Inflammation and Arterial Injury Flashcards
What is the main concern with drug-eluting stents (DES) in relation to late stent thrombosis?
DES can elicit a chronic inflammatory response even after the drug has fully eluted
This reaction is generally localized and hypothesized to be associated with an increased risk of very late stent thrombosis.
What is a significant difference between ticagrelor and clopidogrel?
Ticagrelor is a more potent platelet P2Y12 receptor antagonist than clopidogrel
In the PLATO trial, cardiovascular events were decreased with ticagrelor compared to clopidogrel among patients with ACS.
What does the figure demonstrate regarding vasoconstriction with different stent types?
Significantly more proximal and distal vasoconstriction with PES and SES vs. BMS
This suggests a chronic inflammatory response to permanent polymer.
What is the main outcome of the seminal meta-analysis of randomized controlled trials regarding CoCr EES?
Dramatically reduced rates of definite stent thrombosis at all time points compared to BMS
No other tested DES had lower definite stent thrombosis than BMS at 2-year follow-up.
What role do polymers play in drug-eluting stents (DES)?
Polymers modulate the elution characteristics of the drug on DES
They do not have an independent positive effect on neoatherosclerosis or in-stent restenosis rates.
What are the phases of the healing response after coronary stenting?
Phase I: de-endothelialization, Phase II: release of growth factors, Phase III: migration of smooth muscle cells and re-endothelialization
This process involves acute inflammatory cells and chronic inflammatory cells.
How do Paclitaxel and Sirolimus affect neointimal hyperplasia?
They decrease the amount of neointimal hyperplasia compared to BMS
However, the underlying polymer has no favorable effect on the healing process.
What are the factors that may increase inflammation and restenosis after stenting?
(a) certain polymers/drugs, (b) stent strut thickness, (c) medial injury or lipid core penetration
Deployment of stents in fibrous plaque can reduce inflammation.
What adverse effects can high-dose Paclitaxel have?
Augmented inflammatory response compared to polymer alone
Adverse events related to chronic inflammation and delayed healing were noted with the QuaDS QP-2 stent.
What is the primary systemic marker of inflammation studied in relation to PCI?
CRP (C-reactive protein)
The magnitude of pre-and post-PCI levels of CRP has been associated with adverse events after stenting.
What has been observed regarding the rates of stent thrombosis in newer generation metallic DES?
Progressively decreasing rates of both early and late stent thrombosis compared to early-generation counterparts
This is attributed to thinner struts and better materials.
True or False: Late acquired incomplete stent apposition is more common after BMS than DES.
False
Incomplete stent apposition is more common after DES.
What cytokine is primarily responsible for stimulating CRP production?
IL-6
IL-6 is produced by macrophages and is the main hepatic stimulus for CRP production.
Fill in the blank: The major cause of DES thrombosis is _______.
early cessation of DAPT
Rare hypersensitivity reactions can also occur post-implantation.
What is the impact of statin therapy prior to PCI?
Statin therapy seems to have the most benefit among patients with the highest level of pre-PCI inflammation
Atorvastatin, clopidogrel, and abciximab may blunt the inflammatory response after PCI.
What does flow-mediated dilation of the brachial artery reflect?
Systemic endothelial dysfunction
Abnormal endothelial function can be seen over 6 months after DES placement.
What is the relationship between systemic cytokine rise and restenosis in the DES era?
No difference in systemic cytokine rise has been confirmed between DES and BMS
Local drug delivery likely suppresses inflammation and smooth muscle cell migration despite similar systemic responses.
What occurs during cardiogenic shock according to newer evidence?
A systemic inflammatory response leading to nitric oxide synthase overproduction
This results in inappropriate vasodilation and refractory hypotension.
What medications may blunt the inflammatory response after PCI?
Atorvastatin, clopidogrel, and abciximab
These medications may have a beneficial impact on PCI by reducing inflammation.
What effect did abciximab have on CRP and IL-6 levels after PCI in the EPIC trial?
Blunted the rise of CRP and IL-6
This effect was observed in a subset of patients.
How does clopidogrel affect patients with high CRP levels undergoing PCI?
Attenuates the increased risk associated with PCI
This suggests a protective role in high-risk patients.
In which patients does statin therapy prior to PCI seem to have the most benefit?
Patients with the highest level of pre-PCI inflammation
This indicates that inflammation may influence the effectiveness of statins.
Do systemic medications clearly impact long-term healing such as stent restenosis?
No
However, local applications of statin drugs may be promising for inflammation and smooth muscle cell migration.
What factors have been proposed for increased stent thrombosis rates with bioresorbable scaffolds?
Thicker strut sizes, poorer radial strength, visualized intraluminal masses
These may represent early thrombi or late malapposed struts.
What has been observed in follow-up studies from the ABSORB trials regarding bioabsorbable vascular scaffolds?
No residual struts seen at 5 years
Dilation improved but did not return completely to normal compared to adjacent undiseased segments.
What did intravascular imaging reveal over areas of prior bioabsorbable vascular scaffolds?
Thick capped neointima
This finding indicates potential changes in the vascular structure post-implantation.
What is the effect of GP IIb/IIIa inhibitors on platelet aggregation?
Decrease platelet aggregation and periprocedural myonecrosis
This is an important aspect of their function in PCI.
What does the EPIC trial suggest about abciximab compared to heparin alone?
Decreased the rise of CRP and IL-6
This highlights its potential anti-inflammatory effects.
What is the significance of the TARGET trial regarding tirofiban?
Inferiority of tirofiban compared to abciximab
This may relate to inadequate dosing and lack of anti-inflammatory effects.
Have GP IIb/IIIa inhibitors been shown to prevent intimal hyperplasia and in-stent restenosis?
No
This raises questions about their long-term efficacy in preventing these conditions.
