Small-for-gestational-age birth and maternal plasma antioxidant levels in mid-gestation: a nested case-control study.

OBJECTIVE: To assess whether maternal plasma antioxidant levels in mid-pregnancy are associated with small-for-gestational-age (SGA) birth. DESIGN: Case-control study nested within a population-based cohort study. SETTING: Four hospitals in Montreal, Canada. POPULATION: Pregnant women recruited before 24 weeks of gestation, whose pregnancies were not complicated by pre-eclampsia or preterm delivery. METHODS: Blood samples were obtained at 24-26 weeks and assayed for nutritionally derived antioxidant levels in SGA cases (n = 324) and randomly selected controls with birthweights between the 25th and 75th centiles (n = 672). We performed logistic regression analyses using the standardised z-score of each antioxidant as the main independent variable, after summing highly correlated antioxidants or combining via principle component analysis. We adjusted for risk factors for SGA that were associated with antioxidant levels. MAIN OUTCOME MEASURES: SGA, birthweight <10th centile for gestational age and sex. RESULTS: Retinol was positively associated with risk of SGA (adjusted odds ratio [OR] 1.41; 95% confidence interval [95% CI] 1.22-1.63, per SD increase). Carotenoids (log of the sum of ß-carotene, lutein/zeaxanthin, α- and ß-cryptoxanthin) were negatively associated with SGA (adjusted OR 0.64; 95% CI 0.54-0.78, per SD increase). We found no significant associations between SGA and lycopene or any of the forms of vitamin E assessed, including α-tocopherol, corrected α-tocopherol (per nmol/l of low-density lipoprotein articles), or γ-tocopherol. CONCLUSIONS: Elevated retinol may be associated with an increased risk of SGA, whereas elevated carotenoid levels may reduce the risk. A better understanding of the nature of these associations is required, however, before recommending specific nutritional interventions in an attempt to prevent SGA birth.

The VEINES-QOL/Sym questionnaire is a reliable and valid disease-specific quality of life measure for deep vein thrombosis in elderly patients.

PURPOSE: To prospectively evaluate the psychometric properties of the Venous Insufficiency Epidemiological and Economic Study (VEINES-QOL/Sym) questionnaire, an instrument to measure disease-specific quality of life and symptoms in elderly patients with deep vein thrombosis (DVT), and to validate a German version of the questionnaire. METHODS: In a prospective multicenter cohort study of patients aged ≥ 65 years with acute venous thromboembolism, we used standard psychometric tests and criteria to evaluate the reliability, validity, and responsiveness of the VEINES-QOL/Sym in patients with acute symptomatic DVT. We also performed an exploratory factor analysis. RESULTS: Overall, 352 French- and German-speaking patients were enrolled (response rate of 87 %). Both language versions of the VEINES-QOL/Sym showed good acceptability (missing data, floor and ceiling effects), reliability (internal consistency, item-total and inter-item correlations), validity (convergent, discriminant, known-groups differences), and responsiveness to clinical change over time in elderly patients with DVT. The exploratory factor analysis of the VEINES-QOL/Sym suggested three underlying dimensions: limitations in daily activities, DVT-related symptoms, and psychological impact. CONCLUSIONS: The VEINES-QOL/Sym questionnaire is a practical, reliable, valid, and responsive instrument to measure quality of life and symptoms in elderly patients with DVT and can be used with confidence in prospective studies to measure outcomes in such patients.

Risk of prostate cancer death in long-term users of warfarin: a population-based case-control study.

PURPOSE: Recent evidence suggests that warfarin use may be associated with a reduced risk of prostate cancer. We aimed to determine whether exposure to warfarin is also associated with a reduced risk of prostate cancer death. METHODS: A nested case-control study was conducted within a population-based cohort of 10,012 men aged ≥50 years with newly diagnosed prostate cancer between 1985 and 2002 and with no history of cancer since 1970 using the linked records of Saskatchewan Health and Saskatchewan Cancer Agency registry. We identified 2,309 cases who died of prostate cancer during follow-up. For each case, one control alive at the time of the case's death and matched for length of follow-up (±6 months) was randomly selected. Prescription counts were used to define warfarin exposure. Multivariate conditional logistic regression analysis was used to calculate the adjusted incidence rates of prostate cancer death in relation to warfarin use while adjusting for confounding by age, year of prostate cancer diagnosis, clinical stage and grade of cancer at diagnosis, Chronic Disease Score, and use of warfarin before diagnosis. RESULTS: Ever use of warfarin following a diagnosis of prostate cancer was associated with an adjusted rate ratio of 1.44 (95 % confidence interval (CI) 1.33-1.84) for prostate cancer death. The adjusted rate ratio with one-year use of warfarin was 1.77 (95 % CI 1.25-2.50) compared to never use. The unadjusted rate ratio with five-year use of warfarin was 0.64 (95 % CI 0.40-1.00) and remained unchanged in the adjusted analysis (0.65, 95 % CI 0.37-1.13), although no longer statistically significant. CONCLUSION: Our study does not provide conclusive evidence for a protective effect of long-term warfarin on prostate cancer-specific mortality. Moreover, short-term warfarin use may be associated with an increased risk of prostate cancer death.

