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O8 Predicting DVT in pregnancy: out in “left” field?
3rd Women’s Health Issues in Thrombosis and Haemostasis O7 A study of peripartum haemostasis E. Lefkou1 , A. Mamopoulos2 , S. Masouridou2 , K. Parmar1 , A. Karagiannis2 , B.J. Hunt1 . 1 Haematology Department, Guy’s & St Thomas’ Hospital, London, UK, 2 3rd University Department of Obstetrics & Gynaecology, Hippokrateion Hospital, Thessaloniki, Greece Background: The major cause of maternal mortality and morbidity worldwide is obstetric haemorrhage (OH). Appropriate management requires understanding of normal haemostatic changes during labour. There are no major studies reporting peripartum haemostatic changes. Aim: The aim of this pilot study was to evaluate peripartum haemostatic changes in healthy women. Methods: Blood was collected from 20 women peripartum, into 0.102 M trisodium citrate tubes from the antecubital fossa using flawless venepuncture; (1) antepartum, (2) after delivery of placenta, (3) 24hrs post-partum and (4) 48 hrs post-partum. Plasma was aliquoted and stored in 70ºC until the following assays were performed: D-Dimer levels (Dade Behring, Sysmex UK), prothrombin fragments 1+2 (PF 1+2) (Dade Behring, Sysmex, UK), tissue plasminogen activator antigen (t-PA:Ag) (Biopool, Trinity Biotech, UK), prothrombin time (PT) (PT-Fib HS), activated partial thromboplastin time (APTT) (APTT micronized silica) and Clauss fibrinogen (Fib-C reagent), reagents from Instrumentation Laboratories Ltd UK. Results: Median (range) results are shown in the Table. Assay (normal ranges)
PF 1+2 D-Dimers (4 52 ug/l) (0.2 1.2 pmol/l)
Antepartum 231 (122 900) Labour 482 (117 1,044) Post Labour 24 h 309 (65 931) 48 h 235 (85 614)
PT t-PA:Ag APTT (pregnant (12 16 s) (26 38s) women: 3 11 g/ml)
Clauss fibrinogen (1.52 4.12 g/l)
570 12 (7.2 23) (352 1,533) 968 18 (480 1,858)* (8.6 40.6)*
12 (10 14) 13 (10 15)
31 5.2 (3.1 8.7) (24 36) 30 5.3 (2.2 9.8) (24 36)
568 7 (4 22.6)* (264 1,080)* 648 7 (3 18)* (371 2,287)
33 5.3 (4 11) 13 (10 16)* (27 41)* 12 31 5.7 (3.5 11) (10 16) (23 43)
*p < 0.05 using the Mann-Whitney U test between the 1st and each of the other three.
Conclusion: These findings demonstrate prothrombotic peripartum changes with shortened PT, APTT and increased fibrinogen levels, thrombin generation and fibrinolytic activity. t-PA antigen is most notably elevated immediately post delivery. O8 Predicting DVT in pregnancy: out in “left” field? W.S. Chan1 , A. Lee2 , F.A. Spencer2 , M. Crowther2 , M. Rodger3 , T. Ramsay4 , J.S. Ginsberg. 1 Department of Medicine, University of Toronto, Toronto, Ontario, Canada, 2 Department of Medicine, McMaster University, Hamilton, Ontario, Canada , 3 Department of Medicine, University of Ottawa & Clinical Epidemiology Unit, Ottawa Health Research Institute, Ottawa, Ontario, Canada, 4 Department of Epidemiology and Community Medicine, University of Ottawa & Clinical Epidemiology Unit, Ottawa Health Research Institute, Ottawa, Ontario, Canada Background: Clinicians’ assessment of pre-test probability based on subjective criteria or prediction rules, is central to the diagnosis of deep venous thrombosis (DVT). Pre-test probability assessment for DVT diagnosis has never been evaluated in pregnant patients. Objective: (a) To evaluate the accuracy of clinicians’ subjective assessment of pre-test probability for DVT diagnosis, and b) to identify prediction variables that could be used for pretest probability assessment in pregnant women with suspected DVT.
