Cancer-associated thrombosis in patients with implanted ports: a prospective multicenter French cohort study (ONCOCIP).

The need to accurately identify cancer outpatients at high risk of thrombotic complications is still unmet. In a prospective, multicenter cohort study (ONCOlogie et Chambres ImPlantables [ONCOCIP]), consecutive adult patients with a solid tumor and implanted port underwent 12-month follow-up. Our primary objective was to identify risk factors for (1) catheter-related thrombosis, defined as ipsilateral symptomatic upper-limb deep-vein thrombosis with or without pulmonary embolism, and (2) venous thromboembolism other than catheter-related, defined as any symptomatic superficial- or deep-vein thrombosis (other than catheter-related) or pulmonary embolism, and incidental pulmonary embolism. All events were objectively confirmed and centrally adjudicated. Rate assessments integrated competing risk of death. Overall, 3032 patients were included (median age: 63 years; women: 58%). The most frequent cancer locations were breast (33.7%), lung (18.5%), and colorectal (15.6%), cancer being metastatic in 43.2% of patients. Most patients (97.1%) received chemotherapy. By 12 months, 48 (1.6%) patients had been lost to follow-up and 656 (24.6%) had died; 3.8% (n = 111) of patients had experienced catheter-related thrombosis, and 9.6% (n = 276) venous thromboembolism other than catheter-related. By multivariate analysis, use of cephalic vein for catheter insertion predicted catheter-related thrombosis, whereas ongoing antiplatelet therapy was protective; risk factors for venous thromboembolism other than catheter-related were advanced age, previous venous thromboembolism, cancer site, and low hemoglobin level or increased leukocyte count before chemotherapy. In conclusion, this large prospective cohort study showed a high rate of venous thromboembolism in patients with a solid tumor and implanted port. Risk factors for catheter-related thrombosis differed from those for venous thromboembolism not catheter-related. This trial was registered at www.clinicaltrials.gov as #NCT02025894.

Edoxaban for treatment of venous thromboembolism in patients with cancer. Rationale and design of the Hokusai VTE-cancer study.

Direct oral anticoagulants may be effective and safe for treatment of venous thromboembolism (VTE) in cancer patients, but they have not been compared with low-molecular-weight heparin (LMWH), the current recommended treatment for these patients. The Hokusai VTE-cancer study is a randomised, open-label, clinical trial to evaluate whether edoxaban, an oral factor Xa inhibitor, is non-inferior to LMWH for treatment of VTE in patients with cancer. We present the rationale and some design features of the study. One such feature is the composite primary outcome of recurrent VTE and major bleeding during a 12-month study period. These two complications occur frequently in cancer patients receiving anticoagulant treatment and have a significant impact. The evaluation beyond six months will fill the current gap in the evidence base for the long-term treatment of these patients. Based on the observation that the risk of recurrent VTE in patients with active cancer is similar to that in those with a history of cancer, the Hokusai VTE-cancer study will enrol patients if whose cancer was diagnosed within the past two years. In addition, patients with incidental VTE are eligible because their risk of recurrent VTE is similar to that in patients with symptomatic disease. The unique design features of the Hokusai VTE-cancer study should lead to enrolment of a broad spectrum of cancer patients with VTE who could benefit from oral anticoagulant treatment.

Oral rivaroxaban versus standard therapy for the treatment of symptomatic venous thromboembolism: a pooled analysis of the EINSTEIN-DVT and PE randomized studies.

