Genomic and transcriptomic association studies identify 16 novel susceptibility loci for venous thromboembolism.

Venous thromboembolism (VTE) is a significant contributor to morbidity and mortality. To advance our understanding of the biology contributing to VTE, we conducted a genome-wide association study (GWAS) of VTE and a transcriptome-wide association study (TWAS) based on imputed gene expression from whole blood and liver. We meta-analyzed GWAS data from 18 studies for 30 234 VTE cases and 172 122 controls and assessed the association between 12 923 718 genetic variants and VTE. We generated variant prediction scores of gene expression from whole blood and liver tissue and assessed them for association with VTE. Mendelian randomization analyses were conducted for traits genetically associated with novel VTE loci. We identified 34 independent genetic signals for VTE risk from GWAS meta-analysis, of which 14 are newly reported associations. This included 11 newly associated genetic loci (C1orf198, PLEK, OSMR-AS1, NUGGC/SCARA5, GRK5, MPHOSPH9, ARID4A, PLCG2, SMG6, EIF5A, and STX10) of which 6 replicated, and 3 new independent signals in 3 known genes. Further, TWAS identified 5 additional genetic loci with imputed gene expression levels differing between cases and controls in whole blood (SH2B3, SPSB1, RP11-747H7.3, RP4-737E23.2) and in liver (ERAP1). At some GWAS loci, we found suggestive evidence that the VTE association signal for novel and previously known regions colocalized with expression quantitative trait locus signals. Mendelian randomization analyses suggested that blood traits may contribute to the underlying risk of VTE. To conclude, we identified 16 novel susceptibility loci for VTE; for some loci, the association signals are likely mediated through gene expression of nearby genes.

Effect of a near-universal hospitalization-based prophylaxis regimen on annual number of venous thromboembolism events in the US.

The annual number of US venous thromboembolism (VTE) events, the number of potentially preventable events, and the effect of hospitalization-based prophylaxis are uncertain. We estimated VTE attack (incident plus recurrent VTE) rates and the total annual number of US VTE events related and unrelated to hospitalization using Rochester Epidemiology Project resources to identify all Olmsted County, Minnesota, residents with incident or recurrent VTE over the 6-year period 2005-2010. The average annual VTE attack rates related and unrelated to hospitalization were 282 and 8 per 10 000 person-years, respectively. The estimated average number of US VTE events was 495 669 per year (48% unrelated to hospitalization). Among Olmsted County residents hospitalized at a Mayo Clinic hospital from 2005 to 2010, the proportion of patients receiving VTE prophylaxis or with an indication that prophylaxis was unnecessary increased from ∼40% in 2005 to ∼90% by 2010. The annual age- and sex-adjusted hospitalization-related (in-hospital) VTE attack rates from 2005 to 2010 ranged from 251 to 306 (1155 to 1751) per 10 000 person-years (bed-years) and did not change significantly. The median durations of hospitalization and in-hospital prophylaxis were 3 days and 70 hours, respectively. A total of 75% of VTE events occurred after hospital discharge, with a 19.5-day median time to VTE. Additional efforts are needed to identify the individual inpatient and outpatient at high risk for incident and recurrent VTE and target (longer duration) primary and secondary prophylaxis to high-risk individuals who would benefit most.

Correction to: Assessing the causal relationship between obesity and venous thromboembolism through a Mendelian Randomization study.

The co-author name Immaculata DeVivo was incorrectly published. The correct name is given below.

Diagnostic laboratory standardization and validation of platelet transmission electron microscopy.

