Published online before print July 11, 2005, doi: 10.1161/CIRCULATIONAHA.104.512834
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
(Circulation. 2005;112:416-422.)
© 2005 American Heart Association, Inc.
Preventive Cardiology |
Eight-Year Follow-Up of Patients With Permanent Vena Cava Filters in the Prevention of Pulmonary Embolism
The PREPIC (Prévention du Risque d’Embolie Pulmonaire par Interruption Cave) Randomized Study
From the Thrombosis Research Group, Clinical Pharmacology Department, University Hospital, Saint-Etienne, France.
Correspondence to Hervé Decousus, MD, Groupe de Recherche sur la Thrombose (EA3065), CIC-EC (DHOS/INSERM), Centre Hospitalier et Universitaire de St-Etienne, Hôpital Bellevue, F-42055 Saint-Etienne, France. E-mail herve.decousus{at}chu-st-etienne.fr
Received October 6, 2004; revision received February 18, 2005; accepted March 3, 2005.
 |
Abstract |
|---|
 Top Abstract IntroductionMethodsResultsDiscussionAppendixReferences |
|---|
Background— In a randomized trial in patients with proximal deep-vein thrombosis, permanent vena cava filters reduced the incidence of pulmonary embolism but increased that of deep-vein thrombosis at 2 years. An 8-year follow-up was performed to assess their very long-term effect.
Methods and Results— Four hundred patients with proximal deep-vein thrombosis with or without pulmonary embolism were randomized either to receive or not receive a filter in addition to standard anticoagulant treatment for at least 3 months. Data on vital status, venous thromboembolism, and postthrombotic syndrome were obtained once a year for up to 8 years. All documented events were reviewed blindly by an independent committee. Outcome data were available in 396 patients (99%). Symptomatic pulmonary embolism occurred in 9 patients in the filter group (cumulative rate 6.2%) and 24 patients (15.1%) in the no-filter group (P=0.008). Deep-vein thrombosis occurred in 57 patients (35.7%) in the filter group and 41 (27.5%) in the no-filter group (P=0.042). Postthrombotic syndrome was observed in 109 (70.3%) and 107 (69.7%) patients in the filter and no-filter groups, respectively. At 8 years, 201 (50.3%) patients had died (103 and 98 patients in the filter and no-filter groups, respectively).
Conclusions At 8 years, vena cava filters reduced the risk of pulmonary embolism but increased that of deep-vein thrombosis and had no effect on survival. Although their use may be beneficial in patients at high risk of pulmonary embolism, systematic use in the general population with venous thromboembolism is not recommended.
Key Words: vena cava filters • prevention • thrombosis • trials • pulmonary embolism
|
Introduction |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionAppendixReferences |
|---|
Although anticoagulation remains the primary treatment for venous thromboembolism, vena cava filters are an important alternative or add-on therapeutic strategy,1 used in up to 15% of patients with deep-vein thrombosis in a recent prospective registry.2 However, very few reliable data on the long-term efficacy and safety of these devices are available.3,4 Venous thromboembolism is a chronic disease with risk of recurrence that may persist for many years, and permanent vena cava filters may provide lifelong protection from potentially fatal pulmonary embolism. Conversely, use of vena cava filters may be complicated by adverse events, the frequency of which may increase over time. They have no prophylactic effect on the recurrence of deep-vein thrombosis, and their use may favor the development of the postthrombotic syndrome.3
See p 298
The PREPIC (Prévention du Risque d’Embolie Pulmonaire par Interruption Cave) study is the only long-term randomized study of filter placement in the prevention of pulmonary embolism.5 In 400 patients with proximal deep-vein thrombosis followed up for 2 years, the insertion of a vena cava filter in combination with standard anticoagulation was associated with a reduction in the occurrence of pulmonary embolism compared with anticoagulation alone. However, this beneficial effect was counterbalanced by a significant increase in deep-vein thrombosis; in addition, filters had no impact on mortality. We followed up the patients enrolled in the PREPIC study for up to 8 years to assess the very long-term effect of vena cava filters on venous thromboembolism recurrence, the development of postthrombotic syndrome, and mortality.
|
Methods |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionAppendixReferences |
|---|
Study Population
The study protocol and population have been described previously.5 Briefly, the multicenter trial enrolled consecutive patients over 18 years of age with acute proximal deep-vein thrombosis confirmed by bilateral venography, with or without concomitant symptomatic pulmonary embolism, and considered to be at high risk for pulmonary embolism.5 Using a factorial design, the trial compared the use of a permanent vena cava filter with no filter and the administration of a low-molecular-weight heparin (enoxaparin, Aventis Pharma) with unfractionated heparin, both anticoagulant treatments being given for 8 to 12 days. All patients received vitamin K antagonists for at least 3 months, with a target international normalized ratio of 2.0 to 3.0. Thus, from September 1991 to February 1995, 400 patients with acute proximal deep-vein thrombosis were randomly assigned to receive a filter (200 patients) or not (200 patients). The main baseline demographic and clinical characteristics of patients were similar (Table 1).
|
Vena Cava Filter
Four types of permanent vena cava filter were used: Vena Tech LGM (B. Braun), titanium Greenfield (Boston Scientific), Cardial (Bard), and Bird’s Nest (Cook Group).5 All filters were inserted percutaneously under fluoroscopic control through a femoral or jugular vein. For patients in the filter group, cavography was performed immediately to ensure that the upper extremity of the filter was located in the inferior vena cava, immediately below the renal veins.
