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At least 91 records · Page 5Linked to original sources

Guidelines for management of left-sided prosthetic valve thrombosis: a role for thrombolytic therapy. Consensus Conference on Prosthetic Valve Thrombosis.

OBJECTIVES: We sought to form a consensus recommendation for management of prosthetic valve thrombosis (PVT) from previous case and uncontrolled reports from a consensus of international specialists. BACKGROUND: PVT and thromboembolism relate to inadequate anticoagulation and valve type and location. PVT is suspected by history (dyspnea) and auscultation (muffled valve sounds or new murmurs) and confirmed by Doppler echocardiography showing a marked valve gradient. METHODS: A consensus conference was held to recommend management of left-sided PVT. RESULTS: Transesophageal Doppler echocardiography is used to visualize abnormal leaflet motion and the size, location and mobility of thrombus. Thrombolysis is used for high risk surgical candidates with left-sided PVT (New York Heart Association functional class III or IV) because cerebral thromboembolism may occur in 12% of patients. Duration of thrombolysis depends on resolution of pressure gradients and valve areas to near normal by Doppler echocardiography performed every few hours. Lysis is stopped after 72 or 24 h if there is no hemodynamic improvement (operation indicated). Heparin infusion with frequent measurement of activated partial thromboplastin time (aPTT) begins when aPTT is more than twice control levels and can be converted to warfarin (international normalized ratio [INR] 2.5 to 3.5) plus aspirin (81 to 100 mg/day). Patients in functional class I or II have lower surgical mortality, and those with large immobile thrombi on the prosthetic valve or left atrium have responded to endogenous lysis with combined subcutaneous heparin every 12 h (aPTT 55 to 80 s) plus warfarin (INR 2.5 to 3.5) for 1 to 6 months. Operation is advised for nonresponders or patients with mobile thrombi. CONCLUSIONS: Thrombolysis, followed by heparin, warfarin and aspirin, is advised for high risk surgical candidates with left-sided PVT.

Aortic Valve↗

Use of low molecular weight heparin (dalteparin), once daily, for the treatment of deep vein thrombosis. A feasibility and health economic study in an outpatient setting. Swedish Venous Thrombosis Dalteparin Trial Group.

OBJECTIVES: To test the safety and feasibility of treating deep vein thrombosis (DVT) in an outpatient setting, using the low molecular weight heparin dalteparin, to calculate the potential and actual cost reductions achievable as a result of such a treatment regimen. DESIGN: An open, nonrandomized, multicentre trial. SETTING: Fourteen hospitals in central Sweden. SUBJECTS: Ambulant patients, aged 18 years or older. with symptomatic DVT in the leg, diagnosed using phlebography or ultrasound (Duplex-Doppler). INTERVENTIONS: Dalteparin (Fragmin) at a fixed dose of 200 i.u. kg-1 body weight, was administered once daily subcutaneously for at least 4 consecutive days. Treatment with warfarin was initiated from the first day of dalteparin administration. Outpatient treatment was encouraged whenever possible Financial calculations were performed independently at two hospitals, giving an average cost for all actions. OUTCOME MEASURES: Increasing severity of symptoms (or thromboembolic recurrences during the 3-months follow-up period), pulmonary embolism (PE), bleeding events, and death during the initial phase and follow-up period. RESULTS: Of 434 patients, 35% and 64% were treated in hospital within 24 and 72 h, respectively, and thereafter as outpatients. The overall frequency of serious complications was 0.92% (exact 95% confidence interval, 0.25-2.35%) during the initial phase and one patient suffered a PE and three patients had a recurrent DVT during the follow-up period. A cost reduction of 2705529 Swedish crowns (34.5%) was achieved in this study compared with traditional in-patient treatment. CONCLUSIONS: Dalteparin, administered subcutaneously, once daily, for the initial treatment of DVT yields large cost reductions and is well tolerated and effective in an outpatient setting.

Aged↗

Clinical features and prognostic factors of cerebral venous sinus thrombosis in a prospective series of 59 patients. For The Cerebral Venous Sinus Thrombosis Study Group.

