Stent thrombosis is a rare but serious complication of percutaneous coronary intervention (PCI) with mortality rates between 25-40%. It is classified based on timing (acute, subacute, late, very late) and etiology (primary, secondary). Risk factors include premature discontinuation of dual antiplatelet therapy, smoking, diabetes, chronic kidney disease, acute coronary syndrome, and high platelet reactivity. Strategies to minimize stent thrombosis involve careful patient selection, optimal stent deployment, adherence to potent dual antiplatelet regimens, and treatment involving emergent thrombectomy with escalated antiplatelet therapy.

1. STENT
THROMBOSIS
DR. SAYEEDUR RAHMAN KHAN RUMI
dr.rumibd@gmail.com
MD (CARDIOLOGY) FINAL PART STUDENT
NHFH&RI

2. Introduction
•Stent thrombosis is a rare but devastating complication
of PCI.
•Incidence: 0.5% to 1%
•Mortality rates are reported from 25% to 40%
•20% of patients with a first stent thrombosis
experience a recurrent stent thrombosis episode within
2 years.

3. Classification
On the basis of duration Stent thrombosis is defined as:
Acute (<24 hours)
Subacute (within 30 days)
Late (between 1 month and 1 year)
Very late (>1 year)
•Both bare metal stent and drug-eluting stent
thrombosis occurs most commonly in the acute or
subacute time frame.
•Drug-eluting stents, however, also have a higher risk of
thrombosis in the late and very late period, due to
incomplete endothelialization.

4. •Stent thrombosis is also classified as:
Primary: if it is directly related to an implanted
stent, or
Secondary: if it occurs at the stent site after an
intervening TLR event.
•In an attempt to standardize the definition of stent
thrombosis, the Academic Research Consortium
divided the criteria for stent thrombosis into
Definite
Probable
Possible

5. Academic Research Consortium Criteria for Stent
Thrombosis
Definition Criteria
Definite stent thrombosis An acute coronary syndrome with
angiographic or autopsy evidence
of thrombus or occlusion with in
or adjacent to a stent.
Probable stent thrombosis Unexplained death with in 30 days
after stent implantation or acute
myocardial infarction involving the
target-vessel territory without
angiographic confirmation.
Possible stent thrombosis Unexplained death occurring more
than 30 days after the index
procedure

6. Factors Influencing
the Risk of
Stent Thrombosis

7. Patient-related factors
•Premature discontinuation or cessation of dual
antiplatelet therapy
•Smoking
•Diabetes
•Chronic kidney disease
•Acute coronary syndrome presentation
•Thrombocytosis
•High post treatment platelet reactivity
•CYp2C19 polymorphism

8. Lesion-based factors
•Diffuse coronary artery disease with long-stented
segments
•Small vessel disease
•Bifurcation disease
•Thrombus-containing lesions
•Significant inflow or outflow lesions proximal or
distal to the stented segment

9. Stent-related factors
•Poor stent expansion
•Edge dissections limiting inflow or outflow
•Delayed or absent endothelialization of stent struts
•Thicker stent struts
•Hypersensitivity/inflammatory and/or thrombotic
reactions to specific DES polymers
•Strut fractures
•Late malapposition/aneurysm formation
•Development of neoatherosclerosis with in stents with
new plaque rupture

10. Risk factors for stent thrombosis

12. Strategies to Minimize
the Occurrence of
Stent Thrombosis
Circulation. 2011;124:1283-1287
Originally published September 12, 2011

13. Patient selection:
•Screening for likely adherence to prescribed medical
regimens (including ability to afford dual antiplatelet
therapy)
•Careful screening for bleeding risk (or ability to tolerate
dual antiplatelet therapy)
•Confirmation of no upcoming surgical procedures in the
recent future (6 wk for BMS, 6–12 mo for DES)

14. Stent selection and deployment:
•Consider use of stents with proven lower stent
thrombosis
•Appropriate vessel sizing
•High-pressure stent deployment and post-dilation
•Ensuring absence of edge dissections
•Ensuring adequate inflow and outflow
•Avoiding the use of 2 stents in bifurcation lesions (if
possible)

15. Peri- and post-procedure care:
•Use of more potent oral antiplatelet regimens (eg,
prasugrel, ticagrelor) in appropriately indicated
clinical scenarios such as acute coronary syndromes
in patients with acceptable bleeding risk
•Patient education and clinical follow-up emphasizing
the importance of adherence to prescribed dual
antiplatelet therapy
•Continuation of dual antiplatelet therapy without
interruption whenever possible if a dental,
endoscopic, or surgical procedure is necessary (which
is feasible for most surgeries other than
neurovascular)

16. Treatment of Stent Thrombosis
• Stent thrombosis may be treated with emergent
thrombectomy (either aspiration or mechanical) or with
balloon angioplasty alone, often in conjunction with
administration of more potent antiplatelet regimens
including glycoprotein IIb/IIIa inhibitors.
• The placement of additional stents should usually be
avoided unless a mechanical reason for the initial
thrombotic event is ascertained (e.g. edge dissection or
residual untreated disease) .
• The use of adjunctive imaging such as IVUS or OCT will often
reveal a possible cause of stent thrombosis, such as stent
under expansion or malapposition, residual dissection, or
significant inflow or outflow stenosis, and is thus
recommended following thrombectomy.

17. Treatment (Cont’d)
•In the absence of a mechanical cause, hematologic
evaluation should be performed to exclude a
hypercoagulable state (including resistance to
aspirin or clopidogrel) or thrombocytosis.
•Maintenance antiplatelet therapy is typically
escalated in cases of stent thrombosis (e.g.
clopidogrel is switched to prasugrel or ticagrelor)

18. Thank You