Follow-Up
Follow-up visits were scheduled at 3 months and 1 year. At 2 years and then once per year, all patients received a telephone call from the coordinating center, the members of which were unaware of the treatment assignment. Each patient was asked to report any new symptoms of pulmonary embolism, recurrent deep-vein thrombosis, or postthrombotic syndrome. To improve reporting of new events to the coordinating center, all patients had an individualized card to be given to all practitioners who monitored them. Practitioners who had managed the events reported by the patient were contacted, and all clinical, biological, and radiological data were recorded centrally by the coordinating center. The vital status was recorded each year using the centralized administrative survival inquiry procedure with the death registry of city halls.
Clinical Outcomes
The primary efficacy outcome was symptomatic pulmonary embolism up to 8 years. Symptomatic pulmonary embolism was considered to have occurred if it was documented objectively (positive angiography, high-probability lung scan, spiral computed tomography (CT), or chest radiograph,)5–10 or, in the event of death, at autopsy or if there was strong evidence that pulmonary embolism was the cause of death. The angiographic diagnosis of pulmonary embolism required the visualization of a new intraluminal defect or a sudden new arterial cutoff in comparison with the most recent angiographic examination. On ventilation/perfusion lung scanning, diagnosis was based on the visualization of at least 2 new segmental mismatched perfusion defects with no improvement in other areas in cases of initial extensive perfusion defects on the more recent lung scan. On spiral CT, pulmonary embolism was diagnosed if a central filling defect outlined by contrast material or complete occlusion was seen in a segmental or more proximal pulmonary artery. Diagnosis of recurrent pulmonary embolism could be based on abnormal chest radiograph suggestive of pulmonary embolism if there was strong clinical evidence of pulmonary embolism and associated acute proximal deep-vein thrombosis. Other outcomes were symptomatic recurrent deep-vein thrombosis, total clinical venous thromboembolism, postthrombotic syndrome, mechanical filter complications, major bleedings, and death due to any cause. Recurrence of deep-vein thrombosis, including deep-vein thrombosis of the lower limbs and filter thrombosis, was diagnosed if there was a new intraluminal filling defect on venography, a lack of compressibility at a new site or an extension to a new venous segment of the thrombus on ultrasonography, or a partial or complete occlusion of an abdominal vein (iliac or caval) on contrast-enhanced CT scan.11,12 Diagnosis of postthrombotic syndrome was considered if, compared with the initial assessment at inclusion, at least 1 of the following objective features appeared or worsened: edema, varicose veins, trophic disorders, or ulcers. All documented outcome events were reviewed by an independent adjudication committee unaware of the treatment assignments.
Statistical Analysis
Only analysis of the comparison filter versus no filter was performed, the comparison between the 2 types of heparin being irrelevant 8 years after a 10-day treatment. All analyses were performed on an intention-to-treat basis. Cumulative rates of events were calculated by the Kaplan-Meier method. Data on patients who died or were lost to follow-up were censored. Comparison between groups was assessed with a 2-sided Mantel-Haenszel (log-rank) test.13 Evaluation of baseline demographic and clinical characteristics of patients as predictors of long-term events was performed with Cox proportional hazards models. The hazard ratio and associated 95% CI for these various potential predictors of long-term events were calculated. Stepwise modeling was performed to screen potential variables for inclusion in the final model, with a probability value of 0.15 or less required for a variable to enter and/or to leave each model (univariate analysis). A probability value of 0.05 or less was used for the final model.
|
Results |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionAppendixReferences |
|---|
Among 400 patients initially recruited in the study, outcome data were available in 396 (99%). No information on nonfatal clinical events between 3 months and 8 years was available for 3 patients, and the 8-year vital status was not known for 1 patient. At 8 years, 198 patients (49.5%) were alive, and 201 (50.3%) patients had died.
Concomitant Treatments
Vitamin K antagonists were prescribed for only 3 months after the index thromboembolic event in 38% of patients in the filter group and 36% of patients in the no-filter group. Thirty-five percent of patients in both groups received vitamin K antagonists over the entire 8-year study period or until their death. At 8 years, vitamin K antagonists were being prescribed to 50% of living patients in both groups (Figure 1). Nineteen percent of patients in both groups wore elastic stockings for only 3 months after the index thromboembolic event; they were worn during the entire study period by 45% and 47% of patients in the filter and no-filter group, respectively. At 8 years, 61% and 63%, respectively, of living patients were still using elastic stockings.
