Impact of time since diagnosis and mortality rate on cancer-associated venous thromboembolism: the Scandinavian Thrombosis and Cancer (STAC) cohort.

Essentials Competing risk by death may lead to overestimation of venous thromboembolism (VTE) risk in cancers. We assessed the risk of VTE in cancer with and without accounting for competing risk by death. The risk of VTE was influenced by the mortality rate and the time since cancer diagnosis. Competing risk by death should be taken into account when exploring VTE risk in cancer. SUMMARY: Background Venous thromboembolism (VTE) is a common complication in cancer, and studies have suggested that aggressive cancers create the highest risk of VTE. However, competing risk by death may result in overestimation of VTE risk in patients with cancers associated with high mortality. Therefore, we estimated the risk of VTE by cancer site, accounting for the differential mortality between cancers. Methods The Scandinavian Thrombosis and Cancer cohort included 144 952 participants followed from 1993-1997 to 2008-2012. Incidence rates, cause-specific hazard ratios (HRs) and subdistribution HRs (SHRs) were assessed for overall cancer and by cancer site according to time intervals since cancer diagnosis. Results During follow-up, 14 272 subjects developed cancer, and 567 had cancer-related VTE. In cause-specific analyses, the VTE risk was highest in the first 6 months after cancer diagnosis (HR 17.5, 95% confidence interval [CI] 15.1-20.3), and declined rapidly thereafter. However, when mortality was taken into account, the risk was similar in the periods 6 months before (SHR 4.8, 95% CI 3.6-6.4) and 6 months after (SHR 4.6, 95% CI 3.9-5.4) cancer diagnosis. The range of the 2-year cumulative VTE incidence rates was substantially narrowed for all cancer sites after competing risk by death was taken into account (from 1-10% to 1-4%). Conclusion VTE risk by cancer site was influenced by the mortality rate and the time since cancer diagnosis. Our findings suggest that the cancer itself is a major contributor to VTE risk, and that competing risk by death should be taken into account when VTE risk in cancer is explored.

The impact of initial cancer stage on the incidence of venous thromboembolism: the Scandinavian Thrombosis and Cancer (STAC) Cohort.

Essentials Impact of cancer stage on venous thromboembolism (VTE) risk is not well-known in all cancers. The Scandinavian Thrombosis and Cancer Cohort provides person-time data and validated VTEs. Impact of cancer stage on VTE incidence tended to vary with cancer type. Cancer stage may not per se be a risk factor for VTE in all cancer types. SUMMARY: Background Absolute measures of the impact of cancer stage on the incidence of venous thromboembolism (VTE) in patients with distinct cancer types have not been investigated in a large population-based cohort study. Objectives To investigate differences in the incidence rates of objectively confirmed VTE according to the development of cancer in a large population-based cohort study. Cancer type and stage at the time of diagnosis were taken into account. Patients and Methods The Scandinavian Thrombosis and Cancer Cohort includes data regarding cancer types, stages and objectively confirmed VTE diagnoses among 144 952 participants followed from 1993 to 2012. We studied stage-specific incidence rates of VTE, and calculated incidence rate differences (IRDs) for VTE according to stages in patients with 10 types of solid cancer. Results During the entire follow-up, 335 VTEs occurred, of which 293 occurred within 5 years. The IRD of VTE in patients with distant metastasis as compared with those with localized disease indicated large variation depending on cancer type. The highest IRD was observed for pancreatic cancer (IRD of 187.0 × 10-3 person-years [p-y]; 95% confidence interval [CI] - 6.7 to 380.8), and the lowest IRD was observed for prostate cancer (IRD of 3.7 × 10-3 p-y; 95% CI - 7 to 15.2). Regional spread as compared with localized disease also indicated large variation depending on cancer type; the highest IRD was observed for uterine cancer (IRD of 37.6 × 10-3 p-y; 95% CI - 23.7 to 99), and the IRDs for breast and prostate cancer were close to zero. Conclusion More advanced cancer at the time of diagnosis was associated with a higher risk of VTE, but the strength of the associations differed substantially between cancer types.

Venous thrombosis in pancreaticobiliary tract cancer: outcome and prognostic factors.

