Three doors, three locks: a domain-specific framework for the residual door-to-balloon gap in STEMI care : Matters Arising, commentary on Krishnan et al., Int J Emerg Med 2026;19:113.

Krishnan and colleagues report that 91% of STEMI patients at a large Indian tertiary centre received primary PCI within the 90-minute door-to-balloon (D2B) target, a meaningful achievement in contemporary STEMI care. Their analysis of the 9% who missed the target is equally valuable: delays distributed almost evenly across three categories, delayed informed consent, hemodynamic instability, and diagnostic ambiguity. We argue these categories are not interchangeable quality-improvement targets. They are mechanistically distinct problems requiring different solutions. We propose a conceptual, hypothesis-generating framework rather than a validated taxonomy. Future STEMI quality improvement efforts should categorize residual delays by domain rather than reporting them in aggregate, and should match interventions to the specific mechanism of delay.