Low-molecular-weight-heparin versus a coumarin for the prevention of recurrent venous thromboembolism in high- and low-risk patients with active cancer: a post hoc analysis of the CLOT Study

Journal of Thrombosis and Thrombolysis - In patients with active cancer and acute venous thromboembolism (VTE), the low-molecular-weight-heparin (LMWH) dalteparin is more effective than vitamin K...     

Duration of oral anticoagulant therapy in venous thromboembolism]

PURPOSE: The optimal duration of oral anticoagulant therapy after a first episode of venous thromboembolism is still a matter of debate. It is essential to balance the desired effect of the anticoagulants in reducing recurrences against the risk of major bleeding. The aims of this paper are to describe the current concepts in this field. CURRENT KNOWLEDGE AND KEY POINTS: Recent data, based on randomised controlled trials, suggest that it is necessary to tailor the duration of anticoagulation individually according to the topography of venous thromboembolism and the presence of risk factors. A 6-week treatment for patients with isolated calf vein thrombosis is sufficient. For proximal thrombosis and/or pulmonary embolism, a short anticoagulant course seems sufficient in patients with temporary risk factors (3 months) and a longer anticoagulant course (6 months at least) is recommended for cases with permanent risk factors or idiopathic venous thromboembolism. The inherited or acquired hypercoagulable states can be divided into those that are common and associated with a modest risk of recurrence (i.e., isolated factor V Leiden or G20210A prothrombin gene) and those that are uncommon but associated with a high risk of recurrence (i.e., antithrombin, protein C or S deficiencies and anticardiolipin antibodies). Thus, the presence of one of these last abnormalities favours more prolonged anticoagulant therapy. FUTURE PROSPECTS AND PROJECTS: 1) For patients at high risk of recurrence, there is a paucity of evidence-based medicine, particularly for patients with biological thrombophilia, and randomised controlled trials in this population are required. An assessment of low- or fixed-dose oral anticoagulation is also necessary in order to reduce the bleeding risk. 2) It is not always possible to precisely determine the optimal duration with the available data. We have performed a meta-analysis on summary data which suggests that a long course of oral anticoagulant therapy is superior to a short course. An individual meta-analytic approach is needed to draw more precise conclusions on an interesting and important clinical topic and we propose to perform this analysis in a international collaborative group.     

Management of oral anticoagulant treatment in patients with venous thromboembolism

Oral anticoagulants (OAs) are the drugs of choice for the prevention of recurrence and death in patients with venous thromboembolism (VTE). Oral anticoagulant treatment (OAT) aims to retard blood coagulation to obtain maximum protection against thromboembolic events with the lowest risk of bleeding. The intensity of OAT is ascertained by measuring the prothrombin time (PT), which is expressed as the international normalized ratio (INR). The efficacy and safety of these drugs depends on the ability to maintain the level of anticoagulation as close as possible to the therapeutic target (INR = 2.5) or inside the therapeutic range (INR = 2.0 to 3.0). Given that dosage of oral anticoagulants varies from patient to patient and within the single patient, clinical and laboratory (biological effect of the drug) check-ups must be performed periodically. The management of patients with VTE, as well as that of other patients receiving OAT, includes medical controls and expertise that are better available in specialized centers (anticoagulation clinics).     

Clotting activation after oral anticoagulant therapy discontinuation: a risk factor for recurrent venous thromboembolism.

A hypercoagulable state has been reported in some patients treated for venous thromboembolism (VTE) after oral anticoagulant treatment (OAT) discontinuation. It is unclear whether this is a risk factor for thrombosis recurrence. We investigated 139 patients with VTE and followed them up for a median of 20.5 months (6-90 months) to evaluate whether fragment 1 + 2 (F1 + 2) plasma levels are prognostic for VTE recurrence and to confirm clotting activation after OAT withdrawal. Fourteen patients had recurrences during the follow-up. F1 + 2 was measured the day before OAT withdrawal (T0) and 4 weeks later (T1) and its levels were similar in patients with spontaneous VTE versus those with transient risk factors for VTE. F1 + 2 levels increased from T0 to T1 (P < 0.0005). At T1, F1 + 2 values were significantly higher in patients with recurrence than in those without (P < 0.005). The negative predictive value of normal levels of F1 + 2 at T1 was 95%. In carriers of thrombophilic conditions no correlation was found between F1 + 2 levels and VTE recurrence. The results of this study confirm clotting activation after OAT discontinuation and suggest that higher F1 + 2 plasma levels are an independent risk factor for VTE recurrence.     

