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Alexander G G Turpie - One of the best experts on this subject based on the ideXlab platform.
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replacement of venography in suspected venous thrombosis by Impedance Plethysmography and 125i fibrinogen leg scanning
Annals of Internal Medicine, 2020Co-Authors: Russell D Hull, Jack Hirsh, Alexander G G Turpie, A Zielinsky, David L Sackett, P Powers, Wayne D. Taylor, C O Carter, Michael GentAbstract:Abstract Noninvasive diagnostic testing is gaining acceptance in the evaluation of patients with clinically suspected venous thrombosis. Although clinically useful, all these tests have limitations...
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low molecular weight heparinoid orgaran is more effective than aspirin in the prevention of venous thromboembolism after surgery for hip fracture
Circulation, 1996Co-Authors: M Gent, Jack Hirsh, J R Leclerc, William H Geerts, Mark Levine, Richard M Jay, Peter Powers, Jean Neemeh, Jeffrey S Ginsberg, Alexander G G TurpieAbstract:Background The study objective was to determine the relative efficacy and safety of a low-molecular-weight heparinoid (Orgaran) compared with aspirin for the prevention of postoperative venous thromboembolism in patients undergoing surgery for fractured hips. A double-blind, randomized, controlled trial was used to study 251 consecutive eligible and consenting patients undergoing surgery for hip fracture in seven participating hospitals. Methods and Results Patients received either fixed-dose Orgaran by subcutaneous injection every 12 hours in a dose of 750 anti–Factor Xa units or aspirin 100 mg orally twice daily; both regimens were started 12 to 24 hours after surgery and continued for 14 days or until discharge, if sooner. All patients had postoperative 125I-fibrinogen leg scanning and Impedance Plethysmography. If the results of one or both tests were positive, then venography was performed. Otherwise, venography was done at day 14, or sooner if the patient was ready for discharge. Pulmonary embolism ...
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a comparison of real time compression ultrasonography with Impedance Plethysmography for the diagnosis of deep vein thrombosis in symptomatic outpatients
The New England Journal of Medicine, 1993Co-Authors: H Heijboer, Anthonie W A Lensing, Harry R Buller, Alexander G G Turpie, L P Colly, J Ten W CateAbstract:Background Impedance Plethysmography performed serially over a one-week period has been shown to be an effective diagnostic strategy for patients with clinically suspected acute deep-vein thrombosis. Compression ultrasonography has a high sensitivity and specificity for the detection of proximal-vein thrombosis. The clinical value of repeated ultrasonography in the management of symptomatic deep-vein thrombosis is unknown. Methods We conducted a randomized trial in 985 consecutive outpatients with clinically suspected deep-vein thrombosis to compare the diagnostic value of serial Impedance Plethysmography (494 patients) and serial compression ultrasonography (491 patients). We compared the positive predictive values of both tests for the diagnosis of venous thrombosis, using contrast venography as a reference. The frequencies of venous thromboembolism during a six-month follow-up period were also compared in patients with repeatedly normal results in order to evaluate the safety of withholding anticoagula...
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a low molecular weight heparinoid compared with unfractionated heparin in the prevention of deep vein thrombosis in patients with acute ischemic stroke a randomized double blind study
Annals of Internal Medicine, 1992Co-Authors: Alexander G G Turpie, Michael Gent, J R Leclerc, William H Geerts, Mark Levine, Richard M Jay, Peter Powers, Robert Cote, Jeffrey S Ginsberg, Jean NeemehAbstract:Objective To compare the relative safety and efficacy of a low-molecular-weight heparinoid (ORG 10172) with unfractionated heparin in the prevention of deep vein thrombosis in patients with acute ischemic stroke. Design Double-blind randomized trial. Setting Seven Canadian university-affiliated hospitals. Participants Eighty-seven patients with acute ischemic stroke resulting in lower-limb paresis. Intervention Patients received either low-molecular-weight heparinoid, 750 anti-factor Xa units twice daily, or unfractionated heparin, 5000 units subcutaneously twice daily. Treatment was continued for 14 days or until hospital discharge if sooner. Measurements Deep vein thrombosis was diagnosed using 125I-labeled fibrinogen leg scanning and Impedance Plethysmography. Venography was indicated if either test was positive. Overt hemorrhage, major or minor, was assessed clinically. Results Venous thrombosis occurred in four patients (9%) given low-molecular-weight heparinoid and in 13 patients (31%) given heparin (relative risk reduction, 71%; 95% CI, 16% to 93%. The corresponding rates for proximal vein thrombosis were 4% and 12%, respectively (relative risk reduction, 63%; P greater than 0.2). The incidence of hemorrhage was 2% in both groups. Conclusion Low-molecular-weight heparinoid, given in a fixed dose of 750 anti-factor Xa units subcutaneously twice daily, is more effective than subcutaneous low-dose heparin for the prevention of deep vein thrombosis in patients with acute ischemic stroke.