Measuring functional limitations after venous thromboembolism: Optimization of the Post-VTE Functional Status (PVFS) Scale.

INTRODUCTION: We recently proposed a scale for assessment of patient-relevant functional limitations following an episode of venous thromboembolism (VTE). Further development of this post-VTE functional status (PVFS) scale is still needed. METHODS: Guided by the input of VTE experts and patients, we refined the PVFS scale and its accompanying manual, and attempted to acquire broad consensus on its use. RESULTS: A Delphi analysis was performed involving 53 international VTE experts with diverse scientific and clinical backgrounds. In this process, the number of scale grades of the originally proposed PVFS scale was reduced and descriptions of the grades were improved. After these changes, a consensus was reached on the number/definitions of the grades, and method/timing of the scale assessment. The relevance and potential impact of the scale was confirmed in three focus groups totaling 18 VTE patients, who suggested additional changes to the manual, but not to the scale itself. Using the improved manual, the κ-statistics between PVFS scale self-reporting and its assessment via the structured interview was 0.75 (95%CI 0.58-1.0), and 1.0 (95%CI 0.83-1.0) between independent raters of the recorded interview of 16 focus groups members. CONCLUSION: We improved the PVFS scale and demonstrated broad consensus on its relevance, optimal grades, and methods of assessing among international VTE experts and patients. The interobserver agreement of scale grade assignment was shown to be good-to-excellent. The PVFS scale may become an important outcome measure of functional impairment for quality of patient care and in future VTE trials.

Scoring and psychometric validation of the Perception of Anticoagulant Treatment Questionnaire (PACT-Q).

BACKGROUND: The 'Perception of Anti-Coagulant Treatment Questionnaire' (PACT-Q) was developed to assess patients' expectations of, and satisfaction with their anticoagulant treatment. This questionnaire needs to be finalised and psychometrically validated. METHODS: The PACT-Q was included in the United States, The Netherlands and France into three phase III multinational clinical trials conducted to evaluate efficacy and safety of a new long-acting anticoagulant drug (idraparinux) compared to vitamin K antagonist (VKA). PACT-Q was administered to patients with deep venous thrombosis (DVT), atrial fibrillation (AF) or pulmonary embolism (PE) at Day 1, to assess patients' expectations, and at 3 and 6 months to assess patients' satisfaction and treatment convenience and burden. The final structure of the PACT-Q (Principal Component Analysis--PCA--with Varimax Rotation) was first determined and its psychometric properties were then measured with validity of the structure (Multitrait analysis), internal consistency reliability (Cronbach's alpha coefficients) and known-group validity. RESULTS: PCA and multitrait analyses showed the multidimensionality of the "Treatment Expectations" dimension, comprising 7 items that had to be scored independently. The "Convenience" and "Burden of Disease and Treatment" dimensions of the hypothesised original structure of the questionnaire were combined, thus resulting in 13 items grouped into the single dimension "Convenience". The "Anticoagulant Treatment Satisfaction" dimension remained unchanged and included 7 items. All items of the "Convenience" and "Anticoagulant Treatment Satisfaction" dimensions displayed good convergent and discriminant validity. The internal consistency reliability was good, with a Cronbach's alpha of 0.84 for the "Convenience" dimension, and 0.76 for the "Anticoagulant Treatment Satisfaction" dimension. Known-group validity was good, especially with regard to occurrence of thromboembolic events within 3 months from randomisation. CONCLUSION: The PACT-Q is a valid and reliable instrument that allows the assessment of patients' expectations and satisfaction regarding anticoagulant treatment, as well as their opinion about treatment convenience of use. Its two-part structure--assessment of expectations at baseline in the first part, and of convenience, burden and treatment satisfaction in the second--was validated and displays good and stable psychometric properties. These results are not sufficient to recommend the use of satisfaction as primary endpoint in clinical trials; further validation work is needed to support the interpretation of PACT-Q dimension scores. However, this first validation makes the PACT-Q an appropriate measure for use in clinical and pharmacoepidemiological research, as well as in real-life studies. TRIAL REGISTRATION: (ClinicalTrials.gov numbers, NCT00067093, NCT00062803 and NCT00070655).