The prognosis of cerebral venous sinus thrombosis (CVST) is variable, and outcome may range from complete recovery to death. Prognostic factors to predict outcome in the acute phase of CVST have not been analysed in a prospective study. Prognostic factors in patients enrolled in a clinical treatment trial were prospectively investigated. Poor outcome after 12 weeks, defined as death or dependency (Oxford handicap score > or =3), was used as the principle outcome measure. Univariate relations between possible prognostic factors and outcome at 12 weeks were analyzed with chi(2) tests. Treatment and all factors associated with prognosis (p< or = 0.25) were forced into a logistic regression model with a forward selection procedure. Fifty nine patients (50 women, nine men) were studied, with a mean age of 37 years (range 18 to 80 years). After 12 weeks 10 patients (17%) had a poor outcome. The univariate identified factors related to poor outcome were papilloedema, altered consciousness, coma, age older than 33 years, diagnostic delay < or =10 days, intracerebral haemorrhage, and involvement of the straight sinus. Isolated intracranial hypertension and a delta sign on CT were associated with good outcome. In the multivariate analysis coma and cerebral haemorrhage were significantly associated with a poor outcome, with odds ratios of 8.2 (95% confidence interval (95% CI) 1. 3-50.1) and 20.7 (95% CI 1.6-264.3) respectively. Involvement of the straight sinus was also weakly, but not significantly, associated with poor outcome. In conclusion, coma and intracerebral haemorrhage are independent predictors for poor outcome of CVST.

Adolescent↗

Seminars in thrombosis, thrombolysis, and vascular biology. Part 2: Coagulation and thrombosis.

The hemostatic mechanism is a critical component of a normally functioning circulatory system, preventing life-threatening hemorrhage and assisting in the maintenance of vascular integrity. For longer than half a century, however, nonphysiological intravascular coagulation and thrombosis have been recognized as playing central roles in cardiovascular morbidity and mortality. In order to provide a conceptual framework for the use of antithrombotic therapy, the pathogenetic mechanisms underlying thrombotic events must be clearly understood. The purpose of this review is to define these mechanisms, and discuss the use of anticoagulants in both the prevention and treatment of cardiovascular diseases.

Anticoagulants↗

Comparison of 3 and 6 months of oral anticoagulant therapy after a first episode of proximal deep vein thrombosis or pulmonary embolism and comparison of 6 and 12 weeks of therapy after isolated calf deep vein thrombosis.

BACKGROUND: The optimal duration of oral anticoagulant therapy after a first episode of venous thromboembolism remains controversial. METHODS AND RESULTS: We performed an open-label, randomized trial comparing a short oral anticoagulant course (3 months for proximal deep vein thrombosis [P-DVT] and/or pulmonary embolism [PE]; 6 weeks for isolated calf DVT [C-DVT]) with a long course of therapy (6 months for P-DVT/PE; 12 weeks for C-DVT). The outcome events were recurrences and major, minor, or fatal bleeding complications. A total of 736 patients were enrolled. There were 23 recurrences of venous thromboembolism in the short treatment group (6.4%) and 26 in the long treatment group (7.4%); the 2 treatment regimens had an equivalent effect. For the hemorrhage end point, the difference between the short and the long treatment groups was not significant: 15.5% versus 18.4% for all events (P=0.302), 1.7% versus 2.8% (P=0.291) for major events, and 13.9% versus 15.3% for minor bleeding. Subgroup analysis demonstrated that the rate of recurrence was lower for C-DVT than for P-DVT or PE. CONCLUSIONS: After isolated C-DVT, 6 weeks of oral anticoagulation is sufficient. For P-DVT or PE, we demonstrated an equivalence between 3 and 6 months of anticoagulant therapy. For patients with temporary risk factors who have a low risk of recurrence, 3 months of treatment seems to be sufficient. For patients with idiopathic venous thromboembolism or permanent risk factors who have a high risk of recurrence, other trials are necessary to assess prolonged therapy beyond 6 months.

Administration, Oral↗

[Coronary atherosclerosis, coronary thrombosis and myocardial infarction in autopsy cases. 4th communication: coronary thrombosis (author's transl)].

28978 cases of young (after the 14th year of age) and adult patients autopsied during the period from 1.1 1951 until 31. 12. 1969 in our Institute were scored for coronary thrombosis and analysed concerning frequency and distribution of age and sex, resp. In this material the evidence of morphological changes was proved by longitudinal dissection of the coronary vessels. We analysed the age of thrombi, the localization and the grading of coronary vessels occlusions. Coronary thrombi were found in 2,31 per cent of all autopsies (2,81 per cent in males,1,31 per cent in females). Coronary thromboses showed an increase during the observation period. These thrombi were found more frequently in younger patients. Most of the thrombi (62,20 per cent) were localized in the Arteria coronaria sinistra, 37,80 per cent we found in the Arteria coronaria dextra. Fresh thrombi (57,51 per cent) and those being in organization (42,49 per cent) were not significantly different. Obturating thromboses showed an increase. The numbers of non-obturating thromboses decreased during the observation period. Our findings correspond to similar results published in literature.

Adolescent↗

Exclusion of deep venous thrombosis with D-dimer testing--comparison of 13 D-dimer methods in 99 outpatients suspected of deep venous thrombosis using venography as reference standard.