Jeffrey S Ginsberg - One of the best experts on this subject based on the ideXlab platform.
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Clinical Utility of a Rapid Whole-Blood D-Dimer Assay in Patients with Cancer Who Present with Suspected Acute
2016Co-Authors: Deep Venous Thrombosis, Jeffrey S GinsbergAbstract:tive predictive values for the diagnosis of deep venous thrombosis, their accuracy in patients with cancer is un-certain. Objective: To compare the clinical utility of a whole-blood D-dimer assay for the diagnosis of deep venous thrombosis in patients with and those without cancer. Design: Retrospective analysis of three prospective studies. Setting: Two tertiary care hospitals. Patients: 1068 consecutive outpatients with suspected deep venous thrombosis. Measurements: All patients underwent D-dimer testing and assessment with a priori diagnostic strategies that incorporated Impedance Plethysmography, compression ultrasonography, or contrast venography. Patients in whom deep venous thrombosis was not diagnosed initially were followed for 3 months for the development of thrombosis. Results of D-dimer testing were assessed ac-cording to the final diagnosis based on objective testing and clinical follow-up. Cancer status was identified at pre-sentation. Results: The prevalence of deep venous thrombosis was 48.8 % in 121 patients with cancer and 14.6 % in 947 pa-tients without cancer. Although the sensitivity of the D-dimer assay was similar in patients with and those without cancer (86.4 % [95 % CI, 75.0 % to 94.0%] and 82.6 % [CI, 75.2 % to 88.5%], respectively), the specificity was signifi-cantly lower in patients with cancer (48.4 % [CI, 35.5 % to 61.4%] and 82.2 % [CI, 79.4 % to 84.8%]), as was the nega-tive predictive value (78.9 % [CI, 62.7 % to 90.4%] and 96.5 % [CI, 94.9 % to 97.8%]). In contrast, the likelihood ratios of a negative test result (0.28 [CI, 0.14 to 0.56] and 0.21 [CI, 0.15 to 0.31]) did not differ significantly. Conclusions: A negative D-dimer test result in patients with cancer does not reliably exclude deep venous throm-bosis because the negative predictive value of the test is significantly lower in these patients than in patients with-out cancer. Ann Intern Med. 1999;131:417-423
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diagnosis of deep vein thrombosis and pulmonary embolism in pregnancy a systematic review
Journal of Thrombosis and Haemostasis, 2006Co-Authors: Mathilde Nijkeuter, Jeffrey S Ginsberg, Menno V HuismanAbstract:Summary. Introduction: Diagnosing deep vein thrombosis (DVT) and pulmonary embolism (PE) in pregnancy is challenging. Many of the common diagnostic tests, including compression ultrasonography (CUS), ventilation-perfusion scintigraphy (VQ scan) and helical computed tomography (hCT) that have been extensively investigated in non-pregnant patients, have not been appropriately validated in pregnancy. Extrapolating results of diagnostic studies of DVT and PE in non-pregnant patients to those who are pregnant may not be correct because during pregnancy, physiologic and anatomic changes may affect diagnostic test results, presentation and natural history of VTE. Methods: We performed a systematic analysis of published studies addressing accurate diagnostic testing for DVT and PE in pregnancy to determine the accuracy of these tests in pregnancy. Results: Our initial search yielded 530 articles of which four remained for inclusion, three studies investigating diagnostic testing in patients with a clinical suspicion of DVT or PE and one study in patients with a clinical suspicion of PE. Conclusions: From our systematic analysis of published studies investigating diagnostic testing for a clinical suspicion of DVT in pregnancy we conclude that; (i) two studies support withholding anticoagulant therapy in pregnant women with a clinical suspicion of DVT and normal results on serial IPG (Impedance Plethysmography), however, IPG is no longer used; (ii) one study demonstrated that a normal CUS at presentation combined with a normal D-dimer test or an abnormal D-dimer test combined with normal serial CUS appears promising for safely excluding DVT in pregnant patients, but too few patients were included in this pilot-study to draw firm conclusions; and (iii) one study investigated pregnant patients with a clinical suspicion of PE and this study concluded that in patients with normal or non-diagnostic VQ scans, withholding anticoagulant therapy might be safe, but this needs confirmation in larger studies. Recommendations on diagnostic testing of pregnant patients with a clinically suspected DVT or PE are provided.
