Studies of haemostasis in acute coronary syndromes and diabetes mellitus
Author: Skeppholm, Mika
Date: 2011-12-09
Location: Aulan, Danderyds sjukhus.
Time: 09.00
Department: Inst för kliniska vetenskaper, Danderyds sjukhus / Dept of Clinical Sciences, Danderyd Hospital
Abstract
The pathophysiology of acute coronary syndromes (ACS) includes atherosclerotic plaque rupture and coronary thrombus formation. Antithrombotic treatment is effective but recurrent atherothrombotic or bleeding complications are not uncommon.
Aim: To study new markers and methods concerning haemostasis in ACS and conditions associated with high risk of this disease, in the search for laboratory tools that could help increase understanding of disease mechanisms and help to identify patients at risk.
Methods and Results: Eighty-seven patients suffering from ACS were investigated at admission (S1), after 24 h on standard antithrombotic treatment (S2), and six months after the acute event (S3). Sex- and age-matched healthy controls were also investigated. Thrombin generation in vivo was assessed by measurement of prothrombin fragment F1+2 in plasma and in vitro by using the calibrated automated thrombogram (CAT). Fibrinolysis was measured by assessment of PAI-1 and TAFI activity concentrations. The latter method was used as a result of a methods evaluation study. We also employed a global method developed by our group (Oh- index), to evaluate haemostasis. Oh-index gives a measure of fibrin formation and degradation capacity in plasma. Furthermore, a flow cytometric assay set up by our group was employed to measure platelet microparticles (PMP) in plasma formed upon platelet activation. In addition, we investigated ADAMTS13, an enzyme previously called von Willebrand factor (VWF)-degrading protease, and we also measured its substrate (i.e. VWF). The ACS patients, of whom more than half were high-risk patients (TIMI score ≥ 4), showed signs of inflammation and endothelial activation, as expected. Only the CAT method could detect hypercoagulability in the patients (increased peak thrombin concentration) and this finding was evident acutely and 6 months after the event. Thrombin generation in vivo (F1+2) or fibrin generation capacity in plasma did not indicate hypercoagulability at any time point. CAT, F1+2 and fibrin generation capacity were strongly reduced following initiation of antithrombotic treatment (S2), as expected. PAI-1 and TAFI levels were elevated, reflecting impaired fibrinolysis, but this was not observed with our method that assesses fibrin degradation capacity; rather, this method indicated increased fibrinolytic capacity at admission and this capacity was grossly increased after initiation of standard antithrombotic treatment (S2). ADAMTS13 activity and antigen concentrations were unchanged during and after ACS, but the VWF:ADAMTS13 ratio was significantly elevated in ACS patients and two different populations of patients with diabetes mellitus. The ACS patients had significantly elevated concentrations of PMP at admission, particularly PMP subpopulations with exposed P-selectin and tissue factor (TF). Concentrations of PMP decreased following initiation of antithrombotic treatment (S2), but in the subpopulations with exposed P-selectin and TF they remained significantly higher than in controls at 6 months (S3).
Conclusions: Our PMP data are in agreement with the concept of a dominating role of platelets in the pathophysiology of ACS, and PMP deserve to be studied in more detail in coronary artery disease, including their roles in the effects of treatment and relationships to coagulation, risk and prognosis. However, the data on coagulation and fibrinolysis obtained in this study indicate that there is not yet sufficient information to support the clinical use of markers to assess coagulation or fibrinolysis in individual patients.
Aim: To study new markers and methods concerning haemostasis in ACS and conditions associated with high risk of this disease, in the search for laboratory tools that could help increase understanding of disease mechanisms and help to identify patients at risk.
Methods and Results: Eighty-seven patients suffering from ACS were investigated at admission (S1), after 24 h on standard antithrombotic treatment (S2), and six months after the acute event (S3). Sex- and age-matched healthy controls were also investigated. Thrombin generation in vivo was assessed by measurement of prothrombin fragment F1+2 in plasma and in vitro by using the calibrated automated thrombogram (CAT). Fibrinolysis was measured by assessment of PAI-1 and TAFI activity concentrations. The latter method was used as a result of a methods evaluation study. We also employed a global method developed by our group (Oh- index), to evaluate haemostasis. Oh-index gives a measure of fibrin formation and degradation capacity in plasma. Furthermore, a flow cytometric assay set up by our group was employed to measure platelet microparticles (PMP) in plasma formed upon platelet activation. In addition, we investigated ADAMTS13, an enzyme previously called von Willebrand factor (VWF)-degrading protease, and we also measured its substrate (i.e. VWF). The ACS patients, of whom more than half were high-risk patients (TIMI score ≥ 4), showed signs of inflammation and endothelial activation, as expected. Only the CAT method could detect hypercoagulability in the patients (increased peak thrombin concentration) and this finding was evident acutely and 6 months after the event. Thrombin generation in vivo (F1+2) or fibrin generation capacity in plasma did not indicate hypercoagulability at any time point. CAT, F1+2 and fibrin generation capacity were strongly reduced following initiation of antithrombotic treatment (S2), as expected. PAI-1 and TAFI levels were elevated, reflecting impaired fibrinolysis, but this was not observed with our method that assesses fibrin degradation capacity; rather, this method indicated increased fibrinolytic capacity at admission and this capacity was grossly increased after initiation of standard antithrombotic treatment (S2). ADAMTS13 activity and antigen concentrations were unchanged during and after ACS, but the VWF:ADAMTS13 ratio was significantly elevated in ACS patients and two different populations of patients with diabetes mellitus. The ACS patients had significantly elevated concentrations of PMP at admission, particularly PMP subpopulations with exposed P-selectin and tissue factor (TF). Concentrations of PMP decreased following initiation of antithrombotic treatment (S2), but in the subpopulations with exposed P-selectin and TF they remained significantly higher than in controls at 6 months (S3).
