Self-managed long-term low-molecular-weight heparin therapy: the balance of benefits and harms. A randomised open-label trial comparing long-term sub-cutaneous low-molecular-weight heparin compared with oral-anticoagulant therapy in the treatment of deep venous thrombosis. Long-term low-molecular-weight heparin versus usual care in proximal-vein thrombosis patients with cancer. Comparison of subcutaneous low-molecular-weight heparin with intravenous standard heparin in proximal deep-vein thrombosis. Prevention of venous thromboembolism after knee arthroscopy with low-molecular weight heparin (reviparin): Results of a randomized controlled trial. Venographic comparison of subcutaneous low-molecular weight heparin with oral anticoagulant therapy in the long-term treatment of deep venous thrombosis. Low-molecular-weight heparin versus warfarin for prevention of recurrent venous thromboembolism: a randomized trial. Fixed-dose, body weight-independent subcutaneous LMW heparin versus adjusted dose unfractionated intravenous heparin in the initial treatment of proximal venous thrombosis. EASTERN Investigators. Low molecular weight heparin versus acenocoumarol in the secondary prophylaxis of deep vein thrombosis.
A substantial clinical need exists for an alternate to vitamin K antagonists for treating deep vein thrombosis in many patients. Long-term low-molecular-weight heparin (LMWH), body-weight adjusted, avoids anticoagulant monitoring and may be associated with less bleeding. We evaluated the effectiveness and safety of long-term LMWH compared with vitamin K antagonist therapy in a broad spectrum of patients with proximal vein thrombosis.
                We performed a multicenter, randomized, open-label clinical trial using objective outcome measures comparing therapy for 3 months. Outcomes were assessed at 3 and 12 months.
                Of 737 patients, 18 of 369 receiving tinzaparin (4.9%) had recurrent venous thromboembolism at 3 months compared with 21 of 368 (5.7%) receiving usual care (absolute difference, -0.8%, 95% confidence interval -4.1-2.4). Hemorrhagic complications occurred less frequently in the LMWH group largely because of less minor bleeding: 48 of 369 patients (13.0%) versus 73 of 368 patients (19.8%) receiving usual-care anticoagulation (absolute difference -6.8%; P = .011; risk ratio = 0.66). New major bleeding events ceased early (by day 23, P = .034) for patients receiving LMWH but persisted throughout the study treatment interval for patients receiving vitamin K antagonist therapy. No mortality advantage was shown for LMWH.
                Our study shows that LMWH is similar in effectiveness to the usual-care vitamin K antagonist treatment for preventing recurrent venous thromboembolism in a broad spectrum of patients. It causes less harm and enhances the clinicians' therapeutic options for patients with proximal deep vein thrombosis. Our findings reported here suggest the possibility of a broader role for long-term LMWH in selected patients. To evaluate whether low-molecular-weight heparin (LMWH) could be equally (or more) effective than oral anti-vitamin-K agents (AVK) in the long-term treatment of deep venous thrombosis (DVT).
                A randomised, open-label trial.
                In this trial, 241 patients with symptomatic proximal DVT of the lower limbs confirmed by duplex ultrasound scan were included. After initial LMWH, patients received 6 months of treatment with full therapeutic dosage of tinzaparin or acenocoumarol. The primary outcome was the 12-month incidence of symptomatic recurrent venous thrombo-embolism (VTE). Duplex scans were performed at 6 and 12 months.
                During the 12-month period, six patients (5%) of 119 who received LMWH and 13 (10.7%) of 122 who received AVK had recurrent VTE (p=0.11). In patients with cancer, recurrent VTE tended to be lower in the LMWH group (two of 36 [5.5%]) vs. seven of 33 [21.2%]; p=0.06). One major bleeding occurred in the LMWH group and three in the AVK group. Venous re-canalisation increased significantly at 6 months (73.1% vs. 47.5%) and at 12 months (91.5% vs. 69.2%) in the LMWH group.
                Tinzaparin was more effective than AVK in achieving re-canalisation of leg thrombi. Long-term tinzaparin was at least as efficacious and safe as AVK for preventing recurrent VTE, especially in patients with cancer. A substantial clinical need exists for an alternative to vitamin K antagonists for treating deep-vein thrombosis in cancer patients who are at high risk of both recurrent venous thromboembolism and bleeding. Low-molecular-weight heparin, body-weight adjusted, avoids anticoagulant monitoring and has been shown to be more effective than vitamin-K-antagonist therapy.