Platelet transmission electron microscopy (PTEM) is considered the gold standard test for assessing distinct ultrastructural abnormalities in inherited platelet disorders (IPDs). Nevertheless, PTEM remains mainly a research tool due to the lack of standardized procedures, a validated dense granule (DG) count reference range, and standardized image interpretation criteria. The aim of this study was to standardize and validate PTEM as a clinical laboratory test. Based on previously established methods, we optimized and standardized preanalytical, analytical, and postanalytical procedures for both whole mount (WM) and thin section (TS) PTEM. Mean number of DG/platelet (plt), percentage of plts without DG, platelet count (PC), mean platelet volume (MPV), immature platelet fraction (IPF), and plt light transmission aggregometry analyses were measured on blood samples from 113 healthy donors. Quantile regression was used to estimate the reference range for DG/plt, and linear regression was used to assess the association of DG/plt with other plt measurements. All PTEM procedures were standardized using commercially available materials and reagents. DG interpretation criteria were established based on previous publications and expert consensus, and resulted in improved operator agreement. Mean DG/plt was stable for 2 days after blood sample collection. The median within patient coefficient of variation for mean DG/plt was 22.2%; the mean DG/plt reference range (mid-95th %) was 1.2-4.0. Mean DG/plt was associated with IPF (p = .01, R2 = 0.06) but not age, sex, PC, MPV, or plt maximum aggregation or primary slope of aggregation (p > .17, R2 < 0.02). Baseline ultrastructural features were established for TS-PTEM. PTEM was validated using samples from patients with previously established diagnoses of IPDs. Standardization and validation of PTEM procedures and interpretation, and establishment of the normal mean DG/plt reference range and PTEM baseline ultrastructural features, will facilitate implementation of PTEM as a valid clinical laboratory test for evaluating ultrastructural abnormalities in IPDs.

Assessing the causal relationship between obesity and venous thromboembolism through a Mendelian Randomization study.

Observational studies have shown an association between obesity and venous thromboembolism (VTE) but it is not known if observed associations are causal, due to reverse causation or confounding bias. We conducted a Mendelian Randomization study of body mass index (BMI) and VTE. We identified 95 single nucleotide polymorphisms (SNPs) that have been previously associated with BMI and assessed the association between genetically predicted high BMI and VTE leveraging data from a previously conducted GWAS within the INVENT consortium comprising a total of 7507 VTE cases and 52,632 controls of European ancestry. Five BMI SNPs were associated with VTE at P < 0.05, with the strongest association seen for the FTO SNP rs1558902 (OR 1.07, 95% CI 1.02-1.12, P = 0.005). In addition, we observed a significant association between genetically predicted BMI and VTE (OR = 1.59, 95% CI 1.30-1.93 per standard deviation increase in BMI, P = 5.8 × 10-6). Our study provides evidence for a causal relationship between high BMI and risk of VTE. Reducing obesity levels will likely result in lower incidence in VTE.

Pharmacogenomics of estrogens on changes in carotid artery intima-medial thickness and coronary arterial calcification: Kronos Early Estrogen Prevention Study.

Prior to the initiation of menopausal hormone treatment (MHT), genetic variations in the innate immunity pathway were found to be associated with carotid artery intima-medial thickness (CIMT) and coronary arterial calcification (CAC) in women (n = 606) enrolled in the Kronos Early Estrogen Prevention Study (KEEPS). Whether MHT might affect these associations is unknown. The association of treatment outcomes with variation in the same 764 candidate genes was evaluated in the same KEEPS participants 4 yr after randomization to either oral conjugated equine estrogens (0.45 mg/day), transdermal 17ß-estradiol (50 µg/day), each with progesterone (200 mg/day) for 12 days each month, or placebo pills and patch. Twenty SNPs within the innate immunity pathway most related with CIMT after 4 yr were not among those associated with CIMT prior to MHT. In 403 women who completed the study in their assigned treatment group, single nucleotide polymorphisms (SNPs) within the innate immunity pathway were found to alter the treatment effect on 4 yr change in CIMT (i.e., significant interaction between treatment and genetic variation in the innate immunity pathway; P < 0.001). No SNPs by treatment effects were observed with changes of CAC >5 Agatston units after 4 yr. Results of this study suggest that hormonal status may interact with genetic variants to influence cardiovascular phenotypes, specifically, the pharmacogenomic effects within the innate immunity pathway for CIMT.

Predictors of venous thromboembolism recurrence and bleeding among active cancer patients: a population-based cohort study.