Development of a clinical prediction model for the postthrombotic syndrome in a prospective cohort of patients with proximal deep vein thrombosis.

Essentials We developed a prediction model for postthrombotic syndrome (PTS) after deep vein thrombosis (DVT). High risk predictors were iliac vein DVT, BMI>35 and moderate-severe Villalta category. Patients with a score ≥4 had an odds ratio of 5.9 (95% CI 2.1-16.6) for PTS. SOX-PTS score may select DVT patients for close monitoring or aggressive strategies to treat DVT. SUMMARY: Background Postthrombotic syndrome (PTS) is a chronic complication that develops in 20-50% of patients after deep vein thrombosis (DVT). Although individual risk factors for PTS have been characterized, the ability to predict which DVT patients are likely to develop PTS remains limited. Objective To develop a clinical prediction score for PTS in patients with DVT. Methods The derivation cohort consisted of participants in the SOX Trial, a randomized double-blind placebo-controlled trial of elastic compression stockings versus placebo stockings worn for 2 years after DVT to prevent PTS in patients with a first proximal DVT, enrolled in 24 community and tertiary-care hospitals from 2004 to 2010. Multivariable logistic regression analysis of baseline characteristics was performed. The outcome was the occurrence of PTS, diagnosed starting from 6 months or later according to Ginsberg's criteria. Results Seven hundred and sixty-two patients were included in the analysis. The median follow-up was 728 days. The model includes three independent predictors, and has a range of possible scores from 0 to 5. High-risk predictors were: index DVT in the iliac vein; body mass index of ≥ 35 kg m-2 ; and moderate-severe Villalta severity category at DVT diagnosis. As compared with patients with a score of 0, those with a score of ≥ 4 had an odds ratio of 5.9 (95% confidence interval 2.1-16.6) for developing PTS. Conclusions To our knowledge, this is the first clinical prediction score for PTS. We identified three independent predictors that, when combined, predicted PTS risk after a first proximal DVT. The SOX-PTS score requires external validation before it can be considered for clinical use.

Determining the minimal clinically important difference for the PEmbQoL questionnaire, a measure of pulmonary embolism-specific quality of life.

Essentials The minimal clinically important difference (MCID) for PEmbQoL has not yet been determined. We estimated the MCID for PEmbQoL and its subscales via anchor- and distribution-based approaches. Our results indicate that MCID for PEmbQoL appears to be 15 points. Our work enables interpretation of changes or differences in PEmbQoL. SUMMARY: Background Pulmonary embolism (PE) reduces quality of life (QOL). The PEmbQoL questionnaire, a PE-related QOL measure, was recently developed and validated and has been used to quantify disease-specific QOL in clinical studies of patients with PE. However, to date, interpretation of PEmbQoL scores has been limited by a lack of information on the minimal clinically important difference (MCID) of this measure. Objective To determine the MCID for PEmbQoL and its subscales using anchor-based and distribution-based approaches. Methods We analyzed data from the ELOPE Study, a prospective, multicenter cohort study of long-term outcomes after a first episode of acute PE. At baseline and 1, 3, 6 and 12 months after PE, we measured generic QOL (SF-36), PE-specific QOL (PEmbQoL) and dyspnea severity (UCSD Shortness of Breath Questionnaire). We used time-varying repeated-measures mixed-effect models to estimate anchor-based MCID and effect sizes to estimate distribution-based MCID. Results Eighty-two patients participated in this sub-study. Their mean age was 49.4 years, 60% were male and 84% had PE diagnosed in an outpatient setting. Using both anchor- and distribution-based approaches, the MCID for PEmbQoL appears to be 15 points. Based on this MCID, 42%, 59%, 66% and 75% of patients experienced at least one MCID unit of improvement in PEmbQoL from baseline to 1, 3, 6 and 12 months, respectively. Conclusion Our results provide new information on the MCID of PEmbQoL, a PE-specific QOL questionnaire that can be used by researchers and clinicians to measure and interpret changes in PE-specific QOL over time, or as an outcome in clinical trials.

