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.     

Randomized controlled trial of tissue plasminogen activator in proximal deep venous thrombosis

PURPOSE: To compare the efficacy and safety of recombinant human tissue-type plasminogen activator (rt-PA, supplied as Activase) with heparin alone or rt-PA plus heparin in the treatment of venographically documented proximal deep venous thrombosis (DVT) of the leg. PATIENTS AND METHODS: Sixty-four patients underwent 65 randomizations to rt-PA alone (n = 36), rt-PA plus heparin (n = 17), or heparin alone (n = 12) in a prospective, multicenter, randomized, open-label trial, with efficacy assessed by a radiology panel unaware of treatment assignment. Patients randomly assigned to rt-PA received 0.05 mg/kg/hour for 24 hours via a peripheral vein, with a maximum dose of 150 mg. All patients then received heparin and warfarin for the remainder of the hospitalization. Follow-up venography was performed 24 to 36 hours after initiation of therapy. RESULTS: Complete or more than 50% lysis occurred in 10 (28%) patients treated with rt-PA, five (29%) patients with rt-PA plus heparin, and no patient treated with heparin. No lysis occurred in 16 (44%) patients treated with rt-PA plus heparin, and 10 (83%) patients who received heparin alone (p = 0.04). There was one major complication, a nonfatal intracranial hemorrhage in a patient who received rt-PA alone. At 7 to 10 days after initiation of treatment, the level of serum glutamic oxaloacetic transaminase nearly doubled among all patients, including those assigned to receive heparin alone. CONCLUSION: (1) rt-PA and rt-PA plus heparin cause more clot lysis than heparin alone; (2) the addition of heparin to rt-PA does not improve the lysis rate; (3) DVT treated with heparin is commonly associated with a rise in the transaminase level; (4) heparin does not increase the risk of bleeding from rt-PA therapy; and (5) alternative dosing regimens and modes of administration of rt-PA should be investigated to improve further its efficacy and safety in the treatment of acute DVT.     

Fibrinolytic therapy of deep vein thrombosis with continuous intravenous infusion of a recombinant tissue plasminogen activator

Recombinant human rt-PA was administered to 22 patients with deep vein thrombosis at a dosage of 30 to 120 mg/day (0.5 to 1.76 mg/kg body weight/24 hr) over 2 to 10 days. rt-PA induced phlebographically documented substantial recanalization in 18 of 21 patients. The lowest dose of 0.5 mg/kg/24 hr tested here was thrombolytically effective, whereas a dose of 0.95 mg/kg/24 hours and more led to hemorrhagic complications and premature discontinuation of therapy in four of six patients. Blood clotting analysis did not reveal any substantial decrease in fibrinogen concentrations, whereas the euglobulin clot lysis time and thromboelastography demonstrated a systemic fibrinolytic effect. Therapy with rt-PA can thus be considered as an alternative and effective method of therapy in treatment of deep vein thrombosis. The results of this study show that even a dosage of lower than 0.5 mg/kg/24 hr might prove to be effective. Further studies would be required to show whether the fibrin specificity of rt-PA leads to a superiority of this fibrinolytic substance over the conventional thrombolytic agents, streptokinase and urokinase.     

Increased concentration of the fast-acting plasminogen activator inhibitor in plasma associated with familial venous thrombosis

We have earlier demonstrated that in a family with a tendency to recurrent venous thrombosis the release of tissue plasminogen activator (t-PA) activity in blood after stimulation was abnormally low. This observation could be related either to an impaired release of t-PA into the blood stream or to a masking of the released t-PA by a high concentration of PA inhibitor(s). In order to distinguish between these two possibilities the family was reinvestigated using various newer techniques, including an ELISA for t-PA, an assay for quantitation of the fast-acting PA inhibitor and SDS polyacrylamide gel electrophoresis followed by fibrin-enzymography. Hereby the family members were demonstrated to have a high concentration in plasma of the PA inhibitor. After stimulation the release of t-PA into the blood was normal, the t-PA activity, however, was immediately inactivated by complex formation with the fast-acting PA inhibitor.     

