Stent thrombosis

Stent thrombosis

1. Which of the following is the most common cause of stent thrombosis?
💬 Discontinuation of dual antiplatelet therapy is the leading cause of stent thrombosis, especially early after implantation.

2. Which time frame defines “very late” stent thrombosis?
💬 According to ARC definitions, very late stent thrombosis occurs more than 12 months after stent implantation.

3. What type of stents has a higher incidence of late stent thrombosis?
💬 First-gen DES are more thrombogenic due to delayed endothelialization and polymer issues.

4. Which antiplatelet agent is most associated with stent thrombosis when prematurely stopped?
💬 Premature cessation of clopidogrel is a major cause of stent thrombosis, especially within the first month.

5. Which of the following is a risk factor for early stent thrombosis?
💬 Early thrombosis is often procedural—e.g., underexpansion, dissection, or poor apposition.

6. The diagnosis of stent thrombosis is best confirmed by:
💬 Angiography is the gold standard to visualize thrombus or occlusion in the stented segment.

7. Which condition increases the risk of late stent thrombosis the most?
💬 Diabetes is strongly linked to delayed healing and late stent thrombosis.

8. Optimal DAPT duration for DES to reduce stent thrombosis risk is:
💬 Most guidelines recommend at least 6–12 months of DAPT following DES to reduce thrombosis risk.

9. Which stent feature reduces thrombosis risk in second-generation DES?
💬 Biocompatible or bioabsorbable polymers reduce inflammation and late thrombosis.

10. Stent thrombosis most commonly presents as:
💬 Stent thrombosis often causes abrupt occlusion → STEMI with high mortality.

11. Which imaging modality best assesses stent apposition and expansion?
💬 IVUS provides detailed cross-sectional images to assess stent expansion and apposition, guiding PCI.

12. Stent thrombosis rates are lowest with:
💬 Second-gen DES show reduced stent thrombosis due to better polymers and thinner struts.

13. What is the recommended management for confirmed stent thrombosis?
💬 Urgent PCI is the preferred treatment to restore perfusion in stent thrombosis.

14. The Academic Research Consortium (ARC) classification of stent thrombosis includes:
💬 ARC classifies thrombosis based on certainty: definite, probable, or possible, to standardize studies.

15. Which P2Y12 inhibitor provides the fastest and most potent platelet inhibition?
💬 Prasugrel offers more rapid and potent inhibition of platelet aggregation than clopidogrel.

16. Which of the following increases risk of acute stent thrombosis?
💬 Incomplete stent expansion or malapposition is a key cause of acute thrombosis post-implantation.

17. Very late stent thrombosis is commonly caused by:
💬 Hypersensitivity reactions to stent polymers can cause delayed inflammation and thrombosis.

18. Bioabsorbable scaffolds are associated with:
💬 Early devices had mechanical limitations, causing increased thrombosis risk during resorption.

19. Which laboratory test predicts high platelet reactivity on clopidogrel?
💬 The VerifyNow test assesses P2Y12 receptor inhibition and guides antiplatelet therapy adjustment.

20. Which action best reduces stent thrombosis risk during PCI?
💬 Ensuring full stent expansion with proper apposition is the most important preventive step.

📌 20-Point Summary: Stent Thrombosis
#Key Point
1Most common cause is premature discontinuation of antiplatelet therapy.
2“Very late” stent thrombosis occurs after 1 year post-PCI.
3First-generation DES have higher thrombosis risk than second-gen.
4Clopidogrel discontinuation is a key factor in early thrombosis.
5Procedural issues like underexpansion lead to early thrombosis.
6Coronary angiography is the gold standard for diagnosis.
7Diabetes is a strong risk factor for late thrombosis.
8Recommended DAPT duration after DES is 6–12 months.
9Biocompatible polymers in 2nd-gen DES reduce thrombosis.
10STEMI is the most common presentation of stent thrombosis.
11IVUS helps evaluate stent apposition and expansion.
12Second-generation DES have lowest thrombosis rates.
13Primary PCI is the treatment of choice for thrombosis.
14ARC classifies stent thrombosis as definite, probable, or possible.
15Prasugrel provides faster, stronger platelet inhibition.
16Underdeployment increases acute thrombosis risk.
17Very late thrombosis may result from hypersensitivity to polymers.
18Bioabsorbable scaffolds can raise early thrombosis risk.
19VerifyNow P2Y12 assay detects high platelet reactivity on clopidogrel.
20Ensuring full stent expansion is key to preventing thrombosis.