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clinical utility of a rapid whole blood d dimer assay in patients with cancer who present with suspected acute deep venous thrombosis
Annals of Internal Medicine, 1999Co-Authors: Jim A Julian, Mark Levine, Clive Kearon, Jeffrey I Weitz, Philip Wells, Jeffrey S GinsbergAbstract:Background: Although D-dimer assays have high negative predictive values for the diagnosis of deep venous thrombosis, their accuracy in patients with cancer is uncertain. Objective: To compare the clinical utility of a whole-blood D-dimer assay for the diagnosis of deep venous thrombosis in patients with and those without cancer. Design: Retrospective analysis of three prospective studies. Setting: Two tertiary care hospitals. Patients: 1068 consecutive outpatients with suspected deep venous thrombosis. Measurements: All patients underwent D-dimer testing and assessment with a priori diagnostic strategies that incorporated Impedance Plethysmography, compression ultrasonography, or contrast venography. Patients in whom deep venous thrombosis was not diagnosed initially were followed for 3 months for the development of thrombosis. Results of D-dimer testing were assessed according to the final diagnosis based on objective testing and clinical follow-up. Cancer status was identified at presentation. Results: The prevalence of deep venous thrombosis was 48.8% in 121 patients with cancer and 14.6% in 947 patients without cancer. Although the sensitivity of the D-dimer assay was similar in patients with and those without cancer (86.4% [95% Cl, 75.0% to 94.0%] and 82.6% [Cl, 75.2% to 88.5%], respectively), the specificity was significantly lower in patients with cancer (48.4% [Cl, 35.5% to 61.4%] and 82.2% [Cl, 79.4% to 84.8%]), as was the negative predictive value (78.9% [Cl, 62.7% to 90.4%] and 96.5% [Cl, 94.9% to 97.8%]). In contrast, the likelihood ratios of a negative test result (0.28 [Cl, 0.14 to 0.56] and 0.21 [Cl, 0.15 to 0.31]) did not differ significantly. Conclusions: A negative D-dimer test result in patients with cancer does not reliably exclude deep venous thrombosis because the negative predictive value of the test is significantly lower in these patients than in patients without cancer.
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low molecular weight heparinoid orgaran is more effective than aspirin in the prevention of venous thromboembolism after surgery for hip fracture
Circulation, 1996Co-Authors: M Gent, Jack Hirsh, J R Leclerc, William H Geerts, Mark Levine, Richard M Jay, Peter Powers, Jean Neemeh, Jeffrey S Ginsberg, Alexander G G TurpieAbstract:Background The study objective was to determine the relative efficacy and safety of a low-molecular-weight heparinoid (Orgaran) compared with aspirin for the prevention of postoperative venous thromboembolism in patients undergoing surgery for fractured hips. A double-blind, randomized, controlled trial was used to study 251 consecutive eligible and consenting patients undergoing surgery for hip fracture in seven participating hospitals. Methods and Results Patients received either fixed-dose Orgaran by subcutaneous injection every 12 hours in a dose of 750 anti–Factor Xa units or aspirin 100 mg orally twice daily; both regimens were started 12 to 24 hours after surgery and continued for 14 days or until discharge, if sooner. All patients had postoperative 125I-fibrinogen leg scanning and Impedance Plethysmography. If the results of one or both tests were positive, then venography was performed. Otherwise, venography was done at day 14, or sooner if the patient was ready for discharge. Pulmonary embolism ...
