Deep venous thrombosis in peripheral vascular disease

Predictors and outcomes of deep venous thrombosis in patients with acute ischemic stroke: results from the Chinese Stroke Center Alliance

BACKGROUND

No large-scale, multicenter studies have explored the incidence rate and predictors of deep vein thrombosis (DVT) in patients with acute ischemic stroke (AIS). We aimed to determine the risk factors of DVT, and assess the association between DVT and clinical outcomes in AIS patients.

METHODS

In total, 106,612 patients with AIS enrolled in the Chinese Stroke Center Alliance between August 2015 and July 2019 were included. The predictors of DVT in AIS patients were screened based on the logistic regression analysis for the comparison of the characteristics and clinical outcomes of patients with and without DVT.

RESULTS

The overall incidence of DVT after AIS was 4.7%. Factors associated with increased incidence of DVT included advanced age, female sex, high admission National Institutes of Health Stroke Scale score, history of cerebral hemorrhage, transient ischemic attack (TIA), dyslipidemia, atrial fibrillation, and peripheral vascular disease, International Normalized Ratio (INR) <0.8 or >1.5, and blood uric acid >420 μmol/L. Ambulation and early antithrombotic therapy were associated with a lower incidence of DVT. Patients with DVT was associated with longer hospital stay (OR=1.44, 95% CI: 1.35-1.54), and higher in-hospital mortality (OR=1.68, 95% CI: 1.25-2.27).

CONCLUSIONS

This large-scale, multi-center study showed that the occurrence of DVT in AIS patients is associated with various modifiable and objective indicators, such as abnormal INR and uric acid >420 μmol/L. Ambulatory status and early antithrombotic therapy can reduce the occurrence of DVT in AIS patients. In AIS patients, DVT may prolong the hospital stay and increase the risk of in-hospital mortality. Future research should focus on the clinical implementation of existing evidence on DVT prevention in AIS patients.

Impact of venous thromboembolism on incidence of arterial thromboembolism - An analysis of German outpatient claims data

BACKGROUND

Venous thromboembolism (VTE) and arterial thromboembolism (ATE) are considered as two separate disease-entities. In recent years, studies have reported clear associations between VTE and atherosclerosis. We aimed to evaluate the long-term risk of ATE in VTE patients in comparison to controls without VTE.

METHODS

Nationwide outpatient claims data of all inhabitants with statutory health insurance in Germany were used for secondary data analysis between the years 2011 and 2020. Patients treated in 2013 were stratified by VTE event, and groups were 1:2-matched by age and sex. The hazard for an ATE event in a 5-year follow-up period between patients with and without VTE was calculated with multivariable Cox regression adjusted for age, sex, cardiovascular risk factors, and comorbidities.

RESULTS

Of 69,699,277 individuals treated in the year 2013 by German physicians in outpatient care, in total 686,382 individuals (age 59.8 ± 17.5 years, 65.4 % females) were included comprising 228,794 patients with VTE and 457,588 controls without VTE. VTE patients more often had cardiovascular risk factors (81.6 % vs. 62.2 %) and traditional VTE risk factors. The occurrence of ATE events during follow-up was 1.8 %-points higher in VTE patients in comparison to the controls (9.7 % vs. 7.9 %). VTE events were independently associated with increased occurrence of ATE events within follow-up (HR_adjusted 1.19 [99%CI 1.16-1.23], p < 0.0001).

CONCLUSIONS

Patients with a VTE event have an increased long-term risk for subsequent arterial cardiovascular events. Large prospective cohorts are needed to identify patient subgroups with a very high ATE risk after VTE.

Atherosclerosis and Its Impact on the Outcomes of Patients with Deep Venous Thrombosis

Introduction: Atherosclerosis and pulmonary embolism (PE) affect cardiovascular mortality substantially. We aimed to investigate the impact of atherosclerosis on the outcomes of patients with deep venous thrombosis (DVT) and to identify the differences in DVT patients with and without PE. Methods: Patients with DVT with and without symptomatic atherosclerosis (defined as coronary artery disease, myocardial infarction and/or peripheral artery disease) as well as with and without PE under oral anticoagulation were enrolled during January 2011−April 2013 and compared. The impact of symptomatic atherosclerosis on several outcomes was analyzed. Results: Overall, 509 DVT patients (70.0 [56.0−77.0] years, 51.9% females) were included in this study. Among them, 179 (36.3%) had symptomatic atherosclerosis and 204 (40.1%) a concomitant PE. DVT patients with symptomatic atherosclerosis were older (74.0 [IQR 65.0−80.0] vs. 63.0 [48.0−75.0] years, p < 0.0001), more often male (56.4% vs. 43.9%, p = 0.0087) and had a higher prevalence of classical CVRF and a higher Charlson comorbidity index (7.00 [5.00−8.00] vs. 4.00 [2.00−6.00], p < 0.001). Symptomatic atherosclerosis was associated with increased mortality (HR 1.98 [95%CI 1.12−3.49], p = 0.018) and hospitalizations (HR 1.64 [95%CI 1.21−2.21], p = 0.0012) and primary long-term outcome (HR 1.99 [95%CI 1.31−3.04], p = 0.0013) during the 2 years follow-up-period in DVT patients. DVT patients without PE had diabetes mellitus (28.2% vs. 16.3%, p < 0.01) and symptomatic atherosclerosis (42.9% vs. 26.4%, p < 0.001) more often compared to DVT patients with PE, and symptomatic atherosclerosis was associated with isolated DVT (without PE) (OR 2.01 [95%CI 1.28−3.16], p < 0.01). Conclusions: Atherosclerosis was associated with isolated DVT (without PE) and increased mortality in DVT patients under oral anticoagulation. The profile of CVRF and comorbidities differed between DVT patients with and without a concomitant PE. In the case of DVT or PE, patients should be screened for concomitant atherosclerotic disease. Clinical Trial Registration: at clinicaltrials with Unique identifier NCT01809015.