Active cancer is the major predictor of venous thromboembolism (VTE) recurrence, but further stratification of recurrence risk is uncertain. In a population-based cohort study of all Olmsted County, Minnesota, residents with active cancer-related incident VTE during the 35-year period from 1966 to 2000 who survived 1 day or longer, we estimated VTE recurrence, bleeding on anticoagulant therapy, and survival and tested cancer and noncancer characteristics and secondary prophylaxis as predictors of VTE recurrence and bleeding, using Cox proportional hazards modeling. Of 477 patients, 139 developed recurrent VTE over the course of 1533 person-years of follow-up. The adjusted 10-year cumulative VTE recurrence rate was 28.6%. The adjusted 90-day cumulative incidence of major bleeding on anticoagulation was 1.9%. Survival was significantly worse for patients with cancer who had recurrent VTE (particularly pulmonary embolism) and with bleeding on anticoagulation. In a multivariable model, brain, lung, and ovarian cancer; myeloproliferative or myelodysplastic disorders; stage IV pancreatic cancer; other stage IV cancer; cancer stage progression; and leg paresis were associated with an increased hazard, and warfarin therapy was associated with a reduced hazard, of recurrent VTE. Recurrence rates were significantly higher for cancer patients with 1 or more vs no predictors of recurrence, suggesting these predictors may be useful for stratifying recurrence risk.

The epidemiology of venous thromboembolism.

Venous thromboembolism (VTE) is categorized by the U.S. Surgeon General as a major public health problem. VTE is relatively common and associated with reduced survival and substantial health-care costs, and recurs frequently. VTE is a complex (multifactorial) disease, involving interactions between acquired or inherited predispositions to thrombosis and VTE risk factors, including increasing patient age and obesity, hospitalization for surgery or acute illness, nursing-home confinement, active cancer, trauma or fracture, immobility or leg paresis, superficial vein thrombosis, and, in women, pregnancy and puerperium, oral contraception, and hormone therapy. Although independent VTE risk factors and predictors of VTE recurrence have been identified, and effective primary and secondary prophylaxis is available, the occurrence of VTE seems to be relatively constant, or even increasing.

Longitudinal effects of menopausal hormone treatments on platelet characteristics and cell-derived microvesicles.

Activated platelets serve as a catalyst for thrombin generation and a source of vasoactive and mitogenic factors affecting vascular remodeling. Oral menopausal hormone treatments (MHT) may carry greater thrombotic risk than transdermal products. This study compared effects of oral and transdermal MHT on platelet characteristics, platelet proteins, and platelet-derived microvesicles (MV) in recently menopausal women. Platelets and MV were prepared from blood of a subset of women (n = 117) enrolled in the Kronos Early Estrogen Prevention Study prior to and after 48 months of treatment with either oral conjugated equine estrogen (0.45 mg/day), transdermal 17ß-estradiol (50 µg/day), each with intermittent progesterone (200 mg/day for 12 days a month), or placebo pills and patch. Platelet count and expression of platelet P-selectin and fibrinogen receptors were similar across groups. An aggregate measure of 4-year change in vasoactive and mitogenic factors in platelet lysate, by principle component analysis, indicated significantly lower values in both MHT groups compared to placebo. Increases in numbers of tissue factor positive and platelet-derived MV were significantly greater in the transdermal compared to placebo group. MHT was associated with significantly reduced platelet content of vasoactive and mitogenic factors representing a potential mechanism by which MHT may affect vascular remodeling. Various hormonal compositions and doses of MHT could differentially regulate nuclear transcription in bone marrow megakaryocytes and non-genomic pathways in circulating platelets thus determining numbers and characteristics of circulating MV. Thrombotic risk associated with oral MHT most likely involves liver-derived inflammatory/coagulation proteins rather than circulating platelets per se.

A genome-wide association study for venous thromboembolism: the extended cohorts for heart and aging research in genomic epidemiology (CHARGE) consortium.

