ST elevation myocardial infarction anticoagulant and antithrombotic therapy
ST elevation myocardial infarction Microchapters
ST elevation myocardial infarction anticoagulant and antithrombotic therapy On the Web
Editor-In-Chief: C. Michael Gibson, M.S., M.D. ; John Alexander, M.D. , Duke Clinical Research Institute As an active clinical researcher, Dr. Gibson has received research and grant support from the majority of manufacturers of antithrombin and antiplatelet agents. You can view his complete disclosure statement here.
Management of the patient with ST elevation myocardial infarction requires inhibition of both the generation of thrombin (i.e inhibition of the coagulation cascade via antithrombins) as well as the platelet (via antiplatelet agents). Selection of the appropriate antithrombin depends upon a variety of factors including the choice of revascularization strategy. This chapter reviews data supporting the optimal selection of both parenteral antithrombotic and oral antithrombotic (anticoagulant) agents for a given patient.
|IV Antithrombin||In Conjunction with Fibrinolytic||In Conjunction with Primary PCI|
|Bivalirudin||Reduces recurrent MI with Streptokinase, more mild to moderate bleeding||Less bleeding than UFH + GP IIBIIIa, more stent thrombosis in first 24 hours|
|Enoxaparin||When given for duration of hospitalization, reduces death/MI vs 48 hrs of UFH, more bleeding||Insufficient data|
|Fondaparinux||Excellent safety, efficacious vs placebo, no greater efficacy than UFH||Do not use, clot forms on wires. If you do use, add another antithrombin with Factor II activity during PCI|
Sites of Action of Antithrombins
The majority of established and investigational antithrombins target two factors in the coagulation cascade: Factor Xa and Factor IIa.  Factor Xa lies higher in the coagulation cascade at the intersection of the intrinsic and extrinsic pathways. Inhibition of Factor Xa limits the initial thrombin generation irrespective of whether the coagulation cascade was triggered by activation of the intrinsic or extrinsic pathway. Factor IIa (thrombin) lies lower in the coagulation cascade and is involved in the conversion of fibrinogen to fibrin.
Parenteral Drugs Targeting Factor Xa
Indirect Inhibitors Requiring Antithrombin
Direct Inhibitors Not Requiring Antithrombin
Oral Drugs Targeting Factor Xa
Parenteral Drugs Targeting Factor IIa
Oral Drugs Targeting Factor IIa
- Ximelogatran (removed from market)
Parenteral Drugs Targeting Both Factor IIa and Factor Xa
- Enoxaparin inhibits Factor Xa more than Factor IIa
- Unfractionated heparin (UFH) inhibits Factor IIa more than Factor Xa
Specific Agents Most Commonly Administered in the Management of the STEMI Patient
By itself, unfractionated heparin (UFH) actually exerts little or no direct effect on thrombin, and for this reason UFH is not classified as a direct thrombin inhibitor. The enzymatic activity is actually achieved indirectly via antithrombin III (AT III). When UFH combines with AT III, the enzymatic activity of AT III is tremendously increased, and for this reason, UFH is classified as an indirect thrombin inhibitor. While the major target of UFH is the indirect inhibition of Factor IIa, UFH also has some anti-Factor Xa activity.
Early trial data supporting the superiority of UFH over placebo in STEMI management
Two trials conducted in the early 1990s, The Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto Miocardico (GISSI 2)  and the Third International Study of Infarct Survival (ISIS-3) , provided data in over 53,000 patients regarding the relative efficacy of UFH vs placebo among STEMI patients treated with a fibrinolytic agent and aspirin. UFH in these early trials was administered by the slower acting subcutaneous (SQ) route 4 to 12 hours after the administration of fibrinolytic therapy. The delayed administration of the agent via a route that is associated with a delay in achieving therapeutic anticoagulation (the SQ route) may have accounted for the modest efficacy of this strategy: an absolute reduction in 35 day mortality of only 0.7%. 
