Invasive Cardiology Board Review Flashcards
What characterizes plaque rupture?
A necrotic core with an overlying thin-ruptured cap infiltrated by macrophages and lymphocytes
Few or no smooth muscle cells within the cap. Collagen fibers appear bright yellow or orange and thinner fibers appear green under polarized microscopy.
What is effective efferocytosis?
The ability of macrophages to remove apoptotic bodies from the core of atherosclerotic plaques
It is a key characteristic of plaque stabilization.
What are the characteristics of ruptured plaques?
Decreased collagen content, increased lipid content, and increased metalloproteinase expression
These changes contribute to plaque vulnerability.
Where do plaque ruptures typically occur?
At the shoulder regions where circumferential stress is highest
This is due to mechanical stress on the plaque.
What does a rise in troponin likely indicate in the context of a plaque?
A ruptured plaque with thrombus and downstream emboli
Rapid progression of a stable plaque in a month is unlikely.
How do angioscopic findings differ between NSTEMI and STEMI plaques?
NSTEMI plaques are predominantly platelet-based and white to gray, while STEMI plaques are red due to fibrin and red cell deposition
This reflects different underlying pathophysiologies.
What is the role of smooth muscle cells in atherosclerotic plaques?
They are responsible for strengthening the fibrous cap
Increased smooth muscle cell activity is associated with plaque stability.
What is the relationship between systemic inflammation and complex plaques?
Multiple complex plaques indicate systemic inflammation contributing to plaque rupture
Patients with multiple plaques often have higher levels of inflammatory markers.
What is CRP and its role in atherosclerosis?
CRP is produced in the liver as a proinflammatory response to IL-6
It is a marker for inflammation and related to cardiovascular risk.
What characterizes TCFAs compared to other advanced plaques?
They have a lesser degree of calcification
This makes them more susceptible to rupture.
What is the beneficial effect of aspirin related to?
CRP levels in primary prevention
Aspirin is more effective in patients with higher CRP levels.
What does remodeling of plaques preserve?
The lumen but does not protect from heart attacks
Remodeling is often seen in plaques from patients with acute coronary events.
What is intraplaque neovascularization associated with?
Plaque growth, hemorrhage, and vulnerability
It primarily occurs from the vasa vasorum.
What defines a thick cap fibroatheroma?
A plaque with a dense layer of tissue covering the lipid core
What is the mechanism of action of nitroglycerin?
Acts directly on the smooth muscle cell of the tunica media
This is known as endothelial-independent relaxation.
What is the main body of evidence regarding vascular smooth muscle cells?
Transformation into osteoblast cells contributes to calcification
This process plays a role in plaque stability and vulnerability.
What is Heyde’s syndrome associated with?
Acquired von Willebrand’s deficiency and arteriovenous malformations
It is commonly linked to severe aortic stenosis.
What are the distinct differences in acquired vasculopathy in transplanted hearts?
Presence of abundant proteoglycan and less collagen deposition
This contrasts with native atherosclerosis.
Where do lesions more often occur in relation to bifurcations?
At the walls opposite the carina where shear stress is lower
This environment favors lesion growth.
