Background Paramedics convey patients with non-ST elevation acute coronary syndrome (NSTEACS) to emergency departments (EDs). The patient should be risk stratified using a risk stratification model (RSM) in the ED to determine the risk of death or adverse cardiovascular events. This determines if the patient should be transferred to a specialist heart attack centre (HAC) for an invasive procedure. If paramedics were to risk stratify the patients in the prehospital environment using a Modified Thrombolysis in Myocardial Infarction (MTIMI) RSM this could result in primary triage to an appropriate hospital. This could reduce secondary transfers, decrease demand on EDs, provide better patient care, reduce length of hospital stay and could provide cost savings to the National Health Service.

Aim To determine if paramedics' use of a MTIMI RSM is more accurate than current practice at identifying and risk stratifying patients suffering from suspected high risk NSTEACS.

Methods A retrospective medical record review.

Results 108 patient notes were used in this study, 84 from the ED and 24 from the HAC. Current practice produced a c-statistic (c) of 0.73 (95% Confidence Interval (CI) 0.62 to 0.85) and the MTIMI RSM (c=0.72, 0.61 to 0.83). The best RSM overall was the abbreviated MTIMI RSM with only three variables identified through logistic regression [diabetes mellitus, over 65 years and the electrocardiogram (ECG)] (c=0.79, 0.68 to 0.89).

Conclusions The main reason that current practice was similar to the MTIMI RSM was that they both used the ECG variable, which alone was approximately twelve times more prognostic than any other variable. The need to identify a RSM with a good prognostic power that can be used in the prehospital environment still exists. Therefore, other RSMs should be explored in a prospective study.