While these two early trials evaluated the efficacy of SQ UFH relatively late in the course of STEMI, 4 other trials compared the more rapidly acting preparation of intravenous (IV) UFH to placebo among patients who had been administered both a fibrinolytic agent and aspirin ASA. In a meta-analysis of these 4 trials which enrolled a total of 1,239 patients, UFH was not associated with a significant reduction in reinfarction or death (52 events (4.2%) in the UFH group vs 48 events (3.9%) in the control group, p=NS).  UFH was asociated with an increase in both minor and major bleeding compared with placebo. The excess rate of minor bleeding did reach statistical significance (odds ratio [OR], 1.72; 95% confidence interval [CI], 1.22–2.43). 
In the large GUSTO 1 trial, there was no difference in mortality outcomes among patients treated with IV vs SQ UFH in conjunction with streptokinase administration (7.2% mortality for SQ vs 7.4% mortality for IV UFH, p=NS).
Advanatges of Unfractionated Heparin
- Low cost and wide availability
- In the presence of bleeding or if there is the need for an invasive procedure, UFH can be reversed by the administration of protamine (1 mg of Protamine for every 100 Units of UFH)
- For patients undergoing PCI, the dosing can be titrated based upon the activated clotting times (ACT)
- There is no need to adjust the dose of UFH in renal dysfunction
- There is a longstanding familiarity of practitioners with its use
Limitations of Unfractionated Heparin
Despite its wide use as antithrombotic therapy in ST elevation MI (STEMI), there are several limitations to unfractionated heparin:
- UFH binds to the glycoprotein IIbIIIa receptor and activates platelets
- When UFH is discontinued, there is a rebound of excess thrombin generation (i.e. Heparin rebound)
- UFH requires the presence of antithrombin III a a cofactor to work. This is why UFH is called an indirect thrombin inhibitor. Given that the levels of antithrombin III vary from patient to patient, and given that the potency of UFH varies from manufacturing lot to lot, there is substantial variability in the pharmacodynamic response to UFH.
- UFH dosing requires monitoring and adjustment via the partial thromboplastin time (PTT) as a result of this variability.
- UFH can crystalize other drugs infusing in the same IV line such as the fibrinolytic rPA
- UFH binds non-specifically to heparin binding proteins and to other platelet factors. This non specific binding can trigger heparin induced thrombocytopenia or HIT. HIT type II is due to an autoimmune reaction with antibodies formed against platelet factor 4 (PF4), neutrophil-activating peptide 2 (NAP-2) and interleukin 8 (IL8) which form complexes with heparin. The most common antigenic complex is the heparin-PF4 complex.
Current use of UFH in STEMI
As a result of its low cost, the ability to reverse UFH with protamine (1 mg of Protamine for every 100 Units of UFH), the ability to titrate the dosing based upon activated clotting times (ACT), the lack of a need to adjust the dose in renal dysfunction, and the longstanding familiarity of practitioners with its use, UFH remains the most widely administered antithrombin in conjunction with fibrinolysis worldwide. Administration of UFH carries a Class 1 recommendation in the AHA / ACC Guidelines when a fibrin specific fibrinolytic agent is administered.  It should be noted, however, that approximately 8% of physicians withhold the adminstration of UFH in conjunction with SK. 
Bivalirudin (Hirulog) is a parenteral direct thrombin inhibitor. Bivalirudin has the following advantages over UFH:
- It is a direct thrombin inhibitor meaning that it does not require antithrombin III as a co-factor to exert its action.
- Bivalirudin acts directly on clot bound thrombin unlike UFH which acts on thrombin in the dissolved fluid phase.
- Bivalirudin does not activate platelets unlike UFH
- Bivalirudin does not bind to platelet factor 4, and therefore does not cause heparin induced thrombocytopenia
Hirudin is another direct thrombin inhibitor, and there are several hirudin based anticoagulant pharmaceutical products such as Lepirudin (Refludan) and Desirudin (Revasc/Iprivask) that are not used as widely at present in the management of STEMI patients.
