Stent Thrombosis Causes by Timing — EECC MCQ

Correct answer: E — Procedural factors — inadequate stent expansion, stent malapposition, residual dissection, geographic miss, or underexpansion are the dominant causes of acute/subacute stent thrombosis; antiplatelet non-compliance becomes the leading cause of late and very late stent thrombosis

Stent thrombosis is classified by timing: acute (<24h), subacute (1-30 days), late (1-12 months), very late (>12 months). Causes by timing: ACUTE/SUBACUTE: predominantly procedural — inadequate stent expansion (strongest predictor), malapposition, edge dissection, residual stenosis, underexpansion, slow flow. LATE: antiplatelet non-compliance (the leading cause — even 1 missed dose of P2Y12 inhibitor significantly increases risk), neoatherosclerosis, late malapposition. VERY LATE: neoatherosclerosis (new atherosclerotic plaque forming within the stent — the biological process underlying DES late failure). The 2024 ESC CCS Guidelines recommend: (1) intravascular imaging (IVUS/OCT) during PCI to optimise stent deployment (Class I for complex PCI); (2) ensuring adequate DAPT duration and compliance; (3) post-dilation with non-compliant balloon at high pressure to achieve optimal expansion.

Reference: ESC (2024): CCS Guidelines