was 14 (mortality risk of about 15%). Thrombus location was femoropopliteal in 5 patients, iliacal in 2 and peroneal in 1 patient. Five VTE patients had concomitant PE (62.5% of VTE, 4.9% of all patients). No predictors of prevalent VTE were identified from univariable regression analysis although relative risk was high in patients with a history of smoking (RR 3.40), immobility (RR 2.50), and elevated D-Dimer levels (RR 3.49).

Conclusions

Prevalent VTE and concomitant PE were frequent in acutely admitted ICU patients.

[Importance of thrombophilia screening]

Thrombophilia testing denotes a test battery for inherited or acquired features associated with a tendency for clot formation. Currently, it is being used in a frequency and to an extent which is not supported by evidence. In order to protect patients from unnecessary worry and stigmatization, but also for reasons of cost effectiveness, thrombophilia testing should be reduced to a very small number of medically justifiable indications which are outlined in this review.Those indications include the following: secondary prevention of venous thromboembolism in patients from a thrombophilic family, i.e., with two or more first degree relatives with venous thromboembolism (VTE), or patients with suspected antiphospholipid syndrome; women prior to oral contraception or planning to become pregnant if they had no prior VTE but have one or more first-degree relatives with VTE-provided they are willing to follow the consequences of positive test results; women with recurrent miscarriage. The inappropriate indications are discussed as well.The test panel for inherited thrombophilias includes deficiencies of antithrombin, protein C and protein S, factor V Leiden and prothrombin 20210 mutation. Patients with suspicion of antiphospholipid syndrome have to be tested for lupus anticoagulans, anti-cardiolipin antibodies, and anti-β2-glycoprotein I-antibodies. It is important to do the blood sampling at an appropriate point in time.

Edoxaban versus warfarin for the treatment of symptomatic venous thromboembolism

BACKGROUND

Whether the oral factor Xa inhibitor edoxaban can be an alternative to warfarin in patients with venous thromboembolism is unclear.

METHODS

In a randomized, double-blind, noninferiority study, we randomly assigned patients with acute venous thromboembolism, who had initially received heparin, to receive edoxaban at a dose of 60 mg once daily, or 30 mg once daily (e.g., in the case of patients with creatinine clearance of 30 to 50 ml per minute or a body weight below 60 kg), or to receive warfarin. Patients received the study drug for 3 to 12 months. The primary efficacy outcome was recurrent symptomatic venous thromboembolism. The principal safety outcome was major or clinically relevant nonmajor bleeding.

RESULTS

A total of 4921 patients presented with deep-vein thrombosis, and 3319 with a pulmonary embolism. Among patients receiving warfarin, the time in the therapeutic range was 63.5%. Edoxaban was noninferior to warfarin with respect to the primary efficacy outcome, which occurred in 130 patients in the edoxaban group (3.2%) and 146 patients in the warfarin group (3.5%) (hazard ratio, 0.89; 95% confidence interval [CI], 0.70 to 1.13; P<0.001 for noninferiority). The safety outcome occurred in 349 patients (8.5%) in the edoxaban group and 423 patients (10.3%) in the warfarin group (hazard ratio, 0.81; 95% CI, 0.71 to 0.94; P=0.004 for superiority). The rates of other adverse events were similar in the two groups. A total of 938 patients with pulmonary embolism had right ventricular dysfunction, as assessed by measurement of N-terminal pro-brain natriuretic peptide levels; the rate of recurrent venous thromboembolism in this subgroup was 3.3% in the edoxaban group and 6.2% in the warfarin group (hazard ratio, 0.52; 95% CI, 0.28 to 0.98).

CONCLUSIONS

Edoxaban administered once daily after initial treatment with heparin was noninferior to high-quality standard therapy and caused significantly less bleeding in a broad spectrum of patients with venous thromboembolism, including those with severe pulmonary embolism. (Funded by Daiichi-Sankyo; Hokusai-VTE ClinicalTrials.gov number, NCT00986154.).

Diagnosis of recurrent deep vein thrombosis

Deep vein thrombosis is a chronic disease with a continuing risk of recurrence. In a patient with recurrence long term prognosis and treatment are significantly altered both carrying their own risks not only in the acute phase but mainly in the long term perspective. Thus, accurate diagnosis of recurrence is of utmost importance for the fate of the patient. Diagnosis of a first DVT episode is well established and follows an algorithm including clinical prediction rules, D-Dimer testing and compression ultrasound. Due to the previous episode the efficiency of all three elements is impaired in a patient with suspected recurrence. This opens up areas of uncertainty which have to be filled by individual clinical judgement. Guidelines reflect this difficulty by providing mainly weak recommendations based on sparse data. The present review summarizes what is known about the performance of tools for DVT diagnosis, discusses recent guidelines, and finally gives personally weighed recommendations how to deal with this peculiar diagnostic situation. In conclusion, it will turn out that the well accepted diagnostic algorithm for a first DVT may be applied as well if the lower efficiency is regarded. Compression ultrasound largely benefits from a baseline assessment at the end of the previous episode. The order of tests may be discussed according to local and regional attitudes.