Tissue plasminogen activator for the treatment of deep venous thrombosis of the lower extremity: a systematic review

OBJECTIVE: To assess, by systematic review, the efficacy and safety of recombinant tissue plasminogen activator (rt-PA) in the treatment of lower extremity deep venous thrombosis (DVT). A secondary objective is to assess the optimal dose and route of administration of rt-PA. METHODS: Included studies were randomized, controlled trials comparing rt-PA plus unfractionated heparin (UFH) to UFH alone, rt-PA at different doses, or rt-PA by different routes of administration in the treatment of DVT. Outcomes had to be described in terms of percent change in venographic patency for efficacy (>50% lysis) and in sufficient detail for complications (major and minor hemorrhages and other). The search strategy included searching electronic databases and contacting pharmaceutical agencies and content experts. Study quality was assessed using the Jadad scale. A threshold quality score was used to exclude trials. RESULTS: Five studies met the following inclusion criteria: three comparing rt-PA plus UFH vs UFH alone (180 patients); one comparing high-dose vs low-dose rt-PA (32 patients); and one comparing systemic vs local administration of rt-PA (151 patients). In studies comparing rt-PA vs placebo, patients assigned to rt-PA were more likely to have > 50% lysis and complications (summary odds ratios [OR], 11.7; 95% confidence interval [CI], 2.61 to 52.5; and OR, 9.95; 95% CI, 2.21 to 44.7, respectively). Major and intracerebral hemorrhages were not significantly increased. One study comparing different doses demonstrated that high-dose and low-dose rt-PA were equally efficacious (OR, 0.88; 95% CI, 0.05 to 14.78). Local rt-PA was neither more efficacious nor riskier than systemic rt-PA. CONCLUSION: This systematic review does not support routine use of rt-PA for DVT.     

Residual vein thrombosis for assessing duration of anticoagulation after unprovoked deep vein thrombosis of the lower limbs: the extended DACUS study

The safest duration of anticoagulation after idiopathic deep vein thrombosis (DVT) is unknown. We conducted a prospective study to assess the optimal duration of vitamin K antagonist (VKA) therapy considering the risk of recurrence of thrombosis according to residual vein thrombosis (RVT). Patients with a first unprovoked DVT were evaluated for the presence of RVT after 3 months of VKA administration; those without RVT suspended VKA, while those with RVT continued oral anticoagulation for up to 2 years. Recurrent thrombosis and/or bleeding events were recorded during treatment (RVT group) and 1 year after VKA withdrawal (both groups). Among 409 patients evaluated for unprovoked DVT, 33.2% (136 of 409 patients) did not have RVT and VKA was stopped. The remaining 273 (66.8%) patients with RVT received anticoagulants for an additional 21 months; during this period of treatment, recurrent venous thromboembolism and major bleeding occurred in 4.7% and 1.1% of patients, respectively. After VKA suspension, the rates of recurrent thrombotic events were 1.4% and 10.4% in the no-RVT and RVT groups, respectively (relative risk = 7.4; 95% confidence interval = 4.9-9.9). These results indicate that in patients without RVT, a short period of treatment with a VKA is sufficient; in those with persistent RVT, treatment extended to 2 years substantially reduces, but does not eliminate, the risk of recurrent thrombosis.     

Determination of plasma tissue type plasminogen activator and plasminogen activator inhibitor activity in patients with ischemic stroke

Plasma tissue-type plasminogen activator and plasminogen activator inhibitor were determined during the acute, recovery and sequelae stages of patients with ischemic stroke by chromophoric substrate assay. The result showed that t-PA activity was elevated during the acute phase, remained elevated during the recovery stage and declined during the sequelae stage. Lowering of PAI activity was found during acute phase, which reversed during recovery phase and remained significantly elevated during sequelae stage. As a result, the ratio of PAI/t-PA fluctuated during different stages of the disease. Significant elevation of PAI and PAI/t-PA ratio during sequelae stage may be one of the risk factors of further thrombosis and contribute partly to the high relapsing rate of the disease. In addition, a positive correlation was found between PAI and serum cholesterol content.     

The release of plasminogen activators (t-PA and u-PA) and plasminogen activator inhibitor (PAI-1) after venous stasis.

The aim of the present study was to compare plasma levels of urokinase-type plasminogen activator (u-PA), before and after 20 min of venous stasis, with those of tissue-type plasminogen activator (t-PA), type 1 plasminogen activator inhibitor (PAI-1) and t-PA/PAI-1 complexes, to determine whether both plasminogen activators and their inhibitor respond similarly to the same stimulus. We studied 36 patients with recurrent venous thrombosis in whom no coagulation defects predisposing them to thrombosis had been detected (mean age 38.2 years, range 15-70 years). Twenty healthy individuals (mean age 34.3 years, range 20-60 years) served as a control group. t-PA, PAI-1 and u-PA activity and antigen, as well as the t-PA/PAI-1 complex antigen, were measured before and after venous stasis. Post-stasis fibrinolytic parameters were corrected for the haemoconcentration which occurred during the venous occlusion test. Pathologically high PAI-1 levels (antigen and activity) were found in four out of 36 patients who were excluded from study. Functional and antigenic u-PA increased significantly after venous stasis when analysed as the absolute differences between paired samples (P less than 0.01). This increase in u-PA did not correlate with changes in t-PA or PAI-1 (r = 0.28 and r = 0.36 respectively). This leads us to suggest that different mechanisms relating to clearance and/or release from diverse sources might be involved in elevations of u-PA in response to a local endothelial stimulus. We conclude that venous stasis might not be the elective choice when evaluating 'bad responders' predisposed to thrombosis.     