BACKGROUND: Standard treatment for venous thromboembolism (VTE) consists of a heparin combined with vitamin K antagonists. Direct oral anticoagulants have been investigated for acute and extended treatment of symptomatic VTE; their use could avoid parenteral treatment and/or laboratory monitoring of anticoagulant effects. METHODS: A prespecified pooled analysis of the EINSTEIN-DVT and EINSTEIN-PE studies compared the efficacy and safety of rivaroxaban (15 mg twice-daily for 21 days, followed by 20 mg once-daily) with standard-therapy (enoxaparin 1.0 mg/kg twice-daily and warfarin or acenocoumarol). Patients were treated for 3, 6, or 12 months and followed for suspected recurrent VTE and bleeding. The prespecified noninferiority margin was 1.75. RESULTS: A total of 8282 patients were enrolled; 4151 received rivaroxaban and 4131 received standard-therapy. The primary efficacy outcome occurred in 86 (2.1%) rivaroxaban-treated patients compared with 95 (2.3%) standard-therapy-treated patients (hazard ratio, 0.89; 95% confidence interval [CI], 0.66-1.19; pnoninferiority < 0.001). Major bleeding was observed in 40 (1.0%) and 72 (1.7%) patients in the rivaroxaban and standard-therapy groups, respectively (hazard ratio, 0.54; 95% CI, 0.37-0.79; p = 0.002). In key subgroups, including fragile patients, cancer patients, patients presenting with large clots, and those with a history of recurrent VTE, the efficacy and safety of rivaroxaban were similar compared with standard-therapy. CONCLUSION: The single-drug approach with rivaroxaban resulted in similar efficacy to standard-therapy and was associated with a significantly lower rate of major bleeding. Efficacy and safety results were consistent among key patient subgroups. TRIAL REGISTRATION EINSTEIN-PE: ClinicalTrials.gov, NCT00439777; EINSTEIN-DVT: ClinicalTrials.gov, NCT00440193.

Superficial venous thrombosis and compression ultrasound imaging.

BACKGROUND: A current debate concerning suspected superficial vein thrombosis (SVT) focuses on the need of performing a compression ultrasound (CUS) exploration for confirming the diagnosis of SVT. This study was conducted to determine the clinical relevance and optimal CUS exploration in patients with symptomatic SVT. METHODS: We analyzed the characteristics of SVT and concomitant deep vein thrombosis (DVT) in patients included in the Prospective Observational Superficial Thrombophlebitis (POST) multicenter, observational prospective study. All patients underwent complete bilateral lower limb CUS, exploring both the superficial and deep venous systems. RESULTS: A total of 844 patients with clinical symptoms of SVT were recruited, of which 99 isolated SVTs (21.4%) had saphenofemoral/popliteal junction involvement, and 198 (23.5%) had a concomitant DVT, with 41.8% of them proximal DVTs. In 83 patients (41.9%), DVT and SVT were not contiguous. Five of 639 patients (1%) had an isolated contralateral DVT (ie, not bilateral). Age ≥ 75 years (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.6-3.4), inpatient status (OR, 5.4; 95% CI, 3.4-8.7), a personal history of DVT or pulmonary embolism (OR, 1.8; 95% CI, 1.2-2.8), and SVT on nonvaricose veins (OR, 3.3; 95% CI, 2.1-5.0) were significantly and independently associated with an increased risk of concomitant DVT. Half of the patients exhibited none of these risk factors, and the prevalence of concomitant DVT dropped to 11%. CONCLUSIONS: In patients with symptomatic SVT, a CUS exploration screening the whole venous system of the affected limb is useful because it provides information that has important consequences for the management of these patients.

The risk of subsequent cancer and arterial cardiovascular events in patients with superficial vein thrombosis in the legs.

Although it has been clearly demonstrated that venous thromboembolism is associated with an increased risk of subsequent overt cancer and arterial cardiovascular events in comparison with control populations, whether this association also applies to patients with isolated (ie, without concomitant involvement of the deep vein system) superficial vein thrombosis (SVT) in the legs is unknown. In 737 consecutive patients with isolated SVT not involving the sapheno-femoral junction, we conducted a retrospective investigation to assess the rate of cancer and that of arterial cardiovascular events occurring during follow-up. The event rates were compared with those occurring in 1438 controls having comparable characteristics. Both cases and controls were followed-up for an average period of 26 ± 8 months (range, 3-45). Malignancy was diagnosed in 26 cases (3.5%) and 56 controls (3.9%), leading to a hazard ratio of 0.86 (95% confidence interval, 0.55%-1.35%). Arterial cardiovascular events occurred in 32 cases (4.3%) and 63 controls (4.4%), leading to a hazard ratio of 0.97 (95% confidence interval, 0.63%-1.50%). We conclude that the occurrence of isolated SVT in the legs does not place patients at an increased risk of malignancies or arterial cardiovascular events. Whether this conclusion also applies to patients whose thrombosis involves the sapheno-femoral junction remains to be demonstrated.

