Across 117,142 consecutive emergency department presentations in Scotland's Lothian region between 2014 and 2024, high-sensitivity cardiac troponin testing rose from 61 to 103 tests per 1,000 ED attendances — a 69% increase — while confirmed myocardial infarction incidence fell from 73 to 47 per 1,000 tested patients (adjusted OR 0.62). Crucially, hospital admission rates dropped from 59% to 38%, yet one-year cardiac and cardiovascular mortality for diagnosed MI patients remained statistically unchanged.
This finding carries significant implications for emergency cardiology. The data suggest that rapid rule-out troponin pathways — tools that became standard practice following high-sensitivity assay adoption around 2012–2015 — are achieving exactly what they promised: safely triaging lower-risk patients away from unnecessary admissions without compromising outcomes for those who genuinely need care. The unchanged mortality signal is reassuring, though it cannot confirm causation; the population being tested shifted toward lower cardiovascular risk over time, which itself may partly explain the falling MI rate.
Limitations deserve attention: this is a single Scottish health board region with approximately one million people, limiting global generalizability. The registry is observational, and while regression models adjust for age, sex, deprivation, and comorbidity, residual confounding remains possible. Preventative prescriptions and revascularization rates were unchanged — an unexpected plateau worth investigating.
As a preprint posted to medRxiv and not yet peer-reviewed, these results should be interpreted cautiously. Still, this represents one of the largest real-world troponin-pathway evaluations published, offering confirmatory, population-level evidence for early rule-out strategies.