Moll, Stephan

Background Hereditary and acquired thrombophilia are risk factors for venous thromboembolism (VTE). Whether testing helps guide management decisions is controversial. Objective These evidence-based guidelines from the American Society of Hematology (ASH) intend to support decision making about thrombophilia testing. Methods ASH formed a multidisciplinary guideline panel covering clinical and methodological expertise and minimizing bias from conflicts of interest. The McMaster University GRADE Centre provided logistical support, performed systematic reviews, and created evidence profiles and evidence-to-decision tables. The Grading of Recommendations Assessment, Development, and Evaluation approach (GRADE) was used. Recommendations were subject to public comment. Results The panel agreed on 23 recommendations regarding thrombophilia testing and associated management. Nearly all recommendations are based on very low certainty in the evidence due to modeling assumptions. Conclusions The panel issued a strong recommendation against testing the general population before starting combined oral contraceptives (COCs) and conditional recommendations for thrombophilia testing in the following scenarios: (a) patients with VTE associated with nonsurgical major transient or hormonal risk factors; (b) patients with cerebral or splanchnic venous thrombosis, in settings where anticoagulation would otherwise be discontinued; (c) individuals with a family history of antithrombin, protein C, or protein S deficiency when considering thromboprophylaxis for minor provoking risk factors and for guidance to avoid COCs/hormone replacement therapy; (d) pregnant women with a family history of high-risk thrombophilia types; and (e) patients with cancer at low or intermediate risk of thrombosis and with a family history of VTE. For all other questions, the panel provided conditional recommendations against testing for thrombophilia.

Abstract Background: Compared to Whites, Black-Americans may have a 40% higher incidence of idiopathic VTE. However, whether other VTE characteristics vary by race is uncertain. Objective: To compare demographic and baseline characteristics among White- and Black-Americans with VTE. Methods: Using a standardized data-collection form, demographic and baseline characteristics were prospectively collected from consecutive consenting patients enrolled in seven Thrombosis and Hemostasis Centers from August 2003 to March 2008. For patients with objectively diagnosed VTE, demographic and baseline characteristics were compared among White- and Black-American VTE patients, both overall, and by age and gender. Results: Among 1960 White- and 368 Black-Americans with VTE, compared to Whites, Blacks had significantly less isolated DVT (73.9% vs. 86.5%, p<0.001) and significantly more PE ± DVT (45.1 vs. 39.6%, p=0.05). Blacks and Whites did not differ in mean age (43.4 vs. 44.3 years), but a significantly higher proportion of Black men VTE patients were in age groups 20–39 and 80+ years. Blacks and Whites differed significantly by gender, with a significantly higher proportion of Black women with VTE (69.8% vs. 59.1%, p=0.0001). Blacks had a significantly higher mean BMI (32.3 vs. 29.4 kg/m2, p<0.0001), a significantly lower proportion with recent surgery or trauma, active cancer and infection, and a significantly lower proportion with a family history of VTE or documented thrombophilia (solely due to reduced Factor V Leiden and Prothrombin G20210A prevalence). Conversely, Blacks had a significantly higher proportion with hypertension, hyperlipidemia, diabetes mellitus, chronic renal disease and dialysis, HIV and sickle cell disease. The two races did not differ significantly regarding the proportion with idiopathic VTE, CHF, CAD/MI, peripheral artery disease, stroke or other chronic neurological disease (i.e., cerebral palsy), chronic liver disease or autoimmune disease, including antiphospholipid syndrome. Compared to White women VTE patients, Black women VTE patients had a significantly lower proportion with recent surgery, trauma, infection, oral contraceptive use and possibly hormone therapy; and a significantly higher proportion with idiopathic VTE, hypertension, diabetes mellitus, chronic renal disease, HIV and sickle cell disease. Compared to White men VTE patients, Black men VTE patients did not differ significantly regarding recent surgery, trauma, cancer, infection or autoimmune disease, but Black men had a significantly higher proportion with hypertension, diabetes mellitus, HIV and sickle cell disease. Black and White men with VTE did not differ significantly regarding idiopathic VTE, CHF, CAD/MI, stroke, peripheral arterial disease and chronic renal disease. Conclusion: White- and Black-Americans with VTE differ significantly regarding demographic and baseline characteristics that may be risk factors for VTE.