Predictive and associative models to identify hospitalized medical patients at risk for VTE.

BACKGROUND: Acutely ill hospitalized medical patients are at risk for VTE. We assessed the incidence of VTE in the observational International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) study and derived VTE risk assessment scores at admission and associative VTE scores during hospitalization. METHODS: Data from 15,156 medical patients were analyzed to determine the cumulative incidence of clinically observed VTE over 3 months after admission. Multiple regression analysis identified factors associated with VTE risk. RESULTS: Of the 184 patients who developed symptomatic VTE, 76 had pulmonary embolism, and 67 had lower-extremity DVT. Cumulative VTE incidence was 1.0%; 45% of events occurred after discharge. Factors independently associated with VTE were previous VTE, known thrombophilia, cancer, age > 60 years, lower-limb paralysis, immobilization ≥ 7 days, and admission to an ICU or coronary care unit (first four were available at admission). Points were assigned to each factor identified to give a total risk score for each patient. At admission, 67% of patients had a score ≥ 1. During hospitalization, 31% had a score ≥ 2; for a score of 2 or 3, observed VTE risk was 1.5% vs 5.7% for a score ≥ 4. Observed and predicted rates were similar for both models (C statistic, 0.65 and 0.69, respectively). During hospitalization, a score ≥ 2 was associated with higher overall and VTE-related mortality. CONCLUSIONS: Weighted VTE risk scores derived from four clinical risk factors at hospital admission can predict VTE risk in acutely ill hospitalized medical patients. Scores derived from seven clinical factors during hospitalization may help us to further understand symptomatic VTE risk. These scores require external validation.

Factors at admission associated with bleeding risk in medical patients: findings from the IMPROVE investigators.

BACKGROUND: Acutely ill, hospitalized medical patients are at risk of VTE. Despite guidelines for VTE prevention, prophylaxis use in these patients is still poor, possibly because of fear of bleeding risk. We used data from the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) to assess in-hospital bleeding incidence and to identify risk factors at admission associated with in-hospital bleeding risk in acutely ill medical patients. METHODS: IMPROVE is a multinational, observational study that enrolled 15,156 medical patients. The in-hospital bleeding incidence was estimated by Kaplan-Meier analysis. A multiple regression model analysis was performed to identify risk factors at admission associated with bleeding. RESULTS: The cumulative incidence of major and nonmajor in-hospital bleeding within 14 days of admission was 3.2%. Active gastroduodenal ulcer (OR, 4.15; 95% CI, 2.21-7.77), prior bleeding (OR, 3.64; 95% CI, 2.21-5.99), and low platelet count (OR, 3.37; 95% CI, 1.84-6.18) were the strongest independent risk factors at admission for bleeding. Other bleeding risk factors were increased age, hepatic or renal failure, ICU stay, central venous catheter, rheumatic disease, cancer, and male sex. Using these bleeding risk factors, a risk score was developed to estimate bleeding risk. CONCLUSIONS: We assessed the incidence of major and clinically relevant bleeding in a large population of hospitalized medical patients and identified risk factors at admission associated with in-hospital bleeding. This information may assist physicians in deciding whether to use mechanical or pharmacologic VTE prophylaxis.

Idraparinux versus standard therapy in the treatment of deep venous thrombosis in cancer patients: a subgroup analysis of the Van Gogh DVT trial.

