Cath Lab Preactivated Less Than Half the Time in STEMI Cases: ACTION Registry

The catheterization laboratory is preactivated for STEMI cases in just 41% of emergency medical services (EMS)-transported patients, even though this practice is associated with faster reperfusion times and a lower unadjusted risk of mortality, according to the results of a new study.  

Among 27,840 STEMI patients from 744 PCI-capable hospitals included in the ACTION Registry from the National Cardiovascular Data Registry (NCDR), the cath lab was preactivated—defined as a more than 10-minute heads-up to the cath lab team—in just 11,379 patients. Preactivation was associated with a 12-minute shorter door-to-device time and a higher proportion of patients treated within 90 minutes of first medical contact.

“If the cath lab is activated before the patient arrives then the entire team, especially after hours, is coming in as the patient is coming in,” lead investigator Jay Shavadia, MD (Duke Clinical Research Institute, Durham, NC), told TCTMD. “By the time patient arrives, the lab is ready—equipment has been opened up, the table’s been set. The patient just gets on the table and we’re good to go. If the cath lab is activated after the patient arrives, then it’s another 10, 15, or 20 minutes” depending on the city or season.

The faster reperfusion metrics, say investigators, were likely achieved because preactivation led to an increase in patients being directly transported to cath lab on hospital arrival. For patients in whom the cath lab was preactivated, 23.3% were taken directly there lab for primary PCI. In contrast, only 5.3% of STEMI patients were taken to the cath lab when no preactivation call was made.

Prashant Kaul, MD (Piedmont Heart Institute, Atlanta, GA), who was not involved in the analysis, said there is a strong recommendation to facilitate earlier activation of the catheterization lab based on the 2006 Reperfusion in Acute MI in Carolina Emergency Departments (RACE) Initiative, as well subsequent efforts from the American College of Cardiology’s Door-to-Balloon (D2B) Alliance and the American Heart Association’s Mission: Lifeline.

“However, in practice, this ends up being a function of the strength of the collaboration between local EMS services and PCI-capable hospitals,” he said. “Other variables that will influence the likelihood of preactivation include the availability of educational resources that EMS agencies might have available to them to train their personnel in ECG interpretation.”

To TCTMD, Kaul said the study “reemphasizes previous work that demonstrates earlier activation and bypassing the emergency room improves outcomes,” In an ideal system, following prompt symptom recognition, early ECG transmission to the interventional cardiologist would lead to preactivation of the cath lab. Although there is a concern for "false positives,” Kaul said the rate is relatively low—probably in the 15-20% range—and is typically “offset by faster treatment times for the majority of patients in whom the cath lab is appropriately activated.”

The study was published September 17, 2018, in JACC: Cardiovascular Interventions.

Wide National Variability

Cath lab activation prior to hospital arrival for STEMI is known to be beneficial, with studies in the past showing it facilitates more rapid primary PCI, but it requires coordinated treatment protocols between EMS and the PCI-capable hospitals, said Shavadia. In the present study, the researchers wanted to determine how often the cath lab was activated prior to the arrival of STEMI patients, suspecting preactivation might be substantially underutilized or vary between hospitals.

Overall, the door-to-device time with preactivation was 40 minutes compared with 52 minutes for STEMI patients for whom the lab wasn’t activated ahead of hospital arrival (P < 0.001). Preactivation also led to shorter hospital arrival-to-cath lab arrival times. When the cath lab was alerted ahead of time, significantly more patients received a device within 90 minutes of first medical contact (69.2% vs 58.6%; P < 0.001). The benefit of preactivation was observed in patients who presented during off and working hours.

In an unadjusted analysis, preactivation was associated with a lower risk of in-hospital mortality (2.8% vs 3.4%), but the difference was not statistically significant in a fully adjusted model (OR 0.87; 95% CI 0.75-1.01). Researchers observed wide interhospital variability in the rate of preactivation and better outcomes among those that more consistently made the cath lab ready before patient arrival. Among hospitals who preactivated the cath lab the least—those in the lowest tertile of preactivation (median rate 19%)—there was a significant 33% increased risk of in-hospital mortality compared with hospitals in highest tertile of preactivation (median rate 58%). 

Currently, prehospital activation of the cath lab is poorly defined, said Shavadia. In the present study, they selected 10 minutes as the cut point to define preactivation, as they felt this would be sufficient time for staff to make their way in and for the cath lab to be readied for the incoming STEMI patient. There were 9,326 STEMI patients in which the cath lab was notified of a patient less than 10 minutes away from hospital but the researchers classified these cases as “no preactivation.”

“If the cath lab is activated 5 minutes before the patient arrives at the hospital, well, that’s no use to the cath lab,” said Shavadia. “You’ve activated the lab just as you’re rolling into the emergency bay.”

While there are no studies defining the ideal time to activate the cath lab, a “10-minute” cutoff has been used in clinical guidelines for other aspects of care, such as the EMS reading the ECG within 10 minutes patient contact, said Shavadia. He pointed out, however, that within the “entire prehospital process of STEMI care, there is no real direction or guidelines to state the cath lab should be activated at ‘X’ point in time.”

To TCTMD, Pinak Shah, MD (Brigham and Women’s Hospital, Boston, MA), said he wasn’t surprised that the rate of preactivation was just 40%, noting that preactivation depends largely on the hospital system.        

“For many years, we have allowed only Boston EMS to preactivate the cath lab at Brigham and Women’s,” he said. “After an initial pilot, we found that they were correct in calling a true STEMI more than 95% of time and therefore it made sense to allow them to activate the lab by calling our emergency department. Until recently we had not allowed other EMS services to preactivate the lab, but we eventually did open it up to all EMS services.”

Shah noted that his hospital is not a particularly high-volume STEMI center because most STEMI care happens in the suburbs, but those hospitals have “not seen an unacceptable rate of false activations.” That said, false activations do remain a significant concern for high-volume STEMI hospitals, particularly since off-hours activation involves many people rushing to the hospital, which increases the risk of accidents and unnecessarily keeps the staff up at night when they need to work the next day, said Shah. A vetting process for all STEMI cases prior to activating the lab, such as a physician review of the ECG and discussion of the case, helps reduce the risk of false activations.

Shavadia agrees with the idea of having physician review and a discussion prior to cath lab activation. “There’s an economic impact there,” he said, referring to false activations. “Or you might be exposing patients to unnecessary procedures—there’s a risk associated with that.”