                Subjects were patients with cancer and acute symptomatic proximal-vein thrombosis. We performed a multi-centre randomized, open-label clinical trial using objective outcome measures comparing long-term therapeutic tinzaparin subcutaneously once daily with usual-care long-term vitamin-K-antagonist therapy for 3 months. Outcomes were assessed at 3 and 12 months.
                Of 200 patients, 100 received tinzaparin and 100 received usual care. At 12 months, the usual-care group had an excess of recurrent venous thromboembolism; 16 of 100 (16%) versus 7 of 100 (7%) receiving low-molecular-weight heparin (P=.044; risk ratio=.44; absolute difference -9.0; 95% confidence interval [CI], -21.7 to -0.7). Bleeding, largely minor, occurred in 27 patients (27%) receiving tinzaparin and 24 patients (24%) receiving usual care (absolute difference -3.0; 95% CI, -9.1 to 15.1). In patients without additional risk factors for bleeding at the time of randomization, major bleeding occurred in 0 of 51 patients (0%) receiving tinzaparin and 1 of 48 patients (2.1%) receiving usual care. Mortality at 1 year was high, reflecting the severity of the cancers; 47% in each group died.
                Our findings confirm the limited but benchmark data in the literature that long-term low-molecular-weight heparin is more effective than vitamin-K-antagonist therapy for preventing recurrent venous thromboembolism in patients with cancer and proximal venous thrombosis. In view of the potential of low-molecular-weight heparins (LMWH) to simplify initial therapy and allow outpatient treatment of proximal deep-vein thrombosis, we undertook a randomised comparison of fixed-dose subcutaneous LMWH with adjusted-dose intravenous standard heparin in the initial treatment of this disorder. Our main objectives were to compare the efficacy of these regimens for 6 months of follow-up and to assess the risk of clinically important bleeding. Of 170 consecutive symptomatic patients with venographically proven proximal deep-venous thrombosis, 85 received standard heparin (to achieve an activated partial thromboplastin time of 1.5 to 2.0 times the pretreatment value) and 85 LMWH (adjusted only for body weight) for 10 days. Oral coumarin was started on day 7 and continued for at least 3 months. The frequency of recurrent venous thromboembolism diagnosed objectively did not differ significantly between the standard-heparin and LMWH groups (12 [14%] vs 6 [7%]; difference 7% [95% confidence interval -3% to 15%]; p = 0.13). Clinically important bleeding was infrequent in both groups (3.5% for standard heparin vs 1.1% for LMWH; p greater than 0.2). We conclude that fixed-dose subcutaneous LMWH is at least as effective and safe as intravenous adjusted-dose heparin in the initial treatment of symptomatic proximal-vein thrombosis. Since there is no need for laboratory monitoring with the LMWH regimen, patients with venous thrombosis can be treated at home. Deep venous thrombosis (DVT) is a common, important complication of major orthopaedic surgery, particularly knee arthroplasty. Knee arthroscopy is increasingly performed on an outpatient basis. Few reports have elucidated the incidence of venous thromboembolism (VTE) in patients undergoing arthroscopic surgery receiving no prophylaxis. The objective of the present trial was to evaluate the risk of VTE in those patients and to determine efficacy and safety of a low-molecular weight heparin (LMWH) in preventing VTE.
                This is the first controlled randomized trial using objective diagnostic methods with blinded outcome assessment to reveal the incidence of VTE in outpatient arthroscopy and determine efficacy and safety of a LMWH (reviparin sodium) in preventing VTE in these patients.
                There were 262 patients undergoing elective knee arthroscopy prospectively randomized to receive either no treatment or reviparin once daily subcutaneously for 7 to 10 days. The blindly assessed primary outcome measure was the incidence of DVT detected by compression color-coded sonography. Both groups were comparable with regard to demographics and baseline characteristics.
