Study population

Patients aged ≥ 75 years successively admitted with a main diagnosis of STEMI were retrospectively included in the study. This population was identified between January 2004 and December 2008 via the computer databases of the four main EDs in the city of Lyon.

After identifying patients with a discharge diagnosis of acute coronary syndromes (ACS) during the period of the study, analysis of all files allowed patients with suspected STEMI to be selected. These patients’ medical records reported a systematic ST-segment elevation in an arterial territory, which the emergency physician suspected was an acute or subacute myocardial infarction. Patients with a pacemaker or left bundle branch block were considered as suspected STEMI only if the emergency physician considered it equivalent to STEMI. This suspicion of STEMI was confirmed in each case by an elevation of troponin. Only patients with confirmed STEMI were included, after exclusion of differential diagnoses made in cardiology and patients with missing data.

Data collection

Data collection was carried out using computerized patient records from the four EDs. The recorded reasons for admission were those mentioned by the triage nurses. Atypical presentations were those of patients not admitted to the ED for chest pain. If several reasons for admission were noted, including chest pain, only chest pain was considered. If several reasons were noted, but not including chest pain, only the main complaint for admission was considered.

Demographic data (age, gender, residence [home or nursing home]), clinical data related to STEMI (prehospital time delay, arterial territory, Killip score), medical history and chronic treatment information were collected from the ED records. The comorbidity scale of the Short Emergency Geriatric Assessment (SEGA) tool was used to classify patients into three groups: (1) no pathology; (2) 1–3 diseases and (3) ≥ 3 diseases and/or history of stroke and/or chronic obstructive pulmonary disease and/or cardiac failure (i.e. polypathology). Diabetes was recorded if mentioned in the medical history and/or in cases of previous treatment with oral antidiabetic drugs or insulin.

Regarding patient management in the EDs, the waiting time was estimated based on the time to registration at the reception desk and the time to first medical contact (with a hospital intern or physician). Time taken for diagnosis and decision-making corresponded to the period of time between the first medical observation and that of the note in which the therapeutic strategy chosen was described for the first time. Patients whose impaired communication skills were explicitly mentioned during the collection of medical history (considered difficult or impossible) were identified.

Data regarding management in the cardiology departments were collected from the computerized files or paper records in case of missing data. Reperfusion therapy was defined as thrombolysis or therapeutic coronary angiography.

One-month mortality was determined for all patients via telephone calls by the physician or cardiologist, after exclusion of patients with a differential diagnosis following their cardiology check-up.

Statistical analysis

Quantitative variables are expressed as mean ± standard deviation (SD) and qualitative variables as counts and percentages. A χ ² test was used to compare qualitative variables between the chest pain and atypical presentation groups, with an α risk of 0.05. Quantitative variables were compared using Student’s t -test. To identify predictive factors for death at 1 month, multivariable logistic regression was performed, which included all variables significantly associated with 1-month mortality in the univariate analysis. All statistical analyses were performed with XLSTAT 2011 (Addinsoft).