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Factor VII and extrinsic pathway inhibitor in acute coronary disease
P M Sandset1, P A Sirnes, U Abildgaard
1Medical Department, Aker Hospital, University of Oslo, Norway.
Insights
In acute ischemic heart disease, coagulation factor VII (FVII) phospholipid complex activity increased, while extrinsic pathway inhibitor (EPI) levels rose, suggesting a balanced coagulation system despite altered FVII activity.
Area of Science:
- Cardiovascular Medicine
- Hematology
- Biochemistry
Background:
- Acute ischemic heart disease involves complex coagulation system alterations.
- Coagulation Factor VII (FVII) and its inhibitors play critical roles in hemostasis.
- Understanding the extrinsic pathway's role in heart disease is crucial for therapeutic development.
Purpose of the Study:
- To investigate the activation of coagulation factor VII (FVII) and extrinsic pathway inhibition in patients with acute ischemic heart disease.
- To compare FVII activity and extrinsic pathway inhibitor (EPI) levels in patients versus healthy controls.
- To explore correlations between FVII-phospholipid complex, triglycerides, and EPI in ischemic heart disease.
Main Methods:
- Plasma levels of FVII amidolytic activity, FVII clotting activity, and EPI were measured.
- The FVII-phospholipid complex fraction, sensitive to phospholipase C, was quantified.
- Statistical analyses compared patient groups (acute myocardial infarction, angina pectoris, heart failure/arrhythmia) with controls.
Main Results:
- No significant differences in mean FVII amidolytic or clotting activity between patients and controls.
- The FVII-phospholipid complex was elevated in acute myocardial infarction patients (19%) compared to controls (8%).
- Extrinsic pathway inhibitor (EPI) levels were significantly increased in all patient groups (132-150%) compared to controls (110%).
- The FVII clotting/EPI ratio decreased significantly in acute myocardial infarction and heart failure patients.
Conclusions:
- Despite a moderate increase in procoagulant activity (FVII-phospholipid complex), there is a marked increase in anticoagulant activity (EPI) in acute ischemic heart disease.
- The extrinsic coagulation pathway appears to maintain a balanced activation system in this patient population.
- These findings suggest complex regulatory mechanisms within the coagulation cascade during ischemic heart events.
Abstract:
This report describes studies on the activation of coagulation factor VII (FVII) and the inhibition of the extrinsic coagulation pathway in acute ischaemic heart disease. FVII and the inhibitor of the tissue thromboplastin-FVII complex, called extrinsic pathway inhibitor (EPI), were determined in plasma from 68 patients and compared to findings in 37 normal individuals. The mean FVII amidolytic activity, the mean FVII clotting activity, as well as the FVII clotting/FVII amidolytic ratio were not significantly different in the patient groups as compared to the controls. The fraction of FVII clotting activity that is sensitive to phospholipase C, 'the FVII-phospholipid complex', was 8% in controls, 19% (P less than 0.05) in patients with acute myocardial infarction, 15% (n.s.) in angina pectoris and 13% (n.s.) in heart failure/arrhythmia patients. The 'FVII-phospholipid complex' was highly significantly correlated to triglycerides in plasma in patients with acute myocardial infarction (r = 0.88, P less than 0.001) and angina pectoris (r = 0.89, P less than 0.001). The mean EPI levels were significantly increased in patients with acute myocardial infarction (132%), angina pectoris (134%), and heart failure (150%) as compared to the control population (110%). The FVII clotting/EPI ratio was significantly decreased both in patients with acute myocardial infarction and heart failure, whereas the FVII amidolytic/EPI ratio was significantly decreased only in the heart failure group. Apparently, in patients with acute ischaemic heart disease, a moderate increase in the procoagulant activity is accompanied by a marked increase in the anticoagulant activity of the extrinsic coagulation pathway, suggesting a balanced activation system.