Hospitalization for vitamin-K-antagonist-related bleeding: treatment patterns and outcome

BACKGROUND

Bleeding complications are common side effects of vitamin-K antagonist (VKA) therapy. Data on the in-hospital management and outcomes of these bleeding events are scarce and information is mostly derived from trial cohorts.

OBJECTIVES

The objective was to collect data on the management and clinical outcome of hospitalizations owing to VKA-related bleeding in real-world practice.

PATIENTS AND METHODS

We performed a multicenter observational cohort study involving 21 secondary and tertiary care hospitals in the administrative district Dresden, Saxony, Germany throughout the year 2005. All consenting patients presenting with VKA-related bleeding complications were included. No exclusion criteria applied. Data were collected at admission, at discharge and at 90 days to evaluate resource consumption, length of hospital stay and risk factors for in-hospital- and 3-month mortality.

RESULTS

Two hundred and ninety patients were included (median age 74 years; 50.7% male). The main indications for VKA therapy were atrial fibrillation (63.4%), prior thromboembolism (18.6%) and mechanical heart valves (11.4%), and most common bleeding localizations were large hematoma (23.1%), upper gastrointestinal (GI) tract (17.9%) and intracranial bleeding (14.1%). On hospital admission, the median International Normalized Ratio (INR) was 3.0 (range 0.9-12.5, interquartile range [IQR] 2.1-3.9). In-hospital mortality was 7.6% with impaired renal function as the most relevant risk factor. At 90 days mortality was 14.1% and 15.3% of survivors were help-dependent.

CONCLUSIONS

VKA-related bleeding leading to hospitalization is associated with long hospitalization, relevant resource utilization, high mortality or persistent sequlae. Patient-related factors such as impaired renal function, chronic cardiac or pulmonary disease and dementia are predictive of in-hospital and 3-month mortality.

Venous Thromboembolism Risk in Ischemic Stroke Patients Receiving Extended-Duration Enoxaparin Prophylaxis: Results From the EXCLAIM Study

Background and Purpose—

The optimal duration of venous thromboembolism prophylaxis in acute stroke patients is unknown. This subanalysis of the Extended Prophylaxis for Venous ThromboEmbolism in Acutely Ill Medical Patients With Prolonged Immobilization (EXCLAIM) study investigated extended-duration thromboprophylaxis with enoxaparin, compared with placebo following standard-duration enoxaparin, in ischemic stroke patients.

Methods—

Acutely ill medical patients with recently reduced mobility received open-label enoxaparin 40 mg for 10±4 days, and they were then randomized to double-blind enoxaparin 40 mg daily or placebo for further 28±4 days. Venous thromboembolism incidence (symptomatic/asymptomatic deep-vein thrombosis, symptomatic/fatal pulmonary embolism) up to day 28 after randomization and major bleeding rates up to 48 h after the last dose of study treatment were reported.

Results—

In total, 389 of 5963 (6.5%) randomized patients had ischemic stroke: 198 received extended-duration prophylaxis and 191 placebo. Extended-duration prophylaxis reduced venous thromboembolism incidence versus placebo (2.4% versus 8.0%; absolute risk difference, −5.6%; 95% CI, −10.5% to −0.7%), but it was associated with an increase in major bleeding (1.5% versus 0% in enoxaparin and placebo groups; absolute risk difference, +1.5%; 95% CI, −0.2% to 3.2%).

Conclusion—

Extended-duration thromboprophylaxis with enoxaparin was associated with reduced venous thromboembolism risk and increased major bleeding in the subgroup of patients with ischemic stroke in the EXCLAIM study.

Clinical Trial Registration Information—

URL: http://clinicaltrials.gov . Unique Identifier: NCT00077753.

Predictors of deep venous thrombosis in patients admitted to rehabilitation clinics after major orthopaedic surgery