Venous thromboembolism (VTE) is a common, heritable disease resulting in high rates of hospitalization and mortality. Yet few associations between VTE and genetic variants, all in the coagulation pathway, have been established. To identify additional genetic determinants of VTE, we conducted a two-stage genome-wide association study (GWAS) among individuals of European ancestry in the extended cohorts for heart and aging research in genomic epidemiology (CHARGE) VTE consortium. The discovery GWAS comprised 1,618 incident VTE cases out of 44,499 participants from six community-based studies. Genotypes for genome-wide single-nucleotide polymorphisms (SNPs) were imputed to approximately 2.5 million SNPs in HapMap and association with VTE assessed using study-design appropriate regression methods. Meta-analysis of these results identified two known loci, in F5 and ABO. Top 1,047 tag SNPs (P ≤ 0.0016) from the discovery GWAS were tested for association in an additional 3,231 cases and 3,536 controls from three case-control studies. In the combined data from these two stages, additional genome-wide significant associations were observed on 4q35 at F11 (top SNP rs4253399, intronic to F11) and on 4q28 at FGG (rs6536024, 9.7 kb from FGG; P < 5.0 × 10(-13) for both). The associations at the FGG locus were not completely explained by previously reported variants. Loci at or near SUSD1 and OTUD7A showed borderline yet novel associations (P < 5.0 × 10(-6) ) and constitute new candidate genes. In conclusion, this large GWAS replicated key genetic associations in F5 and ABO, and confirmed the importance of F11 and FGG loci for VTE. Future studies are warranted to better characterize the associations with F11 and FGG and to replicate the new candidate associations.

Identification of a novel percent mammographic density locus at 12q24.

Percent mammographic density adjusted for age and body mass index (BMI) is one of the strongest risk factors for breast cancer and has a heritable component that remains largely unidentified. We performed a three-stage genome-wide association study (GWAS) of percent mammographic density to identify novel genetic loci associated with this trait. In stage 1, we combined three GWASs of percent density comprised of 1241 women from studies at the Mayo Clinic and identified the top 48 loci (99 single nucleotide polymorphisms). We attempted replication of these loci in 7018 women from seven additional studies (stage 2). The meta-analysis of stage 1 and 2 data identified a novel locus, rs1265507 on 12q24, associated with percent density, adjusting for age and BMI (P = 4.43 × 10(-8)). We refined the 12q24 locus with 459 additional variants (stage 3) in a combined analysis of all three stages (n = 10 377) and confirmed that rs1265507 has the strongest association in the 12q24 region (P = 1.03 × 10(-8)). Rs1265507 is located between the genes TBX5 and TBX3, which are members of the phylogenetically conserved T-box gene family and encode transcription factors involved in developmental regulation. Understanding the mechanism underlying this association will provide insight into the genetics of breast tissue composition.

The endothelial protein C receptor (PROCR) Ser219Gly variant and risk of common thrombotic disorders: a HuGE review and meta-analysis of evidence from observational studies.

The endothelial protein C receptor (EPCR) limits thrombus formation by enhancing activation of the protein C anticoagulant pathway, and therefore may play a role in the etiology of thrombotic disorders. The rs867186 single-nucleotide polymorphism in the PROCR gene (g.6936A > G, c.4600A > G), resulting in a serine-to-glycine substitution at codon 219, has been associated with reduced activation of the protein C pathway, although its association with thrombosis risk remains unclear. The present study is a highly comprehensive systematic review and meta-analysis, including unpublished genome-wide association study results, conducted to evaluate the evidence for an association between rs867186 and 2 common thrombotic outcomes, venous thromboembolism (VTE) and myocardial infarction (MI), which are hypothesized to share some etiologic pathways. MEDLINE, EMBASE, and HuGE Navigator were searched through July 2011 to identify relevant epidemiologic studies, and data were summarized using random-effects meta-analysis. Twelve candidate genes and 13 genome-wide association studies were analyzed (11 VTE and 14 MI, including 37,415 cases and 84,406 noncases). Under the additive genetic model, the odds of VTE increased by a factor of 1.22 (95% confidence interval, 1.11-1.33, P < .001) for every additional copy of the G allele. No evidence for association with MI was observed.

Health-related quality of life in children and young adults with post-thrombotic syndrome: results from a cross-sectional study.