State-of-the-art-mini review: Dual pathway inhibition to reduce arterial and venous thromboembolism

Venous thromboembolism (VTE) and arterial thromboembolism (ATE) are linked by the common mechanism of thrombin generation. Historically these entities have been treated as separate pathophysiologic processes requiring different treatments: VTE, as the formation of fibrin-/coagulation-factor-derived thrombus in low flow vasculature, requiring anticoagulants; versus ATE, as largely platelet-derived thrombus in high flow vasculature, requiring antiplatelet agents. Observational studies have elucidated shared risk factors and co-morbidities predisposing individuals with VTE to ATE, and vice versa, and have bolstered the strategy of dual pathway inhibition (DPI) – the combination of low dose anticoagulants with antiplatelet agents – to reduce thrombotic outcomes on both sides of the vasculature. Randomized clinical trials have evaluated the efficacy and safety of such regimens - mostly rivaroxaban and aspirin - in high-risk groups of patients, including those with recent acute or chronic coronary syndrome, as well as those with peripheral artery disease with or without revascularization. Studies of extended VTE prophylaxis in acutely ill medical patients have also contributed to the evidence evaluating DPI. The totality of available data supports the concept that DPI can reduce major and fatal thromboembolic outcomes, including stroke, myocardial infarction, VTE, and cardiovascular death in key patient cohorts, with acceptable risk of bleeding. Further data are needed to refine which patients derive the best net clinical benefit from such an approach. At the same time, other novel agents such as contact pathway inhibitors that reduce thrombin generation without affecting hemostasis - and thus maximize safety - should be assessed in appropriate populations.

Potential Association between Distal Deep Vein Thrombosis and Asymptomatic Atherosclerosis

Background  Several studies have previously reported an association between idiopathic proximal deep vein thrombosis (DVT) and atherosclerosis, but whether spontaneous distal DVT is associated with asymptomatic atherosclerosis is still unknown.

Methods  Ultrasonography of the carotid arteries was done for plaque detection and intima-media thickness (IMT) evaluation, and the ankle-brachial index (ABI) in 116 patients with spontaneous DVT and without symptomatic atherosclerosis. Fifty-seven patients (M/F 19/38, age range 54–78 years) had distal DVT and 59 (M/F 24/35, age range 51–73 years) had proximal DVT. A group of 57 (M/F 21/36, age range 64–70 years) matched subjects acted as controls.

Results  No significant difference was found in carotid plaques between patients with distal or proximal DVT versus controls ( p > 0.05 in all comparisons). Carotid IMT (mean ± SD) was significantly increased in patients with distal (1.00 ± 0.20 mm) and proximal (0.98 ± 0.16 mm) DVT versus controls (0.88 ± 0.15 mm, p <0.01 in both comparisons). An ABI £ 0.9 was found in 3/57 (5.3%) and 5/59 (8.5%) patients with distal and proximal DVT, respectively versus no controls with abnormal ABI.

Conclusion  Our results revealed that there may be an association between spontaneous distal DVT and asymptomatic atherosclerosis, and confirmed the known association between idiopathic proximal DVT and asymptomatic atherosclerosis. Larger studies are needed to confirm our results and to evaluate their clinical implications.

Risk Factors for Pulmonary Embolism in Patients with Paralysis and Deep Venous Thrombosis

Background. Venous thromboembolism is a frequent complication and an important cause of death in patients with paralysis. We aimed to investigate predictors of pulmonary embolism (PE) and the impact of PE on the survival of patients with paralysis in comparison to those with deep venous thrombosis or thrombophlebitis (DVT). Methods: Patients were selected by screening the German nationwide inpatient sample (2005–2017) for paralysis, and were stratified for venous thromboembolism (VTE) and the VTE-sub-entity PE (ICD-code I26). Impact of PE on mortality and predictors for PE were analyzed. Results: Overall, 7,873,769 hospitalizations of patients with paralysis were recorded in Germany 2005–2017, of whom 1.6% had VTE and 7.0% died. While annual hospitalizations increased (2005: 520,357 to 2017: 663,998) (β 12,421 (95% CI 10,807 to 14,034), p < 0.001), in-hospital mortality decreased from 7.5% to 6.7% (β −0.08% (95% CI −0.10% to −0.06%), p < 0.001). When focusing on 82,558 patients with paralysis hospitalized due to VTE (51.8% females; 58.3% aged ≥ 70 years) in 2005–2017, in-hospital mortality was significantly higher in patients with paralysis and PE than in those with DVT only (23.8% vs. 6.3%, p < 0.001). Cancer (OR 2.18 (95% CI 2.09–2.27), p < 0.001), heart failure (OR 1.83 (95% CI 1.76–1.91), p < 0.001), COPD (OR 1.63 (95% CI 1.53–1.72), p < 0.001) and obesity (OR 1.42 (95% CI 1.35–1.50), p < 0.001) were associated with PE. PE (OR 4.28 (95% CI 4.07–4.50), p < 0.001) was a strong predictor of in-hospital mortality. Conclusions: In Germany, annual hospitalizations of patients with paralysis increased in 2005–2017, in whom VTE and especially PE substantially affected in-hospital mortality. Cancer, heart failure, COPD, obesity and acute paraplegia were risk factors of PE.

Impact of Systemic Atherosclerosis on Clinical Characteristics and Short-term Outcomes in Patients with Deep Venous Thrombosis or Thrombophlebitis

BACKGROUND

Venous thromboembolism (VTE) and atherosclerosis are accompanied by substantial cardiovascular mortality; links between both disease entities were reported. We aimed to investigate the impact of systemic atherosclerosis on adverse outcomes in patients with deep venous thrombosis or thrombophlebitis (DVT) and to identify differences in DVT patients with and without systemic atherosclerosis.

METHODS

The German nationwide inpatient sample was used for this analysis. Patients admitted for DVT were included in this study and stratified by systemic atherosclerosis (composite of coronary artery disease, myocardial infarction, ischemic stroke, and/or atherosclerotic arterial diseases). We compared DVT patients with (DVT+Athero) and without (DVT-Athero) systemic atherosclerosis and analysed the impact of systemic atherosclerosis on adverse outcomes.

RESULTS

Overall, 489,679 patients with DVT (55.7% females) were included in this analysis. Among these, 53,309 (10.9%) were coded with concomitant systemic atherosclerosis with age-dependent incline. Concomitant PE (4.1% vs.3.8%, P=0.001) was more frequently in DVT-Athero and risk for PE in DVT patients was independently associated with absence of systemic atherosclerosis (OR 0.87 [95%CI 0.83-0.91], P<0.001). In-hospital mortality (3.4% vs.1.4%, P<0.001) and adverse in-hospital events (2.2% vs.0.8%,P<0.001) were more prevalent in DVT+Athero compared to DVT-Athero; both, in-hospital mortality (OR 1.52 [95%CI 1.41-1.63], P<0.001) and adverse in-hospital events (OR 1.49 [95%CI 1.40-1.58], P<0.001) were affected independently of sex, age and comorbidities by systemic atherosclerosis.

CONCLUSIONS

Systemic atherosclerosis in DVT patients was accompanied by poorer outcomes. Systemic atherosclerosis was associated with higher bleeding rate and with isolated DVT (without concomitant PE).