Conclusions: Our PMP data are in agreement with the concept of a dominating role of platelets in the pathophysiology of ACS, and PMP deserve to be studied in more detail in coronary artery disease, including their roles in the effects of treatment and relationships to coagulation, risk and prognosis. However, the data on coagulation and fibrinolysis obtained in this study indicate that there is not yet sufficient information to support the clinical use of markers to assess coagulation or fibrinolysis in individual patients.
List of papers:
I. Skeppholm M, Kallner A, Kalani M, Jörneskog G, Blombäck M, Wallén NH. ADAMTS13 and von Willebrand factor concentrations in patients with diabetes mellitus. Blood Coagul Fibrinolysis. 2009;20:619-26.
Fulltext (DOI)
Pubmed
View record in Web of Science®
II. Skeppholm M, Wallén NH, Malmqvist K, Kallner A, Antovic J. Comparison of two immunochemical assays for measuring thrombin activatable fibrinolysis inhibitor concentration with a functional assay in patients with acute coronary syndrome. Thromb Res. 2007;121:175-81.
Fulltext (DOI)
Pubmed
View record in Web of Science®
III. Skeppholm M, Kallner A, Malmqvist K, Blombäck M, Wallén NH. Is fibrin formation and thrombin generation increased during and after an acute coronary syndrome? Thromb Res. 2011;128:483–89.
Fulltext (DOI)
Pubmed
IV. Skeppholm M, Mobarrez F, Malmqvist K, Wallén NH. Platelet derived microparticles during and after acute coronary syndrome. [Submitted]
I. Skeppholm M, Kallner A, Kalani M, Jörneskog G, Blombäck M, Wallén NH. ADAMTS13 and von Willebrand factor concentrations in patients with diabetes mellitus. Blood Coagul Fibrinolysis. 2009;20:619-26.
Fulltext (DOI)
Pubmed
View record in Web of Science®
II. Skeppholm M, Wallén NH, Malmqvist K, Kallner A, Antovic J. Comparison of two immunochemical assays for measuring thrombin activatable fibrinolysis inhibitor concentration with a functional assay in patients with acute coronary syndrome. Thromb Res. 2007;121:175-81.
Fulltext (DOI)
Pubmed
View record in Web of Science®
III. Skeppholm M, Kallner A, Malmqvist K, Blombäck M, Wallén NH. Is fibrin formation and thrombin generation increased during and after an acute coronary syndrome? Thromb Res. 2011;128:483–89.
Fulltext (DOI)
Pubmed
IV. Skeppholm M, Mobarrez F, Malmqvist K, Wallén NH. Platelet derived microparticles during and after acute coronary syndrome. [Submitted]
Institution: Karolinska Institutet
Supervisor: Wallén, Håkan
Issue date: 2011-11-18
Rights:
Publication year: 2011
ISBN: 978-91-7457-496-8
Statistics
Total Visits
Views | |
---|---|
Studies ...(legacy) | 731 |
Studies ... | 250 |
Total Visits Per Month
March 2024 | April 2024 | May 2024 | June 2024 | July 2024 | August 2024 | September 2024 | |
---|---|---|---|---|---|---|---|
Studies ... | 2 | 1 | 1 | 2 | 2 | 4 | 2 |
File Visits
Views | |
---|---|
Thesis_Mika_Skeppholm.pdf(legacy) | 745 |
Thesis_Mika_Skeppholm.pdf | 716 |
Spikblad_Mika_Skeppholm.pdf(legacy) | 265 |
Spikblad_Mika_Skeppholm.pdf | 41 |
Spikblad_Mika_Skeppholm.pdf.txt(legacy) | 2 |
Thesis_Mika_Skeppholm.pdf.txt(legacy) | 2 |
Top country views
Views | |
---|---|
United States | 405 |
Sweden | 130 |
China | 71 |
Germany | 57 |
South Korea | 19 |
Russia | 18 |
France | 16 |
United Kingdom | 11 |
Denmark | 7 |
Spain | 7 |
Top cities views
Views | |
---|---|
Ashburn | 51 |
Sunnyvale | 44 |
Romeo | 33 |
Beijing | 30 |
Kiez | 16 |
Stockholm | 14 |
Seoul | 13 |
London | 7 |
Ballerup | 6 |
Central District | 6 |