OBJECTIVE: While post-thrombotic syndrome (PTS) is increasingly recognized in children with a history of deep vein thrombosis (DVT), its impact on the health-related quality of life (HRQoL) is unknown. Our objective was to evaluate the association between the PTS and HRQoL by surveying a cohort of patients treated at our institution for DVT. MATERIALS/METHODS: All unique pediatric patients (0-18 years) treated for a DVT at the Mayo Clinic during the 15-year period, 1995-2009 were identified. A previously validated PTS survey instrument and age appropriate Pediatric Quality of Life inventory, version 4 (PedsQL 4.0) were mailed to eligible patients. Linear regression models were fit to compare the HRQoL scores between PTS groups (none, mild, moderate/severe), after adjusting for the presence of potential covariates. RESULTS: Of the 90 respondents, 65 (72%) reported signs and/or symptoms of PTS. Mean age (± SD) at DVT diagnosis and survey completion were 12.8 (± 6.1) and 19.3 (± 7.7) years, respectively. Self-report PedsQL 4.0 module was completed by 79 patients, and 34 guardians completed the parent-proxy module. Patients with moderate to severe PTS reported significantly worse total HRQoL score (mean ± SD, 71.3 ± 13.4) as compared to patients with mild PTS (84.8 ± 14.2) and no PTS (83.4 ± 14) (P = 0.001). CONCLUSION: Moderate to severe PTS has a significant impact on self-reported HRQoL as measured using the generic PedsQL 4.0. Further research is warranted to develop a venous disease-specific quality of life measure for children with a history of DVT.

Association of GATA4 sequence variation with alcohol dependence.

To further explore reports of association of alcohol dependence and response to acamprosate treatment with the GATA4 rs13273672 single nucleotide polymorphism (SNP), we genotyped this and 10 other GATA4 SNPs in 816 alcohol-dependent cases and 1248 controls. We tested for association of alcohol dependence with the 11 SNPs individually and performed a global test for association using a principle components analysis. Our analyses demonstrate significant association between GATA4 and alcohol dependence at the gene level (P = 0.009) but no association with rs13273672. Further studies are needed to identify potential causal GATA4 variation(s) and the functional mechanism(s) contributing to this association.

Genetic polymorphisms associated with carotid artery intima-media thickness and coronary artery calcification in women of the Kronos Early Estrogen Prevention Study.

Menopausal hormone treatment (MHT) may limit progression of cardiovascular disease (CVD) but poses a thrombosis risk. To test targeted candidate gene variation for association with subclinical CVD defined by carotid artery intima-media thickness (CIMT) and coronary artery calcification (CAC), 610 women participating in the Kronos Early Estrogen Prevention Study (KEEPS), a clinical trial of MHT to prevent progression of CVD, were genotyped for 13,229 single nucleotide polymorphisms (SNPs) within 764 genes from anticoagulant, procoagulant, fibrinolytic, or innate immunity pathways. According to linear regression, proportion of European ancestry correlated negatively, but age at enrollment and pulse pressure correlated positively with CIMT. Adjusting for these variables, two SNPs, one on chromosome 2 for MAP4K4 gene (rs2236935, ß = 0.037, P value = 2.36 × 10(-06)) and one on chromosome 5 for IL5 gene (rs739318, ß = 0.051, P value = 5.02 × 10(-05)), associated positively with CIMT; two SNPs on chromosome 17 for CCL5 (rs4796119, ß = -0.043, P value = 3.59 × 10(-05); rs2291299, ß = -0.032, P value = 5.59 × 10(-05)) correlated negatively with CIMT; only rs2236935 remained significant after correcting for multiple testing. Using logistic regression, when we adjusted for waist circumference, two SNPs (rs11465886, IRAK2, chromosome 3, OR = 3.91, P value = 1.10 × 10(-04); and rs17751769, SERPINA1, chromosome 14, OR = 1.96, P value = 2.42 × 10(-04)) associated positively with a CAC score of >0 Agatston unit; one SNP (rs630014, ABO, OR = 0.51, P value = 2.51 × 10(-04)) associated negatively; none remained significant after correcting for multiple testing. Whether these SNPs associate with CIMT and CAC in women randomized to MHT remains to be determined.

Heparin and warfarin anticoagulation intensity as predictors of recurrence after deep vein thrombosis or pulmonary embolism: a population-based cohort study.

