1
|
Computational design, functional analysis and antigenic epitope estimation of a novel hybrid of 12 peptides of hirudin and reteplase. J Mol Model 2015; 21:229. [PMID: 26267298 DOI: 10.1007/s00894-015-2774-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 07/20/2015] [Indexed: 10/23/2022]
Abstract
Cardiovascular and cerebrovascular diseases are leading causes of morbidity and mortality for human beings, and thrombosis is the major risk factor. Thrombolytic therapy has been testified to be the most effective approach to cure thrombosis-related diseases. In clinical treatment, we often adopt a combination therapeutic regimen of both thrombolytic and anticoagulant agents to prevent the recurrence of thrombosis. Thus, a novel hybrid (HV12p-rPA) comprised of the C-terminal 12 residues of hirudin-PA (HV12p) and reteplase (rPA) was designed. The three-dimensional structure of this hybrid was mimicked based on homology modeling and refined with dynamics simulation by utilizing Amber12.0 software. The function of the hybrid was analyzed by structure comparison and the root mean square deviation (RMSD) of Cα atoms between the hybrid and native rPA was calculated. The results showed that HV12p, which was located in the N-terminus of the hybrid, was far from the rPA segment of the hybrid and had no influence on the conformational stability of the rPA domain. The RMSD of Cα atoms of these superimposed proteins was about 40Å, implying that the hybrid had a similar spatial conformation to that of native rPA. Additionally, the antigenic epitopes of the hybrid were predicted by estimations of Hopp-Wood hydrophilicity, Janin accessibility, Zimmermane-Simha polarity, Bhaskaran-Ponnuswamy flexibility, as well as secondary structure analysis and Kolaskar-Tongaonkar antigenicity prediction. The results showed that the most likely antigenic determinants were located at or near regions 148-152, 257-262 and 321-330.
Collapse
|
2
|
Gao L, Zhang C, Li L, Liang L, Deng X, Wu W, Su Z, Yu R. Construction, expression and refolding of a bifunctional fusion protein consisting of C-terminal 12-residue of hirudin-PA and reteplase. Protein J 2012; 31:328-36. [PMID: 22481531 DOI: 10.1007/s10930-012-9407-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
To obtain a bifunctional protein simultaneously showing bioactivity of anticoagulant and fibrinolytic for use in the treatment of thrombotic diseases, we constructed a fusion protein (HV12p-rPA) containing C-terminal 12-residue of hirudin-PA (HV12p) and reteplase (rPA). The fusion protein, in which HV12p was linked to rPA via Gly-Gly-Gly, was successfully expressed in an inactive form of inclusion bodies in Escherichia coli. HV12p-rPA was identified by sodium dodecylsulfate-polyacrylamide gel electrophoresis. The expression level of HV12p-rPA was optimized by an orthogonal method and finally enhanced from 12 % to approximate 30 %. We also deeply investigated the condition of renaturation of HV12p-rPA, and the inactive protein was partly renatured through various conditions. The refolding efficacy of HV12p-rPA estimated by the recovery of fibrinolytic activity varied from 0.03 % to 16.6 % and the anticoagulant activity fluctuated in the range from 41 to 2,297 ATU/mg. Bioassays indicated that the resulted fusion protein, as expected, exhibited both fibrinolytic and anticoagulant activities. These works laid a foundation for further characterization of HV12p-rPA.