BACKGROUND: The differences in outcome among cancer patients with incidental vs. symptomatic venous thromboembolism (VTE) are unknown. In this study, patients with extrahepatic pancreaticobiliary tract cancer (PBC) were selected for a prospective cohort study between February 2008 and February 2011. METHODS: At the time of cancer diagnosis, all patients were examined for deep vein thrombosis with bilateral compression ultrasonography (biCUS). Computed tomography pulmonary angiography was also performed to diagnose pulmonary embolisms. After inclusion, the patients were followed up with clinical examinations, blood collections, and biCUS. RESULTS: A total of 121 PBC patients were enrolled. At the time of cancer diagnosis, 15 patients had experienced a VTE (12.4%, 95% confidence interval [CI] 7.1-19.6), including six symptomatic and nine incidental cases. A total of 25 first-time VTE events were identified (20.7%; 95% CI 13.8-29.0). Patients with a VTE had reduced survival, with a median overall survival (OS) of 4.4 months (95% CI 2.2-11.5). The median OS of the patients with incidental VTE was 3.0 months (95% CI 0.1-15.0), which was not different from the median OS of the patients with symptomatic VTE (5.0 months; 95% CI 2.1-14.5). The median OS was 11.9 months (95% CI 8.1-14.7) in the PBC patients with no VTEs. CONCLUSION: The occurrence of a VTE event in a PBC patient within the first months of the disease is associated with significantly increased mortality.

Evaluation of back scatter interferometry, a method for detecting protein binding in solution.

Back Scatter Interferometry (BSI) has been proposed to be a highly sensitive and versatile refractive index sensor usable for analytical detection of biomarker and protein interactions in solution. However the existing literature on BSI lacks a physical explanation of why protein interactions in general should contribute to the BSI signal. We have established a BSI system to investigate this subject in further detail. We contribute with a thorough analysis of the robustness of the sensor including unwanted contributions to the interferometric signal caused by temperature variation and dissolved gasses. We report a limit of the effective minimum detectability of refractive index at the 10(-7) level. Long term stability was examined by simultaneously monitoring the temperature inside the capillary revealing an average drift of 2.0 × 10(-7) per hour. Finally we show that measurements on protein A incubated with immunoglobulin G do not result in a signal that can be attributed to binding affinities as otherwise claimed in literature.

Prevalence of venous thromboembolism at diagnosis of upper gastrointestinal cancer.

BACKGROUND: Venous thromboembolism (VTE) in patients with upper gastrointestinal (GI) cancer increases morbidity and mortality. This study aimed to determine the prevalence of VTE at diagnosis of upper GI cancer. METHODS: Patients admitted between February 2008 and February 2011 with upper GI cancer (pancreatic, extrahepatic biliary, lower oesophageal, gastro-oesophageal junction or gastric cancer) were investigated in a cross-sectional cohort study. At cancer diagnosis, all patients were examined for deep vein thrombosis (DVT) by means of bilateral compression ultrasonography. From February 2009 and onwards, computed tomographic pulmonary angiography (CTPA) was also performed for the diagnosis of pulmonary embolism (PE). RESULTS: Some 250 patients had ultrasonography; CTPA was performed in 143 patients on admission. DVT was detected in 13 (5·2 per cent) of the 250 patients, eight (3·2 per cent) of whom were asymptomatic. DVT was correlated with tumour location in the pancreaticobiliary tract (odds ratio (OR) 6·27, 95 per cent confidence interval 1·18 to 33·38; P = 0·031) and tumour stage IV (OR 19·34, 2·33 to 160·70; P = 0·006). PE was detected in 11 (7·7 per cent) of 143 patients, eight (5·6 per cent) of whom were asymptomatic. PE embolism was also significantly more common in patients with pancreaticobiliary tract cancer (OR 7·81, 1·28 to 47·62; P = 0·026) and in those with stage IV disease (OR 17·19, 1·83 to 161·50; P = 0·013). CONCLUSION: The prevalence of VTE at cancer diagnosis was significantly higher in patients with pancreaticobiliary tract cancer than in those with other forms of upper GI cancer, and in patients with advanced cancer stage.

Highly sensitive troponin T in patients with acute ischemic stroke.

