Embolism and thrombosis: Difference between revisions

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'''Embolism and thrombosis''' is "a collective term for pathological conditions which are caused by the formation of a blood clot (thrombus) in a blood vessel, or by blocking of a blood vessel with an embolus, undissolved materials in the blood stream."<ref>{{MeSH}}</ref>
'''Embolism and thrombosis''' is "a collective term for pathological conditions which are caused by the formation of a blood clot (thrombus) in a blood vessel, or by blocking of a blood vessel with an embolus, undissolved materials in the blood stream."<ref>{{MeSH}}</ref>


The [[United States]] [[Surgeon General]] has announced a [http://www.surgeongeneral.gov/library/calls/ call to action] to prevent [[Deep venous thrombosis | Deep Vein Thrombosis]] and [[Pulmonary embolism | Pulmonary Embolism]].<ref name="urlThe Surgeon General's Call to Action to Prevent Deep Vein Thrombosis and Pulmonary Embolism">{{cite web |url=http://www.surgeongeneral.gov/topics/deepvein/ |title=The Surgeon General's Call to Action to Prevent Deep Vein Thrombosis and Pulmonary Embolism |author= |authorlink= |coauthors= |date=2008 |format= |work= |publisher=Office of Public Health and Science |pages= |language= |archiveurl= |archivedate= |quote= |accessdate=}}</ref>
The [[United States of America]] [[Surgeon General]] has announced a [http://www.surgeongeneral.gov/library/calls/ call to action] to prevent [[Deep venous thrombosis | Deep Vein Thrombosis]] and [[Pulmonary embolism | Pulmonary Embolism]].<ref name="urlThe Surgeon General's Call to Action to Prevent Deep Vein Thrombosis and Pulmonary Embolism">{{cite web |url=http://www.surgeongeneral.gov/topics/deepvein/ |title=The Surgeon General's Call to Action to Prevent Deep Vein Thrombosis and Pulmonary Embolism |author= |authorlink= |coauthors= |date=2008 |format= |work= |publisher=Office of Public Health and Science |pages= |language= |archiveurl= |archivedate= |quote= |accessdate=}}</ref>


==Classification==
==Classification==
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==Cause/etiology==
==Cause/etiology==
The risk of venous thromboembolism can be estimated with http://www.qthrombosis.org/.
One risk factor is hypercoagulability due to cancer. Cancer can be found in up to 10% of patients within one year of embolism or thrombosis.<ref name="pmid18765702">{{cite journal |author=Carrier M, Le Gal G, Wells PS, Fergusson D, Ramsay T, Rodger MA |title=Systematic review: the Trousseau syndrome revisited: should we screen extensively for cancer in patients with venous thromboembolism? |journal=Annals of internal medicine |volume=149 |issue=5 |pages=323–33 |year=2008 |month=September |pmid=18765702 |doi= |url=http://www.annals.org/cgi/pmidlookup?view=long&pmid=18765702 |issn=}}</ref>
One risk factor is hypercoagulability due to cancer. Cancer can be found in up to 10% of patients within one year of embolism or thrombosis.<ref name="pmid18765702">{{cite journal |author=Carrier M, Le Gal G, Wells PS, Fergusson D, Ramsay T, Rodger MA |title=Systematic review: the Trousseau syndrome revisited: should we screen extensively for cancer in patients with venous thromboembolism? |journal=Annals of internal medicine |volume=149 |issue=5 |pages=323–33 |year=2008 |month=September |pmid=18765702 |doi= |url=http://www.annals.org/cgi/pmidlookup?view=long&pmid=18765702 |issn=}}</ref>


===Genetics===
===Genetics===
The presence of [[Factor V Leiden]] but not [[prothrombin G20210A]] increases risk of recurrence.<ref name="pmid19531787">{{cite journal |author=Segal JB, Brotman DJ, Necochea AJ, ''et al.'' |title=Predictive value of factor V Leiden and prothrombin G20210A in adults with venous thromboembolism and in family members of those with a mutation: a systematic review |journal=JAMA |volume=301 |issue=23 |pages=2472–85 |year=2009 |month=June |pmid=19531787 |doi=10.1001/jama.2009.853 |url=http://jama.ama-assn.org/cgi/pmidlookup?view=long&pmid=19531787 |issn=}}</ref>
In a cohort study. the population attributable risk of venous thromboembolism was:<ref name="pmid23382263">{{cite journal| author=Sode BF, Allin KH, Dahl M, Gyntelberg F, Nordestgaard BG| title=Risk of venous thromboembolism and myocardial infarction associated with factor V Leiden and prothrombin mutations and blood type. | journal=CMAJ | year= 2013 | volume= 185 | issue= 5 | pages= E229-37 | pmid=23382263 | doi=10.1503/cmaj.121636 | pmc=PMC3602271 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23382263  }} </ref>
* 20% for ABO blood type
* 10% for [[factor V Leiden]] R506Q (Activated Protein C Resistance) via G1691A mutation
* 1% for [[prothrombin G20210A]]
 
In an older systematic review, the presence of [[Factor V Leiden]] (homozygotes or heterozygotes) but not [[prothrombin G20210A]] (heterozygoes; homozygotes not clear) increases risk of recurrence.<ref name="pmid19531787">{{cite journal |author=Segal JB, Brotman DJ, Necochea AJ, ''et al.'' |title=Predictive value of factor V Leiden and prothrombin G20210A in adults with venous thromboembolism and in family members of those with a mutation: a systematic review |journal=JAMA |volume=301 |issue=23 |pages=2472–85 |year=2009 |month=June |pmid=19531787 |doi=10.1001/jama.2009.853 |url=http://jama.ama-assn.org/cgi/pmidlookup?view=long&pmid=19531787 |issn=}}</ref>


