Thrombin activatable fibrinolysis inhibitor : its role in slow coronary flow

A Case-Control Study of the Dose-Response Relationship Between Thrombin Activatable Fibrinolysis Inhibitor and Acute Myocardial Infarction

Background

Acute myocardial infarction (AMI) is considered an acute coronary syndrome (ACS), which is caused by the death of myocardial cells after prolonged ischemia, and there is a high risk of sudden death during AMI. Therefore, the purpose of this study is to explore the relationship between thrombin activatable fibrinolysis inhibitor (TAFI) and AMI and provide evidence for their association and potentially the prevention of AMI.

Methods

There were 228 subjects included in this retrospective study, which included 78 AMI patients and 150 controls. The immune turbidimetry was used to measure TAFI concentration in the serum. Mann-Whitney U test was used to compare serum TAFI levels. The logistic regression analysis was used to construct a model of influencing factors of AMI. The dose-response relationship between serum TAFI level and AMI was explored by using the restricted cubic spline (RCS) functions combined with logistic regression analysis.

Results

The serum TAFI levels of the AMI group were higher than the control group's (P = 0.003). The risk of AMI in the high-TAFI level group was 2.24 times higher than the low-TAFI level group (P = 0.007) and it was 2.74 times higher after adjustment of other risk factors (P = 0.025). According to the dose-response curve, the risk of AMI increased significantly with an increase of serum TAFI concentration (P = 0.0387).

Conclusion

Acute myocardial infarction patients had higher serum TAFI levels, and TAFI was an independent risk factor for AMI patients. Serum TAFI levels demonstrated a dose- dependent response to the risk of AMI. Our study provides evidence that TAFI could be used for risk stratification of AMI patients.

Genetic Polymorphisms Associated with Thrombotic Disease Comparison of Two Territories: Myocardial Infarction and Ischemic Stroke

BACKGROUND AND PURPOSE

The thrombin-activatable fibrinolysis inhibitor (TAFI) is an important inhibitor of fibrinolysis and plays a critical role in the pathogenesis of arterial thrombosis; genetic polymorphisms of the TAFI gene affect its activity and increase the risk of thrombosis. Moreover, studies in young patients are still scarce. The aim was to examine the contribution of the Thr325Ile and Ala147Thr polymorphisms with ST acute myocardial infarction (STEMI) or idiopathic ischemic stroke (IIS) in the young Mexican population.

METHODS

A total of 244 patients with STEMI ≤45 years of age and 244 controls. In a second study, 250 patients with IIS ≤45 years of age were recruited, including 250 controls. In both studies, cases and controls were matched by age and sex. The polymorphisms were determined in all participants by PCR-RFLP.

RESULTS

There was significant difference in the Thr325Ile genotype distribution (P = 0.001) and allele frequency (P = 0.001) between STEMI and control groups, but no difference in the Ala147Thr genotype distribution (P = 0.24) and allele frequency (P = 0.46), neither in the Thr325Ile genotype distribution (P = 0.25) nor in the Ala147Thr genotype distribution (P = 0.46) or their allele frequencies; there was significant difference between IIS and the control group. There were independent factors for STEMI: the Ile allele (P = 0.01), type 2 diabetes mellitus (P = 0.001), hypertension (P = 0.001), smoking (P = 0.001), dyslipidemia (P = 0.001), and family history of atherothrombotic disease (P = 0.001). The independent factors for IIS were hypertension (P = 0.001), smoking (P < 0.01), and family history of atherothrombotic disease (P < 0.01).

CONCLUSIONS

The Thr325Ile polymorphism, but no Ala147Thr polymorphism, represents an independent risk factor for STEMI in the young Mexican population.

Increased circulating soluble urokinase-type plasminogen activator receptor (suPAR) levels in patients with slow coronary flow

Introduction

Slow coronary flow (SCF) is an angiographic phenomenon characterized by delayed opacification of epicardial coronary arteries without an obstructive coronary disease. Serum soluble urokinase-type plasminogen activator receptor (suPAR) levels seem closely related to atherosclerosis due to increased inflammation and prothrombotic state. We studied whether circulating suPAR is related to SCF.

Material and methods

The present study was cross-sectional and observational. It included 75 individuals who underwent coronary angiography with suspected CAD and had angiographically normal coronary arteries of varying coronary flow rates. The relationship between suPAR, C-reactive protein (CRP) and SCF was investigated. Forty patients with isolated SCF (mean age: 46.0 ±4.14 years) and 35 age- and gender-matched control participants with normal coronary flow (NCF) and normal coronary arteries (NCA) (mean age: 46.0 ±5.7 years) were included in the study. We used logistic regression analysis to determine the predictors of SCF.

Results

The clinical characteristics were not statistically significantly different between SCF and NCA groups. Serum suPAR level was significantly higher in the SCF group than the control group (2.5–5.4 ng/ml vs. 0.1–1.4 ng/ml; p < 0.001). Also the serum CRP level was higher in the CSF group than the control group (1.57 ±0.43 mg/l vs. 0.53 ±0.23 mg/l; p < 0.001).

Conclusions

This study revealed significantly increased serum suPAR levels in patients with SCF. Although we cannot draw conclusions on the underlying pathological process of SCF, we believe that these findings may be pioneering for further studies investigating the specific roles of circulating suPAR in the SCF phenomenon in the coronary vasculature.