|
Recurrent Venous Thromboembolism
One or more documented episodes of pulmonary embolism occurred in 9 patients (a cumulative rate of 6.2%) in the filter group compared with 24 patients (15.1%) in the no-filter group (hazard ratio 0.37, 95% CI 0.17 to 0.79; P=0.008; Table 2; Figure 2A). Fifteen of these 33 events were diagnosed by ventilation-perfusion lung scanning, 8 by pulmonary angiography, 2 by spiral CT, and 1 by chest radiograph with acute deep-vein thrombosis; 7 events were fatal, and the diagnosis of pulmonary embolism was based on strong evidence that it was the cause of death in 6 patients or at autopsy in 1 patient. There were no differences in the diagnosis methods in the 2 study groups. Pulmonary embolism was fatal in 2 patients in the filter group and 5 in the no-filter group. After adjustment in multivariate analysis, filter insertion remained significantly (P=0.014) associated with reduction of pulmonary embolism (Table 3). Pulmonary embolism at inclusion was significantly (P=0.032) associated with an increased risk of pulmonary embolism at 8 years.
|
|
|
One or more documented episodes of deep-vein thrombosis occurred in 57 patients (35.7%) in the filter group and 41 (27.5%) in the no-filter group (hazard ratio 1.52, 95% CI 1.02 to 2.27; P=0.042; Figure 2B). Of these 98 events, 76 were diagnosed on ultrasonography, 20 on venography, and 2 on contrast-enhanced CT scan. These last 2 cases concerned 2 cancer patients for whom a scan was performed to diagnose thrombosis and exclude an extrinsic compression of the iliac and caval veins. There were no differences in diagnosis methods in the 2 study groups. Two of the 26 filter thromboses observed in patients in the filter group were associated with pulmonary embolism. On multivariate analysis, known cancer at inclusion was associated with a significantly (P=0.007) increased incidence of deep-vein thrombosis recurrence at 8 years (Table 3). Overall, venous thromboembolism occurred in 58 patients (36.4%) in the filter group and 55 (35.4%) in the no-filter group (P=0.54; Table 2). Among these patients, 35 (60%) and 29 (54%), respectively, did not receive a vitamin K antagonist at the time of venous thromboembolism recurrence.
Postthrombotic Syndrome
Postthrombotic syndrome was observed in 109 patients (70.3%) in the filter group and 107 (69.7%) in the no-filter group (Table 2). Approximately half of these patients experienced the first sign of postthrombotic syndrome within 3 years after the index thromboembolic event (data not shown). The most common signs of postthrombotic syndrome were edema and varicose veins.
Mortality
Ninety-eight patients (48.1%) in the filter group and 103 (51.0%) in the no-filter group had died at 8 years (Figure 2C). The main causes of death were cancer (49 patients), unexplained death presumed to be of cardiovascular origin (32 patients), cardiac disease (22 patients), and bleeding (17 patients). Pulmonary embolism was directly involved in the death of 7 patients (1.8%). Known cancer (hazard ratio 2.08, 95% CI 1.47 to 2.95; P<0.001), cardiac or respiratory insufficiency (hazard ratio 1.79, 95% CI 1.32 to 2.45; P<0.001), and age (hazard ratio 1.60 per 10 years, 95% CI 1.37 to 1.88; P<0.001) were the only significant predictors of death at 8 years.
|
Discussion |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionAppendixReferences |
|---|
PREPIC shows that 8 years after the insertion of a permanent vena cava filter in patients with proximal deep-vein thrombosis with or without pulmonary embolism, pulmonary embolism occurrence was reduced significantly, although not eliminated, compared with no-filter patients. However, these beneficial findings were offset by an increased occurrence of deep-vein thrombosis in the lower limbs. Interestingly, vena cava filters did not increase the risk of postthrombotic syndrome. Vena cava filters had no impact on total mortality.
Patients enrolled in the present study may be considered to represent a high-risk population. Their mean age was 5 to 25 years higher than that of patients enrolled in other published long-term studies on venous thromboembolism.14–25 All patients had proximal deep-vein thrombosis, which unlike distal deep-vein thrombosis is a risk factor for venous thromboembolism recurrence.23,26 More than a third had symptomatic pulmonary embolism associated with deep-vein thrombosis. Taken together, these points may explain why, although consistent with the results of previous comparable studies, the rates of clinical events over time observed in the present study are at the higher end of the range observed in these studies.15–17,19–21,23,24 The 8-year rate of mortality was 50.5% compared with rates between 29.8% and 52.5% in previous studies.17,19 Likewise, the cumulative incidence of recurrent venous thromboembolism at 5 years in the present study was 
26%, whereas in other studies, it varied between 13.0% and 27.9%.15,17,20,23 Consequently, this high-risk population was monitored closely, and at 8 years, 60% of living patients were using elastic stockings and 50% were still receiving vitamin K antagonists. Interestingly, overall, 57% of patients with venous thromboembolism recurrence did not receive vitamin K antagonists at the time of the thrombotic event. Similar data were found in a recent large, long-term prospective study of patients with pulmonary embolism, in which 62.5% of venous thromboembolism recurrences occurred after cessation of oral anticoagulant treatment.27
