BALTIMORE—Helicopter transport does not substantially improve treatment times not for patients in more distant hospitals, according to a scientific poster, evaluating the statewide North Carolina RACE project, presented May 4 at the 2011 Society for Cardiovascular Angiography and Interventions (SCAI) scientific sessions.
For patients with ST-elevation MI (STEMI) who are transferred for primary PCI, guidelines call for open vessel within 90 minutes of the first hospital door. Despite this recommendation, fewer than 20 percent of U.S. patients are treated in such a timely fashion, according to the study’s lead author Yele Aluko, MD, medical director of the cardiac cath laboratories at Presbyterian Cardiovascular Institute in Charlotte, N.C.
“This study challenges evolving conventional thinking that primary PCI can be achieved for all patients by enhancing efficient coordination of care through regional heart attack systems,” said Aluko. “Lytic therapy will probably remain an option for patients who cannot be efficiently transported to PCI centers.”
To consider the transfer distance under which timely PCI was feasible, the researchers examined first door to device times by driving distance in the RACE (Reperfusion of Acute MI in North Carolina Emergency Departments) system, a 119-hospital STEMI regional system in North Carolina. Of these, 21 hospitals were staffed and equipped to perform PCI at any time of the day or night for patients who were having a heart attack.
Between July 2008 and December 2009, 6,841 patients were treated in the RACE system, 2,933 of whom underwent hospital transfer for primary PCI (median age 59, 29 percent female, 23 percent diabetes, 9 percent shock on presentation).
However, Aluko and his colleagues found that helicopter transport had little effect on device times, except for a 19 minute advantage for hospitals located beyond 45 minute drive time. They also found that in-hospital mortality increased by distance for PCI patients, but not for the patients who received lytics.
Even when a medical helicopter was used to transport patients, it had little effect on average “first door-to-device times.” The exception, according to the authors, came when transferring patients to the most distant hospitals. In this case, helicopters arrived at the PCI hospital an average of 19 minutes earlier than ambulances.
Though the study was not intended to evaluate clinical outcomes, Aluko noted that the death rate increased with transport distance, from 3.8 percent among patients transferred to a PCI-capable hospital located no more than 30 minutes’ driving time away, to 5.3 percent among those who faced a drive time of 45 minutes or more.
Therefore, the authors concluded that in a well-developed statewide STEMI treatment system, first door to device times within 90 minutes appears most feasible for hospitals within 30 minute drive time.
Funding for this study came from the Kate B. Reynolds Foundation, but Aluko declared no potential conflicts of interest.