Background: Venous thromboembolism (VTE) is a frequent complication of major orthopaedic surgery; prolonged prophylaxis with anticoagulants is standard of care. However, late manifestation of VTE is common and little is known about the predictors of late deep vein thrombosis (DVT) and the distribution of proximal and distal DVT and isolated calf muscle vein thrombosis (MVT). Patients and methods: 482 patients admitted to a rehabilitation clinic (RC) after total hip or knee replacement (THR; TKR) or hip fracture surgery (HFS) underwent complete compression ultrasound (CCUS) screening for VTE within 72 hours after admission into RC. Predictors of VTE were evaluated. Results: DVT was prevalent in 74 events (14.7 %), consisting of 13 (2.7 %) proximal DVT, 17 (3.5 %) distal DVT and 41 (8.5 %) MVT, respectively. Multivariate analyses established history of VTE (OR for proximal DVT 7.0; 95 %-CI 1.9 - 25.9; OR for any DVT 3.9; 95 %-CI 1.7 - 8.9), female gender (OR 3.3; 95 %-CI 1.0 - 10.6), coronary artery disease (OR 3.8; 95 %-CI 1.1 - 12.9) and cancer (OR 8.0; 95 %-CI 1.8 - 35.5) as independent VTE predictors for proximal DVT. For MVT, age (OR 2.4; 95 %-CI 1.2 - 5.0) and a history of musculo-skeletal disease (OR 2.6; 95 %-CI 1.1 - 5.8) or autoimmune disease (OR 3.9; 95 %-CI 1.0 - 15.4) were found to be independent predictors. Conclusions: This study confirms well-known predictors of VTE and high rates of postoperative VTE despite optimal thromboprophylaxis. In addition, independent risk factors for proximal DVT and MVT were identified. The data support the concept or continuing thromboprophylaxis during rehabilitation after major orthopaedic surgery because a considerable percentage of patients had asymptomatic DVT at RC on admission. However, significant differences in the individual risk profile and the distribution pattern of DVT and MVT exist, which could be used for a more individualized thromboprophylaxis strategy.

Benefits and Risks of Preventing Thromboembolism With Enoxaparin in Patients With General Surgery in Real World—The CLEVER Study

Background:

We aimed to document enoxaparin use in real world and identify the risk factors for bleeding complications.

Methods:

Postauthorization study in 448 surgical patients receiving enoxaparin prophylaxis. Complete compression ultrasound (CCUS) was performed at day 10 ± 3.

Results:

During treatment, 11 of 448 patients had suspected deep venous thrombosis (DVT) but none confirmed. One patient had symptoms of pulmonary embolism ([PE] 0.22%; 95% confidence interval [CI] −0.21-0.66). There were no asymptomatic cases detected upon CCUS. At the 90-day follow-up, 4 (0.9%) of the 440 patients had DVT symptoms (95% CI 0.02-1.80) and none had PE; 5.4% had major and 11.6% any type of bleeding complications. Major bleeding was more frequent in those with kidney disease (odds ratio [OR] 5.53), those who are bedridden (OR 5.49), those with peridural indwelling catheters (OR 4.01), and those on nonsteroidal anti-inflammatory drugs (OR 3.33).

Conclusions:

Enoxaparin is effective and safe in surgical patients to prevent venous thromboembolism.

[Novel oral anticoagulants and their use in the perioperative setting]

Novel oral anticoagulants (NOACs) have become available for prevention of venous thromboembolism after major orthopaedic surgery, treatment of venous thromboembolism, and stroke prevention in patients with atrial fibrillation. The thrombin inhibitor Dabigatran has a plasma half life of 11-14 hours which prolongs significantly in renal insufficiency. The two Xa-inhibitors Rivaroxaban and Apixaban have slightly shorter half lifes, and renal elimination is confined to about 30% of active drug. Prior to elective surgery, drug intake needs to be halted. The time period depends on the actual drug half life in that particular situation. Bridging anticoagulation is not necessary. The management of bleeding complications does not differ from that in other anticoagulants. The most uncertainties in clinical practice will arise from the fact that NOACs derange the global clotting tests without any conclusive information about the actual intensity of anticoagulation.

[Digital necrosis in a patient with atherosclerosis: also a paraneoplasia?]

HISTORY AND ADMISSION FINDINGS

A 59-year-old man was admitted with an acral necrosis of the left 3rd finger, which had developed during several weeks. Furthermore, the patient complained of diarrhoea.

INVESTIGATIONS

Acral light plethysmography showed critical ischemia of digitus II and V, and impaired distal perfusion of digitus I and IV. Duplex sonography revealed atherosclerotic plaques in the supraaortal vessels with stenosis of the left axillary artery which was confirmed by ultrasound. However, no differences in the pressure of ulnar and radial arteries existed. Colonoscopy and abdominal computed tomography revealed two colon neoplasms, including hepatic metastasis.

TREATMENT AND COURSE

The stenosis of the left axillary artery was considered as the source of distal embolisation. However, after morphologically successful angioplasty distal necrosis worsened with involvement of additional fingers. Later in the course, diagnostic work-up of diarrhoa established the diagnosis of metastatic colorectal cancer. Finally, the patient died because of intercurrent pneumonia.

CONCLUSION

Spontaneous acral necrosis may develop due to embolisation or local thrombotic vessel occlusion. Progression despite successful treatment of a potential source of embolism points to a significant coagulopathy, as in metastatic cancer.

Heparin based prophylaxis to prevent venous thromboembolic events and death in patients with cancer - a subgroup analysis of CERTIFY

Background

Patients with cancer have an increased risk of VTE. We compared VTE rates and bleeding complications in 1) cancer patients receiving LMWH or UFH and 2) patients with or without cancer.