With respect to the cumulative rate of occurrence of postthrombotic syndrome at 8 years, the 70.1% rate is substantially higher than the 29.1% rate reported in the study by Prandoni et al.17 However, in the latter study, the mean age of patients was 10 years younger than in the present study, and high age is a risk factor for postthrombotic syndrome.28 Also, only patients with a first episode of symptomatic deep-vein thrombosis (including distal events) were enrolled in the study by Prandoni et al.17 In PREPIC, 24% of patients had postthrombotic syndrome at inclusion. Moreover, patients with proximal deep-vein thrombosis are more likely to develop venous stasis syndrome than patients with distal deep-vein thrombosis,29 and rates comparable to ours were found in patients with proximal deep-vein thrombosis.18
This 8-year follow-up study extends the findings obtained previously at 2 years.5 At that time, the occurrence of pulmonary embolism was decreased by 50% in patients in the filter group compared with patients in the no-filter group (P=0.16); the risk was decreased by 63% at 8 years (P=0.008). It must be pointed out that 12 of the 24 pulmonary embolisms that occurred in patients in the no-filter group occurred between 2 and 8 years, which shows that pulmonary embolism may occur many years after the index thromboembolic event. We also confirm that among patients with symptomatic deep-vein thrombosis with or without pulmonary embolism who are treated with anticoagulants for at least 3 months, fatal pulmonary embolism is a relatively rare event,30 and cancer is the leading cause of mortality.15,17,19 The finding of an increased incidence of deep-vein thrombosis in patients with vena cava filters may be related to the thrombotic occlusion of those filters leading to venous stasis upstream in the legs: among 57 patients in the filter group with deep-vein thrombosis, 26 experienced filter thrombosis. Overall, the rate of recurrent symptomatic venous thromboembolism in the filter and no-filter groups was comparable. This result is consistent with the finding by White et al,22 who, in a population-based retrospective analysis of linked hospital discharge abstracts, showed that there was no difference in the 1-year relative hazard of rehospitalization for venous thromboembolism between filter- and no-filter–treated patients. Contrary to what might have been expected,3 vena cava filters did not increase the occurrence of postthrombotic syndrome. It is possible that the use of a clinical scale proven to reproducibly assess postthrombotic syndrome may have yielded different results.17,31 However, 2 factors may have masked a potential deleterious effect of vena cava filters on the development of postthrombotic syndrome: a substantial number of patients had postthrombotic syndrome at inclusion, and the use of elastic stockings18 during the 8 years of follow-up was high in the 2 study groups.
Our findings are likely to be valid. The follow-up rate was close to 100%. All recurrent events were diagnosed objectively by recommended methods and validated by a committee unaware of the treatment. Patients were treated according to standard practice with at least 3 months of anticoagulants. Although the duration of treatment with vitamin K antagonists was not randomized, the administration of anticoagulants was comparable in the 2 study groups; however, it is possible that the diagnosis of pulmonary embolism may have been underestimated in patients in the filter group, because local clinicians tend to suspect pulmonary embolism less frequently in patients with a filter than in patients without a filter.
Risk stratification is essential when choosing the most appropriate treatment of pulmonary embolism. Due to the good benefit-to-risk ratio of long-term anticoagulation,32–34 this therapeutic strategy is generally offered to patients with a high risk of venous thromboembolism recurring as pulmonary embolism.35 The high-risk group includes, as confirmed in the present study, patients whose initial thromboembolic event is a pulmonary embolism,25,30 particularly if this event is idiopathic or if patients also have cancer (Table 3). Likewise, patients who develop venous thromboembolism in nonsurgical situations have a higher risk of pulmonary embolism than those who had venous thromboembolism after surgery.36 Moreover, patients presenting with pulmonary embolism are more likely to die of recurrent pulmonary embolism than are patients presenting with deep-vein thrombosis.30,37,38 However, anticoagulation alone may not be sufficient in such high-risk patients. In PREPIC, among 24 nonfilter patients who developed pulmonary embolism, 46% were receiving vitamin K antagonists at the time of the thrombotic event. Accordingly, trials are warranted to assess the additional benefit provided by vena cave filters in patients at high risk of pulmonary embolism who are receiving long-term anticoagulation.
In conclusion, the present study shows that vena cava filters in patients with deep-vein thrombosis with or without pulmonary embolism protect against the long-term development of pulmonary embolism without favoring the development of postthrombotic syndrome. However, because their insertion is associated with a significant increase in the occurrence of deep-vein thrombosis, the systematic use of permanent vena cava filters in the general population with venous thromboembolism is not recommended. Vena cava filters may be beneficial in selected patients at higher risk of fatal pulmonary embolism, especially those whose initial thromboembolic event is a pulmonary embolism, idiopathic or cancer-associated. Further studies are needed to better define patients in whom the use of vena cava filters may be favorable.
|
Appendix |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionAppendixReferences |
|---|
Writing Commitee: Herve Decousus (Chairman), Fabrice-Guy Barral, Andrea Buchmuller-Cordier, Bernard Charbonnier, Phillippe Girard, Christian Lamer, Silvy Laporte, Alain Leizorovicz, Patrick Mismetti, Florence Parent, Sara Quenet, Karine Rivron-Guillot, Bernard Tardy.
