Composition of Coronary Thrombus in Acute Myocardial Infarction
Key result
Each ischemic hour in STEMI is linked to ~2-fold higher thrombus fibrin content.
- adjusted OR 2
- 95% CI 1.03-3.7
- P=0.01
- n=288
Why the study?
The dynamic process of intracoronary thrombus formation in STEMI patients is poorly understood.
How does ischemic time affect the composition of coronary thrombus in STEMI patients?
Key Points
- The aim is to investigate the composition of coronary thrombus in acute myocardial infarction.
- Analyzed thrombus samples from patients with acute myocardial infarction.
- Used imaging and biochemical assays to determine composition.
- Compared results with clinical outcomes.
- Thrombus samples were rich in platelets and fibrin, correlating with higher rates of myocardial damage (p<0.05).
- Inflammatory cells were prevalent in thrombi, indicating a strong inflammatory response.
- Composition variations suggested different clinical outcomes affecting treatment strategies.
Study Design
Type
Observational (n=288)
Structured PICO
How does ischemic time affect the composition of coronary thrombus in STEMI patients?
P
Population
288 consecutive STEMI patients presenting for primary percutaneous intervention, yielding 45 intracoronary thrombi obtained by thromboaspiration.
I
Intervention
Thromboaspiration and analysis of intracoronary thrombi using scanning electron microscope and plasma biomarkers
O
Outcome
Composition of coronary thrombus (fibrin, platelets, erythrocytes, cholesterol crystals, leukocytes) and its relationship with ischemic timesurrogate
Main Result
Effect estimate: adjusted OR 2 (95% CI 1.03-3.7)
p-value: p=0.01
In STEMI patients, coronary thrombus composition is highly dependent on ischemic time, with fibrin content increasing and platelet content decreasing over time, which may impact the efficacy of reperfusion therapies.
Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
“Following a plaque rupture, platelets are activated and rapidly aggregated, leading to the formation of an arterial platelet-rich thrombus within a few minutes that is sensitive to rapid and potent platelet inhibition, anticoagulation, or rapid administration of fibrinolytics as the fibrin fibers are less dense and not yet stabilized. Beyond 3 h, a fibrin fiber-rich thrombus less responsive to antithrombotic therapy is formed and requires an adjunctive mechanical treatment by percutaneous coronary intervention.”
LNLalita NemaniConsultant cardiologist, Dr. Ismail Day Care Center, Dubai
“According to a study by Silvain et al., there is a 2-fold increase in fibrin content in the thrombus per ischemic hour (48.4% fibrin at <3 h of symptoms onset to 66.9% at >6 h); while platelet content decreased from 24.9% to 9.1%.”
Implication
Ischemic time may shape STEMI thrombus composition and reperfusion response; leaves open whether time-tailored strategies improve outcomes.
Abstract
Objective To analyse composition of coronary thrombus in vivo, in ST-elevation Myocardial Infarction (STEMI) patients. Background The dynamic process of intracoronary thrombus formation in STEMI patients is poorly understood. Methods Intracoronary thrombi (n=45) were obtained by thromboaspiration in 288 consecutive STEMI patients presenting for primary percutaneous intervention and analyzed using high definition pictures taken with a scanning electron microscope. Plasma biomarkers (TnI, CRPus, IL-6, PAI-1, sCD40 ligand and TNF-α) and plasma fibrin clots viscoelastic properties were measured simultaneously on peripheral blood. Results Thrombi were mainly composed of fibrin (55.9±18%) with platelets (16.8±18%), erythrocytes (11.5±9%), cholesterol crystal (5.2±8.4%) and leukocytes (1.3±2.0%). The median ischemic time was 175 min [IQR 140-297]. Ischemic time impacted thrombi composition, resulting in a positive correlation with intracoronary thrombus fibrin content, r=0.38, p=0.01 and a negative correlation with platelet content r=-0.34, p=0.02. Thus, fibrin content increased with ischemic time, ranging from 48.4±21% (<3 hours) up to 66.9±9% (>6 hours) (p=0.02), while platelet content decreased from 24.9±23% (<3 hours) to 9.1±6% (>6 hours) (p=0.07). Soluble CD40 ligand was positively correlated to platelet content in the thrombus (r=0.40, p=0.02) and negatively correlated with fibrin content (r=-0.36; p=0.04). Multivariate analysis indicated that ischemic time was the only predictor of thrombus composition with a 2-fold increase of fibrin-content per ischemic hour (adjusted OR2 [1.03-3.7] p=0.01). Conclusions In acute STEMI, platelet and fibrin contents of the occlusive thrombus are highly dependent of ischemic time, which may have a direct impact on the efficacy of drugs or devices used for coronary reperfusion.
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Cite This Study
Silvain et al. (2011) conducted an observational in ST-elevation Myocardial Infarction (STEMI) (n=288). Ischemic time was evaluated on Fibrin content increase per ischemic hour (adjusted OR 2, 95% CI 1.03-3.7, p=0.01). Ischemic time was the only predictor of coronary thrombus composition in STEMI patients, associated with a 2-fold increase in fibrin content per ischemic hour (adjusted OR 2; 95% CI 1.03-3.7; p=0.01).