BACKGROUND: Newly developed troponin assays have superior diagnostic and prognostic performance in acute coronary syndrome (ACS), when compared to conventional troponin assays; however, highly sensitive troponin has not been evaluated in patients with acute ischemic stroke. METHODS: Highly sensitive troponin T (hsTnT) was measured daily during the first 4 days in 193 consecutive patients with acute ischemic stroke without overt ACS or atrial fibrillation. The patients were previously tested normal with a fourth-generation TnT assay. The patients were followed for 47 months, with all-cause and cardiovascular mortality end-points. RESULTS: A total of 33.7% of the patients had hsTnT levels >14 ng/l following admission. Patients with increased hsTnT were older, had decreased hemoglobin levels and increased creatinine, NT-proBNP and CRP levels. hsTnT concentrations at admission were significantly higher in decedents than in survivors. After adjustment for stroke severity, C-reactive protein, age, NT-proBNP and prior heart and/or renal failure, hsTnT levels were not a significant predictor of long-term all-cause or cardiovascular mortality. CONCLUSION: Elevated levels of hsTnT are frequently present in patients with acute ischemic stroke previously tested normal with a fourth-generation TnT assay. hsTnT did not provide additional prognostic information in these subjects.

Heparin affinity of factor VIIa: implications on the physiological inhibition by antithrombin and clearance of recombinant factor VIIa.

Factor VIIa (FVIIa), a trypsin-like serine protease, plays an essential role in haemostasis by initiating the coagulation in complex with its cofactor, tissue factor (TF). The TF pathway inhibitor is the main physiological inhibitor of FVIIa-TF complex, but FVIIa can also be inhibited by antithrombin, although little is known about this process. Functional analyses by second order kinetic determination and identification of FVIIa-antithrombin complex by electrophoresis, evaluating the effect of different cofactors: pentasaccharide, low molecular weight heparin (LMWH) and unfractionated heparin (UFH), confirmed that any activation of antithrombin significantly enhanced the inhibition of FVIIa. The analysis of the binding of FVIIa to heparin by surface plasmon resonance identified a high affinity interaction under physiologic conditions (K(D)=3.38 µM, with 0.15M of ionic strength) strongly dependent on Ca(2+) and ionic strength. This interaction was verified in cell models, indicating that FVIIa also binds to the surface of endothelial cells with similar requirements. Structural modeling suggests the presence of a potential exosite II in FVIIa. However, the binding of heparin did not display significant changes on both the intrinsic fluorescence and the associated functional consequences of FVIIa. These results indicate that FVIIa binds to exposed glycosaminglycans of the endothelium through an exosite II, structurally similar to that reported for thrombin and suggested for FIXa. This binding may favor its inhibition by antithrombin in the absence of TF, contributing to the physiological control of this protease. This process may also play an important role in the clearance of recombinant FVIIa administered to patients.

Paediatric arterial ischaemic stroke and cerebral sinovenous thrombosis in Denmark 1994-2006: a nationwide population-based study.

AIM: To assess the incidence rates (IR), clinical characteristics, risk factors, treatment and outcomes of paediatric arterial ischaemic stroke (AIS) and cerebral sinovenous thrombosis (CSVT). METHODS: Using population-based, nationwide medical registries, we identified all patients aged 0-18 years at the time of hospitalization with first-ever AIS and/or CSVT in Denmark between 1994 and 2006. Medical records were retrieved and reviewed. RESULTS: We identified 211 patients with AIS and 40 patients with CSVT corresponding to IRs of 1.33 (95% CI 1.16-1.52) and 0.25 (95% CI 0.19-0.34) per 100,000 person-years, respectively. The IRs peaked in infancy (<1 year) for both AIS and CSVT with an additional peak among adolescents (15-18 years) for CSVT. The IR of AIS increased 3.9% per year (p=0.036), whereas no changes were found for CSVT. In total, 48.2% of the patients received antithrombotic treatment; no major complications were observed. All-cause and thrombosis-related 30-day case fatality ratios were 3.6% and 2.4%, respectively; neurological sequelae were found in 56.2% of patients. CONCLUSION: The IR of AIS was highest in infants and had increased with 3.9% annually during the observation period. The IR of CSVT had an additional peak in adolescence and remained unchanged over time.

Effects of acrolein, a natural occurring aldehyde, on the anticoagulant serpin antithrombin.

We studied the effect of acrolein, an alpha,beta-unsaturated aldehyde that causes adduct-modification of lysine, cysteine, and histidine residues, on antithrombin, a key anticoagulant serpin. Intrinsic fluorescence, functionality (anti-FXa and anti-IIa activity), heparin affinity and conformational features of plasma and purified antithrombin were evaluated. In vivo experiments were carried out in mice. Intrinsic fluorescence showed a two-step conformational change. Acrolein, even at low dose, impaired the anticoagulant function of purified antithrombin by affecting its heparin affinity. However, higher concentrations of acrolein and long incubations are required to cause mild functional effects on plasma antithrombin and mice.