Methods

Acutely-ill, non-surgical patients ≥70 years with (n = 274) or without cancer (n = 2,965) received certoparin 3,000 UaXa o.d. or UFH 5,000 IU t.i.d. for 8-20 days.

Results

1) Thromboembolic events in cancer patients (proximal DVT, symptomatic non-fatal PE and VTE-related death) occurred at 4.50% with certoparin and 6.03% with UFH (OR 0.73; 95% CI 0.23-2.39). Major bleeding was comparable and minor bleedings (0.75 vs. 5.67%) were nominally less frequent. 7.5% of certoparin and 12.8% of UFH treated patients experienced serious adverse events. 2) Thromboembolic event rates were comparable in patients with or without cancer (5.29 vs. 4.13%) as were bleeding complications. All cause death was increased in cancer (OR 2.68; 95%CI 1.22-5.86). 10.2% of patients with and 5.81% of those without cancer experienced serious adverse events (OR 1.85; 95% CI 1.21-2.81).

Conclusions

Certoparin 3,000 UaXa o.d. and 5,000 IU UFH t.i.d. were equally effective and safe with respect to bleeding complications in patients with cancer. There were no statistically significant differences in the risk of thromboembolic events in patients with or without cancer receiving adequate anticoagulation.

Trial Registration

clinicaltrials.gov, NCT00451412

Certoparin versus UFH to prevent venous thromboembolic events in the very elderly patient: an analysis of the CERTIFY study

INTRODUCTION

There is an exponential rise of thromboembolic risk with age because of co-morbidities, immobility and pharmacotherapy. We aimed to investigate the benefits and risks of heparin prophylaxis in very elderly patients ≥80 years and the type of heparin used in a subgroup analysis of the CERTIFY trial.

PATIENTS/METHODS

3,239 patients were randomized to 3,000 U aXa o.d. certoparin or 5,000 IU t.i.d. unfractionated heparin (UFH) for 8-20 days.

RESULTS

Patients ≥80 years (n=1,365) were more likely to be female, had a lower mean bodyweight, were more frequently using antiplatelets and had a GFR below 30 ml/min/1.73 m(2) more often than patients <80 years (n=1,875). The combined endpoint of proximal DVT, symptomatic non-fatal PE and VTE related death was experience by 5.26% of patients ≥80 years versus 3.51% in younger patients (OR 1.53; 95%CI 1.05-2.21; p=0.03). There were no significant differences in both minor (OR 1.11; 95%CI 0.75-1.62) and major (OR 2.53; 95%CI 0.93-6.86) bleeding risks. Certoparin and UFH were equally effective in reducing thromboembolic risk in either age group. The risk of any (OR 0.45; 95%CI 0.26-0.79) and minor bleeding (OR 0.42; 95%CI 0.23-0.78) was reduced with certoparin in the very elderly only. There were more adverse events in elderly patients (OR 1.26; 95%CI 1.1-1.46), but rates were otherwise comparable.

CONCLUSIONS

The analysis confirmed the increased thromboembolic risk in very elderly patients, but demonstrated no increased bleeding risk. Certoparin and UFH were equally effective and safe with a reduced risk of minor bleeding complications with certoparin in the very elderly.

CERTIFY: prophylaxis of venous thromboembolism in patients with severe renal insufficiency

Patients with severe renal insufficiency (sRI) have been suggested to be at an increased risk of bleeding with low-molecular-weight heparins (LMWH). We aimed at assessing the benefits and risks of certoparin in comparison to unfractionated heparin (UFH) in these patients. In this subgroup analysis of the CERTIFY trial, acutely ill, non-surgical patients ≥70 years received certoparin 3,000U aXa o.d. or UFH 5,000 IU t.i.d. One hundred eighty-nine patients had a glomerular filtration rate (GFR) ≤30 ml/min/1.73 m2, 3,050 patients served as controls. Patients with sRI had a mean age of 85.9 ± 6.6 years (controls 78.4 ± 6.0) and were treated for a mean of 9.3 ± 3.7 days (9.9 ± 4.3). Thromboembolic event rates were comparable (4.55 vs. 4.21%; OR1.08; 95%CI 0.5-2.37) but bleeding was increased in sRI (9.52 vs. 3.54%; OR2.87; 95%CI 1.70-4.83). The incidence of the combined end-point of proximal DVT, symptomatic non-fatal PE and VTE related death was 6.49% with certoparin and 2.60% with UFH (OR2.60; 95%CI 0.49-13.85). There was a decrease in total bleeding with certoparin (OR0.33; 95%CI 0.11-0.97), which was non-significant in patients with GFR >30 ml/min/1.73 m2. In two multivariable regression models certoparin and immobilisation <10 days were associated with less bleeding while a GFR ≤30 ml/min/1.73 m2 was associated with increased bleeding. A total of 11.3% of certoparin- and 18.5% of UFH-treated patients experienced serious adverse events (14.8 in patients with a GFR ≤30 vs. 5.6% vs. >30 ml/min/1.73 m2). In conclusion, certoparin 3,000U anti Xa o.d. was as efficacious as 5,000 IU UFH t.i.d. in patients with sRI but had a reduced risk of bleeding.