===Malignancy===
===Malignancy===
The prevalence of malignancy is about:<ref name="pmid1528208">{{cite journal| author=Prandoni P, Lensing AW, Büller HR, Cogo A, Prins MH, Cattelan AM et al.| title=Deep-vein thrombosis and the incidence of subsequent symptomatic cancer. | journal=N Engl J Med | year= 1992 | volume= 327 | issue= 16 | pages= 1128-33 | pmid=1528208  
The prevalence of malignancy is about:<ref name="pmid1528208">{{cite journal| author=Prandoni P, Lensing AW, Büller HR, Cogo A, Prins MH, Cattelan AM et al.| title=Deep-vein thrombosis and the incidence of subsequent symptomatic cancer. | journal=N Engl J Med | year= 1992 | volume= 327 | issue= 16 | pages= 1128-33 | pmid=1528208 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=1528208 }}</ref>
| url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=1528208 }} <!--Formatted by http://sumsearch.uthscsa.edu/cite/--></ref>
* 3% of patients with first idiopathic venous thrombosis
* 3% of patients with first idiopathic venous thrombosis
* 17% of patients with idiopathic, idiopathic venous thrombosis
* 17% of patients with idiopathic, idiopathic venous thrombosis


The most common sites of cancer that is diagnosed at the time of, or later than the episode embolism and thrombosis of are:<ref name="pmid11117976">{{cite journal| author=Sørensen HT, Mellemkjaer L, Olsen JH, Baron JA| title=Prognosis of cancers associated with venous thromboembolism. | journal=N Engl J Med | year= 2000 | volume= 343 | issue= 25 | pages= 1846-50 | pmid=11117976  
The most common sites of cancer that is diagnosed at the time of, or later than the episode embolism and thrombosis of are:<ref name="pmid11117976">{{cite journal| author=Sørensen HT, Mellemkjaer L, Olsen JH, Baron JA| title=Prognosis of cancers associated with venous thromboembolism. | journal=N Engl J Med | year= 2000 | volume= 343 | issue= 25 | pages= 1846-50 | pmid=11117976  
| url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=11117976 }} <!--Formatted by http://sumsearch.uthscsa.edu/cite/--></ref><ref name="pmid9554856">{{cite journal| author=Sørensen HT, Mellemkjaer L, Steffensen FH, Olsen JH, Nielsen GL| title=The risk of a diagnosis of cancer after primary deep venous thrombosis or pulmonary embolism. | journal=N Engl J Med | year= 1998 | volume= 338 | issue= 17 | pages= 1169-73 | pmid=9554856  
| url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=11117976 }} <</ref><ref name="pmid9554856">{{cite journal| author=Sørensen HT, Mellemkjaer L, Steffensen FH, Olsen JH, Nielsen GL| title=The risk of a diagnosis of cancer after primary deep venous thrombosis or pulmonary embolism. | journal=N Engl J Med | year= 1998 | volume= 338 | issue= 17 | pages= 1169-73 | pmid=9554856  
| url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=9554856 }} <!--Formatted by http://sumsearch.uthscsa.edu/cite/--></ref>
| url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=9554856 }} </ref>
* [[Lung cancer]]
* [[Lung cancer]]
* [[Prostate cancer]]
* [[Prostate cancer]]
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* [[Breast cancer]]
* [[Breast cancer]]
* [[Ovarian cancer]]
* [[Ovarian cancer]]
==Diagnosis==
[[Clinical practice guideline]]s address this for patients in general<ref name="pmid18574272">{{cite journal |author=Kearon  C, Kahn SR, Agnelli G, Goldhaber S, Raskob GE, Comerota AJ  |title=Antithrombotic therapy for venous thromboembolic disease:  American College of Chest Physicians Evidence-Based Clinical Practice  Guidelines (8th Edition) |journal=Chest |volume=133 |issue=6 Suppl  |pages=454S–545S |year=2008 |month=June |pmid=18574272  |doi=10.1378/chest.08-0658 |url=http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=18574272 |issn=}}</ref> and for patients who are pregnant<ref name="pmid21860313">{{cite journal| author=| title=Practice bulletin no. 123: thromboembolism in pregnancy. | journal=Obstet Gynecol | year= 2011 | volume= 118 | issue= 3 | pages= 718-29 | pmid=21860313 | doi=10.1097/AOG.0b013e3182310c4c | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21860313  }} </ref>.


==Treatment==
==Treatment==
Embolism and thrombosis may be prevented by [[anticoagulation]] with [[anticoagulant]]s.
Embolism and thrombosis may be prevented by [[anticoagulation]] with [[anticoagulant]]s. [[Clinical practice guideline]]s address this for patients in general<ref name="pmid18574272"/> and for patients who are pregnant<ref name="pmid21860313"/>.