Anemia and bleeding in patients receiving anticoagulant therapy for venous thromboembolism

In patients receiving anticoagulant therapy for venous thromboembolism (VTE), the important issue of anemia influence on the risk of bleeding has not been consistently studied. We used the large registry data RIETE (Registro Informatizado Enfermedad Tromboembólica) to compare the rate of major bleeding in patients receiving anticoagulant therapy for VTE according to the presence or absence of anemia at baseline. Patients with or without cancer were separately studied. Until August 2016, 63492 patients had been enrolled. Of these, 21652 (34%) had anemia and 14312 (23%) had cancer. Anemia was found in 57% of the patients with cancer and in 28% without (odds ratio 3.46; 95% CI 3.33–3.60). During the course of anticoagulant therapy, 680 patients with cancer had a major bleeding event (gastrointestinal tract 43%, intracranial 14%, hematoma 12%). Cancer patients with anemia had a higher rate of major bleeding (rate ratio [RR]: 2.52; 95% CI 2.14–2.97) and fatal bleeding (RR 2.73; 95% CI 1.95–3.86) than those without anemia. During the course of anticoagulation, 1133 patients without cancer had major bleeding (gastrointestinal tract 32%, hematoma 24%, intracranial 21%). Patients with anemia had a higher rate of major bleeding (RR 2.84; 95% CI 2.52–2.39) and fatal bleeding (RR 2.76; 95% CI 2.07–3.67) than those without. On a multivariable analysis, anemia independently predicted the risk for major bleeding in patients with and without cancer (hazard ratios: 1.66; 95% CI 1.40–1.96 and 1.95; 95% CI 1.72–2.20, respectively). During anticoagulation for VTE, both cancer- and non-cancer anemic patients had a higher risk for major bleeding than those without anemia. In anemic patients (with or without cancer), the rate of major bleeding during the course of anticoagulant therapy exceeded the rate of VTE recurrences. In patients without anemia the rate of major bleeding was lower than the rate of VTE recurrences.     

Monotherapy with enoxaparin for the prevention of recurrent venous thromboembolism.

This study aimed to determine whether a weight-adjusted dose of subcutaneous enoxaparin is as effective and safe as oral acenocoumarol for the secondary prophylaxis of pulmonary embolism. Three hundred and eighty consecutive noncancer outpatients hospitalized with an episode of symptomatic pulmonary embolism selected treatment with acenocoumarol or enoxaparin at a dose of 1 mg/kg once daily after being informed of the type of administration and expected frequency of laboratory monitoring for both medicinal products. Endpoints were symptomatic recurrent thromboembolic events evaluated by standard objective testing, and a composite endpoint of recurrent venous thromboembolism, major bleeding, and death from any cause. One hundred and ninety-nine patients (52%) chose acenocoumarol therapy and 181 chose enoxaparin monotherapy. Four patients in the enoxaparin group (2.2%) and six patients in the acenocoumarol group (3%) had an objective thromboembolic recurrence (hazard ratio, 1.35; 95% confidence interval, 0.38-4.79; P = 0.64). Nine patients in the enoxaparin group (5.0%) had a hemorrhagic complication compared with 11 in the acenocoumarol group (5.5%) (P = 0.81). The hospital length of stay was shorter with enoxaparin compared with acenocoumarol (11 versus 16 days, P = 0.0001). Enoxaparin is as effective and safe as acenocoumarol in the secondary prevention of recurrent thromboembolic disease and is associated with shorter hospitalization.     

