Editor’s note: Find the latest COVID-19 news and guidance in Medscape’s Coronavirus Resource Center.
In the early weeks of the COVID-19 pandemic in the United States, rates of sustained return of spontaneous circulation after out-of-hospital cardiac arrest were lower throughout the country compared with a year earlier, in one study.
A second study of that period showed that patients with COVID-19 had rates that were better than previously reported of surviving in-hospital cardiac arrest.
Paul S. Chan, MD, presented the out-of-hospital cardiac arrest research and Oscar J. Mitchell, MD, presented the in-hospital cardiac arrest findings in a late-breaking resuscitation science session at the virtual American Heart Association (AHA) 2020 Scientific Sessions. The former study was also simultaneously published online November 14 in JAMA Cardiology.
Importantly, “the survival rates were not zero in either setting,” said Chan, commenting on the implications of both studies taken together.
“The survival rates — either return of circulation or survival to discharge — were not futile,” Chan, from Saint Luke’s Mid America Heart Institute, Kansas City, Missouri, told theheart.org | Medscape Cardiology.
“And I think that’s an overall important message — that we can’t write off patients who have a cardiac arrest at this point,” he stressed. “They deserve a response. Although the outcomes might not be as good as we had seen in years prior, we are seeing patients making it out of the hospital and surviving.”
Mitchell, from the University of Pennsylvania in Philadelphia, echoed this message in an email to theheart.org | Medscape Cardiology.
“I think that the key finding here is that survival is possible after patients with COVID-19 suffer an in-hospital cardiac arrest,” Mitchell said. “We hope that the information from our study will be of use to frontline providers who are treating patients with COVID-19.”
“In coming weeks, there will likely be increased hospital strain and enormous challenges to providing COVID-19 care,” added Benjamin S. Abella, MD, the senior author of the in-hospital study. Abella is also from the University of Pennsylvania and was co-chair of the Resuscitation Science symposium during the AHA meeting.
“It is crucial that hospital leaders prepare now for how they will manage COVID-19 resuscitation efforts,” Abella said. “Emergency medicine and critical care leaders must be mindful that many COVID-19 patients with arrest could survive to return to their families.”
“It is important to note both studies demonstrated variations in outcome, and that those differences were associated with the differential COVID prevalence and mortality,” session co-moderator Cindy H. Hsu, MD, PhD, University of Michigan, told theheart.org | Medscape Cardiology.
“Future studies,” she said, “should address knowledge gaps including associated co-morbidities and affected resuscitation process variables during the COVID-19 pandemic.”
Out-of-Hospital Cardiac Arrest, March 2019 vs March 2020
Compared with 2019, in 2020, the reported rates of return of spontaneous circulation after out-of-hospital cardiac arrest fell from 25% to 10.6% in New York City, and from 13.5% to 5.0% in northern Italy — two areas that were severely affected, Chan noted.
In this study, the researchers aimed to examine whether out-of-hospital cardiac arrest outcomes would be similar throughout the United States, including areas that were less severely affected, in the first weeks of the pandemic.
They linked data from the Cardiac Arrest Registry to Enhance Survival (CARES), which covers an area with about 152 million US residents, with COVID-19 disease mortality data.
There were 9863 out-of-hospital arrests from March 16 to April 30, 2020, compared to 9440 cases during this time in 2019.
The patients in both years had a similar age (mean age, 62) and sex (62% male), but there were more Black patients in 2020 (28% vs 23%).
Overall, in communities with low to high rates of death from COVID-19, the rate of return of spontaneous circulation was 18% lower in that early pandemic period than in the same time in the previous year (23% vs 29.8%; adjusted rate ratio [RR], 0.82).
The rates of return of spontaneous circulation were also lower in communities with a low rate of COVID-19 mortality, but to a lesser extent (11% to 15% lower in 2020 vs 2019).
In the subset of emergency medical agencies with complete data on hospital survival, overall rates of survival to discharge were 17% lower during the studied pandemic period vs the same time a year earlier (6.6% vs 9.8%; adjusted RR, 0.83).
This drop in survival was greater in communities with moderate to high COVID-19 mortality.
These outcomes were not explained by differences in EMS arrival or treatment times, rates of bystander CPR, or initial out-of-hospital cardiac arrest rhythm.
Chan was a co-author of an interim guidance issued April 9, 2020, by the American Heart Association (AHA) and several other medical societies, for ways to protect frontline workers from contracting COVID-19 while they were performing CPR.
Communities that were not heavily affected by COVID-19 could have also been following the recommendations, which might have affected outcomes, he speculated.
For example, “when we pause chest compressions it can potentially worsen survival even if it’s for a short period of time. That might explain the lower rates of return of circulation.”
“That guidance was really meant for heavily affected communities,” Chan added. “Of course, as we speak, the pandemic is pretty much everywhere in the United States. It’s not just in the northeast; it’s not just in Arizona, Florida, California, Texas like it was in the summer, you are seeing surges in 46 of the 50 states.
“If your community is heavily affected by COVID-19 in terms of deaths at this time, paramedics will need to take caution to also help protect themselves, and the guidance may apply at that point,” he said.
In-Hospital Cardiac Arrest, March Through May 2020
The early studies of in-hospital cardiac arrest in patients with COVID-19 showed “concerningly low rates” of return of spontaneous circulation and survival, said Mitchell.
“The first was a study from Wuhan, which demonstrated a 2.9% 30-day survival and the second was a small cohort from NYC with 0% survival to hospital discharge,” he said. “This raised concerns that offering CPR to patients who had a cardiac arrest from COVID-19 might only hold a low probability of success.”
To investigate this, the researchers formed a COVID Study group comprising two hospitals in New York City and nine hospitals in the Northeast and West Coast.
They identified 260 hospitalized adult patients with COVID-19 who had in-hospital cardiac arrest between March 1 and May 31, 2020.
The patients had a median age of 69 and 72% were male. Most had pre-existing comorbidities.
Most of the cardiac arrests were in the ICU (64%), and almost all were witnessed (91%).
Return of spontaneous circulation occurred in 22% of the patients, and 12% had survived 30 days later.
Of the 260 cardiac arrests, most (204) occurred in the New York City hospitals.
There was a huge variation in outcomes. The rate of sustained return of spontaneous circulation was much lower in the two hospitals in New York City compared with elsewhere (11% vs 64%), as was 30-day survival (6% vs 36%).
“Variation in outcomes from [in-hospital cardiac arrest] has been well described prior to the COVID-19 pandemic,” said Mitchell, “and is felt to be due to a range of factors, including variation in detection and prevention of cardiac arrest, management of patients during the cardiac arrest, and differences in post-arrest care — including targeted temperature management and neuroprognostication.”
“We hypothesize that the strains of the COVID-19 pandemic may have amplified these variations (although we were unable to compare hospital performance before and after the pandemic),” he said.
Nevertheless, “in contrast to [earlier] studies, we have found that survival with a good neurological status is possible after in-hospital cardiac arrest in patients with COVID-19, which is certainly reassuring for those of us on the front line.”
Chan has received research support from the American Heart Association (which helps fund CARES), the NHLBI, and Optum Rx. Abella has received honoraria from NeuroproteXeon, Becton Dickinson, and Physio-Control, and research grants from Medtronic, PCORI, Physio-Control, Stryker, and TerSera. Mitchell has disclosed no relevant financial relationships.
American Heart Association (AHA) Scientific Sessions 2020: RESS 2020 Late Breaking Science 100, 102. Presented November 14, 2020.
JAMA Cardiology. Published online November 14, 2020. Full text