Participating Centers (in order of the number of patients enrolled): Bellevue Hospital, Saint-Etienne: Y. Page, B. Tardy, P. Mismetti, I. Cusey, C. Comtet, and J.C. Bertrand; Antoine Béclère Hospital, Clamart: F. Parent, G. Simonneau, and D. Musset; Clinique St. Vincent, Besançon: R. Faivre and P.Y. Petiteau; Trousseau Hospital, Tours: G. Pacouret and B. Charbonnier; General Hospital, Firminy: P. Sagnol and P. Mathern; Laënnec Hospital, Paris: G. Meyer and H. Sors; Cavale Blanche Hospital, Brest: L. Bressolette and D. Mottier; General Hospital, Roanne: P. Mottet and G. Tempelhoff; Hôtel Dieu Hospital, Angers: A. Furber and P. Geslin; Lariboisière Hospital, Paris: G. Simoneau, P. Molho-Sabatier, and J.F. Bergmann; General Hospital Lucien Hussel, Vienne: C. Poulain and B. Veyre; Belle-Isle Hospital, Metz: J. Hermann and H. Joffreau; Nord Hospital, Marseille: C. Juhan and Y. Alimi; Clinique St. Hilaire, Agen: R. Constans and J.L. Leymarie; Fleyriat Hospital, Bourg en Bresse: G. Demingeon and L. Holzapfel; Côte de Nacre Hospital, Caen: O. Coffin; Clinique du Mail, La Rochelle: J.P. Marcadé and J.P. Chantereau; Pasteur Hospital, Nice: F. Lemoigne; St. Joseph Hospital, Paris: P. Priollet, I. Lazareth, and G. Farkas; Germon et Gauthier Hospital, Béthune: B. D’Hautefeuille, C. Mycinski, and A. Senoussi; Lyon Sud Hospital, Lyon: C. Guerin; Hôtel Dieu Hospital, Rennes: B. Schleich and A. Le Helloco; General Hospital, Albi: M. Ammor and D. Galley; General Hospital, Allauch: M. Escande and B. Diadema; General Hospital, Annecy: J.B. Driancourt and P. Achard; General Hospital, Bourgoin-Jailleux: A. Pinel; General Hospital Louis Pasteur, Dole: F. Apffel and D. Magnin; La Tronche Hospital, Grenoble: P. Carpentier; General Hospital, Le Mans: D. Fagart; Dupuytren Hospital, Limoges : P. Lacroix; Broussais Hospital, Paris: J. Emmerich and J.N. Fiessinger; R. Beauchant Hospital, Poitiers: J. Allal; Clinique de la Jomayère, Saint-Etienne: J.M. Gallot-Lavallée; Avicenne Hospital, Bobigny: L. Guillevin; Pellegrin Hospital, Bordeaux: G. Sassous; Intercommunal Hospital, Fréjus: R. Mossaz; Emile Roux Hospital, Le Puy: J.P. Saboye and M. Viallet; Croix Rousse Hospital, Lyon: J.C. Guerin; Salvator Hospital, Marseille: J.M. Sainty; La Beauchée Hospital, St. Brieuc: F. Zimbacca; General Hospital, St. Chamond: J.H. Payre; Purpan Hospital, Toulouse: A. Barret; Steering Committee: H. Decousus, Y. Page, X. Barral, L. Barritault, H. Boccalon, J.P. Boissel, P. Carpentier, B. Charbonnier, J.N. Fiessinger, Y. Huet, A. Leizorovicz, J. Marzelle, G. Meyer, E. Neuhart, H. Rousseau, and G. Simonneau; Independent Adjudication Committee: P. Girard, P. Hervé, and C. Lamer.
|
Acknowledgments |
|---|
This study was supported by grants from Ministère Français de la Santé (PHRC), Paris, France, and from Fondation de l’Avenir. The authors gratefully acknowledge the contributions of all members of the PREPIC Study Group listed in reference 5. They are also indebted to Jean-Yves Darmon and Yves Cadroy (MediBridge Clinical Research, Vélizy, France) for providing editorial assistance.
|
Footnotes |
|---|
*Investigators and Committees participating in the PREPIC study are listed in the Appendix.
|
References |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionAppendixReferences |
|---|
1. Buller HR, Agnelli G, Hull RD, Hyers TM, Prins MH, Raskob GE. Antithrombotic therapy for venous thromboembolic disease: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest. 2004; 126 (suppl): 401S–428S.[CrossRef][Medline] [Order article via Infotrieve]
2. Goldhaber SZ, Tapson VF, for the DVT FREE Steering Committee. A prospective registry of 5,451 patients with ultrasound-confirmed deep vein thrombosis. Am J Cardiol. 2004; 93: 259–262.[CrossRef][Medline] [Order article via Infotrieve]
3. Streiff MB. Vena cava filters: a comprehensive review. Blood. 2000; 95: 3669–3677.
4. Girard P, Stern JB, Parent F. Medical literature and vena cava filters: so far so weak. Chest. 2002; 122: 963–967.[CrossRef][Medline] [Order article via Infotrieve]
5. Decousus H, Leizorovicz A, Parent F, Page Y, Tardy B, Girard P, Laporte S, Faivre R, Charbonnier B, Barral FG, Huet Y, Simonneau G, for the PREPIC Study Group. A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis. N Engl J Med. 1998; 338: 409–415.