Prothrombotic clot properties can predict venous ulcers in patients following deep vein thrombosis: a cohort study

Journal of Thrombosis and Thrombolysis - Venous ulcers are the most severe manifestation of post-thrombotic syndrome (PTS). We have previously demonstrated that formation of compact fibrin clots...     

Baseline fibrinolytic state and the risk of future venous thrombosis. A prospective study of endogenous tissue-type plasminogen activator and plasminogen activator inhibitor.

BACKGROUND. Although isolated abnormalities of plasminogen activation and inhibition have been reported among selected patients with venous thrombosis, it is unclear whether these deficiencies of fibrinolysis are important risk factors for thromboembolic disease. METHODS AND RESULTS. To evaluate whether baseline levels of endogenous tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) predict the future occurrence of venous thrombosis, levels of these proteins were measured in prospectively collected plasma samples from 55 participants in the Physicians' Health Study who later developed deep venous thrombosis or pulmonary embolism and from an equal number of age- and smoking-matched control subjects who remained free of vascular disease during a mean follow-up period of 60.2 months. Overall, there were no statistically significant differences between case patients and control subjects in baseline levels of PAI-1 (50.5 versus 59.5 ng/ml, p = 0.26), t-PA (13.4 versus 13.3 ng/ml, p = 0.94), or PAI-1:t-PA ratio (6.84 versus 6.58, p = 0.82). No evidence of a threshold effect or trend was seen when these data were analyzed by increasing quartiles of PAI-1 (p = 0.73), t-PA (p = 0.62), or PAI-1:t-PA ratio (p = 0.93). These results were unchanged after multivariate analysis that simultaneously controlled for other baseline cardiovascular risk factors. CONCLUSIONS. In contrast to previous uncontrolled case series and smaller retrospective studies, these prospective data provide strong evidence that baseline fibrinolytic state, as measured by t-PA and PAI-1, does not predict the occurrence of future venous thrombosis.     

Tissue plasminogen activator for hepatic vein thrombosis in paroxysmal nocturnal haemoglobinuria

Abstract. Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired clonal disorder thought to arise in a multipotent haemopoietic stem cell. A distinct clinical feature is a tendency to thrombosis, with a particular predilection for the hepatic veins (Budd-Chiari syndrome). We report here on two patients with PNH who developed hepatic vein thrombosis (HVT) and who were treated with tissue plasminogen activator (t-PA). Both patients had a marked clinical and radiological improvement following the t-PA treatment and remain well over 2 years and 6 years after the treatment. This method of thrombolysis for HVT occurring in PNH has only been reported in two previous patients with limited follow-up. We suggest that this therapy is a useful first-line treatment for PNH patients who develop HVT.     

Clinical significance of plasminogen activator inhibitor activity in patients with exercise-induced ischemia

To assess the fibrinolytic system in patients with exercise-induced ischemia and its relation to ischemia and severity of coronary artery disease (CAD), 47 patients with CAD confirmed by results of coronary angiography underwent symptom-limited multistage exercise thallium-201 emission computed tomography. All patients with CAD had exercise-induced ischemia as assessed from thallium-201 images. Pre- and peak exercise blood samples from each patient and preexercise blood samples from control subjects were assayed for several fibrinolytic components and were also assayed for plasma adrenaline. The extent of ischemia was defined as delta visual uptake score (total visual uptake score in delayed images minus total visual uptake score in initial images) and the severity of CAD as the number of diseased vessels. In the basal condition, plasminogen activator inhibitor (PAI) activity was significantly higher in patients with exercise-induced ischemia as compared to control subjects (p less than 0.01), although there were no significant differences in other fibrinolytic variables between the two groups. Moreover, PAI activity in the basal condition displayed a significantly positive correlation with the extent of ischemia (r = 0.47, p less than 0.01). Patients with exercise-induced ischemia were divided into two groups (24 with single-vessel disease and 23 with multivessel disease). There were no significant differences in coronary risk factors, hemodynamics, or plasma adrenaline levels during exercise between single-vessel and multivessel disease except that delta visual uptake score was significantly higher in multivessel disease (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Residual vein obstruction in patients diagnosed with acute isolated distal deep vein thrombosis associated with active cancer

Journal of Thrombosis and Thrombolysis - After acute proximal deep vein thrombosis (DVT) the thrombotic mass decreases, especially during the first months of anticoagulation. The persistence of...     