Certoparin versus unfractionated heparin to prevent venous thromboembolic events in patients hospitalized because of heart failure: a subgroup analysis of the randomized, controlled CERTIFY study

BACKGROUND

Despite the elevated risk for developing venous thromboembolic events in patients with heart failure, there are no randomized, double-blind, controlled trial data on the comparison of low-molecular-weight heparin with unfractionated heparin (UFH) in this patient population.

METHODS

This was a subgroup analysis of the CERTIFY trial, which included 3,239 nonsurgical, acutely ill medical patients 70 years or older. Patients were randomized to receive 3,000-U anti-Xa certoparin once daily or 5,000-IU UFH 3 times a day. The analysis was performed on a subgroup of 542 patients diagnosed with heart failure at hospital admission.

RESULTS

Patients with heart failure differed from patients without heart failure in that they were more likely using antiplatelets (67.2% vs 48.9%; P < .0001) and had a lower glomerular filtration rate (8.0% vs 5.5%; ≤ 30 mL/min per 1.73 m²; P = .0232). Thromboembolic risk was comparable except for a higher incidence of distal deep venous thrombosis (DVT) in patients with heart failure (10.80% vs 7.26%; P = .0144). Within the heart failure population, patient characteristics were comparable between randomized treatment groups. The incidence of the primary end point (proximal DVT, symptomatic nonfatal pulmonary embolism, and venous thromboembolism-related death combined) was numerically, slightly smaller with certoparin (3.78% vs 4.74% with UFH; odds ratio 0.79, 95% CI 0.32-1.94), and the incidence of major bleeding was 0.72% with certoparin versus 0.38% with UFH.

CONCLUSIONS

Patients hospitalized for heart failure are at high risk for developing distal DVT and bleeding complications compared with acutely ill medical patients without heart failure. Within the heart failure population, the observed differences in prophylactic efficacy between 3,000-U anti-Xa certoparin once daily and 5,000-IU UFH 3 times a day were similar to those observed in the overall study population; this suggests that certoparin might be at least as effective as UFH also in this subgroup. There were no relevant differences in bleeding risk or frequency of adverse events.

[The patient with pulmonary embolism or vascular emergency requiring intensive care]

Acute pulmonary embolism requires ICU management only for patients with hemodynamic instability who need artificial ventilation, or for hemodynamically stable patients with significant right ventricular dysfunction. For both patient groups, echocardiography is the most relevant diagnostic method. The main therapeutic consideration is on systemic thrombolysis. It is indicated in almost all patients with hemodynamic instability but only in selected cases of right ventricular dysfunction. All other patients receive standard anticoagulation only. A second vascular emergency scenario is type 2 heparin-induced thrombocytopeniae (HIT II) which may cause venous as well as arterial complications. Alternative anticoagulation has to be established from the first moment of clinical suspicion. It has to be continued in a therapeutic dosage if HIT II is confirmed, and has to be stopped if the diagnosis is refuted. The latter case is by far more frequent. Regarding arterial occlusions (acute limb ischemia, acral gangrene, iatrogenic vascular trauma) hints are given for the management in the setting of intensive care.

Extended-duration venous thromboembolism prophylaxis in acutely ill medical patients with recently reduced mobility: a randomized trial

BACKGROUND

Extended-duration low-molecular-weight heparin has been shown to prevent venous thromboembolism (VTE) in high-risk surgical patients.

OBJECTIVE

To evaluate the efficacy and safety of extended-duration enoxaparin thromboprophylaxis in acutely ill medical patients.

DESIGN

Randomized, parallel, placebo-controlled trial. Randomization was computer-generated. Allocation was centralized. Patients, caregivers, and outcome assessors were blinded to group assignment. (ClinicalTrials.gov registration number: NCT00077753) SETTING: 370 sites in 20 countries across North and South America, Europe, and Asia.

PATIENTS

Acutely ill medical patients 40 years or older with recently reduced mobility (bed rest or sedentary without [level 1] or with [level 2] bathroom privileges). Eligibility criteria for patients with level 2 immobility were amended to include only those who had additional VTE risk factors (age >75 years, history of VTE, or active or previous cancer) after interim analyses suggested lower-than-expected VTE rates.

INTERVENTION

Enoxaparin, 40 mg/d subcutaneously (2975 patients), or placebo (2988 patients), for 28 +/- 4 days after receiving open-label enoxaparin for an initial 10 +/- 4 days.

MEASUREMENTS

Incidence of VTE up to day 28 and of major bleeding events up to 48 hours after the last study treatment dose.

