Rising system delays in STEMI reperfusion: a 10-year analysis of UK MINAP data and contextual literature review

Rapid reperfusion by primary percutaneous coronary intervention (PPCI) is vital for high-risk ST-elevation myocardial infarction (STEMI) cases. The 2023 ESC guidelines recommend system delays of less than 60 minutes from first medical contact to wire-crossing in PCI-capable centres or less than 90 minutes when transfer is required [1]. Similarly, UK standards aim for call-to-balloon (CTB) times of ≤150 minutes and door-to-balloon (DTB) ≤60 minutes. However, emerging UK longitudinal audit data indicate that increasing CTB delays remain despite sustained in-hospital DTB performance, suggesting system bottleneck.

We aimed to quantify temporal trends in UK STEMI performance (2014-2024) to evaluate the associations between system delays and timely reperfusion, supported by a contextual literature review of organisational contributors.

A longitudinal analysis of ten annual UK Myocardial Disease National Audit Project (MINAP) audit cycles was performed, encompassing 300,939 STEMI patients. We restricted inclusion to high-risk STEMI patients, as defined by the dataset. Performance metrics included median CTB, DTB times and proportions meeting CTB<150/ <120 minutes and DTB <90 minutes, with a surrogate outcome of the proportion of patients re-perfused within 12 hours. Trends were evaluated using linear regression in R v4.5.1, with associations assessed by Spearman correlation adjusted for calendar year. A supporting literature search identified key determinants and emerging solutions.

Over the study period, median CTB time increased by 22 minutes, while DTB remained stable (41-44 minutes). Reperfusion <12 hours fell from 76.3% to 68.6%. Each 10-minute CTB increase corresponded to a 0.38-percentage-point lower perfusion probability <12 h (β per min = -0.038, 95% CI -0.432 to 0.356, p = 0.827; model R² = 0.86), adjusted for calendar year. Spearman correlation between CTB and reperfusion <12 h was ρ = -0.93. Target attainment declined over time (CTB <150 min: 69.7% - 54.7%; CTB <120 min: 50% - 34%), whereas DTB <90 min was comparatively unchanged (76.7% - 71%).

Over the past decade, national audit data demonstrate that while improvements have been sustained within hospital catheter lab processes, delays in pre-hospital care have emerged as the primary barrier to timely reperfusion for STEMI patients in the UK. Considering that every 30-minute delay increases patient mortality by up to 7% [2], prompt change is warranted to optimise the upstream heart-team infrastructure. Addressing these gaps requires innovative solutions, including integrated real-time digital tracking from emergency call to reperfusion, unified regional and national governance and continuous open access data feedback. By leveraging open access data and international best practices [3], health systems can identify persistent issues and scale evidence-based interventions to save lives and optimise resource use.

Relative Changes in Performance Metrics