Metabolic syndrome and hyperhomocysteinemia in patients with deep vein thrombosis: a case-control study

We evaluated the prevalences of metabolic syndrome (MS) and hyperhomocysteinemia in patients with unprovoked deep vein thrombosis (DVT) and in controls. MS and hyperhomocysteinemia were significantly more prevalent in DVT patients than in controls. However, only the presence of MS was independently associated with DVT, and the coexistence of both risk factors did not increase the magnitude of the association.     

Recurrent thrombosis in patients with deep vein thrombosis and/or venous thromboembolism associated with anticardiolipin antibodies

Anticardiolipin antibodies represent one of the main hypercoagulation states associated with venous thromboembolism. The aim of this work was to evaluate symptomatic recurrent thrombosis in patients with anticardiolipin antibodies and deep vein thrombosis of the lower limbs with or without thromboembolism. Sixty patients who suffered from deep vein thrombosis were observed for a 5-year period, whether they had anticardiolipin antibodies or not. The group was made up of 34 females and 26 males with ages ranging from 13 to 73 years. All were diagnosed with deep vein thrombosis by means of phlebography and were tested for anticardiolipin antibodies by use of the ELISA method. The symptomatic signs of recurrent thrombosis were evaluated during this period. In total, 56.6% of the group were considered above normal for anticardiolipin antibodies, 25% positive, another 31.6% borderline, and 43.4% negative. Patients were tested positive when the anticardiolipin antibody count was >15 units/mL, borderline between 10 and 15 units/mL, and normal when <10 units/mL. The method of relative risk was used for statistical analysis of the results. Four positive patients, 1 borderline, and 1 normal patient had recurrent events of thrombosis. In the statistical analysis the relative risk for recurrent thrombosis in the positive patients was 6.0; CI 95%; 1.2 to 29.5. In conclusion patients with deep vein thrombosis who are positive for anticardiolipin antibodies present a higher risk of recurrent thrombosis.     

Idiopathic osteonecrosis,hypofibrinolysis, high plasminogen activator inhibitor,high lipoprotein(a), and therapy with stanozolol

In five patients with idiopathic osteonecrosis (ON) of the hip, four having hypofibrinolysis mediated by high plasminogen activator inhibitor (PAI-Fx), and one with high Lp(a), our specific aim was to determine whether therapy (Rx) with the anabolic-androgenic steroid, Stanozolol(6 mg/day), would normalize PAI-Fx and Lp(a) and thus potentially ameliorate ON. Prior to Rx, none of the four patients with high PAI-Fx could normally elevate tissue plasminogen activator (tPA-Fx) after 10 min venous occlusion at 100 mm Hg. After 12-18 weeks on Rx, PAI-Fx and stimulated tPA-Fx normalized in all four patients. Prior to Rx, mean (SD) stimulated tPA-Fx was low, 0.4 ± 0.3 IU/ml (lower limit of normal 2.28 IU/ml). On Rx, stimulated tPA-Fx normalized, rising to 2.83 ± 1.9 IU/ml, P = 0.004. Prior to Rx, mean (SD) basal PAI-Fx was high, 99 ± 68 (upper limit of normal 26.9 U/ml), and fell on Rx to 22.5 ± 22, P = 0.004. In two of the five patients normalization of hypofibrinolysis or high Lp(a) was accompanied by major symptomatic improvement. Prior to Rx, and 2 years after onset of unilateral hip pain, one of the four patients with high PAI-Fx and low stimulated tPA-Fx could walk only one block painfully. After 8 weeks on Stanozolol Rx, and continuing through 54 weeks on Rx, he walked 2 miles per day without pain, despite radiographic progression of ON. In three of the four patients with high PAI and with osteonecrosis present 0.3, 2, and 6 years prior to Stanozolol Rx, there was no clinical improvement after 14-156 weeks of Rx despite normalization of stimulated tPA-Fx and PAI-Fx. The fifth patient, 1 month after onset of disabling hip pain, had normal PAI-Fx but high Lp(a) (27 mg/dl), and MRI evidence of bone marrow edema (“transient osteoporosis”). After 3 weeks on Rx, Lp(a) normalized (14 mg/dl) and there was marked amelioration of symptoms. For the subsequent 11 weeks on Rx, this patient's Lp(a) was 5 mg/dl, and he became totally asymptomatic and remains asymptomatic 14 months later. We speculate that when ON is diagnosed prior to segmental collapse of the femoral head, it may be possible to reverse hypofibrinolysis, and/or to arrest the progression of ON. We postulate that high PAI or high Lp(a) lead to inadequate lysis of venous thrombi in bone, impaired bone venous circulation, venous hypertension of bone, and subsequent, potentially reversible development of ON. © 1995 Wiley-Liss, Inc.