Helicopter transport effectiveness of patients for primary percutaneous coronary intervention.

BACKGROUND: For patients with ST-elevated myocardial infarction (STEMI), time to primary percutaneous coronary intervention (PCI) is an important factor in saving myocardium. Helicopter emergency medical service (HEMS) has become a vital component in regionalized cardiac care. The objective of this study is to assess the logistics of HEMS and ground EMS for interfacility transport of STEMI patients for primary PCI and to determine the effectiveness of HEMS transports in terms of the number of lives saved per 100 flights.

METHODS: This is a retrospective database and records review of interfacility transports of STEMI patients for primary PCI to a single medical center. The study period consisted of 18 months (January 2010 through June 2011).

RESULTS: Ninety-seven of 120 patients met the criteria for review. Of these, 66% were transported by HEMS. The pretransport patient handling times were similar for the HEMS and ground EMS groups. Door-to-PCI in < 120 minutes was achieved in 35.5% (11 of 31) of ground EMS and 24.2% (16 of 66) of HEMS. Patients transported by ground EMS were more likely to get to PCI in < 90 minutes (9.7%, 3 of 31). HEMS patients traveled significantly farther distances, 51 miles (IQR 43-68) than ground EMS, 37 miles (IQR 18-51). This equates to a 38% longer distance for patients transported by HEMS. An estimate of the driving time for HEMS-transported patients suggests HEMS transports saved a median of 41 minutes (IQR 33-48). The proportion of HEMS flights saving more than 30 minutes was 78.8% (95% CI 67.0-87.9%).

CONCLUSION: The results did not show a time savings for HEMS- versus ground EMS-transported patients. When estimates of time spent for ground EMS of actual HEMS transported patients are analyzed, HEMS provides a median savings of 41 minutes, with a savings of at least 30 minutes in 78.8% of the HEMS patients. Based on estimates used in this study, conservative calculations arrived at a time-based mortality effectiveness of HEMS of about 1.2 lives saved per 100 flights.