Frequency of renal impairment, advanced age, obesity and cancer in venous thromboembolism patients in clinical practice.

BACKGROUND: Low-molecular-weight heparin (LMWH) dosed by weight is recommended as first-line therapy for the initial treatment of venous thromboembolism (VTE) and as monotherapy for long-term treatment of cancer-related VTE. In 'special populations' such as those with renal impairment or the elderly, weight-based dosing may be excessive, and capping the dose in obese patients may lead to inadequate dosing. OBJECTIVES: We determined the frequency of 'special population' characteristics (renal impairment, advanced age, obesity) and cancer among VTE patients in clinical practice, and assessed whether these characteristics appeared to influence the type and dose of anticoagulants prescribed. METHODS: During 2004-2005, among consecutive patients with VTE at two large Canadian hospitals, the proportions with the above characteristics were calculated and treatments prescribed were determined. RESULTS: Of 524 VTE patients, 31% were aged > 75 years. Moderate renal impairment [creatinine clearance (CrCl) 30-59 mL min(-1)] was present in 20% of patients, and severe renal impairment (CrCl < 30 mL min(-1)) in 5% of patients. LMWH was prescribed to 67% of patients with severe renal impairment and to 83% of patients with moderate renal impairment. Body weight was > 100 kg in 15% of patients. Underdosing of LMWH by > 10% was documented in 36% of such patients compared with 8% of patients < 100 kg (P < 0.001). Among 26% of patients with active cancer, only one-third were prescribed LMWH monotherapy. CONCLUSIONS: In clinical practice, renal impairment, advanced age, obesity and cancer are frequently present in patients with VTE. A considerable proportion of these patients may not receive the optimal type or dose of medication to treat VTE.

A pilot study of central venous catheter survival in cancer patients using low-molecular-weight heparin (dalteparin) and warfarin without catheter removal for the treatment of upper extremity deep vein thrombosis (The Catheter Study).

BACKGROUND: Central venous catheters in patients with cancer are associated with development of deep vein thrombosis (DVT); however, there is no accepted standard treatment. OBJECTIVES: To assess the safety and effectiveness of a management strategy for central venous catheter-related DVT in cancer patients consisting of dalteparin and warfarin without the need for line removal. PATIENTS/METHODS: Patients older than 18 years of age with an active malignancy and who had symptomatic, acute, objectively documented UEDVT were eligible. Patients were treated with dalteparin 200 IU kg(-1) per day for 5-7 days and warfarin with a target International Normalized Ratio of 2.0-3.0. Patients were followed for 3 months for recurrent venous thromboembolism, major hemorrhage and survival of the central venous catheter. RESULTS: There were 74 patients (48 males). The average age was 58 years. There were no episodes of recurrent venous thromboembolism and three (4%) major bleeds. No lines were removed because of infusion failure or recurrence/extension of DVT. CONCLUSION: Treatment of UEDVTs secondary to central catheters in cancer patients with standard dalteparin/warfarin can allow the central line to remain in situ with little risk of line failure or recurrence/extension of the DVT.

Long-term dalteparin in pregnancy not associated with a decrease in bone mineral density: substudy of a randomized controlled trial.

BACKGROUND: The risk of decreased bone mineral density (BMD) with prophylactic dose long-term low-molecular-weight heparin (LMWH) is unknown. OBJECTIVES: We sought to determine whether long-term prophylactic dalteparin in pregnancy leads to loss of BMD. PATIENTS/METHODS: Patients in a substudy of an ongoing multicenter randomized trial investigating the effect of antepartum dalteparin prophylaxis on pregnancy outcomes in thrombophilic pregnant women were randomized to either dalteparin 5000 U s.c. daily until 20 weeks and then 5,000 U s.c. q12 h until >37 weeks or to the control group. The primary outcome was absolute spine BMD at six weeks postpartum. RESULTS: Of 77 patients eligible for the BMD substudy, 62 were analyzed. 33 patients received a mean of 212 days of dalteparin in the intervention group. 29 patients received a mean of 38 days of postpartum dalteparin in the control group. There was no difference in mean BMD between the intervention (1.11 g cm(-2)) and the control groups (1.14 g cm(-2)). Similarly, there was no difference in T-scores; the difference of -0.34 (95% confidence interval -0.93 to +0.25) in favor of the control group excludes a clinically important increase in fracture risk. CONCLUSIONS: Our results suggest that the use of long-term prophylactic dalteparin in pregnancy is not associated with a significant decrease in BMD. CLINICAL TRIAL REGISTRATION: ISRCTN87441504 at http://www.controlled-trials.com.