恶性肿瘤并发静脉血栓栓塞症的临床分析

目的分析并发静脉血栓栓塞症(VTE)恶性肿瘤患者的原发肿瘤种类、分期、分化程度等,以识别高危患者,提高防治意识,减少VTE的发生。方法回顾性分析北京医院2003年1月至2013年1月期间并发静脉血栓栓塞症的恶性肿瘤患者的年龄、性别、基础疾病、原发肿瘤种类、病理类型、分化程度、TNM分期、化疗方案及预后等临床信息。结果在所有18 531例恶性肿瘤患者中,280例并发VTE,其中男性157例,女性123例,年龄(66.60±12.60)岁。包括单纯肺栓塞(PTE)41例,单纯下肢深静脉血栓形成(DVT)189例,PTE合并DVT 50例。肺癌82例,消化道肿瘤78例,泌尿系肿瘤32例,妇科肿瘤27例,血液科肿瘤27例,乳腺癌12例,其他部位肿瘤22例。相比未并发VTE肿瘤患者,并发VTE多见于肺癌、妇科肿瘤和其他肿瘤患者,差异有统计学意义(P0.05)。151例(53.9%)并发VTE肿瘤患者病理类型为腺癌;206例(73.6%)患者发生VTE时,肿瘤处于进展期;247例有明确TNM分期患者中Ⅲ~Ⅳ期患者187例(66.8%);144例有明确病理组织分化程度报告,中、低度分化程度者120例(85.4%)。至随访结束,共有130例患者死亡,中位生存时间为(24.0±7.8)个月,明确诊断VTE后3,6,9,12个月的累积死亡率分别为46.9%、69.2%、80.0%和82.3%。导致死亡的主要原因是肿瘤本身、肺栓塞和感染。结论肿瘤与VTE密切相关,腺癌、进展期肿瘤、分化程度低的肿瘤患者和化疗方案中含铂类药物者更易发生VTE,临床医师应注意对这部分患者进行VTE风险评估,采取必要的预防措施,减少VTE的发生。     

Anemia and bleeding in patients receiving anticoagulant therapy for venous thromboembolism: comment

Kuperman et al. found that patients with anemia had a higher risk of major bleeding (RR 2.84; 95% CI 2.52–3.39) in RIETE database. Anemia appeared to be an independent predictive factor for major bleeding [hazard ratio (HR) 1.95; 95% CI 1.72–2.20] in this registry. Unfortunately, selection bias due to enrolled patients does not allowed us to use these major results in ambulatory care. The aim of SCORE study was to refine bleeding risk estimation in French vitamin K antagonist (VKA) treated patients and to identifying one or several parameters of prognostic significance. We conducted a prospective, multi-center cohort study of 962 consecutive outpatients from private angiologic offices, clinics and hospitals enrolled in grenoble angiologic network for thromboembolic diseases between May 2009 and December 2010, followed during 1 year by their general practitioner. Main outcome was the occurrence of major bleeding or clinically non major relevant bleeding (CNMRB). Incidence rates major bleeding and CNMRB were 2.86 (95% CI 1.95–4.2) events per 100 patient-years and 12% (95% CI 9.89–14.11) respectively. Cox multivariate analyses showed that only anemia was strongly associated with a risk of major bleeding (HR 6.1; 95% CI 2.7–13.8; p?=?0.001). Logistic regression analyses performed in CNMRB showed that anemia, prior gastro-intestinal bleeding and antiplatelet drug use were strongly associated with a risk of CNMRB at 1 year, respectively OR 2.53, 95% CI (1.4–4.56); p?=?0.002, OR 3.32, 95% CI (1.51–7.31); p?=?0.003 and OR 1.77, 95% CI (1.1–2.83); p?=?0.017. These new data were consistent between major and CRNM bleeding in VKA treated patients. The key role of anemia should be confirmed in other prospective cohort studies, with different anticoagulants use such as direct oral anticoagulant in ambulatory care settings.     

Safety of dalteparin for the prophylaxis of venous thromboembolism in elderly medical patients with renal insufficiency: a pilot study

The aim of this prospective cohort study was to determine the incidence of dalteparin bioaccumulation (measured using anti-Xa levels), and bleeding during thromboprophylaxis in elderly patients with renal failure who were admitted to hospital with an acute medical illness. Patients who met the criteria for being at high thromboembolic risk received dalteparin 5,000 IU subcutaneously once daily while the other patients (low risk) received 2,500 IU daily. Thromboprophylaxis was administered for at least 6 days. Anti-Xa activity was determined before the first dalteparin dose and again on day 6, 4 hours after the administration of the dalteparin dose. Bleeding was assessed daily. Compression ultrasonography was performed to identify any deep vein thromboses. There was no evidence of bioaccumulation on day 6 of therapy, irrespective of renal function. No episodes of major bleeding or venous thromboembolism occurred. Larger, randomized studies are warranted to confirm the safety of dalteparin in this patient population.     

