Abstract 82: Comparison of Outcomes by Type of Treatment for Patients with ST-Elevation Myocardial Infarction (STEMI) who presented to Hospitals without Percutaneous Coronary Intervention (PCI) Facilities in Quebec, Canada

Abstract

BACKGROUND: Guidelines recommend that STEMI patients who present to non-PCI centers generally be treated with fibrinolysis instead of untimely transfer for primary PCI (i.e., first medical contact [FMC] to device ≥120 min). Little real-world evidence exists for this recommendation since transfer patients are often excluded from clinical registries. A provincial field evaluation of the whole system of STEMI care in Quebec (Canada) provided the opportunity to compare the effectiveness of different treatment modalities, including, importantly, inter-hospital transfer for primary PCI. METHODS: All STEMI patients who presented to non-PCI hospitals during two 6-month periods in 2006-7 and 2008-9 were identified (N=2623) and followed up to one year. Detailed information on patient risk factors and treatment delays was extracted from medical charts. We used a multivariate Cox proportional hazards model with time-dependent treatment modelling to assess the hazard ratio of death for 5 treatment modalities: on-site fibrinolysis without later transfer to a PCI center; on-site fibrinolysis with subsequent transfer; timely transfer for primary PCI; untimely transfer for primary PCI; no reperfusion therapy. RESULTS: Median FMC-to-device delay for transfer primary PCI patients was 131 min (interquartile range, IQR: 107-166) and only 29% had timely treatment. Median door-to-needle delay was 30 min (IQR: 20-48) with 70% being transferred, after fibrinolysis, to a PCI center (81% subsequently received PCI). Median time to transfer after fibrinolysis was 17.8 hours (IQR: 3.3-77.3). Compared with untimely transfer for primary PCI, the adjusted hazard ratio was 0.29 (95% CI: 0.15-0.56) for timely primary PCI transfer, 0.52 (95% CI: 0.29-0.95) for fibrinolysis with subsequent transfer, 1.18 (95% CI: 0.75-1.84) for fibrinolysis alone and 1.74 (95% CI: 1.31-2.31) for no reperfusion therapy. CONCLUSION: Timely treatment delay is associated with improved STEMI survival. These results also provide real-world evidence to support the guideline recommendation to prioritize on-site treatment with fibrinolysis (with consideration of subsequent transfer to a PCI center) over untimely transfer for primary PCI. Transfer to a PCI center after fibrinolysis mostly occurred the following day, suggesting that transfer need not necessarily be immediate.