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Activation of coagulation and fibrinolysis during cardiothoracic operations
B J Hunt1, R N Parratt, H C Segal
1Department of Cardiothoracic Surgery, Imperial College School of Medicine at The National Heart and Lung Institute, Harefield Hospital, Middlesex, United Kingdom.
Insights
Cardiopulmonary bypass, not the surgery itself, significantly activates coagulation and fibrinolysis during cardiac operations. This leads to a hypercoagulable state post-surgery.
Area of Science:
- Cardiovascular Surgery
- Hemostasis and Thrombosis
Background:
- Cardiac operations with cardiopulmonary bypass (CPB) activate coagulation and fibrinolysis.
- The distinct roles of CPB and the surgical procedure in this activation require clarification.
Purpose of the Study:
- To differentiate the contributions of CPB and thoracic surgery to coagulation and fibrinolysis activation.
- To assess the temporal changes in hemostatic markers in relation to CPB exposure.
Main Methods:
- Sequential blood samples were collected from 7 thoracic surgery patients (no CPB) and 8 cardiac surgery patients (with CPB).
- Measurements included thrombin-antithrombin III complexes, D-dimers, tissue plasminogen activator, and plasminogen activator inhibitor-1 activity.
- Samples were analyzed from pre-operation to 48 hours post-operation.
Main Results:
- Thoracic surgery patients showed no significant increase in coagulation markers until 24 hours post-operation.
- Cardiac patients exhibited significant increases in thrombin-antithrombin III complexes and D-dimers during CPB.
- Increased tissue plasminogen activator and a hypercoagulable state, indicated by elevated thrombin-antithrombin III complexes and plasminogen activator inhibitor-1 activity, were observed post-cardiac surgery.
Conclusions:
- Cardiopulmonary bypass is the primary driver of coagulation and fibrinolysis activation during cardiac surgery.
- CPB induces a more pronounced and immediate hypercoagulable state compared to non-CPB thoracic surgery.
Background:
During open cardiac operations using cardiopulmonary bypass, there is activation of coagulation and fibrinolysis. We assessed the separate contributions of the surgical procedure itself and cardiopulmonary bypass to this, by studying sequential samples from patients undergoing routine open cardiac operations or thoracic operations without cardiopulmonary bypass.
Methods:
Activation of coagulation and the extent of fibrinolysis were measured from sequential samples obtained before the operation to 48 hours after the operation for 7 thoracic patients and 8 cardiac patients.
Results:
In the thoracic group operation length was shorter (p = 0.002), and there was no significant increase in thrombin-antithrombin III complexes or D-dimers until 24 hours postoperatively. In contrast, there was a highly significant increase in thrombin-antithrombin III complexes (p = 0.0043) and D-dimer levels (p = 0.009) during cardiopulmonary bypass. The increase in fibrinolytic activity was caused by an increase in tissue plasminogen activator (p = 0.013). At 48 hours postoperatively, the cardiac patients had a more hypercoagulable state than thoracic patients with significantly higher levels of thrombin-antithrombin III complexes (p = 0.041) and plasminogen activator inhibitor-1 activity (p = 0.0033).
Conclusions:
This study suggests the major activation of coagulation and fibrinolysis seen during cardiac operations is caused by the use of cardiopulmonary bypass.