Risk of thromboembolic events and associated risk factors, including treatments, in patients with immune-mediated diseases

PURPOSE

This study assessed the association between thromboembolic events (TEs) and immune-mediated diseases (IMDs) and characterized the risk profile of TEs among patients with IMDs.

METHODS

An administrative claims database (2014-2018) was used to identify adults with ≥2 diagnoses on different dates for ≥1 IMD (IMD cohort; ankylosing spondylitis, atopic dermatitis, inflammatory bowel disease, multiple sclerosis, psoriasis, psoriatic arthritis, rheumatoid arthritis, and systemic lupus erythematosus); patients without an IMD diagnosis were assigned to the non-IMD cohort. Patients in the IMD cohort were matched 1:1 to patients in the non-IMD cohort on age, sex, and index date. Incremental risk of TE (ie, deep vein thrombosis [DVT], pulmonary embolism [PE], myocardial infarction [MI], and ischemic stroke [IS]) was assessed using adjusted incidence rate ratios (aIRRs) to control for covariates in both cohorts. Risk factors for TEs were assessed in the IMD cohort and included age, female sex, comorbidities, baseline TEs, non-IMD treatments, and IMD treatments.

FINDINGS

A total of 182,431 patients were included in each cohort (mean age, [51.3] years; 64.3% female). A higher proportion of patients in the IMD cohort versus the non-IMD cohort had ≥1 baseline TE (4.1% vs 2.7%; P < 0.0001). The IMD cohort had a 1.80 (95% CI, 1.68-1.92; P < 0.0001) times higher rate of TEs versus patients in the non-IMD cohort. After adjustments, patients in the IMD cohort had a 1.49 (95% CI, 1.40-1.59; P < 0.0001) times higher rate of TEs versus patients in the non-IMD cohort. Similar results were observed across individual TEs (DVT: aIRR = 1.78; PE: aIRR = 1.66; MI: aIRR = 1.17; IS: aIRR = 1.35; all P < 0.05). Risk factor profiles varied by TE. The greatest risk factor was respective TE during baseline (eg, patients with baseline DVT had 41.1 times the rate of DVT during the study period vs patients without baseline DVT; P < 0.001). Comorbidities, such as cardiovascular diseases, type 2 diabetes, and peripheral vascular disease, were associated with increased rates of MI (IRR = 2.60, 1.30, and 1.54, respectively; all P < 0.05) and IS (IRR = 1.53, 1.54, and 1.24, respectively; all P < 0.05). Janus kinase inhibitors were associated with an increased rate of PE (IRR = 2.52; P < 0.05) and nonsignificant, numerically higher rates of DVT (IRR = 1.23; P = NS) and IS (IRR = 1.82; P = NS). Sphingosine 1-phosphate receptor modulators were associated with decreased rates of TEs (DVT: IRR = 0.61, P = NS; PE: IRR = 0.30, P = NS; MI: IRR = 0.54, P = NS; IS: IRR = 0.33, P < 0.05).

IMPLICATIONS

The risk of TEs was higher among patients with IMD versus patients without IMD; several factors may affect this risk.

Primary prophylaxis for venous thromboembolism in people undergoing major amputation of the lower extremity

BACKGROUND

People undergoing major amputation of the lower limb are at increased risk of venous thromboembolism (VTE). Risk factors for VTE in amputees include advanced age, sedentary lifestyle, longstanding arterial disease and an identifiable hypercoagulable condition. Evidence suggests that pharmacological prophylaxis (e.g. heparin, factor Xa inhibitors, vitamin K antagonists, direct thrombin inhibitors, antiplatelets) is effective in preventing deep vein thrombosis (DVT), but is associated with an increased risk of bleeding. Mechanical prophylaxis (e.g. antiembolism stockings, intermittent pneumatic compression and foot impulse devices), on the other hand, is non-invasive and has minimal side effects. However, mechanical prophylaxis is not always appropriate for people with contraindications such as peripheral arterial disease (PAD), arteriosclerosis or bilateral lower limb amputations. It is important to determine the most effective thromboprophylaxis for people undergoing major amputation and whether this is one treatment alone or in combination with another. This is an update of the review first published in 2013.

OBJECTIVES

To determine the effectiveness of thromboprophylaxis in preventing VTE in people undergoing major amputation of the lower extremity.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials, MEDLINE, Embase and Cumulative Index to Nursing and Allied Health Literature databases, the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 5 November 2019. We planned to undertake reference checking of identified trials to identify additional studies. We did not apply any language restrictions.

SELECTION CRITERIA

We included randomised controlled trials and quasi-randomised controlled trials which allocated people undergoing a major unilateral or bilateral amputation (e.g. hip disarticulation, transfemoral, knee disarticulation and transtibial) of the lower extremity to different types or regimens of thromboprophylaxis (including pharmacological or mechanical prophylaxis) or placebo.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted data and assessed risk of bias. We resolved any disagreements by discussion. Outcomes of interest were VTE (DVT and pulmonary embolism (PE)), mortality, adverse events and bleeding. We used GRADE criteria to assess the certainty of the evidence. The two included studies compared different treatments, so we could not pool the data in a meta-analysis.

MAIN RESULTS

We did not identify any eligible new studies for this update. Two studies with a combined total of 288 participants met the inclusion criteria for this review. Unfractionated heparin compared to low molecular weight heparin One study compared unfractionated heparin with low molecular weight heparin and found no evidence of a difference between the treatments in the prevention of DVT (odds ratio (OR) 1.23, 95% confidence interval (CI) 0.28 to 5.35; 75 participants; very low-certainty evidence). No bleeding events occurred in either group. Deaths and adverse events were not reported. This study was open-label and therefore at a high risk of performance bias. Additionally, the study did not report the method of randomisation, so the risk of selection bias was unclear. Heparin compared to placebo In the second study, there was no evidence of a benefit from heparin use in preventing PE when compared to placebo (OR 0.84, 95% CI 0.35 to 2.01; 134 participants; low-certainty evidence). Similarly, no evidence of improvement was detected when the level of amputation was considered, with a similar incidence of PE between the two treatment groups: above knee amputation (OR 0.79, 95% CI 0.31 to 1.97; 94 participants; low-certainty evidence); and below knee amputation (OR 1.53, 95% CI 0.09 to 26.43; 40 participants; low-certainty evidence). Ten participants died during the study; five underwent a post-mortem and three were found to have had a recent PE, all of whom had been on placebo (low-certainty evidence). Bleeding events were reported in less than 10% of participants in both treatment groups, but the study did not present specific data (low-certainty evidence). There were no reports of other adverse events. This study did not report the methods used to conceal allocation of treatment, so it was unclear whether selection bias occurred. However, this study appeared to be free from all other sources of bias. No study looked at mechanical prophylaxis.