[[Dabigatran]] is given orally and may be as  effective as [[warfarin]] and with less bleeding but increased [[dyspepsia]] for the treatment of embolism and thrombosis.<ref name="pmid19966341">{{cite journal|  author=Schulman S, Kearon C, Kakkar AK, Mismetti P, Schellong S,  Eriksson H et al.| title=Dabigatran versus warfarin in the treatment of  acute venous thromboembolism. | journal=N Engl J Med | year= 2009 |  volume= 361 | issue= 24 | pages= 2342-52 | pmid=19966341  
[[Dabigatran]] is given orally and may be as  effective as [[warfarin]] and with less bleeding but increased [[dyspepsia]] for the treatment of embolism and thrombosis.<ref name="pmid19966341">{{cite journal|  author=Schulman S, Kearon C, Kakkar AK, Mismetti P, Schellong S,  Eriksson H et al.| title=Dabigatran versus warfarin in the treatment of  acute venous thromboembolism. | journal=N Engl J Med | year= 2009 |  volume= 361 | issue= 24 | pages= 2342-52 | pmid=19966341  
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===Duration of treatment===
===Duration of treatment===
This topic has been reviewed in a [[meta-analysis]] using individual patient data.<ref name="pmid21610040">{{cite journal| author=Boutitie F, Pinede L, Schulman S, Agnelli G, Raskob G, Julian J et al.| title=Influence of preceding length of anticoagulant treatment and initial presentation of venous thromboembolism on risk of recurrence after stopping treatment: analysis of individual participants' data from seven trials. | journal=BMJ | year= 2011 | volume= 342 | issue=  | pages= d3036 | pmid=21610040 | doi=10.1136/bmj.d3036 | pmc=PMC3100759 | url= }} </ref>
{| class="wikitable"
{| class="wikitable"
|+ Randomized controlled trials since 1995 of the duration of anticoagulation
|+ Randomized controlled trials since 1995 of the duration of anticoagulation
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| Levine, 1995<ref name="pmid8584992">{{cite journal |author=Levine MN, Hirsh J, Gent M, ''et al'' |title=Optimal duration of oral anticoagulant therapy: a randomized trial comparing four weeks with three months of warfarin in patients with proximal deep vein thrombosis |journal=Thromb. Haemost. |volume=74 |issue=2 |pages=606–11 |year=1995 |month=August |pmid=8584992 |doi= |url= |issn=}}</ref> || Acute DVT with normal normal impedance plethysmogram (IPG) after 4 weeks || 1 mo || 3 mos || Prolonged tended to do better
| Levine, 1995<ref name="pmid8584992">{{cite journal |author=Levine MN, Hirsh J, Gent M, ''et al'' |title=Optimal duration of oral anticoagulant therapy: a randomized trial comparing four weeks with three months of warfarin in patients with proximal deep vein thrombosis |journal=Thromb. Haemost. |volume=74 |issue=2 |pages=606–11 |year=1995 |month=August |pmid=8584992 |doi= |url= |issn=}}</ref> || Acute DVT with normal normal impedance plethysmogram (IPG) after 4 weeks || 1 mo || 3 mos || Prolonged tended to do better
|}
|}
[[Clinical practice guideline]]s by the [[American College of Chest Physicians]] address the duration of anticoagulation for [[deep venous thrombosis]] and [[pulmonary embolism]].<ref name="pmid18574272">{{cite journal |author=Kearon C, Kahn SR, Agnelli G, Goldhaber S, Raskob GE, Comerota AJ |title=Antithrombotic therapy for venous thromboembolic disease: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition) |journal=Chest |volume=133 |issue=6 Suppl |pages=454S–545S |year=2008 |month=June |pmid=18574272 |doi=10.1378/chest.08-0658 |url=http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=18574272 |issn=}}</ref> Although initial trials suggested lack of benefit from prolonged anticoaguation<ref name="pmid16091573">{{cite journal |author=Ost D, Tepper J, Mihara H, Lander O, Heinzer R, Fein A |title=Duration of anticoagulation following venous thromboembolism: a meta-analysis |journal=JAMA |volume=294 |issue=6 |pages=706–15 |year=2005 |month=August |pmid=16091573 |doi=10.1001/jama.294.6.706 |url=http://jama.ama-assn.org/cgi/pmidlookup?view=long&pmid=16091573 |issn=}}</ref>, trials since 1995 favor longer anticoagulation. In patients who have had ''recurrent DVTs'' (two or more), anticoagulation is generally "life-long."  The [[Cochrane Collaboration]] and others have meta-analyzed the risk and benefits of prolonged anti-coagulation.<ref name="pmid16437432">{{cite journal |author=Hutten BA, Prins MH |title=Duration of treatment with vitamin K antagonists in symptomatic venous thromboembolism |journal=Cochrane database of systematic reviews (Online) |volume= |issue=1 |pages=CD001367 |year=2006 |pmid=16437432 |doi=10.1002/14651858.CD001367.pub2}}</ref><ref name="pmid16091573"/>
[[Clinical practice guideline]]s by the [[American College of Chest Physicians]] address the duration of anticoagulation for [[deep venous thrombosis]] and [[pulmonary embolism]].<ref name="pmid18574272"/> Although initial trials suggested lack of benefit from prolonged anticoaguation<ref name="pmid16091573">{{cite journal |author=Ost D, Tepper J, Mihara H, Lander O, Heinzer R, Fein A |title=Duration of anticoagulation following venous thromboembolism: a meta-analysis |journal=JAMA |volume=294 |issue=6 |pages=706–15 |year=2005 |month=August |pmid=16091573 |doi=10.1001/jama.294.6.706 |url=http://jama.ama-assn.org/cgi/pmidlookup?view=long&pmid=16091573 |issn=}}</ref>, trials since 1995 favor longer anticoagulation. In patients who have had ''recurrent DVTs'' (two or more), anticoagulation is generally "life-long."  The [[Cochrane Collaboration]] and others have meta-analyzed the risk and benefits of prolonged anti-coagulation.<ref name="pmid16437432">{{cite journal |author=Hutten BA, Prins MH |title=Duration of treatment with vitamin K antagonists in symptomatic venous thromboembolism |journal=Cochrane database of systematic reviews (Online) |volume= |issue=1 |pages=CD001367 |year=2006 |pmid=16437432 |doi=10.1002/14651858.CD001367.pub2}}</ref><ref name="pmid16091573"/>


