Improved survival associated with pre-hospital triage strategy in a large regional ST-segment elevation myocardial infarction program

Abstract

Objectives: This study sought to compare the 1-year survival of patients diagnosed with ST-segment elevation myocardial infarction (STEMI) and transferred via pre-hospital triage strategy for primary percutaneous coronary intervention (PCI) with those transferred via inter-hospital transfer within a large suburban region in Canada.

Background: Primary angioplasty is the preferred therapy for STEMI if it is done within 90 min of door-to-balloon time by an experienced team in a high-volume center.

Methods: Patients identified to have STEMI on the ambulances equipped with electrocardiography bypassed the local hospitals and were sent directly to the PCI center, whereas other patients that were picked up by ambulances without electrocardiographic equipment were transported to the local hospitals where the diagnosis of STEMI was made and were re-routed to the PCI center. Patient demographic data, clinical presentation, procedural data, in-hospital course, and vital statistics were prospectively recorded in a provincial cardiac registry.

Results: A total of 167 patients were brought into the PCI center via pre-hospital triage strategy, and 427 patients were brought in via inter-hospital transfer during a 2-year study period. Baseline demographic data, infarct location, cardiovascular history, and hemodynamic status were similar between the 2 groups. When compared with the inter-hospital transfer group, a significantly higher proportion of pre-hospital triaged patients achieved the 90-min door-to-balloon time benchmark (80.4% vs. 8.7%, p < 0.001) and post-procedural Thrombolysis In Myocardial Infarction flow grade 3 after the emergency procedure (97.6% vs. 91.4%, p = 0.02). In addition, the pre-hospital triage strategy was associated with a significantly lower 30-day (5.4% vs. 13.3%, p = 0.006) and 1-year (6.6% vs. 17.5%, p = 0.019) mortality. Pre-hospital triage was an independent predictor for survival at 1 year (hazard ratio: 0.37, 95% confidence interval: 0.18 to 0.75, p = 0.006).

Conclusions: Pre-hospital triage strategy was associated with improved survival rate in patients undergoing primary PCI in a regional STEMI program.