Collapse
Affiliation(s)
- Ling Gao
- Key Laboratory of Drug Targeting and Drug Delivery System, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, China
| | | | | | | | | | | | | | | |
Collapse
|
3
|
Loscalzo J. Joseph Loscalzo, MD, PhD: a conversation with the Editor. Interview by William Clifford Roberts. Am J Cardiol 2006; 97:1110-22. [PMID: 16563929 DOI: 10.1016/j.amjcard.2005.12.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Accepted: 12/20/2005] [Indexed: 11/30/2022]
|
4
|
Erlich JH, Boyle EM, Labriola J, Kovacich JC, Santucci RA, Fearns C, Morgan EN, Yun W, Luther T, Kojikawa O, Martin TR, Pohlman TH, Verrier ED, Mackman N. Inhibition of the tissue factor-thrombin pathway limits infarct size after myocardial ischemia-reperfusion injury by reducing inflammation. THE AMERICAN JOURNAL OF PATHOLOGY 2000; 157:1849-62. [PMID: 11106558 PMCID: PMC1885771 DOI: 10.1016/s0002-9440(10)64824-9] [Citation(s) in RCA: 160] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Functional inhibition of tissue factor (TF) has been shown to improve coronary blood flow after myocardial ischemia/reperfusion (I/R) injury. TF initiates the coagulation protease cascade, resulting in the generation of the serine protease thrombin and fibrin deposition. Thrombin can also contribute to an inflammatory response by activating various cell types, including vascular endothelial cells. We used a rabbit coronary ligation model to investigate the role of TF in acute myocardial I/R injury. At-risk areas of myocardium showed increased TF expression in the sarcolemma of cardiomyocytes, which was associated with a low level of extravascular fibrin deposition. Functional inhibition of TF activity with an anti-rabbit TF monoclonal antibody administered either 15 minutes before or 30 minutes after coronary ligation reduced infarct size by 61% (P = 0.004) and 44% (P = 0.014), respectively. Similarly, we found that inhibition of thrombin with hirudin reduced infarct size by 59% (P = 0.014). In contrast, defibrinogenating the rabbits with ancrod had no effect on infarct size, suggesting that fibrin deposition does not significantly contribute to infarct size. Functional inhibition of thrombin reduced chemokine expression and inhibition of either TF or thrombin reduced leukocyte infiltration. We propose that cardiomyocyte TF initiates extravascular thrombin generation, which enhances inflammation and injury during myocardial I/R.
Collapse
Affiliation(s)
- J H Erlich
- Scripps Research Institute, La Jolla, California. Seattle, Washington. Dresden, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Abstract
The use of antithrombotic therapy has taken on central importance in the field of cardiovascular disease. Currently, anticoagulants and antiplatelet drugs are central to the treatment and the primary and secondary prevention of coronary artery disease. New insights into the "revised" coagulation cascade have highlighted new targets for intervention. In addition, the interactions between the coagulation system and platelets demonstrate ways that anticoagulants may affect platelet function and how antiplatelet agents may have anticoagulant effects. This overview will describe the present understanding of primary and secondary hemostasis, and current and future therapeutic approaches to modify these systems for therapeutic effects in cardiovascular medicine.
Collapse
|
6
|
Thrombin Generation in Patients with Acute Myocardial Infarction Treated with Front-Loaded rt-PA and Recombinant Hirudin (HBW 023). J Thromb Thrombolysis 1998; 5:203-207. [PMID: 10767116 DOI: 10.1023/a:1008839824942] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Thrombin contributes to the pathogenesis of acute myocardial infarction and reocclusion after thrombolysis. Thrombolytic therapy is known to induce a paradoxic increase in thrombin generation. Specific thrombin inhibition enhances thrombolytic therapy in experimental models. The aim of this study was to determine thrombin generation in patients with acute myocardial infarction treated with rt-PA and conjunctive therapy with the specific thrombin inhibitor, recombinant hirudin. Thrombin generation was determined in 17 patients with acute myocardial infarction treated with front-loaded rt-PA (100 mg/90 min) and conjunctive therapy with recombinant hirudin (HBW 023 bolus 0.4 mg/kg, infusion of 0.15 mg/kg/h) over 48 hours. Mean free hirudin plasma levels of 1320-1545 ng/mL produced a stable anticoagulation with mean aPTT values between 63 and 81 seconds throughout the treatment period. Thrombin generation increased during thrombolysis, indicated by a transient elevation of prothrombin fragment 1.2 levels, which were 3.0 nmol/L at baseline, 11.1 nmol/L after 30 minutes, 8.3 nmol/L after 60 minutes, 3.1 nmol/L after 12 hours, and 1.5 nmol/L after 24 hours, respectively. In contrast, thrombin-antithrombin III complex levels during and after thrombolysis did not exceed the baseline level of 21.8 ug/L. Thrombin-hirudin complex levels increased constantly during the 48-hour treatment period from 3.1 ug/L at baseline to 64.2 ug/L. All patients had an open infarct vessel (TIMI 2/3 potency) after 36-48 hours. Thrombolysis with rt-PA is associated with a significant increase in thrombin generation, which is not blocked by r-hirudin, whereas circulating thrombin seems to be effectively inhibited by r-hirudin.