Abstract Abstract 4000 Poster Board III-936 Background There is insufficient information regarding the epidemiology and outcomes of DVT in children. The CDC began a consented registry in August 2003 at eight pilot Centers for Thrombosis and Thrombophilia including six pediatric sites in order to assess the scope and severity of DVT morbidity in children. Methods Data for this analytic project were extracted from the CDC thrombosis registry. We performed a nested case-control study within the registry cohort. Children and adults are eligible to enroll onto this consented registry if they have a history of thrombosis, thrombophilia or a positive family history or either. DVT site, extent, recurrence and BMI were determined clinically. In addition, thrombophilia testing batteries, imaging protocols and determinations of PTS outcomes of DVT were made locally and criteria were not standardized among participating centers. Results As of March 2009 the CDC registry included 316 cases of DVT in infants and children (ages 0-21), and 2414 cases in adults (> 21). There were 16 cases reported to have lower extremity (LE) PTS in children and 184 in adults. Table 1 displays effects of thrombus site, recurrence and BMI on PTS prevalence. The proportion of LE DVT involving the inferior vena cava (IVC) was 5.5-fold higher in children compared to adults (11% vs 2%). Furthermore, among cases of IVC involvement, the prevalence of PTS following IVC thrombosis was remarkably higher in children compared with adults (38.9 vs 6.3%, P < 0.001). The prevalence of PTS following LE DVT overall in children did not differ from adults. Results for upper extremity DVT and resultant PTS were similar. Fifteen percent of children had recurrence. Increasing number of DVT events was associated with an increased risk of PTS. BMI was higher in children who developed PTS (p = 0.06; BMI > 28, OR 3.3 [1.08, 9.59]). In addition, thrombophilia was a risk factor for developing PTS in children (p = 0.02; OR = 2.9 [CI 1.03, 8.05]), with the highest risk determined with antiphospholipid syndrome (p = 0.02; OR = 3.4 [1.09, 9.93]) and protein C deficiency (p = 0.02, OR = 10.9 [0.84, 99.3]). Discussion Children with LE DVT demonstrate a high rate of IVC thrombosis, and a higher relative risk of PTS in cases of IVC involvement. Elevated BMI and thrombophilia augment the risk of PTS in children. The limitations of this study include the lack of standardization in DVT diagnostic and PTS evaluations. The study findings support application of standardized approaches to the diagnosis and follow-up evaluation of children with DVT in order to more meaningfully determine outcomes for future interventive trials. Disclosures: Moll: Ovation: Consultancy; GTC Biotherapeutics: Consultancy; Talecris: Consultancy.

Abstract Abstract 2305 Background. Recurrent venous thromboembolism (VTE) occurs in ∼30% of patients with spontaneous VTE after completion of a standard course of anticoagulant therapy. D-dimer levels and selected clinical parameters have been used to identify patients at low risk for recurrent VTE, who may safely discontinue antithrombotic therapy. We have used gene expression profiles to distinguish patients with a single VTE from patients with recurrent VTE. The purpose of this study was to extend this initial report and identify unique gene expression patterns from whole blood that correlate with different risk profiles for VTE recurrence. Methods. Patients with ≥1 prior VTE, with the first event occurring at age 18 years or older and >3 months from the most recent event were recruited for this study. Patients were allocated into 4 groups: (1) ‘low-risk’ patients had sustained ≥1 provoked VTE; (2) ‘moderate-risk’ patients had sustained 1 unprovoked VTE (with or without provoked VTE); (3) ‘high-risk’ patients had sustained ≥2 unprovoked VTE and had no evidence for antiphospholipid antibodies; and (4) antiphospholipid syndrome (APS) patients met established consensus criteria for APS. A similar number of individuals with no prior history of VTE were enrolled as a control population. Citrated plasma, serum and PAXgene RNA tubes were collected, processed and stored at −80°C until shipped to the CDC for analysis. Antiphospholipid testing was performed on all participants to confirm correct group distribution. Total RNA was isolated from whole blood drawn into PAXgene tubes. Following sample labeling and normalization, cRNA samples were hybridized to Illumina HT-12 Beadchips to assay whole