Related Experiment Video
Updated: Aug 31, 2026

Microfluidics in Assessing Platelet Function
Published on: November 8, 2024
Platelet activation and thrombosis in microvascular obstruction
Craig Balmforth1, Alessandro Giaj Levra1,2, Beth Whittington1
1British Heart Foundation Centre of Research Excellence, University of Edinburgh, Institute for Neuroscience and Cardiovascular Research, Edinburgh, United Kingdom of Great Britain & Northern Ireland.
Aims:
Microvascular obstruction (MVO) remains a major complication following coronary reperfusion, but its pathogenesis is poorly defined. We evaluated myocardial platelet activation and thrombosis using fluorine-18-labelled GP1 ([18F]GP1) positron emission tomography (PET) in patients with anterior ST-segment elevation myocardial infarction.
Methods And Results:
In a single-centre observational cohort study, 100 patients with acute anterior ST-segment elevation myocardial infarction underwent hybrid cardiac [18F]GP1 PET and magnetic resonance (MR) imaging with gadolinium enhancement and repeat imaging at 3-6 months. Myocardial [18F]GP1 uptake was quantified using target-to-background ratio (TBRmax) and percentage myocardial uptake (burden) and compared with MR measures of infarction, MVO and adverse ventricular remodelling. One hundred patients (60 ± 10 years, 91% male) underwent [18F]GP1 PET/MR imaging at a median of 13 days following index presentation. Increased myocardial [18F]GP1 uptake was observed in 44% of participants (TBRmax 1.89 ± 0.50). All 40 patients with MR-defined MVO demonstrated myocardial [18F]GP1 uptake. Myocardial [18F]GP1 uptake burden correlated with (ρ = 0.84; P < 0.001), and exceeded (by 18%), MR-defined burden of MVO. Myocardial [18F]GP1 uptake was associated with infarct size, lower left ventricular ejection fraction and longer time-to-reperfusion. Angiographic no-reflow was the strongest independent association of MVO (adjusted odds ratio 16.15; P < 0.001). Persistent myocardial [18F]GP1 uptake at follow up (22%, 7/32) was associated with lower left ventricular ejection fraction. Resolution of cardiac MR-defined MVO was observed in 78% of patients at follow-up and was universally concordant with resolution of myocardial [18F]GP1 uptake.
Conclusion:
MVO following ST-segment elevation myocardial infarction is universally associated with myocardial platelet activation, extending beyond structural abnormalities identified by cardiac MR. These findings are consistent with an important mechanistic contribution of platelet-mediated microvascular thrombosis to no-reflow and MVO, highlighting a potentially targetable biological pathway in a condition for which effective therapies remain elusive.
More Related Videos
Related Concept Videos
Formation of the Platelet Plug
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
Venous Thrombosis I: Introduction
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Clot Retraction and Fibrinolysis
Disorders of Hemostasis
Thromboembolic Disorders
Two factors primarily cause thromboembolic conditions.
Introduction to Hemostasis
The three phases of hemostasis involve many clotting factors present in plasma and several substances released by platelets and injured tissue cells. It is a fast, localized, and...