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application of a novel and rapid whole blood assay for d dimer in patients with clinically suspected pulmonary embolism
Thrombosis and Haemostasis, 1995Co-Authors: Jeffrey S Ginsberg, Philip Wells, Patrick Brilledwards, Akbar Panju, Dianne Donovan, E J R Van Beek, Ameen PatelAbstract:STUDY OBJECTIVE: To determine the clinical utility of a novel whole blood assay for D-dimer (SimpliRED) in patients with clinically suspected pulmonary embolism (PE). DESIGN: Prospective cohort. PATIENTS: Eighty-six consecutive patients with clinically suspected PE. INTERVENTION: All patients had the SimpliRED D-dimer assay performed and underwent ventilation/perfusion (V/Q) lung scanning and bilateral Impedance Plethysmography (IPG); pulmonary angiography was performed in two patients. Patients were classified as: 1) PE-positive; positive pulmonary angiography or high probability V/Q scan or non-high probability V/Q scan and either abnormal IPG (either at presentation or upon serial testing and confirmed by contrast venography) or symptomatic thromboembolic event within three months of presentation or 2) PE-negative; normal V/Q scan or normal pulmonary angiography or non-high probability V/Q scan and normal serial IPG and absence of symptomatic venous thromboembolism within three months of follow up. Sixteen (19%) patients were classified as PE-positive and 70 (81%) patients were classified as PE-negative. MEASUREMENTS AND RESULT: The sensitivities, specificities, positive predictive values, and negative predictive values of the D-dimer assay were calculated for all patients and for the subgroup of patients without comorbid conditions that independently can cause elevated D-dimer levels. The D-dimer showed a sensitivity of 94%, a negative predictive value of 98%, a specificity of 66%, and a positive predictive value of 38%. In the subgroup of patients without comorbid conditions, the specificity increased to 98% and the positive predictive value to 83%, but because only six patients had an abnormal D-dimer level, the 95% confidence interval on the observed positive predictive value is wide (36-100%). CONCLUSIONS: This study demonstrates that the SimpliRED D-dimer assay, which can be performed and interpreted at the bedside within five minutes, has potential clinical utility as an exclusionary test in patients with clinically suspected PE. The assay should be evaluated in large clinical management studies.
William H Geerts - One of the best experts on this subject based on the ideXlab platform.
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low molecular weight heparinoid orgaran is more effective than aspirin in the prevention of venous thromboembolism after surgery for hip fracture
Circulation, 1996Co-Authors: M Gent, Jack Hirsh, J R Leclerc, William H Geerts, Mark Levine, Richard M Jay, Peter Powers, Jean Neemeh, Jeffrey S Ginsberg, Alexander G G TurpieAbstract:Background The study objective was to determine the relative efficacy and safety of a low-molecular-weight heparinoid (Orgaran) compared with aspirin for the prevention of postoperative venous thromboembolism in patients undergoing surgery for fractured hips. A double-blind, randomized, controlled trial was used to study 251 consecutive eligible and consenting patients undergoing surgery for hip fracture in seven participating hospitals. Methods and Results Patients received either fixed-dose Orgaran by subcutaneous injection every 12 hours in a dose of 750 anti–Factor Xa units or aspirin 100 mg orally twice daily; both regimens were started 12 to 24 hours after surgery and continued for 14 days or until discharge, if sooner. All patients had postoperative 125I-fibrinogen leg scanning and Impedance Plethysmography. If the results of one or both tests were positive, then venography was performed. Otherwise, venography was done at day 14, or sooner if the patient was ready for discharge. Pulmonary embolism ...
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a prospective study of venous thromboembolism after major trauma
The New England Journal of Medicine, 1994Co-Authors: William H Geerts, Richard M Jay, Karen I Code, Erluo Chen, John Paul SzalaiAbstract:Background Although deep-vein thrombosis and pulmonary embolism are considered common complications after major trauma, their frequency and the associated risk factors have not been carefully quantified. Methods We performed serial Impedance Plethysmography and lower-extremity contrast venography to detect deep-vein thrombosis in a cohort of 716 patients admitted to a regional trauma unit. Prophylaxis against thromboembolism was not used. Results Deep-vein thrombosis in the lower extremities was found in 201 of the 349 patients (58 percent) with adequate venographic studies, and proximal-vein thrombosis was found in 63 (18 percent). Three patients died of massive pulmonary embolism before venography could be performed. Before venography, only three of the patients with deep-vein thrombosis had clinical features suggestive of the condition. Deep-vein thrombosis was found in 65 of the 129 patients with major injuries involving the face, chest, or abdomen (50 percent); in 49 of the 91 patients with major hea...