Standard treatment with heparin followed by vitamin K antagonists is frequently complicated by bleeding and recurrent venous thromboembolism (VTE) in cancer patients with VTE. To compare the efficacy, safety and overall survival of long-term idraparinux treatment to standard therapy in cancer patients we conducted a post-hoc analysis in the subgroup of non-active and active cancer patients included in the Van Gogh DVT clinical trial. The cancer patients with deep venous thrombosis (DVT) and without pulmonary embolism (PE) were randomised to standard treatment or a once-weekly subcutaneous injection of idraparinux (2.5 mg), a synthetic pentasaccharide. 421 cancer patients were included. A total of 220 patients received idraparinux and 201 were allocated to standard therapy for three months (8%) or six months (92%). A recurrent VTE was observed during the first six months in 2.5% (n=5) of the idraparinux recipients compared to 6.4% (n=12) in the standard therapy group (hazard ratio 0.39, 95% confidence interval [CI]; 0.14-1.11). The rate of bleeding was comparable (odds ratio 0.89, 95% CI; 0.50-1.59). The outcomes were similar at three months after randomisation in all patients. Of the idraparinux recipients, 22.7% (n=50) died during the study period compared to 48 patients (23.9%) in the standard treatment group (hazard ratio 0.99, 95% CI; 0.66-1.48). In conclusion, no significant safety or survival differences were observed between cancer patients with DVT treated with idraparinux for six months compared to standard therapy. Fewer recurrent VTEs were observed in the idraparinux group; however, this was not statistically significant and also because of study limitations this should be interpreted with caution.

Superficial venous thrombosis and venous thromboembolism: a large, prospective epidemiologic study.

BACKGROUND: Superficial venous thrombosis (SVT) is perceived to have a benign prognosis. OBJECTIVE: To assess the prevalence of venous thromboembolism in patients with SVT and to determine the 3-month incidence of thromboembolic complications. DESIGN: National cross-sectional and prospective epidemiologic cohort study. (ClinicalTrials.gov registration number: NCT00818688) SETTING: French office- and hospital-based vascular medicine specialists. PATIENTS: 844 consecutive patients with symptomatic SVT of the lower limbs that was at least 5 cm on compression ultrasonography. MEASUREMENTS: Incidence of venous thromboembolism and extension or recurrence of SVT in patients with isolated SVT at presentation. RESULTS: Among 844 patients with SVT at inclusion (median age, 65 years; 547 women), 210 (24.9%) also had deep venous thrombosis (DVT) or symptomatic pulmonary embolism. Among 600 patients without DVT or pulmonary embolism at inclusion who were eligible for 3-month follow-up, 58 (10.2%) developed thromboembolic complications at 3 months (pulmonary embolism, 3 [0.5%]; DVT, 15 [2.8%]; extension of SVT, 18 [3.3%]; and recurrence of SVT, 10 [1.9%]), despite 540 patients (90.5%) having received anticoagulants. Risk factors for complications at 3 months were male sex, history of DVT or pulmonary embolism, previous cancer, and absence of varicose veins. LIMITATION: The findings are from a specialist referral setting, and the study was terminated before the target patient population was reached because of slow recruitment. CONCLUSION: A substantial number of patients with SVT exhibit venous thromboembolism at presentation, and some that do not can develop this complication in the subsequent 3 months. PRIMARY FUNDING SOURCE: GlaxoSmithKline, sanofi-aventis, and the Ministère Francais de la Santé et des Sports (Programme Hospitalier de Recherche Clinique).

Treatment of venous thromboembolism in patients with cancer: subgroup analysis of the Matisse clinical trials.

In the initial treatment of venous thromboembolism (VTE) fondaparinux, a pentasaccharide, is a good alternative to heparin. Whether this is also true for cancer patients is unknown. We performed two post-hoc analyses of two randomized studies to compare efficacy, safety and overall survival of fondaparinux to standard initial (low-molecular-weight) heparin (LMWH) treatment in cancer patients with venous thromboembolism. Two hundred thirty-seven cancer patients with deep venous thrombosis (DVT) were initially treated with fondaparinux or enoxaparin. Two hundred forty cancer patients with pulmonary embolism (PE) received fondaparinux or unfractionated heparin. The initial treatment was followed by vitamin K antagonists. In DVT patients, the three-month recurrence rate was 5.4% in the enoxaparin recipients compared to 12.7% in those treated with fondaparinux [absolute difference 7.3%, 95% CI 0.1, 14.5]. A recurrence was observed in 8.9% of the PE patients treated with fondaparinux compared to 17.2% in the unfractionated heparin recipients [absolute difference -8.3, 95% CI -16.7, 0.1]. In both studies no difference in bleeding and overall survival was observed. Regarding overall survival and bleeding fondaparinux is comparable to enoxaparin and unfractionated heparin in cancer patients. No significant differences in recurrent VTE were observed when comparing fondaparinux with unfractionated or LMWH. Because of study limitations these results should be considered hypothesis-generating.