S133
Method: A cross-sectional analysis of a cohort study (in five Canadian Centres conducted over seven years) was performed. 194 unselected pregnant women with suspected first DVT were recruited for analysis. Diagnosis of DVT was established with abnormal compression ultrasound testing at presentation or on serial imaging. Pre-test probability by subjective assessment was recorded for each patient prior to knowledge of results. Measurements: The sensitivity, specificity, negative predictive value, and likelihood ratios of subjective pre-test probability assessment, and their corresponding 95% Confidence Intervals (CIs), were calculated based on the diagnosis of DVT. Patients were defined as being DVT-positive if they had a diagnostic compression ultrasound at initial or serial testing, or symptomatic venous thromboembolism on follow-up; patients with negative compression ultrasound at presentation and no venous thromboembolism on follow-up were categorized as DVT-negative. A prediction rule for assessing DVT was derived and an internal validation study performed to explore its performance. Results: Clinicians’ subjective assessment of pre-test probability categorized patients into two groups: a) low pre-test probability (two-thirds of patients) with a low prevalence of DVT (1.5%, 95%CI 0.05 5.4) with a NPV of 98.47% (95%CI 94.6 99.6), and b) non-low pre-test probability with a higher prevalence of DVT (24.6%, 95%CI 15.5 36.7). Three variables (symptoms in the left leg [L], calf circumference difference of 2 cm [E], first trimester presentation [Ft]) were highly predictive of DVT in pregnant patients. Conclusions: Subjective assessment of pre-test probability appears to exclude DVT when the pre-test probability is low. Moreover, three objective variables (“LEFt”) may improve the accuracy of the diagnosis of DVT in pregnancy. Prospective validation studies are needed. O9 Fondaparinux 2.5 mg for the treatment of symptomatic, isolated superficial thrombophlebitis (ST): preliminary baseline data from the randomized placebo-controlled CALISTO trial H. Decousus1 , A. Leizorovicz2 , P. Prandoni3 . 1 INSERM CIE3, EA3065, University Hospital of Saint-Etienne, France, 2 Clinical Pharmacology Department, Faculty RTH Laennec, Lyons, France, 3 Department of Medical and Surgical Sciences, University of Padua, Padua, Italy Aims: ST is a common disease, especially in women. Although it is associated with clinically significant venous thromboembolism (VTE), the optimal antithrombotic treatment remains unknown. We performed a large scale double-blind, randomized, placebo-controlled trial to evaluate the benefitrisk ratio of fondaparinux 2.5 mg subcutaneously once daily during 45 days in at least 2,500 patients with symptomatic, isolated ST of the lower limbs (without deep-vein thrombosis, DVT, or pulmonary embolism, PE) documented by compression ultrasound (CUS). We present preliminary blinded results of clinical characteristics of the first 2,109 randomized patients. Methods: The primary efficacy outcome is confirmed symptomatic VTE (a composite of PE, DVT, or recurrence or extension of ST with thrombus head <3 cm from the saphenofemoral junction) and/or all-cause death up to Day 45. Safety endpoints include major bleeding, clinically relevant non-major bleeding and death. Baseline data available as of September 2008 are presented. Results: Based on preliminary data, the median age of the population was 57.3 (range: 19 92) years, 37.5% were obese (BMI 30 kg/m2 ). Women represented 63.3% of the overall population. The main predisposing risk factors for ST were varicose veins and a history of ST. More than one ST was observed on baseline CUS in 19.4% of patients; ST was >30 cm in length in 22.4%, and the great saphenous vein was involved in 96.3%.
PF 1+2 D-Dimers (4 52 ug/l) (0.2 1.2 pmol/l)
Antepartum 231 (122 900) Labour 482 (117 1,044) Post Labour 24 h 309 (65 931) 48 h 235 (85 614)
PT t-PA:Ag APTT (pregnant (12 16 s) (26 38s) women: 3 11 g/ml)
Clauss fibrinogen (1.52 4.12 g/l)
570 12 (7.2 23) (352 1,533) 968 18 (480 1,858)* (8.6 40.6)*
12 (10 14) 13 (10 15)
31 5.2 (3.1 8.7) (24 36) 30 5.3 (2.2 9.8) (24 36)
568 7 (4 22.6)* (264 1,080)* 648 7 (3 18)* (371 2,287)
33 5.3 (4 11) 13 (10 16)* (27 41)* 12 31 5.7 (3.5 11) (10 16) (23 43)
*p < 0.05 using the Mann-Whitney U test between the 1st and each of the other three.