genome gene expression with over 47,000 probes against human transcripts. Two hundred and twenty six unique samples passed initial quality control measures. Quality assessment of raw data was done using GenomeStudio. The raw data files were converted to a text file using the IlluminaExpression FileCreator in GenePattern and then log transformed, normalized and median-centered using Cluster. Both unsupervised (hierarchical clustering using Cluster) and supervised analyses (SAM) were used to identify genes that were differentially expressed between the groups. GATHER was used to help understand the biological processes and gene ontology of the gene lists generated by Cluster and SAM. Results. A total of 226 participants were enrolled into the study. Characteristics of the patient groups are summarized in the Table. Demographically, the groups were similar except that patients in the high-risk group tended to be older and were more likely male. The number of events per patient, and the proportion on anticoagulant therapy, increased with the risk group. Antiphospholipid antibodies were detected in several patients in each of the 3 non-APS VTE patient groups, but in most cases this was a single test positive; antiphospholipid antibodies were present in the majority of patients with APS, typically with more than one test positive (37 of 45 with complete testing, 82%). Preliminary analysis of the gene expression profiles using an unsupervised clustering by gene on the high-risk and low-risk groups identified multiple genes that distinguished the two groups, including 18 immune response genes identified by GATHER. These two patient groups were also distinguished by SAM analysis, and multiple genes in the MAPK signaling pathway that separated the two groups were identified by the KEGG pathways in GATHER. Additional analyses are being performed on all of the groups. Conclusions. Whole blood gene expression profiling can be used to develop profiles that distinguish patients with VTE who differ based on their risk of recurrent events. Individual genes identified in these profiles may provide biological insights into the molecular basis for recurrent VTE. Disclosures: Heit: Daiichi Sankyo: Honoraria; Ortho-McNeil Janssen: Honoraria; Covidien: Honoraria. Manco-Johnson:Octapharma AG: Consultancy; Bayer: Research Funding.

Abstract Abstract 4219 Background: Clinical characteristics associated with abdominal vein thrombosis (including hepatic, portal, and mesenteric veins; renal veins; and inferior vena cava [IVC]) overlap with characteristics associated with deep vein thrombosis (DVT) in the legs and pulmonary embolism (PE) but also possess unique attributes. These characteristics may differ between adult and pediatric patient groups. Methods: Using a standardized data-collection form, demographic and baseline characteristics were prospectively collected from consecutive consenting patients enrolled within one of seven Thrombosis and Hemostasis Centers over a seven-year period, August 2003 to June 2010. Patients with intra-abdominal venous thrombosis (defined as abdominal and renal veins, and IVC) were divided into pediatric (age <18 years) and adult (age ≥18 years) groups and compared to patients in the same age ranges with lower extremity DVT and/or PE. RESULTS: As of June 2010, the Patient Registry contained a total of 3105 patients with venous thromboembolism (VTE). A total of 270 patients had intra-abdominal thrombosis (9%) compared to 2276 with lower extremity DVT and/or PE (73%). Of the intra-abdominal clots, pediatric patients were more likely to have IVC thrombus (22 of 42; 52%) than adults (38 of 228; 17%; p<0.0001); conversely, pediatric patients were less likely to have hepatic, portal, and mesenteric thrombosis (n=25; 60%) than adults (n=195; 86%, p<.0001). For adult patients, proportionately more women had abdominal thrombosis (157 of 228; 68.9%) than DVT/PE (1306 of 2140; 61%; p=0.02); in contrast, comparable numbers of female pediatric patients had abdominal thrombosis (20 of 42; 47.6%) and DVT/PE (68 of 136; 50%). The mean age for patients having abdominal thrombosis was lower than patients having DVT/PE for both adults (38.3 vs 43.0 yrs; p<0.0001) and pediatric patients (9.0 vs 11.9 yrs; p=0.014). Similarly, the mean body mass index was lower for patients having abdominal thrombosis than patients having DVT/PE for both adults (28.1 vs 30.8; p<0.0001) and pediatric patients (21.5 vs. 24.7; p=0.05). There were no relationships with