{| class="wikitable"
{| class="wikitable"
|+ Recommendations by the American College of Chest Physicians for the Duration of Therapy<ref name="pmid18574272">{{cite journal |author=Kearon C, Kahn SR, Agnelli G, Goldhaber S, Raskob GE, Comerota AJ |title=Antithrombotic therapy for venous thromboembolic disease: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition) |journal=Chest |volume=133 |issue=6 Suppl |pages=454S–545S |year=2008 |month=June |pmid=18574272 |doi=10.1378/chest.08-0658 |url=http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=18574272 |issn=}}</ref>
|+ Recommendations by the American College of Chest Physicians for the Duration of Therapy<ref name="pmid18574272"/>
! Setting
! Setting
! Recommended duration
! Recommended duration
Line 92: Line 103:
[[Ultrasonography]], using the following protocol may<ref name="pmid19414836">{{Cite journal | volume = 150 | issue = 9 | pages = 577-585 | last = Prandoni | first = Paolo | coauthors = Martin H. Prins, Anthonie W.A. Lensing, Angelo Ghirarduzzi, Walter Ageno, Davide Imberti, Gianluigi Scannapieco, Giovanni B. Ambrosio, Raffaele Pesavento, Stefano Cuppini, Roberto Quintavalla, Giancarlo Agnelli, for the AESOPUS Investigators | title = Residual Thrombosis on Ultrasonography to Guide the Duration of Anticoagulation in Patients With Deep Venous Thrombosis: A Randomized Trial | journal = Ann Intern Med | accessdate = 2009-05-06 | date = 2009-05-05 | pmid=19414836 |url = http://www.annals.org/cgi/content/abstract/150/9/577}}</ref> or may not<ref name="pmid9313000">{{cite journal |author=Robinson KS, Anderson DR, Gross M, ''et al.'' |title=Ultrasonographic screening before hospital discharge for deep venous thrombosis after arthroplasty: the post-arthroplasty screening study. A randomized, controlled trial |journal=Ann. Intern. Med. |volume=127 |issue=6 |pages=439–45 |year=1997 |month=September |pmid=9313000 |doi= |url=http://www.annals.org/cgi/pmidlookup?view=long&pmid=9313000 |issn=}}</ref> help determine when to stop anticoaguation<ref name="pmid19414836"/>:
[[Ultrasonography]], using the following protocol may<ref name="pmid19414836">{{Cite journal | volume = 150 | issue = 9 | pages = 577-585 | last = Prandoni | first = Paolo | coauthors = Martin H. Prins, Anthonie W.A. Lensing, Angelo Ghirarduzzi, Walter Ageno, Davide Imberti, Gianluigi Scannapieco, Giovanni B. Ambrosio, Raffaele Pesavento, Stefano Cuppini, Roberto Quintavalla, Giancarlo Agnelli, for the AESOPUS Investigators | title = Residual Thrombosis on Ultrasonography to Guide the Duration of Anticoagulation in Patients With Deep Venous Thrombosis: A Randomized Trial | journal = Ann Intern Med | accessdate = 2009-05-06 | date = 2009-05-05 | pmid=19414836 |url = http://www.annals.org/cgi/content/abstract/150/9/577}}</ref> or may not<ref name="pmid9313000">{{cite journal |author=Robinson KS, Anderson DR, Gross M, ''et al.'' |title=Ultrasonographic screening before hospital discharge for deep venous thrombosis after arthroplasty: the post-arthroplasty screening study. A randomized, controlled trial |journal=Ann. Intern. Med. |volume=127 |issue=6 |pages=439–45 |year=1997 |month=September |pmid=9313000 |doi= |url=http://www.annals.org/cgi/pmidlookup?view=long&pmid=9313000 |issn=}}</ref> help determine when to stop anticoaguation<ref name="pmid19414836"/>:
:"If veins had not recanalized, we invited patients to have further ultrasonography after 3 and 9 months in patients with secondary DVT and after 3, 9, 15, and 21 months in those with unprovoked DVT. Anticoagulation was discontinued when the veins had recanalized, along with further ultrasonography"
:"If veins had not recanalized, we invited patients to have further ultrasonography after 3 and 9 months in patients with secondary DVT and after 3, 9, 15, and 21 months in those with unprovoked DVT. Anticoagulation was discontinued when the veins had recanalized, along with further ultrasonography"
{| class="wikitable"
|+ Reducing the risk of recurrence after an unprovoked [[deep venous thrombosis]].<ref name="pmid22621626">{{cite journal| author=Becattini C, Agnelli G, Schenone A, Eichinger S, Bucherini E, Silingardi M et al.| title=Aspirin for preventing the recurrence of venous thromboembolism. | journal=N Engl J Med | year= 2012 | volume= 366 | issue= 21 | pages= 1959-67 | pmid=22621626 | doi=10.1056/NEJMoa1114238 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22621626  }} </ref> <ref name="pmid21128814">{{cite journal| author=EINSTEIN Investigators. Bauersachs R, Berkowitz SD, Brenner B, Buller HR, Decousus H et al.| title=Oral rivaroxaban for symptomatic venous thromboembolism. | journal=N Engl J Med | year= 2010 | volume= 363 | issue= 26 | pages= 2499-510 | pmid=21128814 | doi=10.1056/NEJMoa1007903 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21128814  }}  [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21460399 Review in: Evid Based Med. 2011 Oct;16(5):139-40] </ref> <ref name="pmid20956709"/> <ref name="pmid21382171">{{cite journal| author=Carrier M, Rodger MA, Wells PS, Righini M, LE Gal G| title=Residual vein obstruction to predict the risk of recurrent venous thromboembolism in patients with deep vein thrombosis: a systematic review and meta-analysis. | journal=J Thromb Haemost | year= 2011 | volume= 9 | issue= 6 | pages= 1119-25 | pmid=21382171 | doi=10.1111/j.1538-7836.2011.04254.x | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21382171  }} </ref> <ref name="pmid22489957">{{cite journal| author=Tosetto A, Iorio A, Marcucci M, Baglin T, Cushman M, Eichinger S et al.| title=Predicting disease recurrence in patients with previous unprovoked venous thromboembolism: a proposed prediction score (DASH). | journal=J Thromb Haemost | year= 2012 | volume= 10 | issue= 6 | pages= 1019-25 | pmid=22489957 | doi=10.1111/j.1538-7836.2012.04735.x | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22489957  }} </ref>
! &nbsp;!! Treatment or test!!Risk if treated or test result is favorable!!Risk if ''not treated'' or test result is ''unfavorable''!!Comments
|-
| [[Randomized controlled trial]]<ref name="pmid22621626"/>|| Aspirin 100 mg daily for 2 years||6% per year||11.2% per year||0.5% major bleeding
|-
| [[Randomized controlled trial]]<ref name="pmid21128814"/>|| Rivaroxaban for 6-12 months||1% over 6-12 months||7% over 6-12 months||0.7% major bleeding
|-
| [[Systematic review]] of a [[diagnostic test]]<ref name="pmid20956709"/><ref name="pmid22489957"/>|| Normal [[d-dimer]]||4% per year||9% per year
|-
| [[Systematic review]] of a [[diagnostic test]]<ref name="pmid21382171"/>|| Recanalization of veins (no residual vein obstruction or RVO)||colspan="2" align="center"|Insignificant difference
|}
====Extending treatment with aspirin====
Two trials have examined this idea.<ref name="ASPIRE">{{Cite journal
| doi = 10.1056/NEJMoa1210384 | issn = 0028-4793 | last = Brighton
| first = Timothy A. | coauthors = John W. Eikelboom, Kristy Mann, Rebecca Mister, Alexander Gallus, Paul Ockelford, Harry Gibbs, Wendy Hague, Denis Xavier, Rafael Diaz, Adrienne Kirby, John Simes
| title = Low-Dose Aspirin for Preventing Recurrent Venous Thromboembolism
| journal = New England Journal of Medicine | accessdate = 2012-11-05 | url = http://www.nejm.org/doi/full/10.1056/NEJMoa1210384 }}</ref><ref name="pmid22621626">{{cite journal| author=Becattini C, Agnelli G, Schenone A, Eichinger S, Bucherini E, Silingardi M et al.| title=Aspirin for preventing the recurrence of venous thromboembolism. | journal=N Engl J Med | year= 2012 | volume= 366 | issue= 21 | pages= 1959-67 | pmid=22621626 | doi=10.1056/NEJMoa1114238 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22621626  }} </ref>
{| class="wikitable"
|+ [[Randomized controlled trial]]s of [[aspirin]] after discontinuation of [[anticoagulant]]s.<ref name="ASPIRE">{{Cite journal
| doi = 10.1056/NEJMoa1210384 | issn = 0028-4793 | last = Brighton
| first = Timothy A. | coauthors = John W. Eikelboom, Kristy Mann, Rebecca Mister, Alexander Gallus, Paul Ockelford, Harry Gibbs, Wendy Hague, Denis Xavier, Rafael Diaz, Adrienne Kirby, John Simes
| title = Low-Dose Aspirin for Preventing Recurrent Venous Thromboembolism
| journal = New England Journal of Medicine | accessdate = 2012-11-05 | url = http://www.nejm.org/doi/full/10.1056/NEJMoa1210384 }}</ref><ref name="pmid22621626">{{cite journal| author=Becattini C, Agnelli G, Schenone A, Eichinger S, Bucherini E, Silingardi M et al.| title=Aspirin for preventing the recurrence of venous thromboembolism. | journal=N Engl J Med | year= 2012 | volume= 366 | issue= 21 | pages= 1959-67 | pmid=22621626 | doi=10.1056/NEJMoa1114238 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=22621626  }} </ref>
! rowspan="2"|Trial!!rowspan="2"| Patients!!rowspan="2"| Intervention!!rowspan="2"|Comparison !!rowspan="2"|Outcome!!colspan="2"|Results!!rowspan="2"|Comment
|-<br/>
! Intervention!!Control
|-
| ASPIRE, 2012<ref name="ASPIRE"/>|| 822 patients<br/>&bull;&nbsp;first-ever, unprovoked venous thromboembolism<br/>&bull;&nbsp;completed initial [[anticoagulant]]|| Aspirin 100 mg/day||Placebo|| venous thromboembolism at 37 months|| 4.8%|| 6.5%|| [[relative risk ratio]] =  0.74 (95% [[confidence interval|CI]]: 0.52 to 1.05; P=0.09)
|-
| WARFASA, 2012<ref name="pmid22621626"/>|| 502 patients<br/>&bull;&nbsp;first-ever, unprovoked venous thromboembolism<br/>&bull;&nbsp;completed initial [[anticoagulant]]|| [[Aspirin]] 100 mg/day||Placebo||venous thromboembolism at 24 months|| 6.6%|| 11.2%||
0.58 (95% [[confidence interval|CI]]:  0.36 to 0.93)
|}