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a low molecular weight heparinoid compared with unfractionated heparin in the prevention of deep vein thrombosis in patients with acute ischemic stroke a randomized double blind study
Annals of Internal Medicine, 1992Co-Authors: Alexander G G Turpie, Michael Gent, J R Leclerc, William H Geerts, Mark Levine, Richard M Jay, Peter Powers, Robert Cote, Jeffrey S Ginsberg, Jean NeemehAbstract:Objective To compare the relative safety and efficacy of a low-molecular-weight heparinoid (ORG 10172) with unfractionated heparin in the prevention of deep vein thrombosis in patients with acute ischemic stroke. Design Double-blind randomized trial. Setting Seven Canadian university-affiliated hospitals. Participants Eighty-seven patients with acute ischemic stroke resulting in lower-limb paresis. Intervention Patients received either low-molecular-weight heparinoid, 750 anti-factor Xa units twice daily, or unfractionated heparin, 5000 units subcutaneously twice daily. Treatment was continued for 14 days or until hospital discharge if sooner. Measurements Deep vein thrombosis was diagnosed using 125I-labeled fibrinogen leg scanning and Impedance Plethysmography. Venography was indicated if either test was positive. Overt hemorrhage, major or minor, was assessed clinically. Results Venous thrombosis occurred in four patients (9%) given low-molecular-weight heparinoid and in 13 patients (31%) given heparin (relative risk reduction, 71%; 95% CI, 16% to 93%. The corresponding rates for proximal vein thrombosis were 4% and 12%, respectively (relative risk reduction, 63%; P greater than 0.2). The incidence of hemorrhage was 2% in both groups. Conclusion Low-molecular-weight heparinoid, given in a fixed dose of 750 anti-factor Xa units subcutaneously twice daily, is more effective than subcutaneous low-dose heparin for the prevention of deep vein thrombosis in patients with acute ischemic stroke.
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prevention of deep vein thrombosis after major knee surgery a randomized double blind trial comparing a low molecular weight heparin fragment enoxaparin to placebo
Thrombosis and Haemostasis, 1992Co-Authors: J R Leclerc, William H Geerts, Louis Desjardins, F Jobin, F Laroche, F Delorme, S Haviernick, S Atkinson, J BourgouinAbstract:Consecutive patients undergoing knee arthroplasty or tibial osteotomy at four participating hospitals received either enoxaparin, 30 mg subcutaneously every 12 h (n = 66) or an identical-appearing placebo (n = 65). All study medications started the morning after the operation and were continued up to a maximum of 14 days. Patients underwent surveillance with 125I-fibrinogen leg scanning and Impedance Plethysmography. Bilateral contrast venography was performed routinely at Day 14 or at time of discharge, if sooner. Deep vein thrombosis was detected by venography in 35 of 54 patients (65%) in the placebo group and in 8 of 41 patients in the enoxaparin group (19%), a risk reduction of 71%, P less than 0.0001. For the entire study group, deep vein thrombosis was detected by either venography of non-invasive tests in 37 of 64 patients (58%) in the placebo group and in 11 of 65 patients (17%) in the enoxaparin group, a risk reduction of 71%, P less than 0.0001. Proximal vein thrombosis was found in 19% of the placebo patients and in none of the enoxaparin patients, a risk reduction of 100%, P less than 0.001. Bleeding complications occurred in 5 of 65 patients (8%) in the placebo group and in 4 of 66 patients (6%) in the enoxaparin group, P = 0.71. There were no differences in the amount of blood loss, minimum hemoglobin levels and number of units of packed red cells given between the two treatment groups. We conclude that a fixed dose regimen of enoxaparin, started post-operatively, is an effective and safe regimen for reducing the frequency of deep vein thrombosis after major knee surgery.