Collapse
|
7
|
Ren S, Fenton JW, Maraganore JM, Angel A, Shen GX. Inhibition by hirulog-1 of generation of plasminogen activator inhibitor-1 from vascular smooth-muscle cells induced by thrombin. J Cardiovasc Pharmacol 1997; 29:337-42. [PMID: 9125671 DOI: 10.1097/00005344-199703000-00006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Hirulog-1 effectively prevents thrombosis in coronary artery disease and is associated with a low incidence of bleeding complications. Our study characterized the effect of Hirulog-1 on thrombin-induced production of plasminogen activator inhibitor-1 (PAI-1) in cultured baboon aortic smooth-muscle cells (BASMCs). Thrombin increased the steady-state levels of PAI-1 messenger RNA (mRNA) and the release of PAI-1 antigen from BASMCs. Treatments with 10-20 mg/L of Hirulog-1 inhibited >80% of thrombin-induced PAI-1 generation from BASMCs. Hirulog-1 alone did not significantly alter PAI-1 production in the absence of thrombin. Significant reduction of thrombin-induced PAI-1 release was observed in cultures treated with Hirulog-1 for 1 h. The maximal effect of Hirulog-1 on thrombin-induced PAI-1 release was achieved in cultures treated with thrombin plus Hirulog-1 for 3 to 6 h, associated with the normalization of PAI-1 mRNA levels induced by thrombin treatment. Strong inhibition by Hirulog-1 on thrombin-induced PAI-1 release remained in cultures with 8 h of the treatment, but the effect was attenuated 16 h after a single addition of the inhibitor. Our study demonstrates that Hirulog-1 effectively inhibited thrombin-induced PAI-1 production in cultured vascular SMCs at mRNA and protein levels. Vascular SMCs may be exposed to high concentrations of thrombin when endothelium is injured. The information generated from this study suggests that Hirulog-1 potentially prevents intravascular thrombogenesis through inhibiting thrombin-induced PAI-1 production in vascular SMCs, especially when hypercoagulation and endothelial injury occurs.
Collapse
Affiliation(s)
- S Ren
- Department of Internal Medicine, The University of Manitoba, Winnipeg, Canada
| | | | | | | | | |
Collapse
|
8
|
Tomaru T, Nakamura F, Fujimori Y, Omata M, Kawai S, Okada R, Murata Y, Uchida Y. Local treatment with antithrombotic drugs can prevent thrombus formation: an angioscopic and angiographic study. J Am Coll Cardiol 1995; 26:1325-32. [PMID: 7594050 DOI: 10.1016/0735-1097(95)00324-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVES This study was designed to evaluate the efficacy of local versus systemic treatment of thrombosis with various antithrombotic drugs. BACKGROUND Local use of low dose antithrombotic drugs has been proposed as being effective and safe. METHODS Heparin (30 U/kg), an antithrombin agent (argatroban, 0.05 mg/kg body weight) or a defibrinogenating drug (batroxobin, 0.05 U/kg) was locally infused into one side of the canine iliac artery after injury by balloon inflation. The other side was injured as a control. The efficacy of systemic delivery of high dose (heparin [300 U/kg] and argatroban [0.5 mg/kg]) and low dose drugs was also assessed. RESULTS Sixty minutes after local treatment in 22 dogs, no thrombotic stenosis was observed by angiography in locally treated arteries (p < 0.005 vs. mean thrombotic stenosis of 27% in control segments for heparin, 25.3% in control segments for argatroban and 32% in control segments for batroxobin). Angioscopy demonstrated the same trend. In locally treated arteries, thrombus weight was significantly lower in the treated than control side. In the systemic high dose group (n = 10), angiographic thrombotic stenosis was < 5% after high dose drug delivery (p < 0.05 vs. control segments, 37.4% for heparin, 43% for argatroban). In another 10 dogs, low dose systemic delivery was not effective in inhibiting thrombus formation. Activated partial thromboplastin time and fibrinogen levels did not change with local treatment. CONCLUSIONS Compared with systemic administration of antithrombotic drugs, local treatment is a safer and more effective method of preventing thrombosis.