The postthrombotic syndrome: current evidence and future challenges.

Postthrombotic syndrome (PTS) is a chronic complication of deep vein thrombosis (DVT) that develops in 20-50% of patients. PTS manifests as a spectrum of symptoms and signs of chronic venous insufficiency that can impose significant morbidity and have a negative impact on quality of life. Chronic venous hypertension caused by a combination of residual venous obstruction and valvular reflux is believed to play a major role in the pathophysiology of PTS. The Villalta scale is the most widely applied clinical scale used to diagnose and define PTS. Proximal DVT and recurrent ipsilateral DVT are the two principal established risk factors for PTS, and efforts in recent years have been focused on identifying a combination of clinical and biomarker predictors that will define high-risk patients and possibly new therapeutic targets. The best way to prevent PTS is to prevent the occurrence of DVT, and to provide optimal anticoagulation for the acute phase of DVT once it occurs. Recent years have brought progress in our understanding of the role of endovascular techniques in the prevention and treatment of PTS and the subgroups of patients that may benefit from these modalities. Pharmacomechanical catheter-directed thrombolysis is the most promising interventional modality for prevention of PTS. This review summarizes the current state of evidence on PTS of the lower limbs, and highlights areas where uncertainty still exists that require further research.

Long-term risk of venous thromboembolism recurrence after isolated superficial vein thrombosis.

Essentials Long-term risk of recurrence of isolated superficial vein thrombosis (SVT) is under-studied. We analyzed data from a cohort of first SVT and proximal deep vein thrombosis (DVT) without cancer. The risk of recurrence as DVT or pulmonary embolism is twice lower in SVT patients. However, overall risk of recurrence is similar between SVT and proximal DVT patients. Click to hear Dr Decousus' perspective on superficial vein thrombosis SUMMARY: Background Isolated superficial vein thrombosis (iSVT) (without concomitant deep vein thrombosis [DVT] or pulmonary embolism [PE]) is a frequent event, but available data on long-term outcomes are scarce and retrospective. Therefore, we aimed to determine prospectively the risk and type of venous thromboembolism (VTE) recurrence after iSVT and compare them with those of proximal DVT. Methods Using data from the prospective, multicenter, observational, OPTIMEV study, we assessed, at 3 years and after anticoagulants were stopped, the incidence and the type of VTE recurrence (iSVT/DVT/PE) of patients with a first objectively confirmed iSVT without cancer (n = 285), and compared these with those of patients with a first proximal DVT without cancer (n = 262). Results As compared with proximal DVT patients, iSVT patients had a similar overall incidence of VTE recurrence (5.4% per patient-year [PY] versus 6.5% per PY, adjusted hazard ratio [aHR] 0.9, 95% confidence interval [CI] 0.5-1.6), but iSVT recurred six times more often as iSVT (2.7% versus 0.6%, aHR 5.9, 95% CI 1.3-27.1) and 2.5 times less often as deep-VTE events (2.5% versus 5.9%, aHR 0.4, 95% CI 0.2-0.9). Varicose vein status did not influence the risk or the type of VTE recurrence. Saphenian junction involvement by iSVT was not associated with a higher risk of recurrence (5.2% per PY versus 5.4% per PY), but was associated with recurrence exclusively as deep-VTE events. Conclusion In patients with a first iSVT without cancer, after stopping anticoagulants, the incidence of deep-VTE recurrence is half that of DVT patients, but the overall risk of recurrence is similar. Ssaphenian junction involvement seems to influence the risk of deep-VTE recurrence, whereas varicose vein status has no impact or a low impact on VTE recurrence.

Long-term outcomes of cancer-related isolated distal deep vein thrombosis: the OPTIMEV study.