==Prognosis==
==Prognosis==
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*** Recurrent  fatal VTE was 0.3% per 100 patient-years (case-fatality                      rate was 3.6%)
*** Recurrent  fatal VTE was 0.3% per 100 patient-years (case-fatality                      rate was 3.6%)


Elevated [[d-dimer]] levels at the end of treatment predict recurrence.<ref name="pmid20956709">{{cite journal| author=Douketis J, Tosetto A, Marcucci M, Baglin T, Cushman M, Eichinger S et al.| title=Patient-level meta-analysis: effect of measurement timing, threshold, and patient age on ability of D-dimer testing to assess recurrence risk after unprovoked venous thromboembolism. | journal=Ann Intern Med | year= 2010 | volume= 153 | issue= 8 | pages= 523-31 | pmid=20956709 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20956709 | doi=10.1059/0003-4819-153-8-201010190-00009 }} </ref>
Elevated [[d-dimer]] levels at the end of treatment predict recurrence.<ref name="pmid20956709"/>


The presence of [[Factor V Leiden]] but not [[prothrombin G20210A]] increases risk of recurrence.<ref name="pmid19531787">{{cite journal |author=Segal JB, Brotman DJ, Necochea AJ, ''et al.'' |title=Predictive value of factor V Leiden and prothrombin G20210A in adults with venous thromboembolism and in family members of those with a mutation: a systematic review |journal=JAMA |volume=301 |issue=23 |pages=2472–85 |year=2009 |month=June |pmid=19531787 |doi=10.1001/jama.2009.853 |url=http://jama.ama-assn.org/cgi/pmidlookup?view=long&pmid=19531787 |issn=}}</ref>
The presence of [[Factor V Leiden]] but not [[prothrombin G20210A]] increases risk of recurrence.<ref name="pmid19531787">{{cite journal |author=Segal JB, Brotman DJ, Necochea AJ, ''et al.'' |title=Predictive value of factor V Leiden and prothrombin G20210A in adults with venous thromboembolism and in family members of those with a mutation: a systematic review |journal=JAMA |volume=301 |issue=23 |pages=2472–85 |year=2009 |month=June |pmid=19531787 |doi=10.1001/jama.2009.853 |url=http://jama.ama-assn.org/cgi/pmidlookup?view=long&pmid=19531787 |issn=}}</ref>
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==References==
==References==
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[[Category:Suggestion Bot Tag]]

Latest revision as of 17:00, 17 December 2024

This article is a stub and thus not approved.
Main Article
Discussion
Related Articles  [?]
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This editable Main Article is under development and subject to a disclaimer.

Embolism and thrombosis is "a collective term for pathological conditions which are caused by the formation of a blood clot (thrombus) in a blood vessel, or by blocking of a blood vessel with an embolus, undissolved materials in the blood stream."[1]

The United States of America Surgeon General has announced a call to action to prevent Deep Vein Thrombosis and Pulmonary Embolism.[2]

Classification

Cause/etiology

The risk of venous thromboembolism can be estimated with http://www.qthrombosis.org/.