6. The PIOPED Investigators. Value of the ventilation/perfusion scan in acute pulmonary embolism: results of the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED). JAMA. 1990; 263: 2753–2759.
7. Moser KM, Longo AM, Ashburn WL, Guisan M. Spurious scintiphotographic recurrence of pulmonary emboli. Am J Med. 1973; 55: 434–443.[CrossRef][Medline] [Order article via Infotrieve]
8. Girard P, Mathieu M, Simonneau G, Petitpretz P, Cerrina J, Herve P, Rosso J, Musset D, Mensch J, Duroux P. Recurrence of pulmonary embolism during anticoagulant treatment: a prospective study. Thorax. 1987; 42: 481–486.
9. Girard P, Decousus M, Laporte S, Buchmuller A, Herve P, Lamer C, Parent F, Tardy B, for the PREPIC Study Group. Diagnosis of pulmonary embolism in patients with proximal deep vein thrombosis: specificity of symptoms and perfusion defects at baseline and during anticoagulant therapy. Am J Respir Crit Care Med. 2001; 164: 1033–1037.
10. Musset D, Parent F, Meyer G, Maitre S, Girard P, Leroyer C, Revel MP, Carette MF, Laurent M, Charbonnier B, Laurent F, Mal H, Nonent M, Lancar R, Grenier P, Simonneau G, for the ESSEP study group. Diagnostic strategy for patients with suspected pulmonary embolism: a prospective multicentre outcome study. Lancet. 2002; 360: 1914–1920.[CrossRef][Medline] [Order article via Infotrieve]
11. Brandjes DPM, Heijboer H, Büller HR, de Rijk M, Jagt H, ten Cate JW. Acenocoumarol and heparin compared with acenocoumarol alone in the initial treatment of proximal-vein thrombosis. N Engl J Med. 1992; 327: 1485–1489.[Abstract]
12. Prandoni P, Cogo A, Bernardi E, Villalta S, Polistena P, Simioni P, Noventa F, Benedetti L, Girolami A. A simple ultrasound approach for detection of recurrent proximal-vein thrombosis. Circulation. 1993; 88: 1730–1735.
13. Mantel N. Evaluation of survival data and two new rank order statistics arising in its consideration. Cancer Chemother Rep. 1966; 50: 163–170.[Medline] [Order article via Infotrieve]
14. Anderson FA Jr, Wheeler HB, Goldberg RJ, Hosmer DW, Patwardhan NA, Jovanovic B, Forcier A, Dalen JE. A population-based perspective of the hospital incidence and case-fatality rates of deep-vein thrombosis and pulmonary embolism: the Worcester DVT Study. Arch Intern Med. 1991; 151: 933–938.
15. Beyth RJ, Cohen AM, Landefeld CS. Long-term outcomes of deep-vein thrombosis. Arch Intern Med. 1995; 155: 1031–1037.
16. Schulman S, Rhedin AS, Lindmarker P, Carlsson A, Larfars G, Nicol P, Loogna E, Svensson E, Ljungberg B, Walter H. A comparison of six weeks with six months of oral anticoagulant therapy after a first episode of venous thromboembolism. N Engl J Med. 1995; 155: 1031–1037.
17. Prandoni P, Lensing AW, Cogo A, Cuppini S, Villalta S, Carta M, Cattelan AM, Polistena P, Bernardi E, Prins MH. The long-term clinical course of acute deep venous thrombosis. Ann Intern Med. 1996; 125: 1–7.
18. Brandjes DP, Buller HR, Heijboer H, Huisman MV, de Rijk M, Jagt H, ten Cate JW. Randomised trial of effect of compression stockings in patients with symptomatic proximal-vein thrombosis. Lancet. 1997; 349: 759–762.[CrossRef][Medline] [Order article via Infotrieve]
19. Heit JA, Silverstein MD, Mohr DN, Petterson TM, O’Fallon WM, Melton JL III. Predictors of survival after deep vein thrombosis and pulmonary embolism: a population-based cohort study. Arch Intern Med. 1999; 159: 445–453.
20. Heit JA, Mohr DN, Silverstein MD, Petterson TM, O’Fallon WM, Melton JL III. Predictors of recurrence after deep vein thrombosis and pulmonary embolism: a population-based cohort study. Arch Intern Med. 2000; 160: 761–768.
21. Kearon C, Gent M, Hirsh J, Weitz J, Kovacs MJ, Anderson DR, Turpie AG, Green D, Ginsberg JS, Wells P, MacKinnon B, Julian JA. A comparison of three months of anticoagulation with extended anticoagulation for a first episode of idiopathic venous thromboembolism. N Engl J Med. 1999; 340: 901–907.
22. White RH, Zhou H, Kim J, Romano PS. A population-based study of the effectiveness of inferior vena cava filter use among patients with venous thromboembolism. Arch Intern Med. 2000; 160: 2033–2041.
23. Hansson P-O, Sörbo J, Eriksson H. Recurrent venous thromboembolism after deep vein thrombosis: incidence and risk factors. Arch Intern Med. 2000; 160: 769–774.