To test recommended anticoagulation measures as predictors of 180-day venous thromboembolism (VTE) recurrence, we identified all Olmsted County, MN residents with incident VTE over the 14-year period of 1984-1997, and followed each case (N = 1166) forward in time for VTE recurrence. We tested the activated partial thromboplastin time (APTT), international normalized ratio (INR), and other measures of heparin and warfarin anticoagulation as predictors of VTE recurrence while controlling for baseline and time-dependent characteristics using Cox proportional hazards modeling. Overall, 1026 (88%) and 989 (85%) patients received heparin and warfarin, respectively, and 85 (8%) developed VTE recurrence. In multivariable analyses, increasing proportions of time on heparin with an APTT ≥ 0.2 anti-X(a) U/mL and on warfarin with an INR ≥ 2.0 were associated with significant reductions in VTE recurrence, while the hazard with active cancer was significantly increased. Time from VTE onset to heparin start, duration of overlapping heparin and warfarin, and inferior vena cava (IVC) filter placement were not independent predictors of recurrence. At a heparin dose ≥ 30 000 U/d, the median proportion of time with an APTT ≥ 0.2 anti-X(a) U/mL was 92%, suggesting that routine APTT monitoring and heparin dose adjustment may be unnecessary. In summary, lower-intensity heparin and standard-intensity warfarin anticoagulation are effective in preventing VTE recurrence.

Association of the PDYN gene with alcohol dependence and the propensity to drink in negative emotional states.

Synthetic κ-opioid receptor (KOR) agonists induce dysphoric and pro-depressive effects and variations in the KOR (OPRK1) and prodynorphin (PDYN) genes have been shown to be associated with alcohol dependence. We genotyped 23 single nucleotide polymorphisms (SNPs) in the PDYN and OPRK1 genes in 816 alcohol-dependent subjects and investigated their association with: (1) negative craving measured by a subscale of the Inventory of Drug Taking Situations; (2) a self-reported history of depression; (3) the intensity of depressive symptoms measured by the Beck Depression Inventory-II. In addition, 13 of the 23 PDYN and OPRK1 SNPs, which were previously genotyped in a set of 1248 controls, were used to evaluate association with alcohol dependence. SNP and haplotype tests of association were performed. Analysis of a haplotype spanning the PDYN gene (rs6045784, rs910080, rs2235751, rs2281285) revealed significant association with alcohol dependence (p = 0.00079) and with negative craving (p = 0.0499). A candidate haplotype containing the PDYN rs2281285-rs1997794 SNPs that was previously associated with alcohol dependence was also associated with negative craving (p = 0.024) and alcohol dependence (p = 0.0008) in this study. A trend for association between depression severity and PDYN variation was detected. No associations of OPRK1 gene variation with alcohol dependence or other studied phenotypes were found. These findings support the hypothesis that sequence variation in the PDYN gene contributes to both alcohol dependence and the induction of negative craving in alcohol-dependent subjects.

Noncardiac vascular disease in rheumatoid arthritis: increase in venous thromboembolic events?

OBJECTIVE: To investigate the incidence of noncardiac vascular disease in a community-based incidence cohort of patients with rheumatoid arthritis (RA) and compare it to that in the general population and to investigate trends in the incidence of noncardiac vascular disease in patients with RA. METHODS: A population-based inception cohort of patients with incident RA between January 1, 1980 and December 31, 2007 in Olmsted County, Minnesota and a cohort of non-RA subjects from the same population base was assembled and followed up until December 31, 2008. Venous thromboembolic, cerebrovascular, and peripheral arterial events were ascertained by medical record review. RESULTS: The study population included 813 patients with RA with a mean±SD age of 55.9±15.7 years (68% women) and an average length of followup of 9.6±6.9 years. Compared to non-RA subjects of similar age and sex, patients diagnosed as having RA between 1995 and 2007 had a higher incidence (%) of venous thromboembolism (cumulative incidence±SE 6.7±1.7 versus 2.8±1.1, respectively; P=0.005) but similar rates of cerebrovascular and peripheral arterial events. Among patients with RA, the incidence of venous thromboembolic, cerebrovascular, and peripheral arterial events was similar in the 1995-2007 time period compared to the 1980-1994 time period. CONCLUSION: Our findings indicate that the incidence of venous thromboembolism is increased in patients with RA compared to non-RA subjects. The incidence of cerebrovascular events and peripheral vascular disease events is similar in patients with RA compared to non-RA subjects. Among patients with RA, the incidence of noncardiac vascular disease has remained stable in recent decades.

