Rationale and trial findings
“It’s very well established that early bystander CPR [cardiopulmonary resuscitation], early defibrillation, and advanced in-hospital care improves survival,” Dr. Redwood noted. “Despite this, only 1 in 10 survive to leave the hospital.”
Therefore, “a cardiac arrest center has been proposed as a way of improving outcome.” These centers have a catheterization laboratory, open 24 hours a day, 7 days a week, advanced critical care including advanced ventilation, temperature management of the patient, hemodynamic support, and neuroprognostication and rehab “because often these patients will have brain injury.
“There’s quite overwhelming registry data to suggest that these cardiac arrest centers improve outcome,” he said, “but these are limited by bias.”
Between January 2018 and December 2022, London Ambulance paramedics randomly assigned 862 patients who were successfully resuscitated and without a confirmed MI to be transported the nearest hospital emergency department or the catheterization laboratory in a cardiac arrest center.
Data were available for 822 participants. They had a mean age of 63 years, and 68% were male.
The primary endpoint, 30-day mortality, occurred in 258 (63%) of 411 participants in the cardiac arrest center group and in 258 (63%) of 412 in the standard care group (unadjusted risk ratio for survival, 1.00; 95% confidence interval [CI], 0.90-1.11; P = 0.96).
Mortality at 3 months was similar in both groups: 64% in the standard care group and 65% in the cardiac arrest center group.
Neurologic outcomes at discharge and 3 months were similar in both groups.
Eight (2%) of 414 patients in the cardiac arrest center group and three (1%) of 413 in the standard care group had serious adverse events, none of which were deemed related to the trial intervention.
A cardiac cause of arrest was identified in roughly 60% of patients in each group, and of these, roughly 42% were coronary causes, 33% were arrhythmia, and 17% were cardiomyopathy.
The median time from cardiac arrest to hospital arrival was 84 minutes in the cardiac arrest center group and 77 minutes in the standard care group.
“Surprising and important RCT evidence”
In an accompanying editorial, Carolina Malta Hansen, MD, PhD, University of Copenhagen, and colleagues wrote that “this study provides randomized trial evidence that in urban settings such as London, there is no survival advantage of a strategy of transporting patients who have been resuscitated to centres with specialty expertise in care of cardiac arrest. “This result is surprising and important, since this complex and critically ill population would be expected to benefit from centres with more expertise.”
However, “it would be a mistake to conclude that the trial results apply to regions where local hospitals provide a lower quality of care than those in this trial,” they cautioned.
“Where does this leave the medical community, researchers, and society in general?” they asked rhetorically. “Prioritising a minimum standard of care at local hospitals caring for this population is at least as important as ensuring high-quality care or advanced treatment at tertiary centres.
“This trial also calls for more focus on the basics, including efforts to increase bystander cardiopulmonary resuscitation and early defibrillation, aspects of care that are currently being assessed in two ongoing clinical trials (NCT04660526 and NCT03835403) and are most strongly associated with improved survival, when coupled with high-quality prehospital care with trained staff and short response times,” they concluded.
The study was fully funded by the British Heart Foundation. The authors reported that they have no relevant financial disclosures. The financial disclosures of the editorialists are listed with the editorial.
A version of this article first appeared on Medscape.com.