Which factors increase the risk of stent thrombosis and how can it be mitigated?

• A. Not using antiplatelet therapy
• B. Adequate stent expansion; prolonged DAPT; low-risk lesion
• C. Inadequate stent expansion, early discontinuation of dual antiplatelet therapy, high-risk lesion; mitigation includes optimal deployment, appropriate DAPT duration, and antithrombotic management.
• D. No risk factors for stent thrombosis

Answer: (C)

The core idea here is understanding what factors raise the risk of a stent clot forming and how to reduce that danger through careful technique and therapy.

Inadequate stent expansion leaves areas where the stent does not properly contact the vessel wall. This creates turbulent flow and exposes struts to blood, promoting platelet activation and thrombus formation. The remedy is meticulous deployment with proper sizing and adequate expansion, often confirmed with intravascular imaging (like IVUS or OCT) to ensure the stent is fully apposed and well expanded.

Discontinuation of dual antiplatelet therapy too early removes the antiplatelet protection while the stent surface is still healing, allowing platelets to aggregate on exposed stent struts. The mitigation involves continuing dual antiplatelet therapy for the recommended duration based on the stent type and patient bleeding risk, then tailoring duration to balance ischemic protection with bleeding risk.

High-risk lesion characteristics—such as calcified or long lesions, bifurcations, small vessels, ostial locations, or lesions with heavy thrombus—also raise thrombosis risk. Address this with thorough lesion preparation (e.g., plaque modification techniques for calcified lesions), ensuring optimal stent deployment, and selecting an appropriate antiplatelet strategy and duration.

Overall, preventing stent thrombosis hinges on optimal deployment, adherence to the recommended antiplatelet therapy duration, and careful antithrombotic management tailored to the patient and lesion.