Recurrent venous thromboembolism and bleeding complications during anticoagulant treatment in patients with cancer and venous thrombosis

A small proportion of patients with deep vein thrombosis develop recurrent venous thromboembolic complications or bleeding during anticoagulant treatment. These complications may occur more frequently if these patients have concomitant cancer. This prospective follow-up study sought to determine whether in thrombosis patients those with cancer have a higher risk for recurrent venous thromboembolism or bleeding during anticoagulant treatment than those without cancer. Of the 842 included patients, 181 had known cancer at entry. The 12-month cumulative incidence of recurrent thromboembolism in cancer patients was 20.7% (95% CI, 15.6%-25.8%) versus 6.8% (95% CI, 3.9%- 9.7%) in patients without cancer, for a hazard ratio of 3.2 (95% CI, 1.9-5.4) The 12-month cumulative incidence of major bleeding was 12.4% (95% CI, 6.5%-18.2%) in patients with cancer and 4.9% (95% CI, 2.5%-7.4%) in patients without cancer, for a hazard ratio of 2.2 (95% CI, 1.2-4.1). Recurrence and bleeding were both related to cancer severity and occurred predominantly during the first month of anticoagulant therapy but could not be explained by sub- or overanticoagulation. Cancer patients with venous thrombosis are more likely to develop recurrent thromboembolic complications and major bleeding during anticoagulant treatment than those without malignancy. These risks correlate with the extent of cancer. Possibilities for improvement using the current paradigms of anticoagulation seem limited and new treatment strategies should be developed.     

Durée du traitement anticoagulant oral dans la maladie thromboembolique veineuse Duration of oral anticoagulant therapy for venous thromboembolism.

Purpose. – The optimal duration of oral anticoagulant therapy after a first episode of venous thromboembolism is still a matter of debate. It is essential to balance the desired effect of the anticoagulants in reducing recurrences against the risk of major bleeding. The aims of this paper are to describe the current concepts in this field.Current knowledge and key points. – Recent data, based on randomised controlled trials, suggest that it is necessary to tailor the duration of anticoagulation individually according to the topography of venous thromboembolism and the presence of risk factors. A 6-week treatment for patients with isolated calf vein thrombosis is sufficient. For proximal thrombosis and/or pulmonary embolism, a short anticoagulant course seems sufficient in patients with temporary risk factors (3 months) and a longer anticoagulant course (6 months at least) is recommended for cases with permanent risk factors or idiopathic venous thromboembolism. The inherited or acquired hypercoagulable states can be divided into those that are common and associated with a modest risk of recurrence (i.e., isolated factor V Leiden or G20210A prothrombin gene) and those that are uncommon but associated with a high risk of recurrence (i.e., antithrombin, protein C or S deficiencies and anticardiolipin antibodies). Thus, the presence of one of these last abnormalities favours more prolonged anticoagulant therapy.Future prospects and projects. – 1) For patients at high risk of recurrence, there is a paucity of evidence-based medicine, particularly for patients with biological thrombophilia, and randomised controlled trials in this population are required. An assessment of low- or fixed-dose oral anticoagulation is also necessary in order to reduce the bleeding risk. 2) It is not always possible to precisely determine the optimal duration with the available data. We have performed a meta-analysis on summary data which suggests that a long course of oral anticoagulant therapy is superior to a short course. An individual meta-analytic approach is needed to draw more precise conclusions on an interesting and important clinical topic and we propose to perform this analysis in a international collaborative group.     

Tinzaparin for venous thromboembolism in patients with renal impairment: a single-centre,prospective pilot study

Background: Low molecular weight heparins (LMWH) are used extensively for prophylaxis and treatment of venous thromboembolism (VTE), bridging therapy for warfarin and standard of care in cancer-associated VTE (CA-VTE). Tinzaparin has the highest molecular weight of all LMWH and relies least on renal clearance to Cockcroft-Gault creatinine clearance (CrCl) of 20 mL/min. Previous pharmacological studies have demonstrated safety and effectiveness in elderly patients. Prospective clinical trials have confirmed these findings to CrCl 20 mL/min and in CA-VTE. We describe the pilot program developed at Concord Repatriation General Hospital for tinzaparin. Aims: We aim to confirm the deliverability of tinzaparin in patients with renal insufficiency. Methods: Twenty patients were established on tinzaparin as therapeutic anticoagulation with CrCl or CKD-EPI estimated glomerular filtration rate (eGFR) 20–50 mL/min with an indication for anticoagulation. Tinzaparin was given as a subcutaneous injection at 175 units/kg as a single daily dose, rounded to the nearest vial size. Tinzaparin anti-Xa levels were tested at Days 2, 7 and 14 (±1 day) and transition to oral anticoagulants were allowed at clinician discretion. Results: No accumulation of tinzaparin was seen into Day 14. Two patients required dose-adjustment, five patients had bleeding complications (two major, three minor) and four patients died during follow-up, all attributable to patients' comorbidities. CrCl and body surface area-standardised CrCl were significantly correlated with tinzaparin anti-Xa level only on Day 2, and this effect was lost when patients with CrCl >50 mL/min were excluded. Data from our cohort confirm the deliverability of therapeutic tinzaparin in patients with CrCl or CKD-EPI eGFR 20–50 mL/min. Bleeding and death outcomes were also comparable to other trials using tinzaparin in CA-VTE. Conclusion: For patients with renal insufficiency, tinzaparin represents an attractive alternative anticoagulant with once-daily administration in a range of potential indications.     