Clinical predictors for fatal pulmonary embolism in 15,520 patients with venous thromboembolism: findings from the Registro Informatizado de la Enfermedad TromboEmbolica venosa (RIETE) Registry.

BACKGROUND: Clinical predictors for fatal pulmonary embolism (PE) in patients with venous thromboembolism have never been studied. METHODS AND RESULTS: Using data from the international prospective Registro Informatizado de la Enfermedad TromboEmbolica venosa (RIETE) registry about patients with objectively confirmed symptomatic acute venous thromboembolism, we determined independent predictive factors for fatal PE. Between March 2001 and July 2006, 15 520 consecutive patients (mean age+/-SD, 66.3+/-16.9 years; 49.7% men) with acute venous thromboembolism were included. Symptomatic deep-vein thrombosis without symptomatic PE was observed in 58.0% (n=9008) of patients, symptomatic nonmassive PE in 40.4% (n=6264), and symptomatic massive PE in 1.6% (n=248). At 3 months, the cumulative rates of overall mortality and fatal PE were 8.65% and 1.68%, respectively. On multivariable analysis, patients with symptomatic nonmassive PE at presentation exhibited a 5.42-fold higher risk of fatal PE compared with patients with deep-vein thrombosis without symptomatic PE (P<0.001). The risk of fatal PE was multiplied by 17.5 in patients presenting with a symptomatic massive PE. Other clinical factors independently associated with an increased risk of fatal PE were immobilization for neurological disease, age >75 years, and cancer. CONCLUSIONS: PE remains a potentially fatal disease. The clinical predictors identified in the present study should be included in any clinical risk stratification scheme to optimally adapt the treatment of PE to the risk of the fatal outcome.

Thrombophilia and risk of venous thrombosis in patients with cancer.

Venous thrombosis is a common and severe complication in patients with cancer. We reviewed studies assessing whether a state of acquired or congenital thrombophilia influenced the risk of thrombosis in patients with cancer. The results are equivocal. However, the majority of studies were of limited size. The influence of thrombophilia in patients with cancer may be more difficult to demonstrate than in the general population, the risk of thrombosis due to cancer per se possibly outweighing the contribution of thrombophilic factors. Moreover, the results may depend on the genetic background of the population, the type of cancer, the type of thrombosis, and the chemotherapeutic treatment. Nevertheless, it appears that factor V Leiden or G20210A prothrombin gene mutation increases the risk of venous thromboembolism about 2- to 4-fold, compared with patients with cancer without either of these mutations. Similar results were observed for the occurrence of central venous catheter-associated thrombosis. Antiphospholipid antibodies and acquired resistance to activated protein C were frequently observed in patients with cancer and appeared to favor the occurrence of thrombosis. The role of hyperhomocysteinemia deserves further investigation. Since the clinical implications of these findings remain to be clarified, routine screening of cancer patients for thrombophilia cannot yet be recommended on the basis of these studies. Studies designed to assess the value of thromboprophylaxis in high-risk patients, including thrombophilic patients, with long-term central venous catheters may be valuable.

[Initial treatment of venous thromboembolic events]. / Traitement initial de la maladie thrombo-embolique veineuse.

Initial treatment of venous thromboembolic events is currently based on antithrombotics. This treatment is validated and identical for deep vein thrombosis (DVT) and pulmonary embolism. For distal DVT, this treatment has still to be validated. This reference therapeutic strategy is firstly parenteral and based on low-molecular-weight heparins (LMWH) or fondaparinux, subcutaneously prescribed at fixed dosage based on body weight without any systematic dose adjustment on hemostasis tests. Unfractionated heparin is steel the reference treatment in case of severe renal insufficiency. This parenteral treatment has to be relieved by vitamin K antagonists (VKA). VKA has to be co-administrated for at least 3 days, without any loading dose and can be early initiated. VKA dose needs to be adjusted in order to maintain INR between 2 and 3. However, in case of cancer, LMWH have to be carried on for 6 months. A part this antithrombotic treatment, thrombolytics are recommended in case of massive PE and vena cava filter should be used in case of recurrence despite adequate antithrombotic treatment or in case of contraindication to antithrombotic.