Incidence and predictors of venous thromboembolism after debulking surgery for epithelial ovarian cancer.

OBJECTIVE: The aim of this study was to determine the incidence and the risk factors of venous thromboembolism (VTE) within 30 days after primary surgery for epithelial ovarian cancer (EOC). METHODS: In a historical cohort study, we estimated the postoperative 30-day cumulative incidence of VTE among consecutive Mayo Clinic patients undergoing primary cytoreduction for EOC between January 2, 2003, and December 29, 2008. We tested perioperative patient characteristics and process-of-care variables (defined by the National Surgical Quality Improvement Program, >130 variables) as potential predictors of postoperative VTE using the Cox proportional hazards modeling. RESULTS: Among 569 cases of primary EOC cytoreduction and/or staging and no recent VTE, 35 developed symptomatic VTE within 30 days after surgery (cumulative incidence = 6.5%; 95% confidence interval, 4.4%-8.6%). Within the cohort, 95 (16.7%) received graduated compression stockings (GCSs), 367 (64.5%) had sequential compression devices + GCSs, and 69 (12.1%) had sequential compression devices + GCSs + postoperative heparin, with VTE rates of 1.1%, 7.4%, and 5.8%, respectively (P = 0.07, χ(2) test). The remaining 38 (6.7%) received various other chemical and mechanical prophylaxis regimens. In the multivariate analysis, current or past tobacco smoking, longer hospital stay, and a remote history of VTE significantly increased the risk for postoperative VTE. CONCLUSIONS: Venous thromboembolism is a substantial postoperative complication among women with EOC, and the high cumulative rate of VTE within 30 days after primary surgery suggests that a more aggressive strategy is needed for VTE prevention. In addition, because longer hospital stay is independently associated with a higher risk for VTE, methods to decrease length of stay and minimize factors that contribute to prolonged hospitalization are warranted.

Three-month cumulative incidence of thromboembolism and bleeding after periprocedural anticoagulation management of arterial vascular bypass patients.

The objective of this study was to determine 3-month cumulative incidence of peri-procedural thromboembolism (TE) including graft occlusion, and peri-procedural bleeding for chronically anticoagulated vascular bypass graft (BG) patients requiring temporary warfarin interruption for an invasive procedure. Appropriate peri-procedural management of patients receiving chronic warfarin therapy to preserve lower extremity arterial BG patency is unknown. In a protocol driven, cohort study design, all BG patients referred to the Mayo Clinic Thrombophilia Center for peri-procedural anticoagulation (1997-2007) were followed forward in time to estimate the 3-month cumulative incidence of TE and bleeding. Decisions to provide "bridging" low molecular weight heparin (LMWH) were individualized based on estimated risk of TE and bleeding. There were 78 BG patients (69 ± 10 years; 38% women), of whom 73% had a distal autogenous and 53% had prosthetic BG; 45% received antiplatelet therapy. Peri-procedural LMWH was prescribed for 77% of patients and did not vary by BG distal anastomosis location or type. The 3-month cumulative incidence of TE was 5.1% (95% CI 1.4-12.6), including two BG occlusions, one DVT, and one myocardial infarction. Major bleeding occurred in 1 patient (1.28%, 95% CI 0.0-6.94). One patient died due to heart failure. TE and bleeding did not differ by bridging status. The 3-month cumulative incidence of TE among BG patients in whom warfarin is temporarily interrupted for an invasive procedure may be higher than in other "bridging" populations (atrial fibrillation, prosthetic heart valve, venous thromboembolism). This finding underscores the often tenuous nature of distal bypass grafts necessitating an aggressive approach to peri-procedural anticoagulation management.