Bivalirudin use in conjunction with primary percutaneous intervention
The safety and efficacy of administering bivalirudin was compared to UFH plus glycoprotein IIbIIIa inhibition among patients undergoing primary PCI for STEMI in the The Harmonizing Outcomes with RevasculariZatiON and Stents in Acute Myocardial Infarction (HORIZONS-AMI) Trial.   Bivalirudin was associated with a similar rate of major adverse cardiac events (MACE) and a lower rate of bleeding when compared to UFH plus glycoprotein IIbIIIa inhibition. The combination of bivalirudin plus glycoprotein IIbIIIa inhibition was not studied.
Bivalirudin was associated with a significantly higher rate of stent thrombosis in the first 24 hours of the trial. After 24 hours, there was a trend for UFH plus glycoprotein IIbIIIa inhibition to be associated with higher rates of stent thrombosis. While bivalirudin was associated with lower mortality in the HORIZONS AMI trial, a patient level meta-analysis indicates that neither bivalirudin nor direct thrombin inhibitors are in general associated with a reduction in mortality when compared to UFH. 
Bivalirudin use in conjunction with fibrinolytic administration
The safety and efficacy of bivalirudin in conjunction with fibrinolytic administration has been evaluated in the 17,073 patient Hirulog and Early Reperfusion/Occlusion (HERO-2) trial.  1.5 million units of streptokinase was the fibrinolytic agent administered in the trial and the study was open label in design. While bivalirudin is often discontinued at the completion of a PCI, in the HERO-2 trial bivalirudin was administered for 48 hours as was UFH. The primary endpoint was 30 day mortality which did not differ between patients treated with bivalirudin vs UFH ((10.8% vs 10.9%, p=NS). In the first 96 hours of the trial, bivalirudin was associated with a lower rate of reinfarction (p=0.001). While bivalirudin monotherapy has been associated with less bleeding than UFH plus glycoprotein IIbIIIa inhibition in PCI trials, bivalirudin monotherapy was associated with higher rates of moderate and mild bleeding than UFH monotherapy: the rate of moderate bleeding was 1.32 times higher (p<0.0001) and the rate of mild bleeding was 1.47 times higher (p<0.0001).  There were trends for severe bleeding (0.7% vs 0.5%, p=0.07), intracerebral bleeding (0.6% vs 0.4%, p=0.09) and transfusion (1.4% vs 1.1%, p=0.11) to be higher in the bivalirudin monotherapy vs UFH monotherapy groups. 
Current Use of Bivalirudin in STEMI
Among patients undergoing primary PCI, bivalirudin appears to be a reasonable alternative to UFH plus glycoprotein IIbIIIa inhibition. It should be noted that there is a higher risk of stent thrombosis in the first 24 hours with Bivalirudin monotherapy despite treatment with clopidogrel in the majority of these patients. It should also be noted that 60% of patients received UFH prior to bivalirudin in the HORIZONS AMI trial.
Enoxaparin inhibits Factor Xa to a greater extent than Factor IIa. UFH in contrast, inhibits Factor IIa more than Factor Xa. Unlike UFH, it requires no monitoring of the partial thromboplastin time (PTT).
Enoxaparin use in conjunction with fibrinolytic administration
The safety and efficacy of enoxaparin versus UFH in the management of STEMI patients treated with a fibrinolytic agent was most recently evaluated in the randomized double blind Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment (ExTRACT) trial.  The UFH strategy utilized a 60 U/kg bolus followed by a > 48 hour infusion of 12 U/Kg/hour. Enoxaparin was administered for the duration of the hospitalization or for a maximum of 8 days. The bolus of enoxaparin was 30 mg and the maintenance dose was 1 mg / kg subcutaneously every 12 hours. It is important to note that the dose of enoxaparin was reduced in the elderly (patients 75 years or older) from 1 mg / kg subcutaneously every 12 hours to 0.75 mg / kg every 12 hours. This strategy of enoxaparin dosing was associated with a reduction in the 30 day endpoint of death or MI from 12.0% to 9.9% (RR 0.83, p<0.001). When the efficacy is compared at 48 hours while patients in both arms are actively receiving either UFH or enoxaparin, there was a non significant trend in favor of enoxaparin in reducing death or MI (5.2% vs 4.7%, p=0.08). With respect to safety, administration of enoxaparin was associated with an increase in the risk of TIMI major bleeding (1.4% vs 2.1%, p<0.001). Among patients who sustained a TIMI major bleed, mortality was significantly higher in patients treated with enoxaparin compared with UFH (0.8% vs 0.4%, P=0.001).