Smoking and venous thromboembolism: a Danish follow-up study.

BACKGROUND: Large-scale prospective studies are needed to assess whether smoking is associated with venous thromboembolism (VTE) (i.e. deep venous thrombosis and pulmonary embolism) independently of established risk factors. OBJECTIVE: To investigate the association between smoking and the risk of VTE among middle-aged men and women. METHODS: From 1993 to 1997, 27,178 men and 29,875 women, aged 50-64 years and born in Denmark, were recruited into the Danish prospective study 'Diet, Cancer and Health'. During follow-up, VTE cases were identified in the Danish National Patient Registry. Medical records were reviewed and only verified VTE cases were included in the study. Baseline data on smoking and potential confounders were included in gender stratified Cox proportional hazard models to asses the association between smoking and the risk of VTE. The analyses were adjusted for alcohol intake, body mass index, physical activity, and in women also for use of hormone replacement therapy. RESULTS: During follow-up, 641 incident cases of VTE were verified. We found a positive association between current smoking and VTE, with a hazard ratio of 1.52 (95% CI, 1.15-2.00) for smoking women and 1.32 (95% CI, 1.00-1.74) for smoking men, and a positive dose-response relationship. Former smokers had the same hazard as never smokers. CONCLUSIONS: Smoking was an independent risk factor for VTE among middle-aged men and women. Former smokers have the same risk of VTE as never smokers, indicating acute effects of smoking, and underscoring the potential benefits of smoking cessation.

Converting venous acid-base and oxygen status to arterial in patients with lung disease.

The aim of the present study was to evaluate a method for calculating arterial values of pH, carbon dioxide tension (P(CO(2))) and oxygen tension (P(O(2))) from peripheral venous values. In total, 40 patients were studied. Arterial and peripheral venous blood were sampled at a department of respiratory diseases. Arterial values were calculated from venous, and measured and calculated values of arterial pH, P(CO(2)) and P(O(2)) were compared. Measured and calculated values of pH and P(CO(2)) correlated well, with the difference between them having a very small bias and standard deviation (pH -0.001+/-0.013, P(CO(2)) -0.09+/-0.28 kPa) within those considered acceptable for laboratory equipment and clinical practice. All but four patients had peripheral oxygen saturation (S(p,O(2)))

The influence of anaemia on stroke prognosis and its relation to N-terminal pro-brain natriuretic peptide.

Anaemia is a negative prognostic factor for patients with heart failure and impaired renal function, but its role in stroke patients is unknown. Furthermore, anaemia has been shown to influence the level of N-terminal pro-brain natriuretic peptide (NT-proBNP), but this is only investigated in patients with heart failure, not in stroke patients. Two-hundred-and-fifty consecutive, well-defined ischemic stroke patients were investigated. Mortality was recorded at 6 months follow-up. Anaemia was diagnosed in 37 patients (15%) in whom stroke severity was worse than in the non-anaemic group, whilst the prevalence of renal affection, smoking and heart failure was lower. At 6 months follow-up, 23 patients were dead, and anaemia had an odds ratio of 4.7 when adjusted for age, Scandinavian Stroke Scale and a combined variable of heart and/or renal failure and/or elevation of troponin T using logistic regression. The median NT-proBNP level in the anaemic group was significantly higher than in the non-anaemic group, and in a multivariate linear regression model, anaemia remained an independent predictor of NT-proBNP. Conclusively, anaemia was found to be a negative prognostic factor for ischemic stroke patients. Furthermore, anaemia influenced the NT-proBNP level in ischemic stroke patients, an important aspect when interpreting NT-proBNP in these patients.

Serial measurements of N-terminal pro-brain natriuretic peptide after acute ischemic stroke.

BACKGROUND: The exact time-course of N-terminal pro-brain natriuretic peptide (NT-proBNP) and the prognostic importance in the immediate phase of ischemic stroke have not been established. METHODS: NT-proBNP was measured daily from admission to day 5 and again at 6-month follow-up in 250 consecutive patients with acute ischemic stroke. RESULTS: NT-proBNP peaked the day after onset of symptoms (p = 0.007) followed by a decrease until day 5 (p = 0.001, ANOVA). At 6-month follow-up the difference in the level of NT-proBNP was unchanged compared to day 5 (p = 0.42). NT-proBNP levels > or =615 pg/ml at day 2 after onset of symptoms was associated with 6-month mortality. CONCLUSION: NT-proBNP peaks the day after onset of symptoms in patients with acute ischemic stroke. A single measurement of NT-proBNP appears to be an indicator of 6-month mortality.

