Field triage to primary angioplasty combined with emergency department bypass reduces treatment delays and is associated with improved outcome.

Aims: We investigated the net benefit in the outcome of reducing treatment delay through field triage and emergency department (ED) bypass in patients with ST-elevation myocardial infarction (STEMI) treated with primary angioplasty.
Methods and Results: In a prospective registry study, consecutive patients with suspected STEMI were assigned to: (i) pre-hospital ECG and triage or (ii) ECG and triage at the closest ED, solely based on ambulance availability. Four district hospitals and one regional heart centre serviced the 890,000 population metropolitan area and primary angioplasty was the only reperfusion strategy employed. Baseline characteristics were similar in STEMI patients triaged in the field (108) and the EDs (193). Symptom onset to balloon times: 154 [inter-quartile range (IQR) 120-233) vs. 249 (IQR 184-405) min (P<0.001) and peak creatine kinase in early presenters (<2 h): 1435 (95 %CI: 904-1966) U/L vs. 2320 (95% CI: 1881-2762) U/L (P=0.009) were lower in field- than in ED-triaged patients. Mortality in the PCI treated were 1.1 and 8.2% [P=0.025, RR 0.14 (95% CI: 0.01-1.08)] and overall mortality were 1.9 and 7.3% [P=0.046, RR 0.26 (95% CI: 0.05-1.11)].
Conclusion: Field-triage and ED bypass were feasible means of reducing treatment delay in patients with suspected STEMI and resulted in smaller infarct size in early presenters and a trend towards a reduction in mortality.