Collapse
Affiliation(s)
- T Tomaru
- Second Department of Internal Medicine, University of Tokyo, Japan
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Cannon CP, Braunwald E, McCabe CH, Antman EM. The Thrombolysis in Myocardial Infarction (TIMI) trials: the first decade. J Interv Cardiol 1995; 8:117-35. [PMID: 10155224 DOI: 10.1111/j.1540-8183.1995.tb00526.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- C P Cannon
- Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
| | | | | | | |
Collapse
|
10
|
Leya F, Fareed J, Walenga J. Acute Myocardial Infarction: Diagnosis and Management. Clin Appl Thromb Hemost 1995. [DOI: 10.1177/107602969500100209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Acute myocardial infarction is caused by abrupt thrombotic coronary occlusion. About 1.5 million patients will suffer a heart attack and 10 to 20% of them will die in the U.S.A. annually. Accurate diagnosis and early reopening (reperfusion) of infarct-related coronary artery will lower mortality (2 to 7%) and morbidity of patients and improve their post-MI recovery. There are several effective therapies available to reopen closed infarct-related coronary arteries. Thrombolytic or clot dissolving therapy can be safely used in about one-third of heart attack stricken patients. The expected effectiveness of thrombolytic therapy in treated patients is 70 to 80% of reperfusion rates and 7 to 8% mortality rates. Direct coronary angioplasty of the infarct-related coronary artery represents the most aggressive, yet the most effective reperfusion modality available to all patients suffering from acute MI. Direct angioplasty, when used appropriately, will result in 97 to 99% reperfusion rates and 2 to 3% mortality rates. Aggressive approach to the diagnosis and the treatment of acute MI using either thrombolytic therapy or direct coronary angioplasty holds the greatest promise for clinical success.
Collapse
Affiliation(s)
- Ferdinand Leya
- Department of Medicine, Loyola University Medical Center, Maywood, and MacNeal Hospital, Berwyn, Illinois, U.S.A
| | - Jawed Fareed
- Department of Pathology, Loyola University Medical Center, Maywood, and MacNeal Hospital, Berwyn, Illinois, U.S.A
| | - Jeanine Walenga
- Department of Pathology, Loyola University Medical Center, Maywood, and MacNeal Hospital, Berwyn, Illinois, U.S.A
| |
Collapse
|
11
|
Lee LV. Initial experience with hirudin and streptokinase in acute myocardial infarction: results of the Thrombolysis in Myocardial Infarction (TIMI) 6 trial. Am J Cardiol 1995; 75:7-13. [PMID: 7801868 DOI: 10.1016/s0002-9149(99)80517-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Hirudin is a potent, direct, and highly specific inhibitor of both free and clot-bound thrombin. Previous reports have shown hirudin to be superior to heparin when given with tissue plasminogen activator and aspirin for improving the incidence and rate of reperfusion as well as reducing reocclusion of infarct-related arteries. Patients with acute myocardial infarction were randomized to hirudin versus heparin in conjunction with streptokinase (1.5 x 10(6) U) and aspirin (325 mg/day). Study drug treatment was a 5-day infusion of either heparin, as a 5,000 U bolus, followed by a 1,000 U/hour infusion adjusted to a target activated partial thromboplastin time of 65 to 90 