AUTHORS' CONCLUSIONS

We did not identify any eligible new studies for this update. As we only included two studies in this review, each comparing different interventions, there is insufficient evidence to make any conclusions regarding the most effective thromboprophylaxis regimen in people undergoing lower limb amputation. Further large-scale studies of good quality are required.

Arterial and venous thrombosis: What's the link? A narrative review

Arterial thrombosis and venous thromboembolism (VTE) are traditionally considered two different entities. However, patients with unprovoked VTE are at higher risk of developing subclinical and overt atherosclerosis compared to healthy controls challenging these distinctions. Obesity may explain the association between arterial and venous disease: overweight/obese patients are prone to stasis in lower limbs veins, chronic inflammation, dyslipidemia, hypertension, and diabetes mellitus; all of which result in a hypercoagulability, VTE, and atherosclerosis. Novel therapeutic approaches combining and re-purposing traditional arterial therapies (antiplatelets and statins) and venous thrombosis therapies (anticoagulants) are emerging for the management of patients with vascular disease.

Impact of symptomatic atherosclerosis in patients with pulmonary embolism

BACKGROUND

Atherosclerosis is associated with increased cardiovascular mortality. Associations between venous thromboembolism and atherosclerosis were recently reported. We aimed to investigate the impact of symptomatic atherosclerosis on adverse outcomes in patients with pulmonary embolism (PE) and to identify significant differences among patients with PE stratified by symptomatic atherosclerosis.

METHODS

Patients were selected by screening the nationwide inpatients sample for PE (ICD-code I26) stratified by symptomatic atherosclerosis (composite of coronary artery disease [ICD-code I25], myocardial infarction [ICD-code I21], ischemic stroke [ICD-code I63], and/or atherosclerotic arterial diseases [ICD-code I70]). We compared PE patients with (PE + Athero) and without (PE - Athero) symptomatic atherosclerosis and analysed the impact of symptomatic atherosclerosis on adverse outcomes.

RESULTS

Overall, 213,995 patients with PE (54.2% females) were included in this analysis. Of these, 30,157 (14.1%) had symptomatic atherosclerosis with age-dependent incline. Deep vein thrombosis or thrombophlebitis (45.1% vs. 36.9%, P < 0.001) was more commonly observed in the PE - Athero group (Odds Ratio (OR) 0.713 [95% CI 0.695-0.731], P < 0.001). In-hospital mortality (12.1% vs. 9.6%, P < 0.001) and adverse in-hospital events (16.8% vs. 12.6%, P < 0.001) were affected by symptomatic atherosclerosis; both in-hospital mortality (OR 1.107 [95% CI 1.061-1.155], P < 0.001) and adverse in-hospital outcomes (OR 1.143 [95%CI 1.102-1.186], P < 0.001) were affected independently of age, gender, comorbidities, and reperfusion treatments.

CONCLUSIONS

Symptomatic atherosclerosis in patients with PE increased with age and was associated with a poorer outcome. Cardiovascular-atherosclerotic diseases might play a major role in thrombus formation in isolated PE.

Is lipid lowering therapy an independent risk factor for venous thromboembolism? A population-based case-control study

INTRODUCTION

The independent effect of lipid lowering therapy (LLT) on venous thromboembolism (VTE) risk is uncertain.

OBJECTIVE

To test statin and non-statin LLT as potential VTE risk factors.

METHODS

Using Rochester Epidemiology Project resources, we identified all Olmsted County, MN residents with objectively diagnosed incident VTE (cases) over the 13-year period, 1988-2000 (n=1340), and one to two matched controls (n=1538). We reviewed their complete medical records for baseline characteristics previously identified as independent VTE risk factors, and for statin and non-statin LLT. Using conditional logistic regression, we tested the overall effect of LLT on VTE risk and also separately explored the role of statin versus that of non-statin LLT, adjusting for other baseline characteristics.

RESULTS

Among cases and controls, 74 and 111 received statin LLT, and 32 and 50 received non-statin LLT, respectively. Univariately, and after individually controlling for other potential VTE risk factors (i.e., BMI, trauma/fracture, leg paresis, hospitalization for surgery or medical illness, nursing home residence, active cancer, central venous catheter, varicose veins, prior superficial vein thrombosis, diabetes, congestive heart failure, angina/myocardial infarction, stroke, peripheral vascular disease, smoking, anticoagulation), LLT was associated with decreased odds of VTE (unadjusted OR=0.73; p=0.03). When considered separately, statin and non-statin LLT were each associated with moderate, non-significant lower odds of VTE. After adjusting for angina/myocardial infarction, each was significantly associated with decreased odds of VTE (OR=0.63, p<0.01 and OR=0.61, p=0.04, respectively).

CONCLUSIONS

LLT is associated with decreased VTE risk after adjusting for known risk factors.

Symptomatic and incidental venous thromboembolic disease are both associated with mortality in patients with prostate cancer

Introduction

The association between malignancy and venous thromboembolic disease (VTE) is well established. The independent impact of VTE, both symptomatic and incidental, on survival in patients with prostate cancer is not known. We conducted a retrospective cohort study to evaluate the effect of VTE of survival in prostate cancer.

Methods

Data regarding clinical characteristics, treatment and outcomes of 453 consecutive prostate cancer patients were collected. Fisher exact (categorical variables) and t-test (continuous variables) were utilized to test associations with VTE and mortality. Survival was estimated using the Kaplan Meier method. A Cox regression model was used to model the mortality hazard ratio (HR).

Results

At diagnosis, 358 (83%) patients had early stage disease, 43 (10%) had locally advanced disease and 32 (7%) had metastatic disease. During the follow up period, 122 (27%) patients died and 41 (9%) developed VTE (33 deep vein thrombosis, 5 pulmonary embolism, and 3 patients with both DVT and PE). Twenty-five VTE events were symptomatic and 16 were incidentally diagnosed on CT scans obtained for other reasons. VTE was associated with increased mortality [HR 6.89 (4.29–11.08), p<0.001] in a multivariable analysis adjusted for cancer stage, performance status, treatments and co-morbidities. There was no difference in survival between patients who had symptomatic and incidental VTE.

Conclusion

Venous thromboembolic disease, both symptomatic and incidental, is a predictor of poor survival in patients with prostate cancer, especially those with advanced disease. Further studies are needed to evaluate the benefit of prophylactic and therapeutic anticoagulation in this population.