Underutilization of oral anticoagulant therapy for stroke prevention in elderly patients with heart failure

BACKGROUND: Oral anticoagulant therapy is the most effective prophylaxis against stroke in atrial fibrillation. Relatively few studies have examined the use of oral anticoagulant therapy for stroke prevention in a large cohort of elderly patients with heart failure. To examine the use of stroke prevention therapy, we studied elderly patients with heart failure admitted to 30 hospitals in northeast Ohio between 1992 and 1994. METHODS AND RESULTS: The sample consisted of 12,911 Medicare-insured patients > or =65 years of age who were consecutively admitted with a principal diagnosis of heart failure between 1992 and 1994. Baseline demographic and clinical characteristics for patients with the diagnosis of atrial fibrillation were calculated. Bivariate associations between receiving anticoagulant therapy and select demographic and clinical variables were calculated. In our cohort of patients with heart failure, 2093 had atrial fibrillation (16%). Only 414 (20%) of the patients with atrial fibrillation received oral anticoagulant therapy. Older age and history of gastrointestinal bleeding were significantly negatively associated with receiving oral anticoagulant therapy. History of stroke or transient ischemic attack was positively associated with receiving oral anticoagulant therapy. CONCLUSIONS: Atrial fibrillation is common in older patients with heart failure; oral anticoagulant therapy for stroke prevention, which has been shown to be effective, is underutilized in this patient population.     

Clinical risk factors and timing of recurrent venous thromboembolism during the initial 3 months of anticoagulant therapy

BACKGROUND: In patients with venous thromboembolism (VTE), identifying clinical risk factors for recurrence during the initial 3 months of anticoagulant therapy and knowledge of the time course of recurrence may help clinicians decide about the frequency of clinical surveillance and the appropriateness of outpatient treatment. METHODS: Analysis of a randomized controlled trial database involving 1021 patients with VTE (750 with deep vein thrombosis [DVT] and 271 with pulmonary embolism [PE]) who were followed up for 3 months after the start of anticoagulant therapy. All patients received initial treatment with unfractionated heparin or a low-molecular-weight heparin (reviparin) and a coumarin derivative starting the first or second day of treatment, with a target international normalized ratio of 2.0 to 3.0. RESULTS: Four independent clinical risk factors for recurrent VTE were identified: (1) cancer (odds ratio [OR], 2.72; 95% confidence interval [CI], 1. 39-5.32), (2) chronic cardiovascular disease (OR, 2.27; 95% CI, 1. 08-4.97), (3) chronic respiratory disease (OR, 1.91; 95% CI, 0.85-4. 26), and (4) other clinically significant medical disease (OR, 1.79; 95% CI, 1.00-3.21). Older age was associated with a decreased risk for recurrent VTE (OR, 0.76; 95% CI, 0.64-0.92). Previous VTE, sex, and idiopathic VTE were not risk factors for recurrence. In patients with DVT or PE, there was no significant difference in the rates of recurrent nonfatal VTE (4.8% vs 4.1%; P =.62), major bleeding (2.9% vs 2.2%; P =.53), and non-VTE death (6.4% vs 7.8%; P =.45), but recurrent fatal PE was more frequent in patients with PE than DVT (2. 2% vs 0%; P<.01). There was a clustering of recurrent VTE episodes during the initial 2 to 3 weeks after the start of treatment. CONCLUSIONS: During the initial 3 months of anticoagulant therapy, recurrent VTE is more likely to occur in patients with cancer, chronic cardiovascular disease, chronic respiratory disease, or other clinically significant medical disease. Patients with PE are as likely to develop recurrent VTE as those with DVT; however, recurrence is more likely to be fatal in patients who initially present with PE. Arch Intern Med. 2000;160:3431-3436.