race, ethnicity, or inherited thrombophilic disorders. In adults, autoimmune conditions (21.9 vs 13.6; p=0.0007) and recent surgery (14.0 vs 9.2; p=0.02) were more common in patients with abdominal thrombosis, whereas, hyperlipidemia was more frequent in patients with DVT/PE (8.3 vs 13.2; p=0.04). None of these relationships were seen in the pediatric patients, but trauma was more frequently seen in pediatric patients with DVT/PE than abdominal thrombosis. Sixty-one adult (26.8%) and 6 pediatric patients (14.3%) had another VTE elsewhere, with most occurring after the initial event (21 DVT and 7 PE). Similar proportions of adult and pediatric patients had arterial thromboembolic events for both abdominal thrombosis and DVT/PE. CONCLUSIONS: Adult patients with abdominal thrombosis are more likely female, have hepatic, portal and/or mesenteric vein thrombosis, and common co-morbid conditions include recent surgery and autoimmune disorders. Pediatric patients are evenly divided between male and female, more commonly have IVC thrombosis, and co-morbid conditions include recent trauma. Both adult and pediatric patients with abdominal thrombosis tend to be younger and have a lower BMI than patients with DVT and/or PE. We also found a high rate of concurrent thrombosis in both adult and pediatric patients with abdominal thrombosis. In summary, patients with abdominal thrombosis display different clinical characteristics when compared to those with DVT/PE, specifically in terms of gender, location of thrombosis, and associated co-morbidities. Some of these differences, such as higher rates of IVC thrombosis in pediatric patients with abdominal thrombosis, might be caused by variance between genetic and anatomic factors. Further studies are warranted to explain these differences. Disclosures: Kulkarni: Novo Nordisk: Membership on an entity's Board of Directors or advisory committees, Participate in clinical trials. Philipp:Baxter: Research Funding; Wyeth: Research Funding; Octapharma: Research Funding. Ortel:Sanofi-Aventis: Consultancy, Research Funding; Ortho-McNeil: Consultancy; GlaxoSmithKline: Research Funding; Eisai: Research Funding; Pfizer: Research Funding.

Introduction Parenteral anticoagulants may improve outcomes in patients with cancer by reducing risk of venous thromboembolic disease and through a direct antitumour effect. Study-level systematic reviews indicate a reduction in venous thromboembolism and provide moderate confidence that a small survival benefit exists. It remains unclear if any patient subgroups experience potential benefits. Methods and analysis First, we will perform a comprehensive systematic search of MEDLINE, EMBASE and The Cochrane Library, hand search scientific conference abstracts and check clinical trials registries for randomised control trials of participants with solid cancers who are administered parenteral anticoagulants. We anticipate identifying at least 15 trials, exceeding 9000 participants. Second, we will perform an individual participant data meta-analysis to explore the magnitude of survival benefit and address whether subgroups of patients are more likely to benefit from parenteral anticoagulants. All analyses will follow the intention-to-treat principle. For our primary outcome, mortality, we will use multivariable hierarchical models with patient-level variables as fixed effects and a categorical trial variable as a random effect. We will adjust analysis for important prognostic characteristics. To investigate whether intervention effects vary by predefined subgroups of patients, we will test interaction terms in the statistical model. Furthermore, we will develop a risk-prediction model for venous thromboembolism, with a focus on control patients of randomised trials. Ethics and dissemination Aside from maintaining participant anonymity, there are no major ethical concerns. This will be the first individual participant data meta-analysis addressing heparin use among patients with cancer and will directly influence recommendations in clinical practice guidelines. Major cancer guideline development organisations will use eventual results to inform their guideline recommendations. Several knowledge users will disseminate results through presentations at clinical rounds as well as national and international conferences. We will prepare an evidence brief and facilitate dialogue to engage policymakers and stakeholders in acting on findings. Trial registration number PROSPERO CRD42013003526.