Essentials Clinical significance of cancer-related isolated distal deep vein thrombosis (iDDVT) is unknown. We studied patients with iDDVT, with and without cancer, and proximal DVT with cancer. Cancer-related iDDVT patients have a much poorer prognosis than iDDVT patients without cancer. Cancer-related iDDVT patients have a similar prognosis to cancer-related proximal DVT patients. SUMMARY: Background Isolated distal deep vein thrombosis (iDDVT) (infra-popliteal DVT without pulmonary embolism [PE]) is a frequent event and, in the absence of cancer, is usually considered to be a minor form of venous thromboembolism (VTE). However, the clinical significance of cancer-related iDDVT is unknown. Methods Using data from the observational, prospective multicenter OPTIMEV cohort, we compared, at 3 years, the incidences of death, VTE recurrence and major bleeding in patients with cancer-related iDDVT with those in cancer patients with isolated proximal DVT (matched 1:1 on age and sex) and patients with iDDVT without cancer (matched 1:2 on age and sex). Results As compared with patients with cancer-related isolated proximal DVT (n = 92), those with cancer-related iDDVT (n = 92) had a similar risk of death (40.8% per patient-year (PY) vs. 38.3% per PY; aHR = 1.0, 95% CI[0.7-1.4]) and of major bleeding (3.8% per PY vs. 3.6% per PY, aCHR = 0.9 [0.3-3.2]) and a higher risk of VTE recurrence (5.4% per PY vs. 11.5% per PY; aCHR = 1.8 [0.7-4.5]). As compared with patients with iDDVT without cancer (n = 184), those with cancer-related iDDVT had a nine times higher risk of death (3.5% per PY vs. 38.3% per PY; aHR = 9.3 [5.5-15.9]), a higher risk of major bleeding (1.8% per PY vs. 3.6% per PY; aCHR = 2.0 [0.6-6.1]) and a higher risk of VTE recurrence (5.0% per PY vs. 11.5% per PY; aCHR = 2.0 [1.0-3.7]). The results remained similar in the subgroup of patients without history of VTE. Conclusion Patients with cancer-related iDDVT seem to have a prognosis that is similar to that of patients with cancer-related isolated proximal DVT and a dramatically poorer prognosis than patients with iDDVT without cancer. This underlines the high clinical significance of cancer-related iDDVT and the need for additional studies.

Single-arm study of bridging therapy with low-molecular-weight heparin for patients at risk of arterial embolism who require temporary interruption of warfarin.

BACKGROUND: When warfarin is interrupted for surgery, low-molecular-weight heparin is often used as bridging therapy. However, this practice has never been evaluated in a large prospective study. This study was designed to assess the efficacy and safety of bridging therapy with low-molecular-weight heparin initiated out of hospital. METHODS AND RESULTS: This was a prospective, multicenter, single-arm cohort study of patients at high risk of arterial embolism (prosthetic valves and atrial fibrillation with a major risk factor). Warfarin was held for 5 days preoperatively. Low-molecular-weight heparin was given 3 days preoperatively and at least 4 days postoperatively. Patients were followed up for 3 months for thromboembolism and bleeding. Eleven Canadian tertiary care academic centers participated; 224 patients were enrolled. Eight patients (3.6%; 95% CI, 1.8 to 6.9) had an episode of thromboembolism, of which 2 (0.9%; 95% CI, 0.2 to 3.2) were judged to be due to cardioembolism. Of these 8 episodes of thromboembolism, 6 occurred in patients who had warfarin deferred or withdrawn because of bleeding. There were 15 episodes of major bleeding (6.7%; 95% CI, 4.1 to 10.8): 8 occurred intraoperatively or early postoperatively before low-molecular-weight heparin was restarted, 5 occurred in the first postoperative week after low-molecular-weight heparin was restarted, and 2 occurred well after low-molecular-weight heparin was stopped. There were no deaths. CONCLUSIONS: Bridging therapy with subcutaneous low-molecular-weight heparin is feasible; however, the optimal approach for the management of patients who require temporary interruption of warfarin to have invasive procedures is uncertain.

Predictors of the post-thrombotic syndrome during long-term treatment of proximal deep vein thrombosis.