Severity of spontaneous echo contrast in the jugular vein associated with ischemic stroke

This study evaluated the relationship between spontaneous echo contrast (SEC) in the internal jugular vein (JV), atherosclerotic markers and ischemic stroke. One hundred twenty patients with acute ischemic stroke and 120 controls were recruited. SEC score correlated with plasma level of fibrinogen (coefficient: 0.105, p = 0.022), hemoglobin (coefficient: 0.122, p = 0.008) and presence of JV reflux (coefficient: 0.314, p < 0.001) and peak flow velocity (coefficient: -0.244, p < 0.001) in the corresponding JV, but did not correlate with carotid plaque score (coefficient: 0.042, p = 0.358) or intima-media thickness (coefficient: 0.067, p = 0.303). Multivariate regression analysis revealed that fibrinogen level, SEC score, intima-media thickness, plaque score and history of coronary artery disease were associated with acute ischemic stroke. In conclusion, the severity of SEC in the JV might represent the tendency toward thrombogenesis in diseased cerebral circulation possibly through mechanisms other than arterial atherosclerosis.

CHA2DS2-VASc score is directly associated with the risk of pulmonary embolism in patients with atrial fibrillation

BACKGROUND

The risk stratification score, which includes Congestive heart failure, Hypertension, Age ≥ 75 [doubled], Diabetes, Stroke [doubled]- Vascular disease, Age 65-74, and Sex category [female] (CHA2DS2-VASc), is used to predict stroke in atrial fibrillation. However, whether high CHA2DS2-VASc score carries a higher risk of pulmonary embolism remains unknown. We aimed to investigate the association between the severity of CHA2DS2-VASc score and the incidence of pulmonary embolism.

METHODS

A total of 73,541 adults with atrial fibrillation diagnosed before January 1, 2012, and no history of pulmonary embolism, were retrospectively identified from the computerized database of the Clalit Health Services, which is the largest not-for-profit health maintenance organization in Israel. The CHA2DS2-VASc score was calculated for each subject at study entry. The cohort was followed for the first occurrence of pulmonary embolism until December 31, 2012 (70,210 person-years).

RESULTS

Pulmonary embolism developed in 158 subjects, representing an incidence of 225.0 per 100,000 person-years. The incidence of pulmonary embolism increased with increasing CHA2DS2-VASc score (P < .001). On Cox proportional analysis, CHA2DS2-VASc score was significantly associated with pulmonary embolism (hazard ratio, 1.22; 95% confidence interval [CI], 1.13-1.32) for a 1-point increase in CHA2DS2-VASc score. The results were similar after adjusting for anticoagulants and antiplatelet use (hazard ratio, 1.24; 95% CI, 1.14-1.34), and remained unchanged after further adjustment for active malignancy. The predictive values for pulmonary embolism were similar for CHA2DS2-VASc score and the classic risk stratification score which includes Congestive heart failure, Hypertension, Age >75 years, Diabetes, and Stroke [doubled] (CHADS2); the areas under the receiver operating characteristic curves were 0.619 (95% CI, 0.579-0.660) and 0.616 (95% CI, 0.575-0.656), respectively.

CONCLUSIONS

CHA2DS2-VASc score is directly associated with the incidence of pulmonary embolism in atrial fibrillation.

Primary prophylaxis for venous thromboembolism in people undergoing major amputation of the lower extremity

BACKGROUND

Patients undergoing major amputation of the lower limb are at increased risk of venous thromboembolism (VTE). Risk factors for VTE in amputees include advanced age, sedentary lifestyle, longstanding arterial disease and an identifiable hypercoagulable condition. Evidence suggests that pharmacological prophylaxis (for example heparin, factor Xa inhibitors, vitamin K antagonists, direct thrombin inhibitors, antiplatelets) is effective in preventing deep vein thrombosis (DVT) but it is associated with an increased risk of bleeding. Mechanical prophylaxis (for example antiembolism stockings, intermittent pneumatic compression and foot impulse devices), on the other hand, is non-invasive and has no side effects. However, it is not always appropriate in patients with contraindications such as peripheral arterial disease (PAD), arteriosclerosis or bilateral lower limb amputations. It is important to determine the most effective thromboprophylaxis and whether this is one treatment alone or in combination with another. To date, no systematic review has been conducted examining the effectiveness of thromboprophylaxis in preventing VTE in people undergoing amputation.

OBJECTIVES

To determine the effectiveness of thromboprophylaxis in preventing VTE in people undergoing major amputation of the lower extremity.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched May 2013) and CENTRAL (2013, Issue 4). Clinical trials databases were searched (May 2013). No date or language restrictions were applied. Non-English trials were translated where required and reference lists of identified studies were handsearched.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised controlled trials in which people undergoing a major unilateral or bilateral amputation (for example hip disarticulation, transfemoral, knee disarticulation and transtibial) of the lower extremity were allocated to different types or regimens of thromboprophylaxis (including pharmacological or mechanical prophylaxis) or placebo.

DATA COLLECTION AND ANALYSIS

Selection of studies, data extraction and risk of bias were completed independently by two review authors. Any disagreements were resolved by discussion. Meta-analysis could not be completed as the two included studies compared different treatments and therefore the data could not be pooled.

MAIN RESULTS

Two studies with a combined total of 288 participants met the inclusion criteria for this review. One study compared low molecular weight heparin with unfractionated heparin and found no difference between the treatments in the prevention of DVT (odds ratio (OR) 1.23, 95% confidence interval (CI) 0.28 to 5.35). No bleeding events or deaths occurred. This study was open label and therefore at a high risk of performance bias. Additionally, the method of randomisation was not reported and therefore the risk of selection bias was unclear. In the second study heparin did not significantly improve prevention of pulmonary embolism (OR 1.02, 95% CI 0.44 to 2.37) when compared to placebo. Furthermore, when the level of amputation was considered, the incidence of pulmonary embolism was similar between the two treatment groups: above knee amputation (OR 0.79, 95% CI 0.31 to 1.97) and below knee amputation (OR 1.53, 95% CI 0.09 to 26.43). Ten participants died during the study; five underwent a post-mortem and three were found to have had a recent pulmonary embolism, all of whom had been on placebo. Bleeding events were reported in less than 10% of participants in both treatment groups but specific data were not presented. This study did not report the methods used to conceal allocation of treatment and therefore it was unclear if selection bias occurred. However, this study appeared to be free from all other sources of bias. No study looked at mechanical prophylaxis.

AUTHORS' CONCLUSIONS

As only two studies were included in this review, each comparing different interventions, there is insufficient evidence to make any conclusions regarding the most effective thromboprophylaxis regimen in patients undergoing lower limb amputation. Further large-scale studies that are of good quality are required.

