Clinical Outcomes in Pre-Hospital Activation and Direct Cardiac Catheterisation Laboratory Transfer of STEMI for Primary PCI

Abstract

Pre-hospital activation and direct cardiac catheterisation laboratory (CCL) transfer of ST segment elevation myocardial infarction (STEMI) has previously been shown to improve door-to-balloon (DTB) times yet there is limited outcome data in the Australian context. We aimed to assess the impact of pre-hospital activation on STEMI performance measures and mortality. Prospective cohort study of consecutive ambulance transported STEMI patients treated with primary percutaneous coronary intervention (PCI) patients over a 10-year period (1 January 2008-31 December 2017) at The Prince Charles Hospital, a large quaternary referral centre in Brisbane, Queensland Australia. Comparisons were performed between patients who underwent pre-hospital CCL activation and patients who did not. STEMI performance measures, 30-day and 1-year mortality were examined. Amongst 1,009 patients included (mean age: 62.8 yrs±12.6), pre-hospital activation increased over time (26.6% in 2008 to 75.0% in 2017, p<0.001). Median DTB time (35 mins vs 76 mins p<0.001) and percentage meeting targets (DTB<60 mins 92% vs 27%, p<0.001) improved significantly with pre-hospital activation. Pre-hospital activation was associated with significantly lower 30-day (1.0% vs 3.5%, p=0.007) and 1-year (1.2% vs 7.7%, p<0.001) mortality. After adjusting for confounders and mediators, we observed a strong total effect of pre-hospital activation on 1-year mortality (OR 5.3, 95%CI 2.2-12.4, p<0.001) compared to patients who did not have pre-hospital activation. False positive rates were 3.7% with pre-hospital activation. In patients who underwent primary PCI for STEMI, pre-hospital activation and direct CCL transfer is associated with low false positive rates, significantly reduced time to reperfusion and lower 30-day and 1-year mortality.