                239 patients were evaluable (122 no treatment, 117 receiving LMWH). 6 DVT were detected - 5 in the control group (5/117 - 4.1%) and only one in the active treatment group (1/116 - 0.85%). This particular patient had a low level of protein C and a subnormal level of protein S. The odds ratio of 4.95 approximates a relative risk reduction of about 80%. Treatment with reviparin was safe and well tolerated. There was no major bleeding, four patients with minor bleedings. One patient had a transitory fall in platelet count below 100 giga-particles/L without any clinical symptoms.
                Patients undergoing knee arthroscopy have a moderate risk of VTE and effective prophylaxis can be achieved with LMWH (reviparin). The primary objective of this study was to evaluate with venography the rate of thrombus regression after a fixed dose of low-molecular weight heparin (LMWH) per day for 3 months compared with oral anticoagulant therapy for deep venous thrombosis (DVT). Secondary endpoints were the comparisons of the efficacy and safety of both treatments.
                This study was designed as an open randomized clinical study in a university hospital setting. Of the 165 patients finally enrolled in the study, 85 were assigned LMWH therapy and 80 were assigned oral anticoagulant therapy. In the group randomized to oral anticoagulant therapy, the patients first underwent treatment in the hospital with standard unfractionated heparin and then coumarin for 3 months. Doses were adjusted with laboratory monitoring to maintain the international normalized ratio between 2.0 and 3.0. Patients in the LMWH group were administered subcutaneous injections of fixed doses of 40 mg enoxaparin (4000 anti-Xa units) every 12 hours for 7 days, and after discharge from the hospital, they were administered 40 mg enoxaparin once daily at fixed doses for 3 months without a laboratory control assay. A quantitative venographic score (Marder score) was used to assess the extent of the venous thrombosis, with 0 points indicating no DVT and 40 points indicating total occlusion of all deep veins. The rate of thrombus reduction was defined as the difference in quantitative venographic scores after termination of LMWH or coumarin therapy as compared with the scores obtained on the initial venographic results. The efficacy was defined as the ability to prevent symptomatic extension or recurrence of venous thromboembolism (documented with venograms or serial lung scans). The safety was defined as the occurrence of hemorrhages.
                After 3 months of treatment, the mean Marder score was significantly decreased in both groups in comparison with the baseline score, although the effect of therapy was significantly better after LMWH therapy (49.4% reduction) than after coumarin therapy (24.5% reduction; P <.001). LMWH therapy and male gender were independently associated with an enhanced resolution of the thrombus. A lower frequency of symptomatic recurrent venous thromboembolism was also shown in patients who underwent treatment with LMWH therapy (9.5%) than with oral anticoagulant therapy (23.7%; P <.05), although this difference was entirely a result of recurrence of DVT. Bleeding complications were significantly fewer in the LMWH group than in the coumarin group (1. 1% vs 10%; P <.05). This difference was caused by minor hemorrhages. Coumarin therapy and cancer were independently associated with an enhanced risk of complications. Subcutaneous heparin therapy was well tolerated by all patients.
                The patients who were allocated to undergo enoxaparin therapy had a significantly greater improvement in their quantitative venographic score, a significantly lower recurrence rate of symptomatic venous thromboembolism, and a significantly lower incidence of bleeding than patients who underwent treatment with coumarin. LMWH can be used on an outpatient basis as a safer and more effective alternative to classical oral anticoagulant therapy for the secondary prophylaxis of selected patients with DVT. A group of 105 consecutive patients with venographically proved major acute deep vein thrombosis (DVT) were randomized in an open prospective study to evaluate the comparative efficacy and safety of a fixed dose of subcutaneous low-molecular-weight heparin (LMWH) and warfarin for the prevention of recurrent venous thromboembolism. Four patients developed venographically proved recurrent DVT during the 3 months of treatment: three in the LMWH group and one in the warfarin group. Nonfatal pulmonary embolism occurred in two patients in the LMWH group and in one in the warfarin group. Five of the 55 patients (10%) in the warfarin group and none of the 50 patients in the LMWH developed bleeding complications (two-tailed Fisher exact test, p = 0.06). A preliminary assessment of the costs indicated that treatment with LMWH was less expensive by Pounds 900 per patient than warfarin. In conclusion, the fixed daily dose of LMWH and the adjusted dose of warfarin therapy were of similar efficacy in preventing recurrence of DVT. However, warfarin therapy, despite strict laboratory control, is associated with more frequent side effects and is expensive. Another study with a higher dose of LMWH is recommended. Body weight-adjusted subcutaneous low-molecular-weight heparin (LMWH) has been proven to be at least as effective and safe as dose-adjusted intravenous unfractionated heparin (UFH) for the treatment of patients with venous thromboembolism. However, body weight-adjusted dosage of low-molecular-weight heparin may be cumbersome and could lead possibly to incorrect dosing. Therefore a fixed LMWH dose, independent of body-weight, might rationalize initial treatment for venous thromboembolism.