Enoxaparin use in conjunction with primary percutaneous coronary intervention
There are limited data regarding the efficacy and safety of enoxaparin in the setting of primary PCI. 
Fondaparinux use in conjunction with primary percutaneous intervention
In the setting of primary PCI, Fondaparinux administration has been associated with higher rates of clot formation on wires and catheters.  For this reason, fondaparinux may not be an optimal agent for use among patients undergoing primary PCI, and if it is used, supplemental use of a Factor IIa inhibitor such as UFH is recommended.
Fondaparinux use in conjunction with fibrinolytic administration
The safety and efficacy of fondaparinux administered for 8 days was compared to either placebo (Stratum 1: patients who could not receive UFH) or therapy with UFH for 48 hours (Stratum II) in the randomized, double blind multicenter OASIS-6 trial of 12,092 STEMI patients.  The primary endpoint of death or reinfarction at 30 days was signifcantly reduced among patients treated fondaparinux (11.2% vs 9.7%, p=0.008). The secondary endpoint of mortality was also significantly reduced among fondaparinux patients. The primary endpoint was reduced among patients treated with fibrinolytic therapy (HR =0.79 p=0.003). An important caveat is the fact that most patients who received a fibrinolytic agent were in Stratum 1 (patients not deemed appropriate for UFH and largely received streptokinase). While formal interaction testing (which may be underpowered) did not demonstrate heterogeneity between stratum 1 and stratum 2, the magnitude of the benefits of fondaparinux were numerically greater in stratum 1 than in stratum 2 (in whom patients received UFH). Likewise, while the benefits in the primary endpoint were statistically significant for both strata combined, there was no significant benefit of fondaparinux over UFH at 30 days in the primary endpoint.
Following an acute coronary syndrome, there is persistent activation of the coagulation cascade as manifested by persistently elevated levels of prothrombin fragments 1 + 2 (F1 +2).  F1+2 is released from the end of the prothrombin molecule when prothrombin is converted to thrombin, and its levels are a surrogate of Factor Xa activity. Furthermore, clot remains visible on angioscopy in the infarct artery of 70%-80% of patients one month following fibrinolytic therapy for STEMI.  Persistent activation of the coagulation cascade and the ubiquitous presence of chronic thrombus provides in part the basis for chronic anticoagulation therapy following an acute coronary syndrome.
The benefits and risks of oral anticoagulation following presentation with an acute coronary syndrome have been assessed in a large meta-analysis of 5,938 patients enrolled in trials of aspirin alone versus aspirin plus warfarin between 1990 and 2004.  Many large trials of oral anticoagulation such as WARIS II , OASIS , and CARS  were included. The addition of warfarin titrated to an INR of 2.0 was associated with a halving of the annual risk of myocardial infarction (rate ratio, of 0.56 [95% CI, 0.46 to 0.69]). Similarly, the annual risk of ischemic stroke was cut in half (rate ratio, 0.46 [CI, 0.27 to 0.77]). The annual rate of bleeding was increased over two fold (rate ratio, 2.5 [CI, 1.7 to 3.7]). Mortality did not differ between the two strategies.  Taking all the data together you would need to tree 16 patients for 3 months to prevent one MI, and you would need to treet 333 patients to cause one major bleed. With respect to the risk of intracranial hemmorhage, warfarin was associated with only 1 ICH per 1,800 patient years of exposure. The above results are for all patients in the studies, and it should be noted that patients at higher risk of ischemic events would have a greater net clinical benefit, while those at higher risk of bleeding would have a lower net clinical benefit. It should be noted that the majority of this data was collected in the era prior to drug eluting stents and clopidogrel.
While the addition of warfarin to aspirin is efficacious, there is a 20% rate of discontinuation for both warfarin monotherapy, and the combination of warfarin plus aspirin.  This high rate of discontinuation is critical in so far as only those patients who are compliant with warfarin over 70% of the time derived a clinical benefit. 