24. Agnelli G, Prandoni P, Santamaria MG, Bagatella P, Iorio A, Bazzan M, Moia M, Guazzaloca G, Bertoldi A, Tomasi C, Scannapieco G, Ageno W, for the Warfarin Optimal Duration Italian Trial Investigators. Three months versus one year of oral anticoagulant therapy for idiopathic deep venous thrombosis. N Engl J Med. 2001; 345: 165–169.
25. Eichinger S, Weltermann A, Minar E, Stain M, Schonauer V, Schneider B, Kyrle PA. Symptomatic pulmonary embolism and the risk of recurrent venous thromboembolism. Arch Intern Med. 2004; 164: 92–96.
26. Laporte S, Tardy B, Quenet S, Buchmuller-Cordier A, Chabaud S, Epinat M, Decousus H, Mismetti P, for the PREPIC Study Group. The location of deep-vein thrombosis as a predictive factor for recurrence and cancer discovery after proximal deep-vein thrombosis. Haematologica. 2003: 88: ELT08. Letter.
27. Pengo V, Lensing AW, Prins MH, Marchiori A, Davidson BL, Tiozzo F, Albanese P, Biasiolo A, Pegoraro C, Iliceto S, Prandoni P, for the Thromboembolic Pulmonary Hypertension Study Group. Incidence of chronic thromboembolic pulmonary hypertension after pulmonary embolism. N Engl J Med. 2004; 350: 2257–2264.
28. Prandoni P, Lensing AW, Prins MH, Frulla M, Marchiori A, Bernardi E, Tormene D, Mosena L, Pagnan A, Girolami A. Below-knee elastic compression stockings to prevent the post-thrombotic syndrome: a randomized, controlled trial. Ann Intern Med. 2004; 141: 249–256.
29. Heit JA, Silverstein MD, Mohr DN, Petterson TM, Lohse CM, O’Fallon WM, Melton LJ III. The epidemiology of venous thromboembolism in the community. Thromb Haemost. 2001; 86: 452–463.[Medline] [Order article via Infotrieve]
30. Douketis JD, Kearon C, Bates S, Duku EK, Ginsberg JS. Risk of fatal pulmonary embolism in patients with treated venous thromboembolism. JAMA. 1998; 279: 458–462.
31. Villalta S, Bagatella P, Piccioli A, Lensing AWA, Prins MH, Prandoni P. Assessment of validity and reproducibility of a clinical scale for the post-thrombotic syndrome. Hemostasis. 1994; 24 (suppl 1): 157. Abstract.
32. Ridker PM, Goldhaber SZ, Danielson E, Rosenberg Y, Eby CS, Deitcher SR, Cushman M, Moll S, Kessler CM, Elliott CG, Paulson R, Wong T, Bauer KA, Schwartz BA, Miletich JP, Bounameaux H, Glynn RJ, for the PREVENT Investigators. Long-term, low-intensity warfarin therapy for the prevention of recurrent venous thromboembolism. N Engl J Med. 2003; 348: 1425–1434.
33. Kearon C, Ginsberg JS, Kovacs MJ, Anderson DR, Wells P, Julian JA, MacKinnon B, Weitz JI, Crowther MA, Dolan S, Turpie AG, Geerts W, Solymoss S, van Nguyen P, Demers C, Kahn SR, Kassis J, Rodger M, Hambleton J, Gent M, for the Extended Low-Intensity Anticoagulation for Thrombo-Embolism Investigators. Comparison of low-intensity warfarin therapy with conventional-intensity warfarin therapy for long-term prevention of recurrent venous thromboembolism. N Engl J Med. 2003; 349: 631–639.
34. Schulman S, Wahlander K, Lundstrom T, Clason SB, Eriksson H, for the THRIVE III Investigators. Secondary prevention of venous thromboembolism with the oral direct thrombin inhibitor ximelagatran. N Engl J Med. 2003; 349: 1713–1721.
35. Goldhaber SZ. Pulmonary embolism. Lancet. 2004; 363: 1295–1305.[CrossRef][Medline] [Order article via Infotrieve]
36. Monreal M, Kakkar AK, Caprini JA, Barba R, Uresandi F, Valle R, Suarez C. Is the natural history of venous thromboembolism different in surgical and non-surgical patients? Findings from the RIETE registry. Blood. 2003; 102: abstract 4156.
37. Buller HR, Davidson BL, Decousus H, Gallus A, Gent M, Piovella F, Prins MH, Raskob G, van den Berg-Segers AE, Cariou R, Leeuwenkamp O, Lensing AW, for the Matisse Investigators. Subcutaneous fondaparinux versus intravenous unfractionated heparin in the initial treatment of pulmonary embolism. N Engl J Med. 2003; 349: 1695–1702.
38. Buller HR, Davidson BL, Decousus H, Gallus A, Gent M, Piovella F, Prins MH, Raskob G, Segers AE, Cariou R, Leeuwenkamp O, Lensing AW, for the Matisse Investigators. Fondaparinux or enoxaparin for the initial treatment of symptomatic deep-vein thrombosis: a randomized, double-blind non-inferiority trial. Ann Intern Med. 2004; 140: 867–873.
