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Page 2 of 11 Conway et al. Vessel Plus 2020;4:25 I http://dx.doi.org/10.20517/2574-1209.2020.19

INTRODUCTION
Acute medicine encompasses the rapid specialist management of patients suffering from a wide variety
[1]
of medical conditions requiring expedited care . The admitted cohort are a relatively high risk group,
although 30-day in-hospital mortality rates in our institution have improved over time from 6.7% in
2002, to 4.7% in 2012, and 3.7% in 2018; the 7% absolute mortality reduction is comparable with the USA
National Hospital Discharge Survey data showing a decrease of 8% in inpatient hospital deaths over the
[2]
years 2000 to 2010 . Nonetheless there has to be a constant emphasis, if outcomes are to be maintained
and even improved, on risk factor assessment at admission and identifying prognostic factors amenable
[3]
to intervention - the two most important of these are illness severity and comorbidities . As our hospital
covers an inner city catchment area with a predominantly aging population and over 50% of patients have a
[4]
high deprivation index - we also have a focus on the impact of low socioeconomic status (SES).
Among biomarkers that have become available over the past decade, serum troponin T as a cardio-specific
biomarker has achieved widespread use in clinical medicine; with cardiac injury these macromolecules
diffuse into the cardiac interstitium with subsequent detection in the peripheral circulation. Cardiac-
specific troponins have utility because they combine value as a near ideal biologic marker, and also convey
[5]
useful prognostic information that can influence therapeutic decision making . Troponin assays were
[6]
initially developed for their utility in acute coronary syndromes , however, it was quickly recognized that
a range of other medical conditions were also associated with troponin elevation [7-20] . Although troponin
elevation signifies cardiac damage, it may not always imply cardio-specificity with predictive values as
[21]
low as 56% in the diagnosis of acute coronary syndromes . Troponin assays are a relatively common
laboratory diagnostic request in emergency medical admissions.

There has been little published on the utility of troponin in unselected emergency medical admissions.
We have a large database covering all emergency medical patients admitted to our institution (St James’
Hospital, Dublin), between 2002 and 2018 inclusive - but high sensitivity troponin data was limited to
2011-18. The purpose of this study was to examine the predictive role of high sensitivity cardiac troponin
(hscTnT) levels on 30-day in-hospital mortality in acutely ill medical patients admitted via the Emergency
Department (ED).

METHODS
Background
Our institution, St James’s Hospital provides an emergency admission function covering a population of
270,000 adults. This paper covers all patients admitted under the general/internal medicine service from
2011-2018; patients with acute coronary syndromes (ACS) are by design admitted under cardiology and
were not included in this analysis. Medical admissions are by design admitted from the ED to an Acute
Medical Admission Unit (AMAU). We have described the details of the operation and performance of
the AMAU previously [22-26] . As a city centre hospital, St James’s admits visitors to Dublin city and persons
people residing outside of the hospital catchment area, but working in the city, in addition to visitors to the
city. 74.5% of emergency admissions are resident in our catchment area.

Data collection
We have established an anonymous patient database within our institution. This database collates
information for each hospital admission including details from the patient administration system, national
hospital in-patient enquiry (HIPE) scheme, the electronic patient record and laboratory result systems.
HIPE is a national database of coded hospital discharge summaries from all public hospitals within
Ireland [27,28] . The International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)
was used for both diagnosis and procedure coding from 1990 to 2005 with a subsequent transition to