- Oral anticoagulants
- Uncontrolled blood pressure (>180/110 mmHg)
- Cerebrovascular accident > 3 months
- Recent trauma (2-4 weeks)
- Recent internal bleed (@-4 weeks)
- Active gastric ulcer or duodenal ulcer
- Any prior intra-cranial hemorrhage
- Known structural cerebral vascular disease ( arterio-venous malformation, aneurysm
- Known malignant intracranial neoplasm
- Ischemic CVA < 3 months
- Significant closed head/facial trauma < 3 months
- Suspected aortic dissection
- Active bleeding
Hazards of Fibrinolysis
- Myocardial rupture - if rupture occurs it is earlier (<24 hrs) when lytics given with in 6 - 24 hrs period.
May be slight increased risk if lytics given > 14 hrs after symptom onset.
No increased risk if lytics given with in 6 - 12 hrs after onset of symptoms.
Fibrinolysis favored STEMI management strategies
- Symptom onset < 3 hrs
- First door to needle < 30 min
- First door to balloon > 90 min
- No vascular access
2013 Revised and 2009 Focused Updates: ACC/AHA Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction (Updating the 2004 Guideline and 2007 Focused Update) and ACC/AHA/SCAI Guidelines on Percutaneous Coronary Intervention (Updating the 2005 Guideline and 2007 Focused Update) (DO NOT EDIT)
Anticoagulant Therapy to Support Primary PCI (DO NOT EDIT)
|"1. For patients with STEMI undergoing primary PCI, the following supportive anticoagulant regimens are recommended:|
|"a. UFH, with additional boluses administered as needed to maintain therapeutic activated clotting time levels, taking into account whether a GP IIb/IIIa receptor antagonist has been administered (Level of Evidence: C)" or|
|"b. Bivalirudin with or without prior treatment with UFH. (Level of Evidence: B)"|
|Class III (Harm)|
|"1. Fondaparinux should not be used as the sole anticoagulant to support primary PCI because of the risk of catheter thrombosis.(Level of Evidence: B)"|
|"1. In patients with STEMI undergoing PCI who are at high risk of bleeding, it is reasonable to use bivalirudin monotherapy in preference to the combination of UFH and a GP IIb/IIIa receptor antagonist. (Level of Evidence: B)"|
|"1. Patients with STEMI undergoing reperfusion with fibrinolytic therapy should receive anticoagulant therapy for a minimum of 48 hours, and preferably for the duration of the index hospitalization, up to 8 days or until revascularization if performed. (Level of Evidence: A) Recommended regimens include: "|
|"a. UFH administered as a weight-adjusted intravenous bolus and infusion to obtain an activated partial thromboplastin time of 1.5 to 2.0 times control, for 48 hours or until revascularization(Level of Evidence: C) ";|
|"b. Enoxaparin administered according to age, weight, and creatinine clearance, given as an intravenous bolus, followed in 15 minutes by subcutaneous injection for the duration of the index hospitalization, up to 8 days or until revascularization  (Level of Evidence: A) "; or|
|"c. Fondaparinux administered with initial intravenous dose, followed in 24 hours by daily subcutaneous injections if the estimated creatinine clearance is greater than 30 mL/min, for the duration of the index hospitalization, up to 8 days or until revascularization. (Level of Evidence: B) "|
|"2. For patients undergoing PCI after having received an anticoagulant regimen, the following dosing recommendations should be followed: "|
|"a. For prior treatment with UFH, administer additional boluses of UFH as needed to support the procedure, taking into account whether GP IIb/IIIa receptor antagonists have been administered. (Level of Evidence: C) Bivalirudin may also be used in patients treated previously with UFH. (Level of Evidence: C) "|
|"b. For prior treatment with enoxaparin, if the last subcutaneous dose was administered within the prior 8 hours, no additional enoxaparin should be given; if the last subcutaneous dose was administered at least 8 to 12 hours earlier, an intravenous dose of 0.3 mg per kg of enoxaparin should be given. (Level of Evidence: B) "|