RESULTS

Extended-duration enoxaparin reduced VTE incidence compared with placebo (2.5% vs. 4%; absolute risk difference favoring enoxaparin, -1.53% [95.8% CI, -2.54% to -0.52%]). Enoxaparin increased major bleeding events (0.8% vs. 0.3%; absolute risk difference favoring placebo, 0.51% [95% CI, 0.12% to 0.89%]). The benefits of extended-duration enoxaparin seemed to be restricted to women, patients older than 75 years, and those with level 1 immobility.

LIMITATION

Estimates of efficacy and safety for the overall trial population are difficult to interpret because of the change in eligibility criteria during the trial.

CONCLUSION

Use of extended-duration enoxaparin reduces VTE more than it increases major bleeding events in acutely ill medical patients with level 1 immobility, those older than 75 years, and women.

PRIMARY FUNDING SOURCE

Sanofi-aventis.

[Diagnostics in venous thrombosis and pulmonary embolism]

Deep vein thrombosis and pulmonary embolism (venous thromboembolism) have a prevalence as high as 1-2/1000/year. Timely diagnosis and therapy prevent or reduce the acute life threatening and the long term disabling complications. Due to the variability in its signs and symptoms, venous thromboembolism should frequently be considered as a differential diagnosis. When doing so, only one in five or six suspected cases actually will have the disease. A low estimate of the clinical probability in conjunction with a negative D-Dimer test may rule out the diagnosis in 40-50% of cases. All other patients need imaging procedures. Current standard of care for deep vein thrombosis is venous ultrasound of the leg, for pulmonary embolism it is CT pulmonary angiography. Sensitivity and specificity of both methods are high enough to allow for a definitive diagnosis. Diagnostic challenges remain the suspicion of relapsing disease and venous thromboembolism in pregnancy.

A randomized, double-blind study of certoparin vs. unfractionated heparin to prevent venous thromboembolic events in acutely ill, non-surgical patients: CERTIFY Study

BACKGROUND

In medically ill patients, no contemporary double-blind head-to-head evaluation of low molecular weight heparin vs. unfractionated heparin (UFH) for the prevention of venous thromboembolic events is available.

OBJECTIVES

To compare the efficacy and safety of certoparin with those of UFH.

PATIENTS/METHODS

In this double-blind, randomized, controlled trial, acutely ill, non-surgical patients aged > or = 70 years were randomized to certoparin (3000 U of anti-factor Xa once daily) or to UFH (5000 IU t.i.d.). The primary endpoint was the composite of proximal deep vein thrombosis as assessed by bilateral compression ultrasonography, symptomatic non-fatal pulmonary embolism and venous thromboembolism-related death, and was assessed by a blinded central adjudication committee. Non-inferiority margins were set at 1.8 for the odds ratio (OR) and 3.45% for the absolute difference.

RESULTS

Three thousand two hundred and thirty-nine patients aged 78.8 + or - 6.3 years were treated for 9.1 + or - 3.4 days. The incidence of the primary endpoint was 3.94% in the certoparin group and 4.52% in the UFH group, with a difference in proportions of - 0.59% [95% confidence interval (CI) -2.09 to 0.92; P < 0.0001 for non-inferiority], and an OR of 0.87 (95% CI 0.60-1.26; P = 0.0001 for non-inferiority). Major bleeding occurred in 0.43% of certoparin-treated patients and 0.62% of UFH-treated patients (OR 0.69; 95% CI 0.26-1.83). Any bleeding occurred at 3.20% in certoparin-treated patients vs. 4.58% in UFH-treated patients (OR 0.69; 95% CI 0.48-0.99; P < 0.05), and 5.73% of certoparin-treated patients and 6.63% of UFH-treated patients experienced serious adverse events. All-cause mortality was 1.27% in certoparin-treated patients and 1.36% in UFH-treated patients.

CONCLUSIONS

In acutely ill, non-surgical elderly patients, thromboprophylaxis with certoparin (3000 U of anti-FXa once daily) was non-inferior to 5000 IU of UFH t.i.d., with a favorable safety profile.

Safety and sensitivity of two ultrasound strategies in patients with clinically suspected deep venous thrombosis: a prospective management study

BACKGROUND

It remains unclear whether a single complete ultrasound examination, which detects calf vein thrombosis, is as safe as a baseline rapid ultrasound examination, repeated after 1 week when negative, which examines the veins in the groin and the knee. Therefore, we compared the safety and feasibility of two diagnostic ultrasound strategies, involving rapid and complete compression ultrasound (CUS) examination.

METHODS

Consecutive patients with suspected deep vein thrombosis (DVT) underwent clinical probability assessment. In patients with an unlikely clinical probability and a normal D-dimer finding, DVT was considered to be excluded. All others were randomized to undergo a rapid or a single complete CUS examination. Patients in whom DVT was excluded were followed for 3 months to assess the incidence of venous thromboembolism (VTE).