Positive impact of hormone replacement therapy on the fibrinolytic system: a long-term randomized controlled study in healthy postmenopausal women.

BACKGROUND: The mechanisms by which postmenopausal hormone replacement therapy (HRT) may influence risk of cardiovascular disease are still unclear. Impaired fibrinolytic function is associated with an enhanced risk of cardiovascular disease and therefore the effect of HRT on fibrinolysis may be of importance. OBJECTIVES: To investigate the prolonged effect of HRT on the fibrinolytic system and to determine whether two common polymorphisms in the plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (t-PA) genes modulate this effect. METHODS: Healthy postmenopausal women (n = 248) were randomized to HRT (n = 122) or no substitution (n = 126) 5 years prior to investigation. RESULTS: Significantly higher values of t-PA activity and lower values of PAI-1 activity and PAI-1 antigen were found in the HRT group compared with the control group. This effect was independent of smoking and without influence from the two common polymorphisms PAI-1 -675(4G/5G) and t-PA intron8ins311. Furthermore, no difference between opposed estrogen (with norethisterone acetate as the gestagen component) and unopposed estrogen therapy was found. Both an intention-to-treat and a per-protocol analysis were performed and similar results were obtained. CONCLUSIONS: Long-term treatment with HRT in healthy postmenopausal women was found to be associated with a beneficial fibrinolytic profile. This effect was found independent of smoking status, opposed and unopposed estrogen therapy had equal effect, and no influence of the two common polymorphisms PAI-1-675(4G/5G) and t-PA intron8ins311 was found. This effect of HRT on fibrinolytic capacity may be one of the beneficial effects of HRT in relation to cardiovascular diseases.

Effect of long-term hormone replacement therapy on tissue factor pathway inhibitor and thrombin activatable fibrinolysis inhibitor in healthy postmenopausal women: a randomized controlled study.

It was recently reported from the Women's Health Initiative that healthy women using combined hormone replacement therapy (HRT) for 5 years have an increased cardiovascular risk. We hypothesize that the increased risk is confined to subgroups of atherosclerotic women. Such women may have higher arterial tissue factor expression and higher thrombin formation, and changes in tissue factor pathway coagulation inhibitor (TFPI) and thrombin activatable fibrinolysis inhibitor (TAFI) may be deleterious. Healthy postmenopausal women (n = 719) were randomized to hormone therapy [n = 357; opposed (n = 290) and unopposed (n = 67)] or no treatment (n = 362). Plasma TFPI and TAFI and the TFPI -287T/C and TAFI -438G/A polymorphisms were measured 5-6 years after randomization. Concentrations of TFPI were significantly lower in the hormone group than in the control group (P < 0.001) and in all genotypes of the TFPI polymorphism. Overall, concentrations of TAFI did not differ between the two groups but were reduced by hormone therapy in homozygotes for the rare TAFI -438 A allele (P < 0.05). The hormone effects on TFPI and TAFI were similar in smokers and non-smokers and in women using unopposed and opposed therapy. The observed decrease in TFPI may contribute to the increased cardiovascular risk associated with HRT.

A cellular model system of differentiated human myotubes.

The aim of this study was to select an effective and stable protocol for the differentiation of human satellite cells (Sc) and to identify the optimal time period for the experimental use of differentiated human Sc-cultures. In order to identify the differentiation conditions which give a good survival of myotubes and a high grade of differentiation, Sc-cultures were induced to differentiate in media supplemented with either 2% fetal calf serum (FCS) 2% horse serum (HS) or 10% HS. Based on higher CK-activities in cultures differentiating in FCS-supplemented media compared to horse sera, fetal calf serum was chosen to induce differentiation. The ATP, DNA and protein content increased during the first 4 days after induction of differentiation and was followed by a period with minor changes. The maximal differences of ATP, DNA and protein between days 4-10 were evaluated and the differences in the three components were found to be less than 20% of the average value with a certainity of more than 0.9. Day 8-myotubes were investigated morphologically and were found immunoreactive for fast myosin, and expressed areas with clear cross striation. We recommend the use of differentiated Sc-cultures in the period from day 4 to 8 after induction of differentiation as only minor differentation-related changes will take place in the cells during this period of time.