📝 Short-Answer Questions (5 Points Each)

  1. What is the most common cause of early stent thrombosis?
    – Premature discontinuation
    – Of dual antiplatelet therapy (DAPT)
    – Especially within the first 30 days
    – Clopidogrel is often involved
    – Emphasizes importance of compliance

  2. How is “very late” stent thrombosis defined?
    – Occurs more than 1 year
    – After stent implantation
    – Typically due to delayed healing
    – Hypersensitivity to polymers
    – Or neoatherosclerosis

  3. List 5 risk factors for stent thrombosis.
    – Diabetes mellitus
    – Renal failure
    – Non-compliance with antiplatelets
    – Small vessel diameter
    – Bifurcation lesions

  4. Describe the clinical presentation of stent thrombosis.
    – Acute chest pain
    – Often mimics STEMI
    – Sudden cardiac death possible
    – ECG may show ST elevation
    – Requires emergency PCI

  5. Why are second-generation DES preferred over first-generation?
    – Lower thrombosis rates
    – Improved biocompatibility
    – Thinner struts
    – Better polymer coatings
    – Enhanced endothelialization

  6. What is the recommended duration of DAPT after DES?
    – At least 6–12 months
    – Depending on bleeding risk
    – Shorter duration for low risk
    – Longer for high-risk lesions
    – Re-evaluate periodically

  7. How does intravascular ultrasound (IVUS) help in stent thrombosis?
    – Visualizes stent apposition
    – Detects under-expansion
    – Assesses vessel wall
    – Identifies thrombus
    – Guides further intervention

  8. What are the ARC classifications of stent thrombosis?
    – Definite
    – Probable
    – Possible
    – Based on timing and evidence
    – Used in clinical trials

  9. Name 5 procedural causes of stent thrombosis.
    – Underexpansion
    – Malapposition
    – Edge dissection
    – Incomplete lesion coverage
    – Inadequate post-dilation

  10. How does platelet function testing help in thrombosis prevention?
    – Detects resistance to drugs
    – Like clopidogrel
    – VerifyNow is commonly used
    – High reactivity predicts risk
    – Helps guide therapy change

📚 ARC Classification of Stent Thrombosis

  • 1. Acute: Within 24 hours of stent implantation
  • 2. Subacute: >24 hours to 30 days
  • 3. Late: >30 days to 1 year
  • 4. Very Late: >1 year after implantation

By Certainty:

  • Definite: Confirmed by angiography or autopsy
  • Probable: Sudden death or MI in target vessel territory
  • Possible: Any unexplained death within 30 days of PCI

🧬 Pathogenesis of Stent Thrombosis

  • 1. Mechanical Factors:
    • Stent underexpansion
    • Malapposition to vessel wall
    • Edge dissection or incomplete coverage
  • 2. Biological Factors:
    • Endothelial injury from stent struts
    • Delayed healing or neoatherosclerosis
    • Hypersensitivity reaction (especially to polymers)
  • 3. Pharmacologic Causes:
    • Noncompliance with dual antiplatelet therapy
    • Clopidogrel resistance or high platelet reactivity
  • 4. Patient-Related Risk Factors:
    • Diabetes mellitus
    • Chronic kidney disease
    • Acute coronary syndrome presentation

stent thrombosis, restenosis, coronary stent complications, ARC classification, stent thrombosis vs restenosis, neointimal hyperplasia, PCI complications, DAPT failure, interventional cardiology, drug-eluting stents"

Feature Stent Thrombosis Restenosis
Definition Formation of thrombus (clot) inside the stent Re-narrowing of the stented vessel due to neointimal hyperplasia
Time of Onset Early (within days) to late (>1 year) Typically after weeks to months
Clinical Presentation Acute coronary syndrome, sudden death Gradual angina recurrence
Mechanism Platelet aggregation, clot formation Smooth muscle proliferation, extracellular matrix buildup
Trigger Mechanical issues, DAPT noncompliance Natural healing response, vessel injury
Diagnostic Method Angiography shows thrombus Angiography shows gradual narrowing
Treatment Urgent PCI, thrombolysis, antiplatelet therapy Repeat PCI, drug-eluting balloon, re-stenting
Prognosis High mortality if untreated Better prognosis, more gradual course


Stent Thrombosis

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