RESULTS

A total of 1002 patients were included. A clinical decision rule indicating DVT to be unlikely and a normal D-dimer finding occurred in 481 patients (48%), with a VTE incidence of 0.4% [95% confidence interval (CI) 0.05-1.5%] during follow-up. DVT was confirmed in 59 of the 257 patients (23%) who underwent rapid CUS examination, and in 99 of the 264 patients (38%) who underwent complete CUS examination. VTE during follow-up occurred in four patients (2.0%; 95% CI 0.6-5.1%) in the rapid CUS arm, and in two patients (1.2%; 95% CI 0.2-4.3%) in the complete CUS arm.

CONCLUSIONS

A diagnostic strategy with a clinical decision rule, a D-dimer test and a CUS examination is safe and efficient. Both the rapid and the complete CUS test are comparable and efficient strategies, with differing advantages and disadvantages.

[Ultrasound investigation of vessels supplying the extremities]

Ultrasound investigation of the vascular supply to legs and arms has become a standard procedure and is performed in all kinds of both arterial occlusive disease and venous disease. On the arterial side the most common disease is atherosclerosis in which stenoses and occlusions can be identified and characterized with respect to the functional significance. Sensitivity und specificity for the detection of symptomatic occlusions and stenoses are approximately 90% and 99%, respectively. This is the basis for planning invasive procedures, catheter interventions as well as operations. The short term success can be assessed and long term follow-up can be performed by ultrasound. In addition all other kinds of arterial disease (embolisms, aneurysms, inflammation and mechanical alterations) can be examined. On the venous side, the most common indication for ultrasound is the suspicion of deep vein thrombosis. Compression ultrasound of the leg veins allows a reliable diagnosis in almost all cases. The diagnostic failure rate in a 3-month follow up is around 0.5%. The present review summarizes the indications and examination details for leg arteries, arm arteries, leg veins and arm veins. A separate paragraph deals with dialysis shunts, a growing field in vascular medicine.

Incidence, risk profile and morphological pattern of venous thromboembolism after prostate cancer surgery

BACKGROUND

Venous thromboembolism (VTE) is the most common non-surgical complication after major pelvic surgery. Little is known about the risk factors or the time of development of postoperative venous thrombosis.

METHODS

A cohort of 523 consecutive patients undergoing radical prostatectomy with lymphadenectomy was prospectively assessed by complete compression ultrasound at days -1, +8 and +21.

RESULTS

Complete data were available in 415 patients, while four patients had VTE before surgery and were excluded from the analysis. In the remaining 411 patients, 71 VTE events were found in 69 patients (16.8%). Most were limited to calf muscle veins (56.5%), followed by deep calf vein thrombosis (23.2%), proximal deep vein thrombosis (DVT, 14.5%) and pulmonary embolism (PE, 5.8%). Of the 14 patients with proximal DVT/PE, 11 patients (78.6%) developed VTE between days 8 and 21. Risk factors for VTE were a personal history of VTE (OR 3.0), pelvic lymphoceles (LCs) impairing venous flow (OR 2.8) and necessity of more than two units of red blood cells (OR 2.6).

CONCLUSION

Venous thromboembolism is common after radical prostatectomy. A significant proportion develops after day 8, suggesting that prolonged heparin prophylaxis should be considered. Since LCs with venous flow reduction result in higher rates of VTE, hemodynamically relevant lymphoceles should be surgically treated.

Distal DVT: worth diagnosing? Yes

Much of the argument for or against diagnosis of distal deep vain thrombosis (DVT) depends on the extra effort that has to be spent on it. This review presents the data on ultrasound of paired calf veins and calf muscle veins (distal ultrasound) in terms of protocols, feasibility, reliability and expected findings. In summary, provided there is adequate and anatomically sound training of sonographers, distal ultrasound is a valid, 4-minute procedure, which can easily be added to the examination of proximal veins. The second part of the review refers to the pathophysiology of ascending DVT, which is the most common type. Adequate patient care in terms of benefit, harm and cost includes a single non-invasive examination followed by risk adopted treatment allocation. This concept ideally should be valid for any type of DVT. The data extending this concept to distal DVT can only be derived from studies that look closely at this entity (i.e. in fact diagnose distal DVT). Even before these data are available, diagnosing distal DVT at least doubles the number of symptomatic patients in which signs and symptoms can be ascribed to a definitive diagnosis, which in itself is a benefit for patient care.

Ultrasound screening for asymptomatic deep vein thrombosis after major orthopaedic surgery: the VENUS study

BACKGROUND

Venography is currently used to assess the incidence of deep vein thrombosis (DVT) in dose-finding and confirmatory trials of new antithrombotic agents. Centrally adjudicated, complete compression ultrasound (CCUS) could be a non-invasive alternative to venography.

OBJECTIVES

A substudy of two, similarly designed, phase IIb trials of a novel, oral anticoagulant for the prevention of venous thromboembolism after elective hip or knee arthroplasty was undertaken to validate CCUS against venography.