A prospective long-term study of 220 patients with a retrievable vena cava filter for secondary prevention of venous thromboembolism.

BACKGROUND: The immediate and long-term clinical events associated with the placement and removal of a retrievable filter (ALN filter; ALN Implants Chirurgicaux; Ghisonaccia, France) remain largely unknown. METHODS: This was a prospective cohort study with an 18-month follow-up. All consecutive patients scheduled for placement of an ALN filter between April 1999 and June 2005 in the Radiology Department of our hospital were included. RESULTS: During the study period, placement of an ALN filter was indicated in 220 patients (mean age, 70.8 years), who were followed up for a median duration of 338.5 days (range, 1 to 561 days); 148 patients (67.3%) completed the 18-month follow-up. No patients were unavailable for follow-up. All patients had an acute or past venous thromboembolism. Main indications were recurrent venous thromboembolism despite adequate anticoagulation therapy (10.9%), transient bleeding event (21.8%), definitive contraindication for anticoagulant therapy (26.8%), or obligation to stop anticoagulant therapy due to major surgery, major trauma, or invasive procedure (37.7%). Filter insertion was successful in 98.6% of patients and resulted in an immediate complication in 11.8%. The median duration of filter implantation was 166 days (first to third quartiles, 34 to 478 days). Meanwhile, 17.0% (37 of 217 patients) had at least one venous thromboembolic event. Filter retrieval was attempted in 25.3% of patients after a median of 51 days (range, 6 to 352 days); removal was successful at the first attempt in 92.7% of patients. CONCLUSIONS: The filter could be easily inserted and successfully removed up to 1 year after insertion. Its safety and efficacy in preventing pulmonary embolism should be properly assessed in a randomized study.

Do antifibrinolytics reduce allogeneic blood transfusion in orthopedic surgery?

Studies have shown that antifibrinolytic (aprotinin, tranexamic acid, epsilon-aminocaproic acid) reduce blood loss in orthopedic surgery. However, most lacked sufficient power to evaluate the efficacy and safety on clinical outcomes. This meta-analysis aims to evaluate whether intravenous antifibrinolytics, when compared with placebo, reduce perioperative allogeneic erythrocyte transfusion requirement in adults undergoing orthopedic surgery and whether it might increase the risk of venous thromboembolism. From MEDLINE, EMBASE, and the Cochrane Controlled Trials Register, the authors identified 43 randomized controlled trials in total hip and knee arthroplasty, spine fusion, musculoskeletal sepsis, or tumor surgery performed to July 2005 (for aprotinin, 23 trials with 1,268 participants; tranexamic acid, 20 with 1,084; epsilon-aminocaproic acid, 4 with 171). Aprotinin and tranexamic acid reduced significantly the proportion of patients requiring allogeneic erythrocyte transfusion according to a transfusion protocol. The odds ratio was 0.43 (95% confidence interval, 0.28-0.64) for aprotinin and 0.17 (0.11-0.24) for tranexamic acid. Results suggest a dose-effect relation with tranexamic acid. Epsilon-aminocaproic acid was not efficacious. Unfortunately, data were too limited for any conclusions regarding safety. Although the results suggest that aprotinin and tranexamic acid significantly reduce allogeneic erythrocyte transfusion, further evaluation of safety is required before recommending the use of antifibrinolytics in orthopedic surgery.

Factors predictive of venous thrombotic complications in patients with isolated superficial vein thrombosis.

