Stent Thrombosis

Stent thrombosis is defined as a thrombus formation in or next to a coronary stent implanted during percutaneous coronary intervention (PCI), resulting in sudden artery blockage. It is a rare but catastrophic occurrence with high morbidity and mortality. It mainly presents as ST-elevation myocardial infarction (STEMI) or sudden cardiac death.

It is classified by the Academic Research Consortium (ARC) and includes acute (within 24 hours), subacute (24 hours to 30 days), early (?30 days), late (1–12 months), and very late (>12 months) phases. The subacute and extremely late forms predominate in present practice.

Risk factors are multifactorial: patient-associated (diabetes, acute coronary syndrome, poor ejection fraction), lesion-related (bifurcations, lengthy stents), procedural (underexpansion, malapposition) and pharmacologic (premature dual antiplatelet treatment [DAPT] termination). However, incidence with newer drug-eluting stents (DES) has fallen to 0.5-1% in the first year, but extremely late events continue to occur due to neoatherosclerosis or hypersensitivity.
Intravascular imaging, like OCT identifies causes and optimises deployment.

Acute therapy includes immediate PCI, thrombus aspiration, powerful P2Y12 inhibitors and GP IIb/IIIa medications. Prevention is based on image-guided implantation, prolonged DAPT, and risk factor control. But vigilance is still necessary, despite progress.