C oronary stenting is one of the most widely performed cardiac procedures in the world, restoring arterial blood flow rapidly and effectively. Yet a clinically significant proportion of patients who undergo stent placement return — months or years later with recurring symptoms. The question is not marginal: a 2023 meta-analysis in Reviews in Cardiovascular Medicine identified a pooled in-stent restenosis (ISR) rate of approximately 13% for drug-eluting stents, with higher rates in complex anatomical or high-risk metabolic presentations. Understanding why heart blockage after stent placement recurs is essential for any patient managing long-term coronary artery disease. What a Stent Treats — and What It Does Not A stent addresses a localised anatomical obstruction: it mechanically expands a narrowed coronary lumen and, in the case of drug-eluting devices, locally suppresses the cellular proliferation that drives early re-narrowing. This is its precise and limited mandate. ...