seconds (n = 71), or a constant infusion of hirudin at 1 of 3 doses (dose 1, n = 55: 0.15 mg/kg bolus + 0.05 mg/kg/hour infusion; dose 2, n = 31: 0.3 mg/kg bolus + 0.1 mg/kg/hour infusion; or dose 3, n = 36: 0.6 mg/kg bolus + 0.2 mg/kg/hour infusion). The incidence of major hemorrhage was similar between the heparin group (5.6%) and any of the hirudin dose groups (dose 1 = 5.5%, dose 2 = 6.5%, dose 3 = 5.6%). At hospital discharge the occurrence of death, nonfatal reinfarction, congestive heart failure, or cardiogenic shock was greater in patients receiving the lowest dose of hirudin (21.6%) than in those receiving the higher doses of hirudin (dose 2 = 9.7%, dose 3 = 11.4%).(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- L V Lee
- Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts 02115
| |
Collapse
|
12
|
Maksimenko AV. Experimental combined thrombolytic therapy: The current position and directions of progress (review). Pharm Chem J 1994. [DOI: 10.1007/bf02219399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
13
|
Weaver WD, Hartmann JR, Anderson JL, Reddy PS, Sobolski JC, Sasahara AA. New recombinant glycosylated prourokinase for treatment of patients with acute myocardial infarction. Prourokinase Study Group. J Am Coll Cardiol 1994; 24:1242-8. [PMID: 7930246 DOI: 10.1016/0735-1097(94)90105-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVES Three dosage regimens of a new recombinant glycosylated prourokinase (A-74187) were evaluated by measuring coronary artery patency at 90 min in patients with acute myocardial infarction. BACKGROUND Prourokinase is a thrombolytic drug with unique pharmacologic properties that may be clinically advantageous. METHODS Aspirin (325 mg), intravenous heparin and prourokinase (60- or 80-mg monotherapy or 60 mg "primed" with a preceding bolus dose of 250,000 IU of recombinant urokinase) were administered to 128 patients. Coronary angiography was performed at 60 min (wherever possible), 90 min (primary end point) and 24 h to determine arterial patency and reocclusion rates. Plasma was collected serially to measure fibrinogen, plasminogen, thrombin antithrombin III and fibrinopeptide A. Clinical events until hospital discharge were recorded. RESULTS The coronary artery patency rate at 90 min was similar for all three regimens, averaging 73% (95% confidence interval [CI] 64% to 80%); Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow rates averaged 52% (95% CI 42% to 61%). Arterial patency at 60 min was 62% (95% CI 50% to 73%), and reocclusion occurred in 1.4% (95% CI 0.1% to 4.1%). Prourokinase demonstrated relative fibrin specificity at all doses studied. Fibrinopeptide A and thrombin antithrombin III levels were elevated at baseline and declined rapidly during the 1st 12 h. There was no difference in the baseline values of these thrombin markers between patients with patent versus closed arteries at 90 min. There was one death; no strokes occurred. CONCLUSIONS A-74187 prourokinase is a rapid-acting, effective fibrin-specific thrombolytic agent. Reocclusion was unusual, possibly because of aggressive anticoagulation with intravenous heparin or unique features of the drug. Full definition of the clinical effectiveness of this drug merits examination in future randomized trials evaluating clinical and angiographic effectiveness.