This article has been cited by other articles:
 |
|
 |
|
  J. Haspel, K. Bauer, A. Goehler, and D. H. Roberts Long-term Anticoagulant Therapy for Idiopathic Pulmonary Embolism in the Elderly: A Decision Analysis Chest, May 1, 2009; 135(5): 1243 - 1251. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Y.Y. Lee Treatment of Venous Thromboembolism in Patients with Cancer ASCO Educational Book, January 1, 2009; 2009(1): 331 - 336. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Kearon, S. R. Kahn, G. Agnelli, S. Goldhaber, G. E. Raskob, and A. J. Comerota Antithrombotic Therapy for Venous Thromboembolic Disease: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition) Chest, June 1, 2008; 133(6_suppl): 454S - 545S. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Laporte, P. Mismetti, H. Decousus, F. Uresandi, R. Otero, J. L. Lobo, M. Monreal, and the RIETE Investigators Clinical Predictors for Fatal Pulmonary Embolism in 15 520 Patients With Venous Thromboembolism: Findings From the Registro Informatizado de la Enfermedad TromboEmbolica venosa (RIETE) Registry Circulation, April 1, 2008; 117(13): 1711 - 1716. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. P. Janjigian and B. E. Muhs Current Treatment of Acute Lower Extremity Deep Venous Thrombosis International Journal of Lower Extremity Wounds, March 1, 2008; 7(1): 15 - 20. [Abstract] [PDF]
|
|
|
|
 |
|
 J. Chung and R. J.T. Owen Using inferior vena cava filters to prevent pulmonary embolism Can Fam Physician, January 1, 2008; 54(1): 49 - 55. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Falanga, A. Y. Y. Lee, M. B. Streiff, and G. H. Lyman Anticoagulation in the Treatment of Venous Thromboembolism in Patients with Cancer ASCO Educational Book, January 1, 2008; 2008(1): 258 - 268. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. H. Lyman, A. A. Khorana, A. Falanga, D. Clarke-Pearson, C. Flowers, M. Jahanzeb, A. Kakkar, N. M. Kuderer, M. N. Levine, H. Liebman, et al. American Society of Clinical Oncology Guideline: Recommendations for Venous Thromboembolism Prophylaxis and Treatment in Patients With Cancer J. Clin. Oncol., December 1, 2007; 25(34): 5490 - 5505. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 The van Gogh Investigators Extended Prophylaxis of Venous Thromboembolism with Idraparinux N. Engl. J. Med., September 13, 2007; 357(11): 1105 - 1112. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. A. Yegen, D. J. Lederer, R. G. Barr, J. S. Wilt, Y. Fang, E. Bagiella, F. D'Ovidio, J. M. Okun, J. R. Sonett, S. M. Arcasoy, et al. Risk Factors for Venous Thromboembolism After Lung Transplantation Chest, August 1, 2007; 132(2): 547 - 553. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Carlbom and B. L. Davidson Pulmonary Embolism in the Critically Ill Chest, July 1, 2007; 132(1): 313 - 324. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Hoppe, J. A. Kaufman, R. E. Barton, B. D. Petersen, P. C. Lakin, T. G. DeLoughery, Z. Irani, K. Yavuz, and F. S. Keller Safety of Inferior Vena Cava Filter Retrieval in Anticoagulated Patients Chest, July 1, 2007; 132(1): 31 - 36. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. A. Binkert, M. C. Morash, and J. D. Gates Venographic Findings at Retrieval of Inferior Vena Cava Filters Am. J. Roentgenol., April 1, 2007; 188(4): 1039 - 1043. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. B. Segal, M. B. Streiff, L. V. Hofmann, K. Thornton, and E. B. Bass Management of Venous Thromboembolism: A Systematic Review for a Practice Guideline Ann Intern Med, February 6, 2007; 146(3): 211 - 222. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Falanga and F. R. Rickles Management of Thrombohemorrhagic Syndromes (THS) in Hematologic Malignancies Hematology, January 1, 2007; 2007(1): 165 - 171. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Scarvelis and P. S. Wells Diagnosis and treatment of deep-vein thrombosis. Can. Med. Assoc. J., October 24, 2006; 175(9): 1087 - 1092. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Additional articles abstracted in ACP Journal Club Evid. Based Med., February 1, 2006; 11(1): 30 - 30. [Full Text] [PDF]
|
|
|
|
 |
|
 Do Vena Cava Filters Prevent PE? Journal Watch Cardiology, September 2, 2005; 2005(902): 5 - 5. [Full Text]
|
|
|
|
 |
|
 R. F. Sing, F. B. Rogers, Y. W. Novitsky, and B. T. Heniford Optional Vena Cava Filters for Patients with High Thromboembolic Risk: Questions to be Answered Surgical Innovation, September 1, 2005; 12(3): 195 - 202. [Abstract] [PDF]
|
|
|
|
|
|
J. Ansell Vena Cava Filters: Do We Know All That We Need to Know? Circulation, July 19, 2005; 112(3): 298 - 299. [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||