Julian M Stewart - One of the best experts on this subject based on the ideXlab platform.
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mechanisms of vasovagal syncope in the young reduced systemic vascular resistance versus reduced cardiac output
Journal of the American Heart Association, 2017Co-Authors: Julian M Stewart, Marvin S Medow, Richard Sutton, Paul Visintainer, David L Jardine, Wouter WielingAbstract:Background Syncope is a sudden transient loss of consciousness and postural tone caused by cerebral hypoperfusion. The most common form is vasovagal syncope (VVS). Presyncopal progressive early hypotension in older VVS patients is caused by reduced cardiac output (CO); younger patients have reduced systemic vascular resistance (SVR). Using a priori criteria for reduced CO (↓CO) and SVR (↓SVR), we studied 48 recurrent young fainters comparing subgroups of VVS with VVS‐↓CO, VVS‐↓SVR, and both VVS‐↓CO&↓SVR. Methods and Results Subjects were studied supine and during 70‐degrere upright tilt with a Finometer to continuously measure blood pressure, CO, and SVR and Impedance Plethysmography to estimate thoracic, splanchnic, pelvic, and calf blood volumes, blood flows, and vascular resistances and electrocardiogram to measure heart rate and rhythm. Central blood volume was decreased in all VVS compared to control. VVS‐↓CO was associated with decreased splanchnic blood flow and increased splanchnic blood pooling compared to control. Seventy‐five percent of VVS patients had reduced SVR, including 23% who also had reduced CO. Many VVS‐↓SVR increased CO during tilt, with no difference in splanchnic pooling, caused by significant increases in splanchnic blood flow and reduced splanchnic resistance. VVS‐↓CO&↓SVR patients had splanchnic pooling comparable to VVS‐↓CO patients, but SVR comparable to VVS‐↓SVR. Splanchnic vasodilation was reduced, compared to VVS‐↓SVR, and venomotor properties were similar to control. Combined splanchnic pooling and reduced SVR produced the earliest faints among the VVS groups. Conclusions Both ↓CO and ↓SVR occur in young VVS patients. ↓SVR is predominant in VVS and is caused by impaired splanchnic vasoconstriction.
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peripheral vascular adaptation and orthostatic tolerance in fontan physiology
Circulation, 2009Co-Authors: Usha Krishnan, Indu Taneja, Michael H Gewitz, Richard Young, Julian M StewartAbstract:Background— The Fontan circulation is critically dependent on elevated venous pressures to sustain effective venous return. We hypothesized that chronically increased systemic venous pressures lead to adaptive changes in regional and peripheral vessels to maintain cardiac output, especially when patients are upright. Methods and Results— Nine post–Fontan procedure patients (aged 13 to 24 years) and 6 age- and sex-matched controls were compared with techniques to measure circulatory responses (peripheral and compartmental blood flow, venous capacity, and microvascular filtration). Parameters studied included strain-gauge Plethysmography measures of peripheral circulatory function, regional blood volume distribution by Impedance Plethysmography, and head-up tilt testing. Important differences between Fontan patients and controls were seen in several vascular compartments: (1) Calf capacitance was lower (median, 3.5 versus 5.5 mL/100 mL tissue; P=0.005), and resting venous pressure was higher (13.0 versus 10...
J R Leclerc - One of the best experts on this subject based on the ideXlab platform.
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low molecular weight heparinoid orgaran is more effective than aspirin in the prevention of venous thromboembolism after surgery for hip fracture
Circulation, 1996Co-Authors: M Gent, Jack Hirsh, J R Leclerc, William H Geerts, Mark Levine, Richard M Jay, Peter Powers, Jean Neemeh, Jeffrey S Ginsberg, Alexander G G TurpieAbstract:Background The study objective was to determine the relative efficacy and safety of a low-molecular-weight heparinoid (Orgaran) compared with aspirin for the prevention of postoperative venous thromboembolism in patients undergoing surgery for fractured hips. A double-blind, randomized, controlled trial was used to study 251 consecutive eligible and consenting patients undergoing surgery for hip fracture in seven participating hospitals. Methods and Results Patients received either fixed-dose Orgaran by subcutaneous injection every 12 hours in a dose of 750 anti–Factor Xa units or aspirin 100 mg orally twice daily; both regimens were started 12 to 24 hours after surgery and continued for 14 days or until discharge, if sooner. All patients had postoperative 125I-fibrinogen leg scanning and Impedance Plethysmography. If the results of one or both tests were positive, then venography was performed. Otherwise, venography was done at day 14, or sooner if the patient was ready for discharge. Pulmonary embolism ...