In a direct assay comparison we evaluated the diagnostic performance of 10 novel D-Dimer assays for the exclusion of deep venous thrombosis (DVT). In addition, 3 conventional ELISA D-Dimer assays were included as reference tests. The study was performed in 99 consecutive outpatients referred to the emergency department for clinical suspicion of DVT. Venography was used as reference standard and demonstrated the presence of DVT in 50 patients (6 patients with isolated distal DVT and 44 patients with proximal DVT). The qualitative D-Dimer assays Minutex and SimpliRED and the quantitative BC DD showed overall sensitivities (for proximal and distal DVT) of only 80-83% with specificities that ranged from 87 to 94%. Overall sensitivity was 94% for the qualitative INSTANT I.A. and 98% for the quantitative Turbiquant at a cut-off level equal to the detection limit. Using different cut-off levels a sensitivity of 100% for proximal DVT and for proximal as well as distal DVT could be obtained for NycoCard, IL DD, Liatest, Tinaquant and VIDAS D-Dimer assays with specificities that ranged from 31% (NycoCard) to 71% (VIDAS) for proximal DVT and from 12% (NycoCard) to 47% (IL DD) for overall DVT. At a cut-off level equal to the upper limit of the reference range only Tinaquant and VIDAS showed a sensitivity of 100% for proximal as well as for distal DVT with a specificity of 39% and 41% respectively. The results of this study suggest that the VIDAS and Tinaquant D-Dimer assays have the highest sensitivity for the exclusion of DVT in outpatients. In outpatients that have a low or moderate pretest probability for DVT, these tests may be used in management studies where anticoagulation is withheld on the basis of D-Dimer testing alone.

Adult↗

Traveller's thrombosis: a review of deep vein thrombosis associated with travel. The Air Transport Medicine Committee, Aerospace Medical Association.

There is an increasing suspicion among the travelling public and the international media of an association between the occurrence of deep venous thrombosis (DVT) and air travel. It was noted by the UK House of Lords Select Committee on Science and Technology that up to 20% of the total population may have some degree of increased clotting tendency. It follows that some air travellers are at risk of developing DVT when, or soon after, travelling. There have been no epidemiological studies published which show a statistically significant increase in cases of DVT when travelling in the absence of pre-existing risk factors. The literature was reviewed. Current evidence indicates that any association between symptomatic DVT and travel by air is weak, and the incidence is less than the impression given by recent media publicity.

Aircraft↗

A new murine model of coronary artery thrombosis and role of interleukin-8 in the development of coronary thrombosis.

Occlusive vascular disease most often results from thrombosis superimposed on atherosclerotic plaque. In the case of an acute coronary syndrome including an acute myocardium infarction or an unstable angina pectoris thrombus in coronary artery takes significant part as known. There are few reports about animal models of acute coronary artery thrombi, because of the difficulties of operative significance. We have succeeded in making thrombus at murine coronary arteries with ferric chloride. Slight or moderate IL-8 expressions were found in the endothelial cells in the thrombus formed vessel analyzed by immunohistochemistry. The interleukin-8 (IL-8) receptor knockout mice formed the slight thrombus in coronary arteries treated with ferric chloride. We propose a role for IL-8 in the pathogenesis of acute coronary artery thrombi. This hypothesis lends itself to testing using interventions to influence IL-8 secretion and actions in the early phase of coronary thrombotic formation.

Animals↗

[Changes in plasma coagulation and fibrinolysis following cesarean section and relationship to deep venous thrombosis. Results of a randomized prospective comparative study with 6% hydroxyethyl starch 0.62 and low-dose heparin as thrombosis prophylaxis].

Routine postoperative monitoring of plasma coagulation and fibrinolysis system values after cesarean delivery in 191 women who did not develop thrombosis and 16 who did revealed a preoperative defect in the fibrinolysis (PAI, TAT) and inhibitor (AT III) systems. Significant postoperative correlations in the drop in antithrombin levels could not be explained solely by hemodilution. Moreover, a disturbance of the equilibrium of the alpha-2 increase and plasminogen was observed, favouring alpha-2 antiplasmin. Hydroxyethyl starch is capable of simultaneously influencing hypercoagulability and postoperative status. The only difference noted between the two groups of drugs was in the course of the PAI concentration (P less than 0.02). It would therefore appear logical in clinical practice to extend preoperative tests to include determination of the plasminogen activator inhibitor and the thrombin-antithrombin complex.

Adult↗

[Right ventricular thrombosis and pulmonary thrombosis associated with venous-peritoneal diversion (Le Veen). Diagnosis with transesophageal echocardiography].

Central venous thrombosis (CVT) and pulmonary embolism (PE) are complications that have been reported in association with the use of venous-peritoneal shunts (Le Veen). CVT usually develops around the proximal end of the catheter; the clinical course is varied and usually requires venous imaging to confirm the diagnosis. We present a case of CVT associated with PE, in which the thrombus was located in the right ventricular cavity (distal to the catheter tip). Two-dimensional transesophageal echocardiography was used for diagnosis and follow-up.

