Trends in the Assessment, Treatment and Outcomes of Patients with Suspected Acute Coronary Syndrome

Background: Suspected acute coronary syndrome is a frequent Emergency Department (ED) presentation, requiring safe and efficient assessment. We interrogated long-term trends in whole population care for these patients using a new multi-centre regional registry. Methods: The DataLoch Heart Disease Registry links relevant data from primary and secondary healthcare records, with national administrative data for patients registered within the Lothian Health Board region of Scotland (~1M population). We included all adult patients presenting to secondary- or tertiary-care EDs in the region between 2014 and 2024, in whom high-sensitivity cardiac troponin was measured within 24 hours of presentation. Annual diagnostic rates for myocardial infarction, pharmacological and interventional management, and outcomes up to 1 year after ED presentation were studied. Logistic regression models were used to report change in annual trends for myocardial infarction, cardiac death, cardiovascular death and all-cause mortality, adjusted for age, sex, ethnicity, socioeconomic deprivation and comorbidity. Results: Over 10 years, 117,142 consecutive patients (mean age 58 +/- 18 years, 48% female, 6.6% with confirmed myocardial infarction) were included. Cardiac troponin testing increased year on year, from 61 per 1000 ED attendances in 2014 to 103 per 1000 in 2024 (P<0.001), but the proportion of patients admitted to hospital fell (59% in 2014 to 38% in 2024, P<0.001). Associated with these trends, the tested population had fewer cardiovascular risk factors and myocardial infarction incidence fell from 73 per 1000 tested patients in 2014 to 47 per 1000 in 2024 (adjusted odds ratio 0.62, 95% confidence intervals 0.56 to 0.69, P<0.001). In patients diagnosed with myocardial infarction, prescriptions of preventative therapies and numbers of revascularisation procedures were unchanged. After adjustment, no change over time was observed in one-year cardiac or cardiovascular mortality in those with a diagnosis of myocardial infarction. Conclusions: ED testing using cardiac troponin has extended to a broader population at lower risk of myocardial infarction. Despite this trend, early rule-out pathways have reduced hospital admissions, without observable changes in outcomes for those with myocardial infarction.