|"c. For prior treatment with fondaparinux, administer additional intravenous treatment with an anticoagulant possessing anti-IIa activity taking into account whether GP IIb/IIIa receptor antagonists have been administered. (Level of Evidence: C) "|
Anticoagulant Therapy to Support PCI After Fibrinolytic Therapy (DO NOT EDIT)
|"1. For patients with STEMI undergoing PCI after receiving fibrinolytic therapy with intravenous UFH, additional boluses of intravenous UFH should be administered as needed to support the procedure, taking into account whether GP IIb/IIIa receptor antagonists have been administered.(Level of Evidence: C) "|
|"2. For patients with STEMI undergoing PCI after receiving fibrinolytic therapy with enoxaparin, if the last subcutaneous dose was administered within the prior 8 hours, no additional enoxaparin should be given; if the last subcutaneous dose was administered between 8 and 12 hours earlier, enoxaparin 0.3 mg/kg IV should be given.(Level of Evidence: B) "|
|Class III (Harm)|
|"1. Fondaparinux should not be used as the sole anticoagulant to support PCI. An additional anticoagulant with anti-IIa activity should be administered because of the risk of catheter thrombosis.(Level of Evidence: C) "|
- The 2004 ACC/AHA Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction 
- The 2007 Focused Update of the ACC/AHA 2004 Guidelines for the Management of Patients with ST-Elevation Myocardial Infarction 
- 2013 Revised ACC/AHA Guidelines for Management of Patients with ST-Elevation Myocardial Infarction and Guidelines for Percutaneous Coronary Intervention
- ↑ Weitz JI (September 2006). "Emerging anticoagulants for the treatment of venous thromboembolism". Thromb. Haemost. 96 (3): 274–84. doi:10.1160/TH06-05-0234. PMID 16953267.
- ↑ 2.0 2.1 (July 1990) "GISSI-2: a factorial randomised trial of alteplase versus streptokinase and heparin versus no heparin among 12,490 patients with acute myocardial infarction. Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico". Lancet 336 (8707): 65–71. PMID 1975321.
- ↑ 3.0 3.1 (March 1992) "ISIS-3: a randomised comparison of streptokinase vs tissue plasminogen activator vs anistreplase and of aspirin plus heparin vs aspirin alone among 41,299 cases of suspected acute myocardial infarction. ISIS-3 (Third International Study of Infarct Survival) Collaborative Group". Lancet 339 (8796): 753–70. PMID 1347801.
- ↑ 4.0 4.1 4.2 Eikelboom JW, Quinlan DJ, Mehta SR, Turpie AG, Menown IB, Yusuf S (December 2005). "Unfractionated and low-molecular-weight heparin as adjuncts to thrombolysis in aspirin-treated patients with ST-elevation acute myocardial infarction: a meta-analysis of the randomized trials". Circulation 112 (25): 3855–67. doi:10.1161/CIRCULATIONAHA.105.573550. PMID 16344381.
- ↑ 5.0 5.1 (September 1993) "An international randomized trial comparing four thrombolytic strategies for acute myocardial infarction. The GUSTO investigators". N. Engl. J. Med. 329 (10): 673–82. PMID 8204123.
- ↑ Granger CB, Miller JM, Bovill EG, et al (April 1995). "Rebound increase in thrombin generation and activity after cessation of intravenous heparin in patients with acute coronary syndromes". Circulation 91 (7): 1929–35. PMID 7895349.
- ↑ 7.0 7.1 7.2 7.3 Antman EM, Hand M, Armstrong PW, et al (January 2008). "2007 Focused Update of the ACC/AHA 2004 Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines: developed in collaboration With the Canadian Cardiovascular Society endorsed by the American Academy of Family Physicians: 2007 Writing Group to Review New Evidence and Update the ACC/AHA 2004 Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction, Writing on Behalf of the 2004 Writing Committee". Circulation 117 (2): 296–329. doi:10.1161/CIRCULATIONAHA.107.188209. PMID 18071078.
