Glucose levels and diabetes are not associated with the risk of venous thrombosis: results from the MEGA case-control study

It is unclear whether hyperglycaemia or diabetes mellitus are risk factors for a first venous thrombosis (VT). Self-reported diabetes status and fasting glucose (FG) measures were collected from the Multiple Environmental and Genetic Assessment (MEGA) study to confirm these associations. FG levels were categorized based on the World Health Organization criteria [<6·1 (reference), 6·1–7·0 (2nd), ≥7·0 (3rd) mmol/l]. Logistic regression was performed to quantify the associations. Neither increased FG levels [Odds ratio (95% confidence interval): 0·98 (0·69–1·37) 2nd vs. reference, 0·97 (0·58–1·63) 3rd vs. reference] nor self-reported diabetes [1·12 (0·80–1·58)] were associated with an increased risk of a first VT.     

No association between the common MTHFR 677C->T polymorphism and venous thrombosis: results from the MEGA study

BACKGROUND: Increased homocysteine levels are related to the occurrence of venous thrombosis, but whether this relation is causal is unclear. The T-variant of the common methylenetetrahydrofolate reductase (MTHFR) 677C-->T polymorphism mildly increases homocysteine levels. Meta-analyses have demonstrated a weak effect of the MTHFR 677TT genotype on risk but are sensitive to selective publication of positive results. The aim of the present study was to evaluate the effect of the MTHFR genotype on the risk of venous thrombosis, overall and in subgroups of known risk factors, in a single large study. METHODS: In the Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis (MEGA Study), a population-based case-control study, we collected DNA from 4375 patients with a first deep vein thrombosis of the leg or pulmonary embolism and from 4856 control subjects. Information about risk factors for venous thrombosis was obtained from questionnaires. RESULTS: MTHFR 677C-->T was not associated with the risk of venous thrombosis (odds ratio [95% confidence interval], 0.99 [0.91-1.08] for the CT genotype and 0.94 [0.81-1.08] for the TT genotype). Stratification by known risk factors for venous thrombosis provided no evidence of an association in specific groups. CONCLUSIONS: In a single large study, MTHFR 677C-->T was not associated with the risk of venous thrombosis, and the narrow confidence interval excludes even a small effect. Therefore, mildly elevated homocysteine levels as a result of MTHFR 677TT do not seem to cause venous thrombosis. There is no rationale for measuring the MTHFR 677C-->T variant for clinical purposes.     

Identification of persons with high risk of venous thrombosis]

The aim of identification of patients with high risk of deep venous thrombosis is a selective and more efficiency prophylaxis. Deficiencies of coagulation inhibiting and fibrinolytic proteins are implicated in less than 10% of patients. However there are several clinical situations with an increased risk of thrombosis. Thus the characterization of blood abnormalities as screening tests for the diagnosis of patients at risk is an important goal.     

Ruling out deep vein thrombosis in patients with superficial vein thrombosis: external validation of the ICARO score

Journal of Thrombosis and Thrombolysis - A clinical score was recently proposed to rule out concomitant DVT in patients with a clinical suspicion of SVT. This study aimed to assess the external...     

Single nucleotide polymorphisms and the risk of venous thrombosis: results from a Danish case‐cohort study

A number of single nucleotide polymorphisms (SNP) have been linked to higher risk of venous thromboembolism (VTE). We investigated the VTE risk associated with SNPs in the GP6 (rs1613662), SERPINC1 (rs2227589), F11 (rs2036914 and rs2289252), FGG (rs2066865), and F12 (rs1801020) genes. In F11, the CC genotype for rs2036914 and the CT and TT genotypes for rs2289252 were associated with a significantly higher VTE risk. A trend toward a thrombogenic effect was observed for the risk alleles of the GP6 and FGG SNPs. Risk estimates were unaffected by adjustments for blood type and F5 rs6025 (Factor V Leiden) mutation.     

Anemone study: prevalence of risk factors for superficial vein thrombosis in a large Italian population of blood donors

Journal of Thrombosis and Thrombolysis - Knowledge of the distribution of risk factors for superficial thrombosis (SVT) in low-risk population is fundamental to improve the prevention of the...     