One risk factor is hypercoagulability due to cancer. Cancer can be found in up to 10% of patients within one year of embolism or thrombosis.[4]

Genetics

In a cohort study. the population attributable risk of venous thromboembolism was:[5]

In an older systematic review, the presence of Factor V Leiden (homozygotes or heterozygotes) but not prothrombin G20210A (heterozygoes; homozygotes not clear) increases risk of recurrence.[6]

Malignancy

The prevalence of malignancy is about:[7]

  • 3% of patients with first idiopathic venous thrombosis
  • 17% of patients with idiopathic, idiopathic venous thrombosis

The most common sites of cancer that is diagnosed at the time of, or later than the episode embolism and thrombosis of are:[8][9]

Diagnosis

Clinical practice guidelines address this for patients in general[10] and for patients who are pregnant[11].

Treatment

Embolism and thrombosis may be prevented by anticoagulation with anticoagulants. Clinical practice guidelines address this for patients in general[10] and for patients who are pregnant[11].

Dabigatran is given orally and may be as effective as warfarin and with less bleeding but increased dyspepsia for the treatment of embolism and thrombosis.[12]

Thrombolysis

Clinical practice guidelines address the management of severe forms of embolism and thrombosis which may require thrombolysis.[13]

Duration of treatment

This topic has been reviewed in a meta-analysis using individual patient data.[14]

Randomized controlled trials since 1995 of the duration of anticoagulation
  Patients Duration of
short course
Duration of
long course
findings
Campbell, 2007[15] DVT or PE without prior episode within 3 years 3 mos 6 mos Prolonged tended to do slightly better
Schulman, 2003[16] DVT or PE. 13% had prior VTE. 6 mos 24 mos Prolonged did better
Kearon, 2004[17] First episode of VTE due to transient risk factor 1 mo 3 mos Prolonged did better
Ridker, 2003[18] Idiopathic VTE. 30% had prior VTE 6 mos 2.1 yrs Prolonged did better
Agnelli, 2001[19] First episode of idiopathic DVT 3 mos 1 yr Prolonged did better while anticoagulated, but after two years there was no difference
Kearon, 1999[20] First episode of idiopathic VTE. 3 mos 2 yrs Prolonged did better
Pinede, 2001[21] DVT or PE without prior episode within 3 years 6 wks for distal DVT;
3 mos for proximal or PE
12 wks for distal DVT;
6 mos for proximal or PE
Prolonged tended to do slightly better
Levine, 1995[22] Acute DVT with normal normal impedance plethysmogram (IPG) after 4 weeks 1 mo 3 mos Prolonged tended to do better

Clinical practice guidelines by the American College of Chest Physicians address the duration of anticoagulation for deep venous thrombosis and pulmonary embolism.[10] Although initial trials suggested lack of benefit from prolonged anticoaguation[23], trials since 1995 favor longer anticoagulation. In patients who have had recurrent DVTs (two or more), anticoagulation is generally "life-long." The Cochrane Collaboration and others have meta-analyzed the risk and benefits of prolonged anti-coagulation.[24][23]

Recommendations by the American College of Chest Physicians for the Duration of Therapy[10]
Setting Recommended duration
Single DVT due to transient risk factor 3 months
Single unprovoked DVT at least 3 months (longer if favorable risks for anticoagulation)
Second episode of unprovoked VTE long-term treatment
DVT in patients with cancer LMWH for the first 3 to 6 months of long-term anticoagulant therapy

Using D-dimer to determine duration of treatment

For more information, see: D-dimer.

Elevated d-dimer levels at the end of treatment predict recurrence.[25]

Using Ultrasonography to determine duration of treatment

Ultrasonography, using the following protocol may[26] or may not[27] help determine when to stop anticoaguation[26]:

"If veins had not recanalized, we invited patients to have further ultrasonography after 3 and 9 months in patients with secondary DVT and after 3, 9, 15, and 21 months in those with unprovoked DVT. Anticoagulation was discontinued when the veins had recanalized, along with further ultrasonography"


Reducing the risk of recurrence after an unprovoked deep venous thrombosis.[28] [29] [25] [30] [31]
  Treatment or test Risk if treated or test result is favorable Risk if not treated or test result is unfavorable Comments
Randomized controlled trial[28] Aspirin 100 mg daily for 2 years 6% per year 11.2% per year 0.5% major bleeding
Randomized controlled trial[29] Rivaroxaban for 6-12 months 1% over 6-12 months 7% over 6-12 months 0.7% major bleeding
Systematic review of a diagnostic test[25][31] Normal d-dimer 4% per year 9% per year
Systematic review of a diagnostic test[30] Recanalization of veins (no residual vein obstruction or RVO) Insignificant difference

Extending treatment with aspirin

Two trials have examined this idea.[32][28]

Randomized controlled trials of aspirin after discontinuation of anticoagulants.[32][28]
Trial Patients Intervention Comparison Outcome Results Comment
Intervention Control
ASPIRE, 2012[32] 822 patients
• first-ever, unprovoked venous thromboembolism
• completed initial anticoagulant
Aspirin 100 mg/day Placebo venous thromboembolism at 37 months 4.8% 6.5% relative risk ratio = 0.74 (95% CI: 0.52 to 1.05; P=0.09)
WARFASA, 2012[28] 502 patients
• first-ever, unprovoked venous thromboembolism
• completed initial anticoagulant
Aspirin 100 mg/day Placebo venous thromboembolism at 24 months 6.6% 11.2%

0.58 (95% CI: 0.36 to 0.93)

Prognosis

A systematic review of cohort studies found:[33]

  • During the initial 3 months of anticoagulation
    • Recurrent VTE = 3.4%
      • Recurrent fatal VTE was 0.4% (case-fatalityrate was 11.3%)
    • Major bleeding was 1.6%
      • Fatal major bleeding events was 0.2% (case-fatalityrate of 11.3%)
  • After anticoagulation
    • Recurrent VTE = 7.6% per 100 patient-years
      • Recurrent fatal VTE was 0.3% per 100 patient-years (case-fatality rate was 3.6%)

Elevated d-dimer levels at the end of treatment predict recurrence.[25]