AF and Venous Thromboembolism - Pathophysiology, Risk Assessment and CHADS-VASc score

Atrial fibrillation (AF) and venous thromboembolism (VTE) are the two most common medical conditions managed with anti-coagulation therapy. Not all the patients with decreased mobility or AF have a similar risk for thromboembolism. The risk factors for venous thromboembolism and thromboembolism associated with AF are described in various studies. Considering that the two conditions have similar pathophysiologic basis of clot formation, one could imply that the risk factors for the occurrence of thrombosis could be similar. The present review focuses on the similarities and differences in the clinical risk factors of VTE and AF related thromboembolism. We will also be discussing the role of CHADS₂-VASc scoring system in the risk assessment of VTE.

Spontaneous echo contrast in internal jugular veins: a probable indicator for systemic inflammation and a prothrombotic state

The hypothesis that spontaneous echo contrast (SEC) in the internal jugular vein (IJV) is a clinical indicator for systemic inflammation and thrombogenesis is investigated in this study. Fifty-two patients with cardiovascular diseases and 25 nondiseased subjects were evaluated. SEC was observed in 96 of 154 IJVs. The visual grading of SEC showed good interobserver agreement on SEC grades (κ value: 0.846, p < 0.001). Generalized estimating equations analysis was used for univariate and multivariate analysis. Univariate analysis showed that peak flow velocity in corresponding IJV (coefficient -0.001 [95% CI -0.019, -0.001], p = 0.031), jugular venous reflux (JVR, -0.010 [-0.019, -0.001], p = 0.002), plasma levels of fibrinogen (0.464 [0.208, 0.719], p < 0.001) and hs-C-reactive protein (hs-CRP) (0.479 [0.184, 0.774], p = 0.001) and previous history of ischemic stroke (0.779 [0.139, 1.417]; p = 0.017) correlated with the grades of SEC in IJV. Increased plasma levels of fibrinogen and hs-CRP, previous ischemic stroke, lower peak velocity in corresponding IJV and JVR were also independent predictors for the higher grades of SEC in IJV in multivariate regression analysis. SEC in IJV could be evaluated easily and semiquantitatively. SEC in IJVs could be a putative marker of cerebral circulation disturbance and an indicator of systemic inflammatory or prothrombotic state.

Impairment of the vasodilatation capability of the brachial artery in patients with idiopathic venous thrombosis

AIM

Determination of the functional capability of the peripheral arteries is increasingly used as an early marker of vessel disease. The aim of this study was to evaluate flow-mediated (FMD) and glyceryl trinitrate-mediated (NMD) dilation of the brachial artery in patients with idiopathic venous thrombosis (VT).

METHODS

Flow-mediated brachial artery dilatation and the dilatation response to glyceryl trinitrate were measured using high-resolution ultrasound in 97 subjects (49 eligible patients of both sexes, mean age 51.5 ± 14.6 years, with idiopathic venous thrombosis, and 48 age-matched healthy controls).

RESULTS

Compared to the control group, FMD was significantly reduced in the group of patients with idiopathic venous thrombosis -4.9% (95% CI 1.1-8.7%) vs. 12.7% (95% CI 7.8-17.6%), p<0.001. Patients also had diminished NMD of the brachial artery -12.5% (95% CI 6.6-18.4%) vs. 18.5% (95% CI 10.1-26.9%), p<0.001. In patients, significantly higher levels of circulatory markers (P-selectin, von Willebrand factor) of endothelial dysfunction were registered.

CONCLUSIONS

Idiopathic venous thrombosis is associated with impaired flow- and GTN-mediated vasodilatory response of the brachial artery. This may suggest involvement of the functional deterioration of the vessel wall in the pathogenesis of idiopathic VT and indicate a relationship between VT and atherothrombosis.

Idiopathic venous thrombosis is associated with preclinical atherosclerosis

AIM

There is growing evidence that venous thrombotic and arterial atherosclerotic diseases are interrelated. This presumption is supported by the similar ethiopathogenesis, risk factors and clinical appearance of the two diseases. We investigated whether the prevalence of preclinical indicators of atherosclerosis is higher in patients with spontaneous venous thrombosis than in healthy subjects. Further, we studied the extent of preclinical deterioration of the arterial wall in different beds of the arterial system.

METHODS

Forty seven patients of both sexes (mean age, 52.3+/-14.3 years) with idiopathic venous thrombosis and 44-age matched controls were studied. Using ultrasound, bifurcations of the carotid and femoral arteries were investigated and intima-media thickness plus the presence and thickness of atherosclerotic plaques were determined.

RESULTS

The intima-media was on average, and in all beds investigated, significantly thicker in patients than in controls (0.94 mm +/-0.29 vs. 0.71 mm +/-0.15, p<0.001). The prevalence of atherosclerotic plaques was higher in patients (33/47 vs. 15/44, p<0.001). Furthermore, the number of plaques per individual, the number of arterial segments involved, and total plaque thickness were significantly longer in patients than in controls.

CONCLUSION

The findings showed a close interrelationship between idiopathic venous thrombosis and preclinical atherosclerotic changes in different arterial territories. This could mean that in patients with primary arterial or venous disease, the arterial and venous vessel walls deteriorate simultaneously, and that common local or systemic factors influence the clinical appearance of either or both diseases.

[Arterial and venous thrombosis in lung cancer]

We report the case of a 61-year old man in whom a deep venous thrombosis was the presenting feature of disseminated lung carcinoma. A few days later, an arterial thrombosis occurred necessitating amputation. Within a few weeks, the lung cancer progressed dramatically and the patient died. While the association between venous thrombosis and cancer is well known, the relationship between cancer and arterial thrombosis has been less explored. This observation allows discussion of the pathophysiological and clinical aspects of this association, as well as the implications for patient care.

Venous and arterial thrombosis: different sides of the same coin?

Until recently venous and arterial thrombosis were considered mechanistically distinct entities. However, their separate nature has been challenged by several studies showing that these conditions share a number of risk factors such as age, obesity, infections and the metabolic syndrome. The existence of an association is further supported by the finding that patients with venous thromboembolism are at higher risk of arterial events and vice versa. This review article addresses the association between venous and arterial thrombosis and its clinical and therapeutic implications. We conclude that arterial and venous thrombosis are mechanistically different, but that common risk factors are more relevant and frequent than previously thought.