Recurrent venous thromboembolism after deep vein thrombosis: incidence and risk factors

BACKGROUND: The recurrence rate after deep vein thrombosis (DVT) is high and the risk factors for recurrent thromboembolic events have only been investigated on a small scale. OBJECTIVES: To estimate the cumulative incidence of recurrent venous thromboembolic events after a first or a second DVT and to identify possible risk factors for recurrent venous thromboembolism. METHODS: We prospectively followed up 738 consecutive patients with an objectively verified symptomatic DVT for 3.7 to 8.8 years. Medical records and death certificates for all patients were reviewed during follow-up and recurrent DVT and pulmonary embolism were registered. RESULTS: The 5-year cumulative incidence of recurrent venous thromboembolic events was 21.5% (95% confidence interval [CI], 17.7%-25.4%) after a first DVT and 27.9% (95% CI, 19.7%-36.1%) after a second DVT. The 5-year cumulative incidence of fatal pulmonary embolism was 2.6% (95% CI, 1.1%-4.1%) after a first DVT. Proximal DVT (relative risk [RR], 2.40; 95% CI, 1.48-3.88; P<.001), cancer (RR, 1.97; 95% CI, 1.20-3.23; P<.001), and history of a venous thromboembolism (RR, 1.71; 95% CI, 1.16-2.52; P<.01) predicted an independently increased risk of recurrent events in multivariate survival analysis. Postoperative DVT (RR, 0.27; 95% CI, 0.13-0.55; P<.001) and a long duration of oral anticoagulation therapy (RR, 0.95; 95% CI, 0.92-0.98; P<.01) involved a smaller risk of recurrent events. Sex, age, initial antithrombotic therapy, or immobilization did not affect the risk of a recurrent event. CONCLUSIONS: The recurrence rate after a symptomatic DVT is high. Patients with proximal DVT, diagnosed cancer, short duration of oral anticoagulation therapy, or a history of thromboembolic events had a higher risk of recurrent events, while patients with postoperative DVT had a lower recurrence rate. This knowledge could help identify patients who might benefit most from prolonged prophylactic treatment in various risk situations.     

Arterial cardiovascular risk factors and venous thrombosis: results from a population-based, prospective study (the HUNT 2)

Background

An explanation for the increased risk of myocardial infarction and stroke in patients with venous thrombosis is lacking. The objective of this study was to investigate whether risk factors for arterial cardiovascular disease also increase the risk of venous thrombosis.

Design and Methods

Cases who had a first venous thrombosis (n=515) and matched controls (n=1,505) were identified from a population-based, nested, case-cohort study (the HUNT 2 study) comprising 71% (n=66,140) of the adult residents of Nord-Trøndelag County in Norway.

Results

The age- and sex-adjusted odds ratio of venous thrombosis for subjects with concentrations of C-reactive protein in the highest quintile was 1.6 (95% confidence interval: 1.2–2.2) compared to subjects with C-reactive protein in the lowest quintile. This association was strongest in subjects who experienced venous thrombosis within a year after blood sampling with a three-fold increased risk of participants in the highest versus the lowest quintile. Having first degree relatives who had a myocardial infarction before the age of 60 years was positively associated with venous thrombosis compared to not having a positive family history [odds ratio 1.3 (95% confidence interval: 1.1–1.6)]. Subjects with blood pressure in the highest quintile had half the risk of developing venous thrombosis compared to subjects whose blood pressure was in the lowest quintile. There were no associations between the risk of venous thrombosis and total cholesterol, low density lipoprotein-cholesterol, high density lipoprotein-cholesterol, triglycerides, glucose or smoking. We confirmed the positive association between obesity and venous thrombosis.

Conclusions

C-reactive protein and a family history of myocardial infarction were positively associated with subsequent venous thrombosis. Blood pressure was inversely correlated to venous thrombosis. These findings should be confirmed by further investigations.     