                Patients with proven proximal deep-vein thrombosis were randomly assigned to fixed dose subcutaneous LMWH Certoparin (8,000 anti-factor Xa U b.i.d.; 265 patients) or to adjusted dose i.v. UFH (273 patients) for 12 days. Vitamin K antagonists were started between day 3 and 7 and continued for up to 6 months. The primary outcome measure was a 30 percent or greater improvement in the Marder Score, as revealed by repeated venography on day 12 (end of the initial treatment). The secondary composite outcome measure included death, recurrent venous thromboembolism and major bleeding and was assessed at day 12 and after 6 months by a blinded adjunction committee.
                The Marder score improved by 30% or more in 30.3% and 25.0% of patients assigned to LMWH (198 paired venograms) and UFH (192 paired venograms), respectively (2p = 0.26). At the end of the initial treatment, the composite outcome was observed in 4 of the 265 patients (1.5%) randomized to LMWH, as compared with 14 of the 273 patients (5.1%) randomized to UFH (2p = 0.03). At 6 months these figures were 6.8% and 12.8%, respectively (risk reduction 0.53, confidence interval 0.31-0.90, 2p = 0.02).
                Fixed dose subcutaneous LMWH certoparin is at least as efficacious as UFH in resolving proximal vein thrombosis. The aim of this study was to determine the efficacy and safety of subcutaneous weight-adjusted dose low molecular weight heparin (LMWH) compared with oral anticoagulant (OA) in the prevention of recurrent venous thromboembolism. In a prospective multicenter trial, 202 patients with symptomatic proximal deep vein thrombosis (DVT) were included. As soon as the diagnosis of DVT was confirmed by phlebography, 101 were randomly assigned to receive LMWH (nadroparin) for secondary prophylaxis and 101 to receive OA (acenocoumarol). Patients in both groups were initially treated with nadroparin in a dose of 85 anti-Xa IU/kg s.c. every 12 h. Secondary prophylaxis with either nadroparin, 85 anti-Xa IU/kg s. c. once daily, or acenocoumarol was continued for at least 3 months. Three patients in the LMWH group and 6 in the OA group were excluded from analysis for various reasons. During the one-year combined secondary prophylaxis and surveillance period, 7 of of the 98 evaluable patients (7.1%) in the LMWH group and 9 of the 95 evaluable patients (9.5%) in the OA group had a documented recurrence of venous thromboembolism (Fisher's exact test, p = 0.61). Of these, 2 patients who received LMWH and 7 patients on acenocoumarol had recurrences in the 3-month period of secondary prophylaxis. Four patients (4.1%) in the LMWH group developed bleeding complications during this study period, as compared with 7 (7.4%) in the OA group (Fisher's exact test, p = 0.37). There were two major bleedings, one in the LMWH group and one in the OA group. Eleven patients died, 5 (5.1%) in the LMWH group and 6 (6.3%) in the OA group. It is concluded that nadroparin in a dose of 85 anti-Xa IU/kg s.c. once daily provides an effective and safe alternative to oral anticoagulants in the secondary prophylaxis of DVT.
LMWHs are possibly as effective as vitamin K antagonists in preventing symptomatic VTE after an episode of symptomatic deep venous thrombosis, but are much more expensive. Treatment with LMWH is significantly safer than treatment with vitamin K antagonists. LMWH may result in fewer episodes of bleeding and is possibly a safe alternative in some patients, especially those in geographically inaccessible areas, are reluctant to visit the thrombosis service regularly, or with contraindications to vitamin K antagonists. However, treatment with vitamin K antagonists remains the treatment of choice for the majority of patients.