Air versus ground transport of patients with acute myocardial infarction: Experience in a rural-based helicopter medical service

Aims
Primary pre-hospital Helicopter Emergency Medical Service (HEMS) interventions may play a role in timely reperfusion therapy for patients with ST-segment elevation myocardial infarction (STEMI). We designed a prospective study involving patients with acute myocardial infarction aimed at the evaluation of the potential benefit of such primary HEMS interventions as compared with classical EMS ground transport.
Methods & results
This prospective study was conducted from July 1, 2007 to June 15, 2012. Successive patients with ST-segment elevation myocardial infarction (STEMI) eligible for percutaneous coronary intervention (PCI) were included. Simulated ground-based access times were computed using a digital cartographic program, allowing the estimation of healthcare system delay from call to admission to the catheterisation laboratory.
During the study period, 4485 patients benefited from HEMS activations. Of these patients, 342 (8%) suffering from STEMI were transferred for primary PCI. Median primary response time time was 11 min (IQR: 8 - 14 min) using the helicopter and 32 min (25 – 44 min) using road transport. Median transport time using HEMS was 12 min (9 – 15 min) and 50 min (36 – 56 min) by road. The median system delay using HEMS was 52 min (45 – 60 min), while this time was 110 min (95 – 126 min) by road. Finally, the system delay median gain was 60 min (47 – 72 min).
Conclusions
Using HEMS in a rural region allows STEMI patients to benefit from appropriate rescue care with similar delays as those seen in urban patients.