PATIENTS/METHODS

Patients received study drugs until mandatory, bilateral venography was performed 7 +/- 2 days after surgery. CCUS was performed within 24 h after venography by sonographers blinded to the venography result. Sonographers were trained and certified for the standardized examination and documentation procedure. Venograms and sonograms were adjudicated centrally at different sites by two independent readers; discrepancies between readers were resolved by consensus.

RESULTS

A total of 1104 matching pairs of evaluable venograms and sonograms were obtained from the participants of the two trials (n = 1435): 19% of venograms and 20% of sonograms were not evaluable. The observed frequency of any DVT was 18.9% with venography and 11.5% with CCUS. Sensitivity of CCUS compared with venography was 31.1% for any DVT (95% confidence interval 23.4, 38.9), 21.0% (2.7, 39.4) for proximal DVT, and 30.8% (23.1, 38.6) for distal DVT. The figures for specificity were 93.0% (91.0, 95.1), 98.7% (98.0, 99.5), and 93.3% (91.5, 95.3), respectively.

CONCLUSIONS

Based on these results, centrally adjudicated CCUS will be unable to replace venography for DVT screening early after major orthopaedic surgery in studies evaluating anticoagulant drugs.

[Secondary prophylaxis of venous thromboembolism]

Making decisions about any modality of secondary prophylaxis in patients with venous thromobembolism (VTE) has to balance the risk of bleeding induced by anticoagulants against the benefit of reducing the risk of recurrent disease. It has to be kept in mind that the magnitude of risk is not only defined by the number of events per time period but also by the impact of the event on the fate of the patient. With standard intensity vitamin K antagonists (VKA), the risk of bleeding is more closely related to comorbidities than to other factors, eg age. The risk of VTE recurrence differs largely between patient groups. The criterion of presence or absence of a permanent or transient clinical trigger factor for the actual VTE episode has a greater impact than an abnormal result in thrombophilia testing. The standard period of secondary prophylaxis for proximal DVT and for PE is three to six months. The concept of prolonging this period for several months according to the risk of recurrence is seriously challanged by the observation that the prolongation period seems to delay recurrencies rather than truly avoiding them. For this reason, patients who clearly are threatened by recurrent episodes should receive indefinitive secondary prophylaxis. This is the case for cancer patients, patients with the antiphospholipid syndrome, and those who belong to families with severe and symptomatic protein C, protein S, or antithrombin deficiencies. Patients with recurrent VTE, with idiopathic VTE, or with combined thrombophilic conditions may only benefit from indefinitive secondary prophylaxis if the bleeding risk of the anticoagulant regimen under consideration is very low.

[Bridging anticoagulation]

Patients on anticoagulants of the vitamin K antagonist type may sometimes be scheduled for invasive procedures or surgical operations. In order to minimize the risk of thromboembolism caused by the interruption of chronic anticoagulation for the procedure, temporary administration of anticoagulants with shorter half-lives is required (so-called bridging anticoagulation). The present review outlines the spectrum of risks during this period regarding both thromboembolism and major bleeding. Low molecular weight heparins may be considered the medication of choice for bridging anticoagulation, mainly for practical reasons. Since they require no coagulation monitoring or dose adjustment, outpatient treatment is feasible. Such heparins are not labelled for the indication of bridging anticoagulation. However, based on recent studies of large patient cohorts, evidence of their efficacy and safety is significantly more solid than for unfractionated heparin. A simple dosing scheme for low molecular weight heparins is given here and all requirements are discussed for safe guidance through episodes of bridging anticoagulation.

Struktur und Funktion des venösen Systems

The peripheral venous system is subdivided into a superficial (epifascial) and a deep (subfascial) system by the superficial fascia. The two systems are interconnected by the transfascial system, called perforanting veins. The blood from the superficial system (great saphenous vein and small saphenous vein) is drained to the deep system. The deep veins accompany the arteries. The direction of venous blood flow is controlled by valves. The number of valves is variable. The veins are surrounded by a venous sheath in which they are movable. The deep veins of the lower leg are arranged in three groups consisting of paired veins. The peroneal vein and the posterior tibial vein unite to form the tibioperoneal trunk. The tibioperoneal trunk is joined by the anterior tibial vein to form the popliteal vein. The superficial femoral vein which arises from the popliteal vein is joined by the deep femoral vein to form the common femoral vein. The latter vessel becomes the external iliac vein above the inguinal ligament. It unites with the internal iliac vein to form the common iliac vein. Both common iliac veins unite to form the inferior vena cava. The veins of the systemic circulation perform two basic tasks, returning venous blood to the heart and storing the blood volume that is not immediately needed. Several factors like venous valves, thoracoabdominal venous pump and peripheral venous pump are necessary to maintain venous return. The second task results from the elastic compliance of the venous system, especially the mesenteric channels.