Better EMS and cath lab collaborations reduce door-to-balloon (D2B) times and lead to better patient care, particularly in STEMI patients, said Ivan C. Rokos, MD, of University of California, Los Angeles, during a presentation at the 59th annual American College of Cardiology scientific session last week.
Rokos said that utilizing a team-based approach and initiating pre-hospital cardiac triage by performing 12-lead EKGs that activate the cath lab are “essential” to producing systems of care that work. “You’ve got to have good transitions,” said Rokos, “otherwise your team is going to fail.”
He noted several steps that must occur for pre-hospital triage and cath lab collaborations to work:
- Diagnoses: Paramedics must be able to diagnose STEMI cases using a pre-hospital EKG;
- Diversion Protocols: The EMS must establish a diversion protocol to avoid simply driving to the nearest hospital down the street. Instead patients should be transported to the nearest primary PCI-capable hospital;
- Accessibility: The cath lab must be accessible 24/7/365. “This is a big issue,” said Rokos, due to overcrowding, some patients are turned away. However, most ERs, even on diversion, will accept trauma and STEMI patients;
- Parallel Processing: Should be able to diagnose a STEMI in someone’s living room and activate the cath lab immediately from that location, which allows patients to be driven into the hospital at the same time the cath lab team is establishing in the lab;
- Back-up Plan: Always have a plan B: “PCI is what we all want,” he said, but plan B for STEMIs should be fibrinolytics;
- Regional Quality Improvement Database to Track Data: “Friends don’t let friends regionalize without some sort of STEMI quality-based initiative database,” said Rokos. “You have to know what you’re doing, track it and continue to work on improving these.”
Additionally, Rokos said that decreasing D2B times can significantly impact patient care and decrease mortality for STEMI patients. He referenced data from 2009 from an analysis of ten STEMI networks in Oregon, California, Minnesota, Michigan, North Carolina and Georgia, which saw a total of 2,712 patients. After integration of pre-hospital EKG, 86 percent had D2B times under the national guidelines of 90 minutes or less, said Rokos.
In fact, 50 percent had D2B times less than 60 minutes and 25 percent less than 45 minutes. Additionally, D2B times of less than 60 minutes decreased mortality by 0.8 percent.
“These door-to-balloon protocols really have the capacity to move patients through the system very, very quickly,” said Rokos.
One important component to making the pre-hospital process even more efficient is deploying a component that looks at EMS to balloon times. Previous trials have shown that 68 percent of EMS2B times were less than 90 minutes.
Taking this one step further, said Rokos, would be measuring “what matters most to the patient" -- 9-1-1 calls-to-balloon times. “The integration of pre-hospital with organized STEMI networks consistently provides very fast reperfusion rates,” he said.
Implementing the 30-30-30 goal, which he said allots 30 minutes of time to EMS, the ED and the cath lab, would further help reach D2B times of 90 minute or less. “This system is the ideal,” he said. “You get your job done and then hand-off to the next STEMI care provider.”
One challenging aspect of pre-hospital care are false positives. Because ECGs are not binary, conditions such as left bundle branch block or true posterior MI make it challenging to diagnose STEMI patients and read ECGs.
Data from LA County in 2008 showed that 646 patients with a pre-hospital ECG were STEMI. While 75 percent of these patients had cath lab activation, 20.4 percent had cath lab activations that were later cancelled.
According to Rokos, false positives are “a tremendous waste of precious resources.” He estimated each cath lab activation that is later cancelled costs hospitals about $5,000.
Rokos said that the next phase comes with attempting to improve the “embarrassing” rates of inter-hospital transfer D2B times. Currently, only 18 percent of these cases report D2B times of 90 minutes or less, and even when given a grace period of 40 minutes, still only 50 percent reached D2B times of 120 minutes or less.
In the next two months, that policy will look at whether or not it would be beneficial for the emergency department at a STEMI referral facility to call 9-1-1 for rapid patient inter-hospital transfer.