Echocardiography, Transesophageal↗

Association between plasma levels of tissue plasminogen activator and postoperative deep vein thrombosis--influence of prophylaxis with a low molecular weight heparin. The Venous Thrombosis Group.

In a prospective, randomized controlled study, tissue plasminogen activator (t-PA) and tissue plasminogen activator antigen (t-PA:ag) were measured pre- and postoperatively in 40 consecutive patients undergoing total hip replacement. Patients received either a subcutaneous injection of low molecular weight heparin or placebo once daily. Deep vein thrombosis was diagnosed by bilateral phlebography. Patients who developed postoperative thromboembolic complications had significantly lower preoperative t-PA activity levels than patients who did not develop such complications. No difference was observed between the two groups with respect to t-PA:ag. Thromboprophylaxis with low molecular weight heparin did not cause any significant changes in t-PA activity and t-PA:ag. This study in high risk patients indicates that impaired fibrinolysis may be associated with development of thromboembolic complications after operation.

Adult↗

Pulmonary embolism in deep venous thrombosis of the upper extremity: more often in catheter-related thrombosis.

BACKGROUND: Pulmonary embolism (PE) is a major complication of deep venous thrombosis (DVT) of the lower extremities. The incidence is approximately 50%. The incidence of DVT of the upper extremity (DVTUE) is increasing mainly due to the increasing use of central venous catheters. The percentage of PE secondary to DVTUE is still being investigated. METHODS: The occurrence of PE in DVTUE was retrospectively analyzed in 78 patients with proven DVTUE. Furthermore, the literature was reviewed. RESULTS: Of the identified patients with DVTUE 16 showed a primary DVTUE and 62 a secondary DVTUE. Secondary DVTUE was catheter-related in 41 (60%), which is 53% of all DVTUE. In this study the percentage of PE as a complication of DVTUE was 6 (95% CI: 0.2-30) in primary DVTUE, 13 (95% CI: 6-24) in secondary DVTUE and 17 (95% CI: 7-32) in catheter-related DVTUE. The relative risk for PE of catheter-related DVTUE versus other causes was 3.4 (95% CI: 0.4-53.5). The overall percentage was 12 (95% CI: 5-21). The literature review showed a percentage of 7 (95% CI: 4-9) in the retrospective studies and 17 (95% CI: 12-23) in the prospective studies. CONCLUSIONS: Indwelling catheters are the most common cause of DVTUE. PE is not an uncommon complication of DVTUE, and is more common in catheter-related DVTUE. The difference between the incidence of PE in DVTUE and DVT of the lower extremity may be explained by a number of factors, such as differences in fibrinolytic activity, mechanical forces and venous flow patterns.

Adult↗

Real-time B-mode ultrasonography in the diagnosis of postoperative deep vein thrombosis in non-symptomatic high-risk patients. The Venous Thrombosis Group.

In a prospective study of 61 patients who were undergoing elective total hip replacement, the accuracy of real-time B-mode ultrasonography (B-US) in the diagnosis of postoperative deep vein thrombosis (DVT) was compared with blindly assessed bilateral ascending phlebography. The overall sensitivity and specificity of ultrasound was 71 and 94%, and the positive and negative predictive values were 77 and 92%, respectively. The sensitivity and specificity for diagnosis of proximal DVT was 73 and 96%, respectively. Thrombi smaller than 1 cm were not detected. It is concluded that B-US may be used as a screening test for postoperative DVT after elective hip surgery.

Adult↗

Induced thrombosis in the pig inferior vena cava: a model of deep venous thrombosis.

PURPOSE: To establish a new animal model of deep venous thrombosis. MATERIALS AND METHODS: Fifteen young pigs underwent temporary interruption of the inferior vena cava (IVC) below the entry of the right renal vein by means of either a silicone band (surgical technique, n = 6) or an intraluminal balloon catheter (endovascular technique, n = 9), followed by injection of absolute ethanol. Lumbar veins within 3 cm below the obstruction were ligated or occluded interventionally. The iatrogenic caval obstruction was relieved after 2 days. RESULTS: Procedure-related mortality was 33% (n = 2) and 11% (n = 1) for the surgical and endovascular groups, respectively. An adherent, occlusive thrombus was found in all four of the remaining surgically treated animals and in six of eight animals treated percutaneously. The IVC remained patent in two animals in whom balloon migration occurred. Severe caval stenosis invariably occurred after surgical banding. CONCLUSION: IVC thrombi suitable for the study of various recanalization therapies can be reliably created with this pig model.

Angioplasty, Balloon↗