- ↑ Berdan LG, Kleiman NS, Woodlief LH, Harrington RA, Granger CB, Califf RM (1997). "Physicians' Use of Heparin Following Thrombolytic Therapy: An International Perspective". J. Thromb. Thrombolysis 4 (3/4): 415–423. PMID 10639646.
- ↑ Mehran R, Brodie B, Cox DA, et al (July 2008). "The Harmonizing Outcomes with RevasculariZatiON and Stents in Acute Myocardial Infarction (HORIZONS-AMI) Trial: study design and rationale". Am. Heart J. 156 (1): 44–56. doi:10.1016/j.ahj.2008.02.008. PMID 18585496.
- ↑ 10.0 10.1 10.2 10.3 Stone GW, Witzenbichler B, Guagliumi G, et al (May 2008). "Bivalirudin during primary PCI in acute myocardial infarction". N. Engl. J. Med. 358 (21): 2218–30. doi:10.1056/NEJMoa0708191. PMID 18499566.
- ↑ (January 2002) "Direct thrombin inhibitors in acute coronary syndromes: principal results of a meta-analysis based on individual patients' data". Lancet 359 (9303): 294–302. doi:10.1016/S0140-6736(02)07495-0. PMID 11830196.
- ↑ White HD (October 1998). "Direct thrombin inhibition and thrombolytic therapy: rationale for the Hirulog and Early Reperfusion/Occlusion (HERO-2) trial". Am. J. Cardiol. 82 (8B): 57P–62P. PMID 9809893.
- ↑ 13.0 13.1 13.2 White H (December 2001). "Thrombin-specific anticoagulation with bivalirudin versus heparin in patients receiving fibrinolytic therapy for acute myocardial infarction: the HERO-2 randomised trial". Lancet 358 (9296): 1855–63. PMID 11741625.
- ↑ Antman EM, Morrow DA, McCabe CH, et al (April 2006). "Enoxaparin versus unfractionated heparin with fibrinolysis for ST-elevation myocardial infarction". N. Engl. J. Med. 354 (14): 1477–88. doi:10.1056/NEJMoa060898. PMID 16537665.
- ↑ Labèque JN, Jaïs C, Dubos O, et al (February 2006). "Prehospital administration of enoxaparin before primary angioplasty for ST-elevation acute myocardial infarction". Catheter Cardiovasc Interv 67 (2): 207–13. doi:10.1002/ccd.20549. PMID 16416473.
- ↑ 16.0 16.1 16.2 16.3 16.4 Yusuf S, Mehta SR, Chrolavicius S, et al (April 2006). "Effects of fondaparinux on mortality and reinfarction in patients with acute ST-segment elevation myocardial infarction: the OASIS-6 randomized trial". JAMA 295 (13): 1519–30. doi:10.1001/jama.295.13.joc60038. PMID 16537725.
- ↑ Merlini PA, Bauer KA, Oltrona L, et al (July 1994). "Persistent activation of coagulation mechanism in unstable angina and myocardial infarction". Circulation 90 (1): 61–8. PMID 8026047.
- ↑ Van Belle E, Lablanche JM, Bauters C, Renaud N, McFadden EP, Bertrand ME (1998). "Coronary angioscopic findings in the infarct-related vessel within 1 month of acute myocardial infarction: natural history and the effect of thrombolysis". Circulation 97 (1): 26–33. PMID 9443428.
- ↑ 19.0 19.1 Rothberg MB, Celestin C, Fiore LD, Lawler E, Cook JR (August 2005). "Warfarin plus aspirin after myocardial infarction or the acute coronary syndrome: meta-analysis with estimates of risk and benefit". Ann. Intern. Med. 143 (4): 241–50. PMID 16103468.
- ↑ Hurlen M, Abdelnoor M, Smith P, Erikssen J, Arnesen H (September 2002). "Warfarin, aspirin, or both after myocardial infarction". N. Engl. J. Med. 347 (13): 969–74. doi:10.1056/NEJMoa020496. PMID 12324552.
- ↑ 21.0 21.1 (February 2001) "Effects of long-term, moderate-intensity oral anticoagulation in addition to aspirin in unstable angina. The Organization to Assess Strategies for Ischemic Syndromes (OASIS) Investigators". J. Am. Coll. Cardiol. 37 (2): 475–84. PMID 11216966.