The presence of Factor V Leiden but not prothrombin G20210A increases risk of recurrence.[6]

Prevention

Among patients with cancer, anticoagulation does not help in the primary prevention of embolism and thrombosis.[34]

Rosuvastatin, a hydroxymethylglutaryl-coenzyme A reductase inhibitor (statin), may reduce embolism and thrombosis according to the Jupiter randomized controlled trial.[35]

References

  1. Anonymous (2024), Embolism and thrombosis (English). Medical Subject Headings. U.S. National Library of Medicine.
  2. The Surgeon General's Call to Action to Prevent Deep Vein Thrombosis and Pulmonary Embolism. Office of Public Health and Science (2008).
  3. Decousus H, Quéré I, Presles E, Becker F, Barrellier MT, Chanut M et al. (2010). "Superficial venous thrombosis and venous thromboembolism: a large, prospective epidemiologic study.". Ann Intern Med 152 (4): 218-24. DOI:10.1059/0003-4819-152-4-201002160-00006. PMID 20157136. Research Blogging.
  4. Carrier M, Le Gal G, Wells PS, Fergusson D, Ramsay T, Rodger MA (September 2008). "Systematic review: the Trousseau syndrome revisited: should we screen extensively for cancer in patients with venous thromboembolism?". Annals of internal medicine 149 (5): 323–33. PMID 18765702[e]
  5. Sode BF, Allin KH, Dahl M, Gyntelberg F, Nordestgaard BG (2013). "Risk of venous thromboembolism and myocardial infarction associated with factor V Leiden and prothrombin mutations and blood type.". CMAJ 185 (5): E229-37. DOI:10.1503/cmaj.121636. PMID 23382263. PMC PMC3602271. Research Blogging.
  6. 6.0 6.1 Segal JB, Brotman DJ, Necochea AJ, et al. (June 2009). "Predictive value of factor V Leiden and prothrombin G20210A in adults with venous thromboembolism and in family members of those with a mutation: a systematic review". JAMA 301 (23): 2472–85. DOI:10.1001/jama.2009.853. PMID 19531787. Research Blogging.
  7. Prandoni P, Lensing AW, Büller HR, Cogo A, Prins MH, Cattelan AM et al. (1992). "Deep-vein thrombosis and the incidence of subsequent symptomatic cancer.". N Engl J Med 327 (16): 1128-33. PMID 1528208.
  8. Sørensen HT, Mellemkjaer L, Olsen JH, Baron JA (2000). "Prognosis of cancers associated with venous thromboembolism.". N Engl J Med 343 (25): 1846-50. PMID 11117976. <
  9. Sørensen HT, Mellemkjaer L, Steffensen FH, Olsen JH, Nielsen GL (1998). "The risk of a diagnosis of cancer after primary deep venous thrombosis or pulmonary embolism.". N Engl J Med 338 (17): 1169-73. PMID 9554856.
  10. 10.0 10.1 10.2 10.3 Kearon C, Kahn SR, Agnelli G, Goldhaber S, Raskob GE, Comerota AJ (June 2008). "Antithrombotic therapy for venous thromboembolic disease: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)". Chest 133 (6 Suppl): 454S–545S. DOI:10.1378/chest.08-0658. PMID 18574272. Research Blogging.
  11. 11.0 11.1 (2011) "Practice bulletin no. 123: thromboembolism in pregnancy.". Obstet Gynecol 118 (3): 718-29. DOI:10.1097/AOG.0b013e3182310c4c. PMID 21860313. Research Blogging.
  12. Schulman S, Kearon C, Kakkar AK, Mismetti P, Schellong S, Eriksson H et al. (2009). "Dabigatran versus warfarin in the treatment of acute venous thromboembolism.". N Engl J Med 361 (24): 2342-52. DOI:10.1056/NEJMoa0906598. PMID 19966341. Research Blogging. Review in: Ann Intern Med. 2010 Apr 20;152(8):JC4-7
  13. Jaff MR, McMurtry MS, Archer SL, Cushman M, Goldenberg N, Goldhaber SZ et al. (2011). "Management of Massive and Submassive Pulmonary Embolism, Iliofemoral Deep Vein Thrombosis, and Chronic Thromboembolic Pulmonary Hypertension: A Scientific Statement From the American Heart Association.". Circulation. DOI:10.1161/CIR.0b013e318214914f. PMID 21422387. Research Blogging.
  14. Boutitie F, Pinede L, Schulman S, Agnelli G, Raskob G, Julian J et al. (2011). "Influence of preceding length of anticoagulant treatment and initial presentation of venous thromboembolism on risk of recurrence after stopping treatment: analysis of individual participants' data from seven trials.". BMJ 342: d3036. DOI:10.1136/bmj.d3036. PMID 21610040. PMC PMC3100759. Research Blogging.
  15. Campbell IA, Bentley DP, Prescott RJ, Routledge PA, Shetty HG, Williamson IJ (March 2007). "Anticoagulation for three versus six months in patients with deep vein thrombosis or pulmonary embolism, or both: randomised trial". BMJ 334 (7595): 674. DOI:10.1136/bmj.39098.583356.55. PMID 17289685. PMC 1839169. Research Blogging.
  16. Schulman S, Wåhlander K, Lundström T, Clason SB, Eriksson H (October 2003). "Secondary prevention of venous thromboembolism with the oral direct thrombin inhibitor ximelagatran". N. Engl. J. Med. 349 (18): 1713–21. DOI:10.1056/NEJMoa030104. PMID 14585939. Research Blogging.
  17. Kearon C, Ginsberg JS, Anderson DR, et al (May 2004). "Comparison of 1 month with 3 months of anticoagulation for a first episode of venous thromboembolism associated with a transient risk factor". J. Thromb. Haemost. 2 (5): 743–9. DOI:10.1046/j.1538-7836.2004.00698.x. PMID 15099280. Research Blogging.
  18. Ridker PM, Goldhaber SZ, Danielson E, et al (April 2003). "Long-term, low-intensity warfarin therapy for the prevention of recurrent venous thromboembolism". N. Engl. J. Med. 348 (15): 1425–34. DOI:10.1056/NEJMoa035029. PMID 12601075. Research Blogging.