Collapse
Affiliation(s)
- W D Weaver
- Myocardial Infarction Triage and Intervention (MITI) Project Group, University of Washington, Seattle
| | | | | | | | | | | |
Collapse
|
14
|
Werns SW, Rote WE, Davis JH, Guevara T, Lucchesi BR. Nitroglycerin inhibits experimental thrombosis and reocclusion after thrombolysis. Am Heart J 1994; 127:727-37. [PMID: 8154409 DOI: 10.1016/0002-8703(94)90538-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Nitroglycerin inhibits platelet aggregation in vitro, but its effect on thrombosis and platelet function in vivo is controversial. This study assessed the effect of nitroglycerin on primary thrombus formation in response to vessel wall injury and secondary thrombus formation, or rethrombosis, after lysis of an existing thrombus. In the first protocol the right carotid artery was instrumented with a flow probe, stenosis, an anodal electrode, and a proximal infusion line. A 300 microA anodal current was used to induce endothelial injury and subsequent thrombotic occlusion of the vessel. Anisoylated plasminogen streptokinase activator complex (APSAC; 0.05 U/kg intraarterially) was injected proximal to the thrombus 30 minutes after occlusion. After APSAC, nitroglycerin (1 microgram/kg/min intraarterially, n = 7) or vehicle (n = 6) was infused proximal to the thrombus for 3 hours. Reocclusion occurred in two of seven nitroglycerin-treated dogs and six of six vehicle-treated dogs (p < 0.05). In the second protocol both carotid arteries were instrumented as described previously. Anodal current (300 microA, 180 minutes) was applied to the right carotid (n = 12) artery to determine control times to occlusion. The left carotid artery served as the test vessel, receiving either nitroglycerin (1 microgram/kg/min intraarterially, n = 6) or trimethaphan (0.05 mg/kg/hr intraarterially, n = 6). Trimethaphan was used to produce controlled hypotension to match the approximately 10% decrease in mean arterial blood pressure that was observed during nitroglycerin infusion. Control arteries and those treated with trimethaphan formed occlusive thrombi in all instances. Nitroglycerin infusion resulted in a lower incidence of occlusion (1 of 6; p < 0.05 vs control value) and inhibited ex vivo platelet aggregation to adenosine diphosphate and arachidonic acid (p < 0.05). Local infusion of nitroglycerin reduced the formation of primary thrombi, independent of the hypotensive effect of the drug, and exerted systemic effects on platelet aggregation. Furthermore, platelet inhibition with nitroglycerin reduced the incidence of secondary thrombus formation (rethrombosis) after thrombolysis. The results suggest that a potential benefit of nitroglycerin therapy may be derived from its ability to inhibit thrombotic events in patients with unstable angina or myocardial infarction.
Collapse
Affiliation(s)
- S W Werns
- Division of Cardiology, University of Michigan Medical Center, University Hospital, Ann Arbor 48109-0022
| | | | | | | | | |
Collapse
|
15
|
Cannon CP, McCabe CH, Henry TD, Schweiger MJ, Gibson RS, Mueller HS, Becker RC, Kleiman NS, Haugland JM, Anderson JL. A pilot trial of recombinant desulfatohirudin compared with heparin in conjunction with tissue-type plasminogen activator and aspirin for acute myocardial infarction: results of the Thrombolysis in Myocardial Infarction (TIMI) 5 trial. J Am Coll Cardiol 1994; 23:993-1003. [PMID: 8144799 DOI: 10.1016/0735-1097(94)90581-9] [Citation(s) in RCA: 185] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVES The purpose of this study was to assess the value of recombinant desulfatohirudin (hirudin) as adjunctive therapy to thrombolysis in acute myocardial infarction. BACKGROUND Failure to achieve initial reperfusion and reocclusion of the infarct-related artery remain major limitations of thrombolytic therapy despite aggressive regimens of heparin and aspirin. Hirudin, a direct thrombin inhibitor, has been shown in experimental models to enhance thrombolysis and reduce reocclusion. METHODS The Thrombolysis in Myocardial Infarction (TIMI) 5 trial was a randomized, dose-ranging, pilot trial of hirudin versus heparin, given with front-loaded tissue-type plasminogen activator and aspirin to 246 patients with acute myocardial