BACKGROUND: The post-thrombotic syndrome is a chronic, poorly understood complication of deep venous thrombosis (DVT). OBJECTIVES: To evaluate predictors of the post-thrombotic syndrome, including intensity of long-term anticoagulation, and to assess the impact of the post-thrombotic syndrome on quality of life. PATIENTS AND METHODS: The setting was 13 Canadian hospitals and one US hospital. One hundred and forty-five patients with an unprovoked episode of proximal DVT who were initially treated with 3 months of conventional-intensity warfarin [target International Normalized Ratio (INR) of 2.5] then participated in a trial comparing two intensities of long-term warfarin therapy (target INR 2.5 vs. INR 1.7). Post-thrombotic syndrome was assessed at the end of the trial using a validated clinical scale. Generic and venous disease-specific quality of life was compared in patients with and without the post-thrombotic syndrome. Multivariable regression analyses were performed to identify predictors of the post-thrombotic syndrome and of its severity. RESULTS: After an average follow-up of 2.2 years, the prevalence of post-thrombotic syndrome was 37% and of severe post-thrombotic syndrome was 4%. Quality of life was worse in patients with the post-thrombotic syndrome compared with patients who did not have it. The presence of factor (F)V Leiden or the prothrombin gene mutation was an independent predictor of both a lower risk (P = 0.006) and reduced severity (P = 0.045) of the post-thrombotic syndrome. Intensity of anticoagulation did not influence the risk of developing the post-thrombotic syndrome. CONCLUSIONS: The post-thrombotic syndrome is a frequent and burdensome complication of proximal DVT, even among patients maintained on long-term oral anticoagulation. While the presence of FV Leiden or prothrombin gene mutation appears to be associated with a reduced risk of post-thrombotic syndrome, this finding requires further evaluation in prospective studies.

The clinical diagnosis of deep venous thrombosis: integrating incidence, risk factors, and symptoms and signs.

Symptoms and clinical signs suggestive of deep venous thrombosis (DVT) are common and have numerous possible causes. Studies have shown that symptoms and clinical signs in themselves are inaccurate for the diagnosis of DVT. However, clinicians have other information at hand, such as data on risk factors for DVT, that may help improve their ability to predict a diagnosis of DVT in the individual patient. Epidemiological data on DVT incidence and risk factors were reviewed, as were published data on the accuracy of clinical diagnosis of DVT, with the use of both symptoms and signs in isolation and symptoms and signs combined with other clinical information in the form of clinical prediction indexes. Symptoms and clinical signs, when combined with other patient information such as the presence or absence of known risk factors for DVT, can improve clinical prediction considerably. Further study is needed to determine whether clinical prediction indexes have a role in improving the diagnostic process in patients with suspected DVT.

Predictive value of markers of inflammation in the postthrombotic syndrome: a systematic review: inflammatory biomarkers and PTS.

BACKGROUND: The postthrombotic syndrome (PTS) is a chronic complication of deep vein thrombosis (DVT). Inflammation may contribute to its pathophysiology. OBJECTIVES: We conducted a systematic review of studies that analyzed the association between biomarkers of inflammation and PTS in DVT patients. METHODS: The electronic databases PubMed, EMBASE, Medline, Scopus and Web of Science were searched for studies published until March 2015 that measured blood inflammation biomarker levels in adult DVT patients and reported their association with PTS development. Two reviewers independently performed full text assessment and data extraction. RESULTS: Ten studies were included. Nine reported on the association between C-reactive protein and PTS; Interleukin (IL)-6 was measured in six studies; IL-8 in four studies; Intracellular adhesion molecule (ICAM)-1 in three studies; IL-10 and vascular cell adhesion molecule-1 in two studies; and monocyte chemotactic protein-1, matrix metalloprotease-9, P-Selectin, tumor necrosis factor α and erythrocyte sedimentation rate were measured in one study. Studies differed in terms of populations included, exclusion criteria, methods used for biomarker measurement and statistical measures of association between biomarkers and PTS. We were able to metaanalyze results only for IL-6 and found no significant association. Descriptively, ICAM-1 was significantly associated with PTS in two out of three studies that measured it. Other biomarkers did not demonstrate a significant association with PTS. CONCLUSIONS: Our systematic review found conflicting results regarding the role of inflammatory biomarkers as predictors of PTS. ICAM -1 appears to be a promising marker for further investigation.

The safety and efficacy of early-initiation exercise training after acute venous thromboembolism: a randomized clinical trial.