  19. Agnelli G, Prandoni P, Santamaria MG, et al (July 2001). "Three months versus one year of oral anticoagulant therapy for idiopathic deep venous thrombosis. Warfarin Optimal Duration Italian Trial Investigators". N. Engl. J. Med. 345 (3): 165–9. PMID 11463010[e]
  20. Kearon C, Gent M, Hirsh J, et al (March 1999). "A comparison of three months of anticoagulation with extended anticoagulation for a first episode of idiopathic venous thromboembolism". N. Engl. J. Med. 340 (12): 901–7. PMID 10089183[e]
  21. Pinede L, Ninet J, Duhaut P, et al (May 2001). "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". Circulation 103 (20): 2453–60. PMID 11369685[e]
  22. Levine MN, Hirsh J, Gent M, et al (August 1995). "Optimal duration of oral anticoagulant therapy: a randomized trial comparing four weeks with three months of warfarin in patients with proximal deep vein thrombosis". Thromb. Haemost. 74 (2): 606–11. PMID 8584992[e]
  23. 23.0 23.1 Ost D, Tepper J, Mihara H, Lander O, Heinzer R, Fein A (August 2005). "Duration of anticoagulation following venous thromboembolism: a meta-analysis". JAMA 294 (6): 706–15. DOI:10.1001/jama.294.6.706. PMID 16091573. Research Blogging.
  24. Hutten BA, Prins MH (2006). "Duration of treatment with vitamin K antagonists in symptomatic venous thromboembolism". Cochrane database of systematic reviews (Online) (1): CD001367. DOI:10.1002/14651858.CD001367.pub2. PMID 16437432. Research Blogging.
  25. 25.0 25.1 25.2 25.3 Douketis J, Tosetto A, Marcucci M, Baglin T, Cushman M, Eichinger S et al. (2010). "Patient-level meta-analysis: effect of measurement timing, threshold, and patient age on ability of D-dimer testing to assess recurrence risk after unprovoked venous thromboembolism.". Ann Intern Med 153 (8): 523-31. DOI:10.1059/0003-4819-153-8-201010190-00009. PMID 20956709. Research Blogging.
  26. 26.0 26.1 Prandoni, Paolo; Martin H. Prins, Anthonie W.A. Lensing, Angelo Ghirarduzzi, Walter Ageno, Davide Imberti, Gianluigi Scannapieco, Giovanni B. Ambrosio, Raffaele Pesavento, Stefano Cuppini, Roberto Quintavalla, Giancarlo Agnelli, for the AESOPUS Investigators (2009-05-05). "Residual Thrombosis on Ultrasonography to Guide the Duration of Anticoagulation in Patients With Deep Venous Thrombosis: A Randomized Trial". Ann Intern Med 150 (9): 577-585. PMID 19414836. Retrieved on 2009-05-06.
  27. Robinson KS, Anderson DR, Gross M, et al. (September 1997). "Ultrasonographic screening before hospital discharge for deep venous thrombosis after arthroplasty: the post-arthroplasty screening study. A randomized, controlled trial". Ann. Intern. Med. 127 (6): 439–45. PMID 9313000[e]
  28. 28.0 28.1 28.2 28.3 28.4 Becattini C, Agnelli G, Schenone A, Eichinger S, Bucherini E, Silingardi M et al. (2012). "Aspirin for preventing the recurrence of venous thromboembolism.". N Engl J Med 366 (21): 1959-67. DOI:10.1056/NEJMoa1114238. PMID 22621626. Research Blogging.
  29. 29.0 29.1 EINSTEIN Investigators. Bauersachs R, Berkowitz SD, Brenner B, Buller HR, Decousus H et al. (2010). "Oral rivaroxaban for symptomatic venous thromboembolism.". N Engl J Med 363 (26): 2499-510. DOI:10.1056/NEJMoa1007903. PMID 21128814. Research Blogging. Review in: Evid Based Med. 2011 Oct;16(5):139-40
  30. 30.0 30.1 Carrier M, Rodger MA, Wells PS, Righini M, LE Gal G (2011). "Residual vein obstruction to predict the risk of recurrent venous thromboembolism in patients with deep vein thrombosis: a systematic review and meta-analysis.". J Thromb Haemost 9 (6): 1119-25. DOI:10.1111/j.1538-7836.2011.04254.x. PMID 21382171. Research Blogging.
  31. 31.0 31.1 Tosetto A, Iorio A, Marcucci M, Baglin T, Cushman M, Eichinger S et al. (2012). "Predicting disease recurrence in patients with previous unprovoked venous thromboembolism: a proposed prediction score (DASH).". J Thromb Haemost 10 (6): 1019-25. DOI:10.1111/j.1538-7836.2012.04735.x. PMID 22489957. Research Blogging.
  32. 32.0 32.1 32.2 Brighton, Timothy A.; John W. Eikelboom, Kristy Mann, Rebecca Mister, Alexander Gallus, Paul Ockelford, Harry Gibbs, Wendy Hague, Denis Xavier, Rafael Diaz, Adrienne Kirby, John Simes. "Low-Dose Aspirin for Preventing Recurrent Venous Thromboembolism". New England Journal of Medicine. DOI:10.1056/NEJMoa1210384. ISSN 0028-4793. Retrieved on 2012-11-05. Research Blogging.
  33. Carrier M, Le Gal G, Wells PS, Rodger MA (2010). "Systematic review: case-fatality rates of recurrent venous thromboembolism and major bleeding events among patients treated for venous thromboembolism.". Ann Intern Med 152 (9): 578-89. DOI:10.1059/0003-4819-152-9-201005040-00008. PMID 20439576. Research Blogging.
  34. Wells PS (May 2008). "Review: evidence for the effectiveness of anticoagulation therapy or prophylaxis for VTE in cancer is limited". ACP J. Club 148 (3): 7. PMID 18489070[e]
  35. Glynn RJ, Danielson E, Fonseca FA, et al (March 2009). "A Randomized Trial of Rosuvastatin in the Prevention of Venous Thromboembolism". N. Engl. J. Med.. DOI:10.1056/NEJMoa0900241. PMID 19329822. Research Blogging.