OBJECTIVE: Superficial vein thrombosis may be complicated with venous thromboembolism. We examined factors predictive of venous thromboembolism in superficial vein thrombosis, which, to our knowledge, had not been prospectively studied before. DESIGN AND METHODS: We performed post hoc analysis of the STENOX trial, a prospective randomized controlled trial that investigated various antithrombotic therapies in 427 hospitalized patients with objectively confirmed symptomatic isolated superficial vein thrombosis. The value of various baseline characteristics as predictive factors of venous thrombotic complications at 3 months was studied with logistic regression. Venous thrombotic complications were defined as deep vein thrombosis or pulmonary embolism, or recurrence or proximal extension of superficial vein thrombosis. RESULTS: Venous thrombotic complications occurred in 78 patients. Independent predictive factors for complications were superficial vein thrombosis of recent onset (odds ratio [OR], 3.01; 95% confidence interval [CI], 1.44-6.27), severe chronic venous insufficiency (OR, 2.75; CI, 1.10-6.89), male gender (OR, 2.17; CI, 1.28-3.68), and history of venous thromboembolism (OR, 2.07; CI 1.06-4.04). Deep vein thrombosis or pulmonary embolism occurred in 19 patients. Only severe chronic venous insufficiency was an independent predictor of this complication (OR, 4.50; CI, 1.30-15.61). CONCLUSIONS: After symptomatic isolated superficial vein thrombosis, venous thrombotic complications are relatively frequent, and are more likely to occur in men, in patients with a history of venous thromboembolism or with severe chronic venous insufficiency, or in whom superficial vein thrombosis is recent. Knowledge of such predictive factors may be useful for determining appropriate treatment in patients with superficial vein thrombosis and for designing future phase III clinical trials.

Optimal low-molecular-weight heparin regimen in major orthopaedic surgery. A meta-analysis of randomised trials.

Low-molecular-weight heparins (LMWH) are routinely used for thromboprophylaxis in major lower limb orthopaedic surgery. However the optimal LMWH regimen, offering the greatest efficacy with an acceptable risk of bleeding, has not been clearly established with regard to dose and timing of treatment initiation. We performed a meta-analysis of all available randomised trials comparing LMWH to placebo. Relative risks (RR) and corresponding 95% confidence intervals (CI) were calculated. By means of subgroup analysis, we evaluated the consistency of the results according to the timing of treatment initiation (preoperative versus postoperative) and dose of LMWH used (low doses, i.e. 4000 anti-Xa IU or below versus high doses). The possibility of a dose-effect relationship of LMWH was also evaluated by meta-regression. Thirteen studies were included (1925 patients). In four studies, LMWH treatment was started postoperatively. Daily LMWH doses ranged from 3000 anti-Xa IU to over 6000 anti-Xa IU. Compared to placebo, LMWH significantly reduced the risk of asymptomatic deep-vein thrombosis (DVT) (RR=0.51, 95% CI=[0.45-0.59], p<0.001) without significantly increasing the risk of major haemorrhage (RR=0.80 [0.36-1.79], p=0.58). We found no convincing evidence that starting prophylaxis preoperatively was associated with a significantly reduced risk of asymptomatic DVT relative to starting postoperatively. Our results showed a strong correlation between the risk of DVT and LMWH dose (meta-regression, test of slope p=0.03). These findings are tentative because the comparisons are across trials, but nevertheless suggest that the different LMWH regimens currently recommended are effective and safe.

Superficial vein thrombosis: risk factors, diagnosis, and treatment.

Superficial vein thrombosis (SVT) risk factors are close to those of venous thromboembolism (VTE). Diagnosis is made in a clinical setting but ultrasonography is useful to eliminate concomitant deep vein thrombosis (DVT). For SVT of the lower limbs, which is the main location, varicose veins represent the principal cause but underlying conditions (e.g.: autoimmune diseases, malignancy or thrombophilia) must be sought in idiopathic, migrant or recurrent SVT and in the absence of varicose veins. Concomitant DVT and pulmonary embolism can occur in approximately 15% and 5% respectively. Historical treatments consist of anti-inflammatory agents plus elastic stockings and, in case of varicose veins, thrombectomy and stripping. Other treatments (anticoagulants, vein ligation) were assessed to limit the VTE risk. A one-month prophylactic dose of low molecular weight heparin plus elastic stockings could be the appropriate strategy in most cases. Other studies are needed before definitive conclusions can be drawn.