Links between arterial and venous disease

An increasing body of evidence suggests the likelihood of a link between arterial and venous disease. According to the results of recent studies, atherosclerosis and venous thromboembolism (VTE) share common risk factors, including age, obesity, diabetes mellitus and metabolic syndrome. Atherosclerosis has the potential to promote the development of thrombotic disorders in the venous system. Another scenario assumes that the two clinical conditions are simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Several recent studies have consistently shown that patients with VTE of unknown origin are at a higher risk of cardiovascular diseases, including atherosclerotic complications, than patients with secondary VTE and matched control individuals. Future studies are needed to clarify the nature of this association, to assess its extent and to evaluate its implications for clinical practice.

Venous thromboembolism and atherosclerosis: is there a link?

After the initial demonstration provided 4 years ago by a case-control study in the New England Journal of Medicine, numerous investigations have addressed the association between venous and arterial thrombotic disorders. According to the results of recent studies, the two conditions are likely to share common risk factors, including age, obesity, cigarette smoking, diabetes mellitus, arterial hypertension, hyperlipemia and metabolic syndrome. The nature of this association is unclear. On the one hand, atherosclerosis has the potential to promote the development of thrombotic disorders in the venous system. On the other hand, the two clinical conditions can be simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Based on the results of two population-based studies carried out in the USA, atherosclerosis is unlikely to constitute a risk factor for venous thromboembolic (VTE) disorders. Several recent studies have consistently shown that subjects with VTE of unknown origin are at a higher risk of subsequent arterial cardiovascular events than subjects with secondary VTE and matched control individuals. In conclusion, the separate nature of arterial and venous disorders has been challenged. Future studies are needed to clarify the nature of this association, to assess its extent, and to evaluate its implications for clinical practice.

Cardiovascular diseases and the risk of venous thromboembolism: a hospital-based case-control study

BACKGROUND

The effects of various cardiovascular diseases on the risk of venous thromboembolism (VTE) are not well defined. To gather more information, we performed a hospital-based case-control study to evaluate the effects of major cardiovascular diseases on the risk of VTE.

METHODS

We identified all incident cases of VTE needing hospitalization and anticoagulant therapy between January 1990 and December 2002 in a large tertiary hospital. Each case was matched with up to 4 controls, randomly selected from inpatients who were not hospitalized due to any of the exposures, on age, sex, calendar time and veteran/nonveteran status.

RESULTS

This study comprised 173 cases of VTE and 546 matched controls. The adjusted odds ratio (OR) of VTE was significant among patients with peripheral atherosclerotic diseases (OR 7.1, 95% confidence interval [CI] 1.4-34.4), and nondebilitating cerebrovascular diseases (OR 2.5, 95% CI 1.4-4.7). Other independent risk factors for VTE included a body mass index>or=25.0 kg/m2, current estrogen use, a history of hyperlipidemia and varicose veins.

CONCLUSION

Peripheral atherosclerotic disease and nondebilitating cerebrovascular disease are important risk factors for VTE. Patients with these diseases should therefore be frequently evaluated for the possible coexistence of VTE and, if appropriate, should be given prophylaxis. Failure to take into account the potential confounding effects of these diseases may also result in an erroneous estimate of the effect of drug exposures on the risk of idiopathic VTE.

Prospective study of subclinical atherosclerosis as a risk factor for venous thromboembolism

BACKGROUND

Whether atherosclerotic disease predisposes to venous thrombosis is uncertain.

OBJECTIVE

To determine whether subclinical atherosclerosis, manifested as increased carotid intima-media thickness (IMT) or presence of carotid plaque, is associated with increased incidence of venous thromboembolism (VTE).

PATIENTS AND METHODS

The Atherosclerosis Risk in Communities study is a prospective cohort of adults aged 45-64 years, examined at baseline (1987-89) and followed for cardiovascular events. Bilateral carotid ultrasound for IMT measurements was done at baseline for portions of the common and internal carotid arteries, and carotid bifurcation and also to detect the presence of carotid plaque. Exclusion criteria included baseline anticoagulant use, history of coronary heart disease, stroke, or VTE, and incomplete data. First VTE during follow-up was validated using abstracted medical records.

RESULTS

Among 13,081 individuals followed for a mean of 12.5 years, 225 first VTE events were identified. Unadjusted hazard ratios (HR) (95% CI) of VTE across quartiles of baseline IMT were 1.0, 1.16 (0.77-1.75), 1.64 (1.12-2.40), and 1.52 (1.03-2.25). However, this association disappeared after adjustment for age, sex, and ethnicity (HRs: 1.0, 1.06, 1.40, and 1.18). Further adjustment for body mass index and diabetes weakened the relative risks even further. Presence of carotid plaque at baseline also was not associated with VTE occurrence; adjusted HR = 0.97, 95% CI = 0.72-1.29.

CONCLUSION

Increased carotid IMT or presence of carotid plaque was not associated with an increased incidence of VTE in this middle-aged cohort, suggesting subclinical atherosclerosis itself is not a VTE risk factor.

[Prevention of venous thromboembolism following cardiac, vascular or thoracic surgery]

In the absence of thromboprophylaxis, coronary artery bypass graft surgery (CABG), intrathoracic surgery (thoracotomy or video-assisted thoracoscopy), abdominal aortic surgery and infrainguinal vascular surgery are high-risk surgeries for the development of venous thromboembolic events (VTE). The incidence of VTE following surgery of the intrathoracic aorta, carotid endarterectomy or mediastinoscopy is unknown. Data from the litterature are lacking to draw evidence-based recommandations for venous thromboprophylaxis after these three types of surgeries, and the following guidelines are but experts'opinions (Grade D recommendations). Thromboprophylaxis is recommended after CABG (Grade D), with either subcutaneous (SC) low molecular weight heparin (LMWH) or SC or intravenous (i.v.) unfractioned heparin (UH) (PTT target = 1.1-1.5 time control value) (both grade D). This may be combined with the use of intermittent pneumatic compression device (Grade B). After valve surgery. The anticoagulation recommended to prevent valve thrombosis is sufficient in order to prevent VTE. We recommend thromboprophylaxis with either LMWH or low dose UH to prevent VTE after aortic or lower limbs infrainguinal vascular surgery (both grade B and D). Vitamine K antagonists (VKA) are not recommended in this indication (Grade D). We recommend thromprophylaxis following intrathoracic surgery via thoracotomy or videoassisted thoracoscopy (grade C). Either subcutaneous LMWH or subcutaneous or i.v. low dose UH may be used (Grade C). Efficacy of intermittent pneumatic compression device has been demonstrated in a study (grade C). VKA are not recommended (grade D). No further recommendation regarding the duration of thromboprophylaxis after these three types of surgeries can be made.

Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy

This article discusses the prevention of venous thromboembolism (VTE) and is part of the Seventh American College of Chest Physicians Conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following. We recommend against the use of aspirin alone as thromboprophylaxis for any patient group (Grade 1A). For moderate-risk general surgery patients, we recommend prophylaxis with low-dose unfractionated heparin (LDUH) (5,000 U bid) or low-molecular-weight heparin (LMWH) [< or = 3,400 U once daily] (both Grade 1A). For higher risk general surgery patients, we recommend thromboprophylaxis with LDUH (5,000 U tid) or LMWH (> 3,400 U daily) [both Grade 1A]. For high-risk general surgery patients with multiple risk factors, we recommend combining pharmacologic methods (LDUH three times daily or LMWH, > 3,400 U daily) with the use of graduated compression stockings and/or intermittent pneumatic compression devices (Grade 1C+). We recommend that thromboprophylaxis be used in all patients undergoing major gynecologic surgery (Grade 1A) or major, open urologic procedures, and we recommend prophylaxis with LDUH two times or three times daily (Grade 1A). For patients undergoing elective total hip or knee arthroplasty, we recommend one of the following three anticoagulant agents: LMWH, fondaparinux, or adjusted-dose vitamin K antagonist (VKA) [international normalized ratio (INR) target, 2.5; range, 2.0 to 3.0] (all Grade 1A). For patients undergoing hip fracture surgery (HFS), we recommend the routine use of fondaparinux (Grade 1A), LMWH (Grade 1C+), VKA (target INR, 2.5; range, 2.0 to 3.0) [Grade 2B], or LDUH (Grade 1B). We recommend that patients undergoing hip or knee arthroplasty, or HFS receive thromboprophylaxis for at least 10 days (Grade 1A). We recommend that all trauma patients with at least one risk factor for VTE receive thromboprophylaxis (Grade 1A). In acutely ill medical patients who have been admitted to the hospital with congestive heart failure or severe respiratory disease, or who are confined to bed and have one or more additional risk factors, we recommend prophylaxis with LDUH (Grade 1A) or LMWH (Grade 1A). We recommend, on admission to the intensive care unit, all patients be assessed for their risk of VTE. Accordingly, most patients should receive thromboprophylaxis (Grade 1A).

An association between atherosclerosis and venous thrombosis

BACKGROUND

In about a third of patients with venous thromboembolism, the cause of the disorder is unexplained. In patients with atherosclerosis, activation of both platelets and blood coagulation and an increase in fibrin turnover are detectable, which may lead to thrombotic complications. Whether atherosclerosis is associated with an increased risk of venous thrombosis is unknown.

METHODS

We performed ultrasonography of the carotid arteries in 299 unselected patients who had deep venous thrombosis of the legs without symptomatic atherosclerosis and in 150 control subjects. Patients with spontaneous thrombosis, patients with secondary thrombosis from acquired risk factors, and control subjects were assessed for plaques.

RESULTS

At least one carotid plaque was detected in 72 of the 153 patients with spontaneous thrombosis (47.1 percent; 95 percent confidence interval, 39.1 to 55.0), 40 of the 146 with secondary thrombosis (27.4 percent; 95 percent confidence interval, 20.2 to 34.6), and 48 of the 150 control subjects (32.0 percent; 95 percent confidence interval, 24.5 to 39.5). The odds ratios for carotid plaques in patients with spontaneous thrombosis, as compared with patients with secondary thrombosis and with controls, were 2.3 (95 percent confidence interval, 1.4 to 3.7) and 1.8 (95 percent confidence interval, 1.1 to 2.9), respectively. In a multivariate analysis that accounted for risk factors for atherosclerosis, the strength of this association did not change.

CONCLUSIONS

There is an association between atherosclerotic disease and spontaneous venous thrombosis. Atherosclerosis may induce venous thrombosis, or the two conditions may share common risk factors.

Deep venous thrombosis in postoperative vascular surgical patients: a frequent finding without prophylaxis

PURPOSE

The place of routine perioperative thromboprophylaxis for vascular surgical patients remains controversial, because the incidence of postoperative deep venous thrombosis (DVT) is said to be quite low. This study was designed to measure the incidence of lower limb DVT after vascular surgical procedures.

METHODS

All consenting, consecutive patients who came to a metropolitan veterans hospital for abdominal or lower-limb arterial surgery were studied. Clinical and operative data were recorded. Lower-limb color flow duplex scans were performed before and after surgery.

RESULTS

Fifty patients, age 75 +/- 1 (mean +/- SEM) years, were studied. Abdominal procedures were performed on 22 patients, and lower-limb procedures were performed on 28 patients. A postoperative DVT was noted in 14 patients (32%), 9 patients (41%) in the abdominal surgical group and 5 patients (18%) in the lower-limb group. Calf DVTs were four times more common than femoropopliteal DVTs.

CONCLUSION

The incidence of postoperative lower-limb DVTs in this cohort of vascular surgical patients was high. The small size of the study population precludes generalized recommendations, but the results indicate an urgent need for definitive investigation.

Prospective screening for postoperative deep venous thrombosis in patients undergoing infrainguinal revascularization

PURPOSE

The incidence of deep venous thrombosis (DVT) in patients undergoing infrainguinal bypass graft procedures has not been well documented, and the need for routine prophylaxis remains controversial. The purpose of this study was to prospectively evaluate the risk of postoperative DVT complicating infrainguinal revascularization.

METHODS

Seventy-four patients undergoing infrainguinal bypass graft procedures during a 12-month period were prospectively screened for DVT. Bilateral lower extremity venous duplex scan imaging was performed preoperatively and within 1 week and 6 weeks, postoperatively. Routine DVT prophylaxis was not used, with anticoagulation reserved for specific indications.

RESULTS

Of the 74 patients screened, three patients (4.1%) had DVT identified on preoperative venous duplex scan imaging and were excluded from the study. Of the remaining 71 patients enrolled, only two patients (2.8%) had postoperative DVT. Postoperative DVT was ipsilateral to the bypass graft extremity in both patients, with involvement of the peroneal vein in one patient and the femoral vein in the other. Although routine prophylaxis was not used, 18 of these patients (25%) were anticoagulated for other indications, with DVT occurring in one patient (5.6%). Of the remaining 53 patients who did not receive postoperative anticoagulation, only one patient (1.8%) had DVT.

CONCLUSIONS

According to this prospective study, the risk of postoperative DVT in patients undergoing infrainguinal revascularization is low. Routine prophylaxis is not recommended, with postoperative anticoagulation reserved for specific indications.