BACKGROUND: Exercise training after myocardial infarction is the standard of care within a cardiac rehabilitation setting. However, there is scant evidence regarding the safety and efficacy of early exercise training following a venous thromboembolism (VTE). METHODS: Eligible consenting participants were randomly allocated, on an individual basis, to either a 3-month exercise and behavioral weight loss intervention group or a control group. The primary clinical outcomes were change in health behavior (body weight and physical activity) and objectively measured fitness (Vo2peak ). RESULTS: From 2013 to 2014, 239 patients presented to a community-based specialty clinic after an acute VTE; 43 (18%) of these met the eligibility criteria for inclusion in the study. Of these, 19 (44%) consented to participate (nine in the intervention group; 10 in the control group). There were no adverse events in either group over a 3-month period. The mean difference in body weight between the intervention and control groups was - 4.6 kg (95% confidence interval [CI] - 11.4 to 2.2) in favor of the intervention. The mean difference in duration of physical activity from baseline to 3 months between the intervention and control groups was 133 min (95% CI 7-248) in favor of the intervention. There was a significant change in fitness over a 3-month period for the intervention group (baseline Vo2peak , 26.1 ± 5.4 mL O2 kg(-1)  min(-1) ; postintervention Vo2peak , 29.8 ± 5.4 mL O2 kg(-1)  min(-1) ). CONCLUSION: Early initiation of exercise training resulted in improvements in physical activity and fitness, and did not result in adverse events while individuals were receiving therapeutic anticoagulation. These are the first data on initiation of an exercise training and behavioral weight loss program in the early post-VTE setting.

Inflammation markers and their trajectories after deep vein thrombosis in relation to risk of post-thrombotic syndrome.

BACKGROUND: Post-thrombotic syndrome (PTS) is a frequent chronic complication of deep vein thrombosis (DVT). OBJECTIVE: In the BioSOX study, we investigated whether inflammation markers predict the risk of PTS after DVT. METHODS: We measured C-reactive protein (CRP), ICAM-1, interleukin (IL)-6, and IL-10, at baseline, and 1 month and 6 months after a first proximal DVT, among 803 participants in the SOX trial. Participants were prospectively followed for 24 months for development of PTS. RESULTS: Median CRP levels at 1 month, ICAM-1 levels at baseline, 1 month and 6 months, IL-6 levels at 1 month and 6 months and IL-10 levels at 6 months were higher in patients who developed PTS than in those who did not. Multivariable regression with the median as a cutoff showed risk ratios (RRs) for PTS of 1.23 (95% confidence interval [CI] 1.05-1.45) and 1.25 (95% CI 1.05-1.48) for ICAM-1 at 1 month and 6 months, respectively, and 1.27 (95% CI 1.07-1.51) for IL-10 at 6 months. Quartile-based analysis demonstrated a dose-response association between ICAM-1 and PTS. ICAM-1 and IL-10 were also associated with PTS severity. Analysis of biomarker trajectories after DVT demonstrated an association between the highest-trajectory group of ICAM-1 and PTS. CONCLUSIONS: In this prospective study, ICAM-1 over time was most consistently associated with the risk of PTS. Further study is required to confirm these findings and assess their potential clinical relevance.

Use of elastic compression stockings after deep venous thrombosis: a comparison of practices and perceptions of thrombosis physicians and patients.

Daily long-term use of elastic compression stockings (ECS) by patients with deep venous thrombosis (DVT) may help to prevent the post-thrombotic syndrome (PTS). However, the effectiveness of ECS in clinical practice is difficult to predict, since the practices and perceptions of patients and thrombosis physicians regarding ECS have not been documented. The objectives were to survey DVT patients and thrombosis physicians on their practices and perceptions regarding use of ECS after DVT, and to evaluate whether physician perceptions are supported by patient responses. Two surveys were conducted. The first was sent to 38 Canadian thrombosis physicians. The second was administered to 80 DVT patients attending Thrombosis Clinic at one of two Canadian university-affiliated hospitals. Most physicians believed that ECS were useful in preventing PTS and in managing venous symptoms. However, there was a lack of consensus regarding the optimal timing of initiation of ECS, duration of therapy, and compression strength, and only one-third routinely prescribed ECS to asymptomatic patients to prevent PTS. Most DVT patients who were prescribed ECS purchased them, 87% wore them daily, and most reported that ECS relieved swelling and symptoms. Physicians underestimated the degree of patient compliance with ECS, but correctly identified the main reasons for non-compliance. There is a lack of consensus among thrombosis physicians regarding ECS use after DVT. Patients with DVT are willing to comply with ECS therapy and most find them to be helpful. Our findings suggest that long-term study of the optimal use of ECS after DVT is both necessary and feasible.