The risk of subsequent cancer and arterial cardiovascular events in patients with superficial vein thrombosis in the legs

Although it has been clearly demonstrated that venous thromboembolism is associated with an increased risk of subsequent overt cancer and arterial cardiovascular events in comparison with control populations, whether this association also applies to patients with isolated (ie, without concomitant involvement of the deep vein system) superficial vein thrombosis (SVT) in the legs is unknown. In 737 consecutive patients with isolated SVT not involving the sapheno-femoral junction, we conducted a retrospective investigation to assess the rate of cancer and that of arterial cardiovascular events occurring during follow-up. The event rates were compared with those occurring in 1438 controls having comparable characteristics. Both cases and controls were followed-up for an average period of 26 ± 8 months (range, 3-45). Malignancy was diagnosed in 26 cases (3.5%) and 56 controls (3.9%), leading to a hazard ratio of 0.86 (95% confidence interval, 0.55%-1.35%). Arterial cardiovascular events occurred in 32 cases (4.3%) and 63 controls (4.4%), leading to a hazard ratio of 0.97 (95% confidence interval, 0.63%-1.50%). We conclude that the occurrence of isolated SVT in the legs does not place patients at an increased risk of malignancies or arterial cardiovascular events. Whether this conclusion also applies to patients whose thrombosis involves the sapheno-femoral junction remains to be demonstrated.     

Follow-up study of patients with clinically suspected deep venous thrombosis and a normal venogram

Abstract. Objectives. To evaluate the clinical course in patients with clinically suspected deep venous thrombosis (DVT) of the leg and a normal venogram. Design. Prospective study over 15 months with a follow-up of 4–12 (median 8.6) months after a normal venogram. A questionnaire survey was performed at follow-up. Information from general practitioners and medical records was reviewed. An alternative diagnosis was established at presentation and at the time of follow-up. Setting. The Department of Internal Medicine in a Danish university hospital. Subjects. A total of 133 consecutive out-patients referred with clinical suspicion of DVT and a normal venogram. Main outcome measures. The state of symptoms at follow-up. The frequency of referrals to hospitals and contacts with general practitioners or medical specialists in the follow-up period. Clinical diagnoses provided at presentation and at follow-up. Results. The follow-up response rate was 78% (n = 104). The symptoms were still present at follow-up in 53 (51%) patients. More than half of the patients had been referred to medical facilities for the same disorder. Diagnoses could be established in 93 (70%) of the 133 patients at presentation and in 119 (89%) at follow-up. Conclusions. The majority of patients with clinical signs and symptoms of a DVT and a normal venogram may require a follow-up surveillance programme to ensure correct diagnosis and adequate treatment. Further studies are recommended to confirm our results and to assess the cost-effectiveness.     

Clinical outcome of patients with upper-extremity deep vein thrombosis: results from the RIETE Registry

BACKGROUND: There is little information on the clinical outcome of patients with upper-extremity deep vein thrombosis (DVT). METHODS: RIETE is an ongoing registry of consecutive patients with objectively confirmed, symptomatic, acute DVT or pulmonary embolism (PE). In this analysis, we analyzed the demographic characteristics, treatment, and 3-month outcome of all patients with DVT in the arm. RESULTS: Of the 11,564 DVT patients enrolled, 512 patients (4.4%) had arm DVT. They presented less often with clinically overt PE (9.0% vs 29%; odds ratio, 0.24; 95% confidence interval [CI], 0.18 to 0.33) than those with lower-limb DVT, but their 3-month outcome was similar. Of the 512 patients with arm DVT, 196 patients (38%) had cancer and 228 patients (45%) had catheter-related DVT. During follow-up, those with cancer DVT had an increased incidence of major bleeding (4.1% vs 0.9%; odds ratio, 4.4; 95% CI, 1.2 to 21), recurrent venous thromboembolism (6.1% vs 2.8%; odds ratio, 2.2; 95% CI, 0.91 to 5.6; p = 0.04), and death (22% vs 3.5%; odds ratio, 7.8; 95% CI, 4.0 to 16). Thirty patients had the composite event of recurrent DVT, symptomatic PE, or major bleeding. They were significantly older, more often had cancer, and presented more frequently with symptomatic PE on hospital admission. On multivariate analysis, only cancer patients with arm DVT had an increased risk for the composite event (odds ratio, 3.0; 95% CI, 1.4 to 6.4). CONCLUSIONS: At presentation, patients with arm DVT have less often clinically overt PE than those with lower-limb DVT, but their 3-month outcome is similar. Among patients with arm DVT, those with cancer have the worse outcome.     