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a low molecular weight heparinoid compared with unfractionated heparin in the prevention of deep vein thrombosis in patients with acute ischemic stroke a randomized double blind study
Annals of Internal Medicine, 1992Co-Authors: Alexander G G Turpie, Michael Gent, J R Leclerc, William H Geerts, Mark Levine, Richard M Jay, Peter Powers, Robert Cote, Jeffrey S Ginsberg, Jean NeemehAbstract:Objective To compare the relative safety and efficacy of a low-molecular-weight heparinoid (ORG 10172) with unfractionated heparin in the prevention of deep vein thrombosis in patients with acute ischemic stroke. Design Double-blind randomized trial. Setting Seven Canadian university-affiliated hospitals. Participants Eighty-seven patients with acute ischemic stroke resulting in lower-limb paresis. Intervention Patients received either low-molecular-weight heparinoid, 750 anti-factor Xa units twice daily, or unfractionated heparin, 5000 units subcutaneously twice daily. Treatment was continued for 14 days or until hospital discharge if sooner. Measurements Deep vein thrombosis was diagnosed using 125I-labeled fibrinogen leg scanning and Impedance Plethysmography. Venography was indicated if either test was positive. Overt hemorrhage, major or minor, was assessed clinically. Results Venous thrombosis occurred in four patients (9%) given low-molecular-weight heparinoid and in 13 patients (31%) given heparin (relative risk reduction, 71%; 95% CI, 16% to 93%. The corresponding rates for proximal vein thrombosis were 4% and 12%, respectively (relative risk reduction, 63%; P greater than 0.2). The incidence of hemorrhage was 2% in both groups. Conclusion Low-molecular-weight heparinoid, given in a fixed dose of 750 anti-factor Xa units subcutaneously twice daily, is more effective than subcutaneous low-dose heparin for the prevention of deep vein thrombosis in patients with acute ischemic stroke.
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prevention of deep vein thrombosis after major knee surgery a randomized double blind trial comparing a low molecular weight heparin fragment enoxaparin to placebo
Thrombosis and Haemostasis, 1992Co-Authors: J R Leclerc, William H Geerts, Louis Desjardins, F Jobin, F Laroche, F Delorme, S Haviernick, S Atkinson, J BourgouinAbstract:Consecutive patients undergoing knee arthroplasty or tibial osteotomy at four participating hospitals received either enoxaparin, 30 mg subcutaneously every 12 h (n = 66) or an identical-appearing placebo (n = 65). All study medications started the morning after the operation and were continued up to a maximum of 14 days. Patients underwent surveillance with 125I-fibrinogen leg scanning and Impedance Plethysmography. Bilateral contrast venography was performed routinely at Day 14 or at time of discharge, if sooner. Deep vein thrombosis was detected by venography in 35 of 54 patients (65%) in the placebo group and in 8 of 41 patients in the enoxaparin group (19%), a risk reduction of 71%, P less than 0.0001. For the entire study group, deep vein thrombosis was detected by either venography of non-invasive tests in 37 of 64 patients (58%) in the placebo group and in 11 of 65 patients (17%) in the enoxaparin group, a risk reduction of 71%, P less than 0.0001. Proximal vein thrombosis was found in 19% of the placebo patients and in none of the enoxaparin patients, a risk reduction of 100%, P less than 0.001. Bleeding complications occurred in 5 of 65 patients (8%) in the placebo group and in 4 of 66 patients (6%) in the enoxaparin group, P = 0.71. There were no differences in the amount of blood loss, minimum hemoglobin levels and number of units of packed red cells given between the two treatment groups. We conclude that a fixed dose regimen of enoxaparin, started post-operatively, is an effective and safe regimen for reducing the frequency of deep vein thrombosis after major knee surgery.
