Reduction in mortality as a result of direct transport from the field to a receiving center for primary percutaneous coronary intervention.

OBJECTIVES: This study sought to determine whether mortality complicating ST-segment elevation myocardial infarction (STEMI) was impacted by the design of transport systems. BACKGROUND: It is recommended that regions develop systems to facilitate rapid transfer of STEMI patients to centers equipped to perform primary percutaneous coronary intervention (PCI), yet the impact on mortality from the design of such systems remains unknown. METHODS: Within the framework of a citywide system where all STEMI patients are referred for primary PCI, we compared patients referred directly from the field to a PCI center to patients transported beforehand from the field to a non-PCI-capable hospital. The primary outcome was all-cause mortality at 180 days. RESULTS: A total of 1,389 consecutive patients with STEMI were assessed by the emergency medical services (EMS) and referred for primary PCI: 822 (59.2%) were referred directly from the field to a PCI center, and 567 (40.8%) were transported to a non-PCI-capable hospital first. Death at 180 days occurred in 5.0% of patients transferred directly from the field, and in 11.5% of patients transported from the field to a non-PCI-capable hospital (p < 0.0001. After adjusting for baseline characteristics in a multivariable logistic regression model, mortality remained lower among patients referred directly from the field to the PCI center (odds ratio: 0.52, 95% confidence interval: 0.31 to 0.88, p = 0.01). Similar results were obtained by using propensity score methods for adjustment. CONCLUSIONS: A STEMI system allowing EMS to transport patients directly to a primary PCI center was associated with a significant reduction in mortality. Our results support the concept of STEMI systems that include pre-hospital referral by EMS.

A citywide protocol for primary PCI in ST-segment elevation myocardial infarction.

BACKGROUND: If primary percutaneous coronary intervention (PCI) is performed promptly, the procedure is superior to fibrinolysis in restoring flow to the infarct-related artery in patients with ST-segment elevation myocardial infarction. The benchmark for a timely PCI intervention has become a door-to-balloon time of less than 90 minutes. Whether regional strategies can be developed to achieve this goal is uncertain. METHODS: We developed an integrated-metropolitan-area approach in which all patients with ST-segment elevation myocardial infarction were referred to a specialized center for primary PCI. We sought to determine whether there was a difference in door-to-balloon times between patients who were referred directly from the field by paramedics trained in the interpretation of electrocardiograms and patients who were referred by emergency department physicians. RESULTS: Between May 1, 2005, and April 30, 2006, a total of 344 consecutive patients with ST-segment elevation myocardial infarction were referred for primary PCI: 135 directly from the field and 209 from emergency departments. Primary PCI was performed in 93.6% of patients. The median door-to-balloon time was shorter in patients referred from the field (69 minutes; interquartile range, 43 to 87) than in patients needing interhospital transfer (123 minutes; interquartile range, 101 to 153; P<0.001). Door-to-balloon times of less than 90 minutes were achieved in 79.7% of patients who were transferred from the field and in 11.9% of those transferred from emergency departments (P<0.001). CONCLUSIONS: Guideline door-to-balloon-times were more often achieved when trained paramedics independently triaged and transported patients directly to a designated primary PCI center than when patients were referred from emergency departments.