infarction. Patients received either intravenous heparin or hirudin at one of four ascending doses for 5 days. Patients underwent coronary angiography at 90 min and at 18 to 36 h, unless rescue angioplasty was performed. RESULTS The primary end point, TIMI grade 3 flow in the infarct-related artery at 90 min and 18 to 36 h without death or reinfarction before the 18- to 36-h catheterization was achieved in 97 (61.8%) of 157 evaluable hirudin-treated patients compared with 39 (49.4%) of 79 evaluable heparin-treated patients (p = 0.07). All four doses of hirudin led to similar findings in the angiographic and clinical end points. At 90 min, TIMI grade 3 flow was present in 105 (64.8%) of 162 hirudin-treated patients compared with 48 (57.1%) of 84 heparin-treated patients (p = NS). Infarct-related artery patency (TIMI grade 2 or 3 flow) was similar in the two groups (82.1% and 78.6%, respectively). At 18 to 36 h, 129 (97.8%) of 132 hirudin-treated patients had a patent infarct-related artery compared with 58 (89.2%) of 65 heparin-treated patients (p = 0.01). Reocclusion by 18 to 36 h occurred in 2 (1.6%) of 123 hirudin-treated patients versus 4 (6.7%) of 60 heparin-treated patients (p = 0.07). Death or reinfarction occurred during the hospital period in 11 (6.8%) of 162 hirudin-treated patients compared with 14 (16.7%) of 84 heparin-treated patients (p = 0.02). Major spontaneous hemorrhage occurred in 1.2% of hirudin-treated patients versus 4.7% of heparin-treated patients (p = 0.09), and major hemorrhage at an instrumented site occurred in 16.3% and 18.6%, respectively (p = NS). CONCLUSIONS Hirudin is a promising agent compared with heparin as adjunctive therapy with thrombolysis for acute myocardial infarction, and its evaluation in larger trials is warranted.
Collapse
Affiliation(s)
- C P Cannon
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Affiliation(s)
- H V Anderson
- Department of Internal Medicine, University of Texas Health Science Center, Houston 77030
| | | |
Collapse
|
17
|
Cannon CP, Maraganore JM, Loscalzo J, McAllister A, Eddings K, George D, Selwyn AP, Adelman B, Fox I, Braunwald E. Anticoagulant effects of hirulog, a novel thrombin inhibitor, in patients with coronary artery disease. Am J Cardiol 1993; 71:778-82. [PMID: 8456753 DOI: 10.1016/0002-9149(93)90823-u] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Selective thrombin inhibitors are a new class of antithrombotic drugs that, unlike heparin, can effectively inhibit clot-bound thrombin and escape neutralization by activated platelets. Hirulog is a 20 amino acid hirudin-based synthetic peptide that has shown promise in experimental models of thrombosis. Little information is available about the effects of hirulog in patients with coronary artery disease. Forty-five patients undergoing cardiac catheterization, who were taking aspirin, were randomized to receive either (1) hirulog, 0.05 mg/kg intravenous bolus followed by 0.2 mg/kg/hour intravenous infusion until the end of the catheterization; (2) hirulog, 0.15 mg/kg intravenous bolus followed by 0.6 mg/kg/hour intravenous infusion; or (3) heparin; 5,000 U intravenous bolus. Serial activated partial thromboplastin time (APTT), prothrombin time, activated clotting time and fibrinopeptide A were measured. Hirulog produced a dose-dependent prolongation of all coagulation parameters; the 0.6 mg/kg/hour dose prolonged the APTT to 218 +/- 50% of baseline after 2 minutes and 248 +/- 50% of baseline after 15 minutes. The half-life of the effect on APTT was 40 minutes. The hirulog blood level correlated well with the APTT, prothrombin time and activated clotting time (r = 0.77, 0.73, and 0.82 respectively, all p < 0.001). Both doses of hirulog potently suppressed the generation of fibrinopeptide A (p < 0.05). There were no major hemorrhagic, thrombotic or allergic complications in patients treated with hirulog or heparin. Thus, hirulog, a direct thrombin inhibitor, provides a predictable level of anticoagulation and appears to have a potent yet well-tolerated anticoagulant profile in patients with coronary artery disease.
Collapse
Affiliation(s)
- C P Cannon
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | | | | | | | | | | | | | | | | | | |
Collapse
|