Switching from helicopter to ground transport between two Texas hospitals cut the time heart attack patients had to wait to have their arteries unblocked by more than half an hour, according to a new study.

“What we showed in our study was by tweaking our system, in this case by changing our mode of transportation from air to ground, we actually took median treatment time from about 121 minutes beforehand to 90 minutes afterward,” Dr. Timothy Mixon told Reuters Health in a phone call.

“That’s about a 30 minute decrease in total treatment time by going by ground,” he said. “Although that seems slower, it really was quicker.”

Mixon is an interventional cardiologist with Scott and White Healthcare in Temple, Texas. He and coauthor Dr. Luis Colato wrote the paper that was published in the Journal of Emergency Medicine.

The change to ground transport resulted in more than 90 percent of patients being treated within national guideline time of less than 120 minutes, the authors say, versus less than half getting treatment within that two-hour window before.

An ST segment elevation myocardial infarction - or STEMI - is usually caused by a total blockage of blood flow to a large portion of the heart, so patients having this kind of heart attack need to get the blockage cleared as soon as possible.

That procedure, known as angioplasty, isn’t done at all hospitals.

“Across the country about 60 percent of patients with this type of heart attack present to hospitals that have the capability of doing angioplasty on a 24/7 basis, but only 25 percent of the hospitals have that capability” Mixon said.

When patients show up at a hospital that doesn’t offer emergency angioplasty, they need to be transferred to one that does.

The study looked at 43 patients who were initially diagnosed with STEMI at Darnall Army Community Hospital in Fort Hood, but who needed to be transferred for angioplasty at Scott and White Memorial Hospital in Temple, about 30 miles away.

The authors compared treatment outcomes and transfer times for 19 STEMI patients who were flown between the two hospitals between 2007 and 2010 with 23 patients who were transported by ground ambulance between 2010 and 2012. One more person was transported by air during the second period.

None of the patients died during the study. But on average, those who were flown between the hospitals had 123 minutes from the time of first medical contact until angioplasty was performed. The patients who were transported by ground ambulance averaged 90 minutes between first medical contact to angioplasty.

This study looked at only one pair of hospitals in Texas, but the need to transfer a patient with a STEMI to a different facility occurs nationwide, Mixon and his coauthor point out.

“Every hospital system is a little different. And 10 miles apart might be prohibitive if you’re in downtown Manhattan - while ten miles apart in a more rural area is not a problem at all,” Mixon said.

“Whether you go by ground or whether you go by air, a lot of people would naturally assume that air transport would be quicker, but basically our findings were that while yes, helicopters can fly faster than a truck can drive, it takes a lot longer to get a patient prepared and the helicopter prepared, and that time essentially offsets the speed of transport and ends up being slower,” Mixon said.

Dr. Harlan Krumholz cautioned that a small, single-center study like this may not be relevant to other places.

Krumholz is director of the Yale-New Haven Hospital Center for Outcomes Research and Evaluation. He was not involved in the study.

“The best thing people can do who think they are having a heart attack is call 911 - too many people still die before getting emergency care and it is best for people not to spend time worrying about which hospital,” he told Reuters Health in an email.

“Ideally the EMS professionals can make an assessment and determine if people need to go straight to a hospital with advanced facilities – and whether, if it is not the closest one, whether it is worth the extra time,” he said.

Mixon agreed that people who may be having a heart attack need emergency help. He added that they should not try to transport themselves to a hospital.

“We don’t want people driving in cars with heart attacks because some of them die - some of them have ventricular fibrillation and don’t survive,” he said.

“On the other hand if that happens when you’re in the back of an ambulance they are equipped to manage that situation, so it’s safe for EMS to take you an extra 10 or 15 minutes, but not necessarily safe for people to go by a private vehicle an extra 10 or 15 minutes,” Mixon said.

SOURCE: The Journal of Emergency Medicine, online April 18, 2014

###

Impact of Mode of Transportation on Time to Treatment in Patients Transferred for Primary Percutaneous Coronary Intervention

Patients suffering ST segment elevation myocardial infarction (STEMI) requiring transfer from a non−percutaneous coronary intervention (PCI) hospital to a PCI-capable hospital often have prolonged treatment times.
Objective

For STEMI transfers, we changed from air to ground transportation, and carefully documented the impact on treatment times.
Methods

This is a retrospective report between two hospitals within one STEMI system. The referring facility controls both air and ground ambulance services. After a 2-year period of air transportation with suboptimal treatment times, the referring hospital switched to ground transport. All pertinent times were carefully recorded and are reported here.
Results

There were 43 patients included, approximately half were transported by air and half by ground. Comparing our early experience (air only) vs. our later experience (predominantly ground-transported patients), median door-in-door-out (DIDO) time at the first facility was 70 min vs. 35 min (p < 0.001), median transport time was 20 min vs. 30 min (p < 0.001), and median first medical contact to balloon time (FMC2b time) was 123 min vs. 90 min (p < 0.001). After changing mode of transport, achievement of the national FMC2b time goal of < 120 min rose from 47% to 92% (p < 0.001).
Conclusions

We document a significantly reduced DIDO and FMC2b time after changing mode of transportation for STEMI patients transferred 30 miles for primary PCI. Utilizing ground rather than air transportation, the median FMC2b time was reduced from 123 to 90 min. We show that mode of transportation can dramatically reduce both DIDO time and FMC2b time.

  Timothy A. Mixon, MD, FACC, FSCAI,
  Luis Colato, MD

Received 1 April 2013; received in revised form 23 December 2013; accepted 9 February 2014. published online 18 April 2014