Pre-hospital delay in patients with first time myocardial infarction: an observational study in a northern Swedish population

Gunnar Nilsson, Thomas Mooe, Lars Söderström, Eva Samuelsson

In myocardial infarction (MI), pre-hospital delay is associated with increased mortality and decreased possibility of revascularisation. We assessed pre-hospital delay in patients with first time MI in a northern Swedish population and identified determinants of a pre-hospital delay ≥ 2 h. A total of 89 women (mean age 72.6 years) and 176 men (mean age 65.8 years) from a secondary prevention study were enrolled in an observational study after first time MI between November 2009 and March 2012. Total pre-hospital delay was defined as the time from the onset of symptoms suggestive of MI to admission to the hospital. Decision time was defined as the time from the onset of symptoms until the call to Emergency Medical Services (EMS). The time of symptom onset was assessed during the episode of care, and the time of call to EMS and admission to the hospital was based on recorded data. The first medical contact was determined from a mailed questionnaire. Determinants associated with pre-hospital delay ≥ 2 h were identified by multivariable logistic regression. The median total pre-hospital delay was 5.1 h (IQR 18.1), decision time 3.1 h (IQR 10.4), and transport time 1.2 h (IQR 1.0). The first medical contact was to primary care in 52.3 % of cases (22.3 % as a visit to a general practitioner and 30 % by telephone counselling), 37.3 % called the EMS, and 10.4 % self-referred to the hospital. Determinants of a pre-hospital delay ≥ 2 h were a visit to a general practitioner (OR 10.77, 95 % CI 2.39-48.59), call to primary care telephone counselling (OR 3.82, 95 % CI 1.68-8.68), chest pain as the predominant presenting symptom (OR 0.24, 95 % CI 0.08-0.77), and distance from the hospital (OR 1.03, 95 % CI 1.02-1.04). Among patients with primary care as the first medical contact, 67.0 % had a decision time ≥ 2 h, compared to 44.7 % of patients who called EMS or self-referred (p = 0.002). Pre-hospital delay in patients with first time MI is prolonged considerably, particularly when primary care is the first medical contact. Actions to shorten decision time and increase the use of EMS are still necessary.