Coagulation of the blood in lusteroid tubes: A study of normal persons and patients with arterial or venous thrombosis

Coagulation times in the lusteroid tubes used throughout this work were in the range of 14 to 28 minutes in a series of fifty normal controls. There is apparently no significant variation in coagulation time obtained when new or used tubes from the same batch were used. However, normal values must be determined for each new batch of tubes before they are put into use.The reliability of the test varies with the range of coagulation time. In the short range the experimental variation is very small; in the normal range it is somewhat greater.In nine (50 per cent) of the eighteen patients with arteriosclerosis obliterans studied, the coagulation times as measured by the lusteroid method were definitely less than for the normal subjects. No cases of acute occlusion were studied.Ten patients with clinically active or quiescent thromboangiitis obliterans with and without phlebitis were studied. In only three (30 per cent) was there any significant decrease of lusteroid coagulation time. These were two of the group of five patients with clinically active cases.The most pronounced shortening to less than normal of lusteroid coagulation time occurred in the patients with acute thrombophlebitis. It was noted in eight of the nine patients studied. Normal coagulation times were found in the two patients with subsiding thrombophlebitis. It is suggested that determination of the coagulation time in lusteroid tubes may be of value in indicating a tendency to thrombosis.     

Residual venous thrombosis as predictive factor for recurrent venous thromboembolim in patients with proximal deep vein thrombosis: a sytematic review

The potential role of the detection of residual thrombosis after deep vein thrombosis (DVT) in the differentiation of patients at risk for recurrent venous thromboembolism (VTE) has not yet been fully established and includes different definitions. We performed a systematic review in order to determine the role of residual thrombosis in predicting recurrent VTE after acute proximal DVT. Databases were searched until June 2010. Randomized, controlled trials or prospective cohort studies were eligible for inclusion if they included patients with objectively diagnosed proximal DVT, measured thrombus diameter after at least 3 months and reported recurrent VTE during follow‐up. Two authors independently reviewed articles and extracted data. Data from 11 studies were used for the current analysis; in total 3203 patients were included. Residual thrombosis was positively correlated with recurrent VTE. Large heterogeneity was present, due to differences in study population, timing and the differences in method of measuring residual thrombosis. The effect was more pronounced in patients with malignancy or was dependent on the criteria used. This systematic review shows a positive relationship between residual thrombosis and recurrent VTE during follow‐up. Assessing residual thrombosis could be useful in individual recurrence risk estimation.     

Low risk of central venous thrombosis with nontunnelled central venous catheters

142 noncuffed, nontunnelled, single lumen central venous catheters were inserted in 103 patients with haematological malignancy. Insertion related complications were minimal and no symptomatic catheter-related central venous thrombosis occurred. Nontunnelled central venous catheters are an excellent alternative to the more commonly used tunnelled devices in terms of convenience, cost-effectiveness and low incidence of side effects.     

An epidemiologic study of risk factors for deep vein thrombosis in medical outpatients: the Sirius study

BACKGROUND: Little information is available concerning risk factors for venous thromboembolism (VTE) in nonhospitalized patients. PARTICIPANTS AND METHODS: An epidemiologic case-control study of deep vein thrombosis (DVT) risk factors was conducted in 1272 outpatients by general practitioners. The case population (636 patients presenting with DVT) was paired with the control population (636 patients presenting with influenzal or rhinopharyngeal syndrome) according to sex and age. Deep vein thrombosis was to be documented by at least 1 objective test. Risk factors were classified into "intrinsic" ("permanent") and "triggering" ("transient") factors and were evidenced using univariate analysis. RESULTS: In the medical population, defined as patients who had not undergone surgery or application of a plaster cast to the lower extremities within the 3 weeks preceding inclusion (494 cases and 494 controls), intrinsic factors such as history of VTE, venous insufficiency, chronic heart failure, obesity, immobile standing position, history of more than 3 pregnancies, and triggering factors such as pregnancy, violent effort, or muscular trauma, deterioration of general condition, immobilization, long-distance travel, and infectious disease were significantly more frequent in the case patients than in the controls (odds ratio, >1; P<.05). In the overall population, additional risk factors were cancer, blood group A, plaster cast of the lower extremities, and surgery. In both populations, the number of risk factors per patient was greater in the case patients than in the controls. CONCLUSION: Several risk factors for DVT were identified in medical outpatients presenting with DVT, and their comprehension may improve appropriateness and efficiency of the different methods available for thromboprophylaxis. Arch Intern Med. 2000;160:3415-3420.