Conclusion: These findings demonstrate prothrombotic peripartum changes with shortened PT, APTT and increased fibrinogen levels, thrombin generation and fibrinolytic activity. t-PA antigen is most notably elevated immediately post delivery. O8 Predicting DVT in pregnancy: out in “left” field? W.S. Chan1 , A. Lee2 , F.A. Spencer2 , M. Crowther2 , M. Rodger3 , T. Ramsay4 , J.S. Ginsberg. 1 Department of Medicine, University of Toronto, Toronto, Ontario, Canada, 2 Department of Medicine, McMaster University, Hamilton, Ontario, Canada , 3 Department of Medicine, University of Ottawa & Clinical Epidemiology Unit, Ottawa Health Research Institute, Ottawa, Ontario, Canada, 4 Department of Epidemiology and Community Medicine, University of Ottawa & Clinical Epidemiology Unit, Ottawa Health Research Institute, Ottawa, Ontario, Canada Background: Clinicians’ assessment of pre-test probability based on subjective criteria or prediction rules, is central to the diagnosis of deep venous thrombosis (DVT). Pre-test probability assessment for DVT diagnosis has never been evaluated in pregnant patients. Objective: (a) To evaluate the accuracy of clinicians’ subjective assessment of pre-test probability for DVT diagnosis, and b) to identify prediction variables that could be used for pretest probability assessment in pregnant women with suspected DVT.
S133
Method: A cross-sectional analysis of a cohort study (in five Canadian Centres conducted over seven years) was performed. 194 unselected pregnant women with suspected first DVT were recruited for analysis. Diagnosis of DVT was established with abnormal compression ultrasound testing at presentation or on serial imaging. Pre-test probability by subjective assessment was recorded for each patient prior to knowledge of results. Measurements: The sensitivity, specificity, negative predictive value, and likelihood ratios of subjective pre-test probability assessment, and their corresponding 95% Confidence Intervals (CIs), were calculated based on the diagnosis of DVT. Patients were defined as being DVT-positive if they had a diagnostic compression ultrasound at initial or serial testing, or symptomatic venous thromboembolism on follow-up; patients with negative compression ultrasound at presentation and no venous thromboembolism on follow-up were categorized as DVT-negative. A prediction rule for assessing DVT was derived and an internal validation study performed to explore its performance. Results: Clinicians’ subjective assessment of pre-test probability categorized patients into two groups: a) low pre-test probability (two-thirds of patients) with a low prevalence of DVT (1.5%, 95%CI 0.05 5.4) with a NPV of 98.47% (95%CI 94.6 99.6), and b) non-low pre-test probability with a higher prevalence of DVT (24.6%, 95%CI 15.5 36.7). Three variables (symptoms in the left leg [L], calf circumference difference of 2 cm [E], first trimester presentation [Ft]) were highly predictive of DVT in pregnant patients. Conclusions: Subjective assessment of pre-test probability appears to exclude DVT when the pre-test probability is low. Moreover, three objective variables (“LEFt”) may improve the accuracy of the diagnosis of DVT in pregnancy. Prospective validation studies are needed. O9 Fondaparinux 2.5 mg for the treatment of symptomatic, isolated superficial thrombophlebitis (ST): preliminary baseline data from the randomized placebo-controlled CALISTO trial H. Decousus1 , A. Leizorovicz2 , P. Prandoni3 . 1 INSERM CIE3, EA3065, University Hospital of Saint-Etienne, France, 2 Clinical Pharmacology Department, Faculty RTH Laennec, Lyons, France, 3 Department of Medical and Surgical Sciences, University of Padua, Padua, Italy Aims: ST is a common disease, especially in women. Although it is associated with clinically significant venous thromboembolism (VTE), the optimal antithrombotic treatment remains unknown. We performed a large scale double-blind, randomized, placebo-controlled trial to evaluate the benefitrisk ratio of fondaparinux 2.5 mg subcutaneously once daily during 45 days in at least 2,500 patients with symptomatic, isolated ST of the lower limbs (without deep-vein thrombosis, DVT, or pulmonary embolism, PE) documented by compression ultrasound (CUS). We present preliminary blinded results of clinical characteristics of the first 2,109 randomized patients. Methods: The primary efficacy outcome is confirmed symptomatic VTE (a composite of PE, DVT, or recurrence or extension of ST with thrombus head <3 cm from the saphenofemoral junction) and/or all-cause death up to Day 45. Safety endpoints include major bleeding, clinically relevant non-major bleeding and death. Baseline data available as of September 2008 are presented. Results: Based on preliminary data, the median age of the population was 57.3 (range: 19 92) years, 37.5% were obese (BMI 30 kg/m2 ). Women represented 63.3% of the overall population. The main predisposing risk factors for ST were varicose veins and a history of ST. More than one ST was observed on baseline CUS in 19.4% of patients; ST was >30 cm in length in 22.4%, and the great saphenous vein was involved in 96.3%.