- ↑ (August 1997) "Randomised double-blind trial of fixed low-dose warfarin with aspirin after myocardial infarction. Coumadin Aspirin Reinfarction Study (CARS) Investigators". Lancet 350 (9075): 389–96. PMID 9259652.
- ↑ van Es RF, Jonker JJ, Verheugt FW, Deckers JW, Grobbee DE (July 2002). "Aspirin and coumadin after acute coronary syndromes (the ASPECT-2 study): a randomised controlled trial". Lancet 360 (9327): 109–13. doi:10.1016/S0140-6736(02)09409-6. PMID 12126819.
- ↑ 24.0 24.1 24.2 24.3 O'Gara PT, Kushner FG, Ascheim DD, et al. (December 2012). "2013 ACCF/AHA Guideline for the Management of ST-Elevation Myocardial Infarction: Executive Summary: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines". Circulation. doi:10.1161/CIR.0b013e3182742c84. PMID 23247303.
- ↑ 25.0 25.1 Antman EM, Anbe DT, Armstrong PW, Bates ER, Green LA, Hand M et al. (2004). "ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction--executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1999 Guidelines for the Management of Patients With Acute Myocardial Infarction).". Circulation 110 (5): 588-636. doi:10.1161/01.CIR.0000134791.68010.FA. PMID 15289388.
- ↑ 
- ↑ 27.0 27.1 Sosnowski C (November 2006). "[Commentary to the article: Antman EM, Morrow DA, McCabe CH, et al. ExTRACT-TIMI 25 Investigators. Enoxaparin versus unfractionated heparin with fibrinolysis for ST-elevation myocardial infarction. N Engl J Med 2006; 354: 1477-88]" (in Polish). Kardiol Pol 64 (11): 1321–4; discussion 1325–6. PMID 17165173.
- ↑ (August 2001) "Efficacy and safety of tenecteplase in combination with enoxaparin, abciximab, or unfractionated heparin: the ASSENT-3 randomised trial in acute myocardial infarction". Lancet 358 (9282): 605–13. doi:10.1016/S0140-6736(01)05775-0. PMID 11530146.
- ↑ Ross AM, Molhoek P, Lundergan C, et al. (August 2001). "Randomized comparison of enoxaparin, a low-molecular-weight heparin, with unfractionated heparin adjunctive to recombinant tissue plasminogen activator thrombolysis and aspirin: second trial of Heparin and Aspirin Reperfusion Therapy (HART II)". Circulation 104 (6): 648–52. PMID 11489769.
- ↑ 30.0 30.1 Antman EM, Louwerenburg HW, Baars HF, et al. (April 2002). "Enoxaparin as adjunctive antithrombin therapy for ST-elevation myocardial infarction: results of the ENTIRE-Thrombolysis in Myocardial Infarction (TIMI) 23 Trial". Circulation 105 (14): 1642–9. PMID 11940541.
- ↑ Gibson CM, Murphy SA, Montalescot G, et al. (June 2007). "Percutaneous coronary intervention in patients receiving enoxaparin or unfractionated heparin after fibrinolytic therapy for ST-segment elevation myocardial infarction in the ExTRACT-TIMI 25 trial". J. Am. Coll. Cardiol. 49 (23): 2238–46. doi:10.1016/j.jacc.2007.01.093. PMID 17560287.
- ↑ Antman EM, Anbe DT, Armstrong PW, Bates ER, Green LA, Hand M, Hochman JS, Krumholz HM, Kushner FG, Lamas GA, Mullany CJ, Ornato JP, Pearle DL, Sloan MA, Smith SC, Alpert JS, Anderson JL, Faxon DP, Fuster V, Gibbons RJ, Gregoratos G, Halperin JL, Hiratzka LF, Hunt SA, Jacobs AK (August 2004). "ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Revise the 1999 Guidelines for the Management of Patients with Acute Myocardial Infarction)". Circulation 110 (9): e82–292. PMID 15339869.
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