Resuscitation Rates Lower Everywhere During COVID-19

Covid-19 shocked the US health system when it first arrived in 2020. The immediate direct consequences were obvious, but with such a dramatic event there will inevitably be many more delayed or indirect consequences of the pandemic and lockdown. Researchers are now studying some of these consequences. In June 2020, early data showed a spike in out-of-hospital cardiac arrest (OHCA) deaths in New York City, an early epicenter of the virus (Lai, 2020). The initial explanation for the spike in OHCA deaths was that the pandemic overwhelmed the emergency medical services (EMS) and higher patient severity from the pandemic. This spurred a research team, led by Dr. Paul Chan, to investigate the broader effects of the pandemic on OHCA outcomes (Chan, 2020).

Over 350,000 Americans suffer out-of-hospital cardiac arrests each year, and less than 30% of those patients live to see the hospital. The data for this study came from the CARES registry, a large collection of EMS and hospital data on OHCA which covers areas accounting for 45% of the US population.

This study focuses primarily on how many people recover from the cardiac arrest and return to a sustained heart rhythm, known as the sustained return of spontaneous circulation (Sustained ROSC), and how many people survive through discharge. Researchers compared 2020 data with data from the same month in 2019, using the ‘pre-pandemic period’ as a control. They then analyzed the differences in sustained ROSC rates for different areas using a multivariate logistic regression model, controlling for demographics and cardiac arrest characteristics. Location of cardiac arrest and whether the patient received bystander CPR prior to EMS arrival were also controlled, since it’s reasonable to think during a lockdown more people would be at home alone. They then grouped these differences by county COVID-19 mortality to test if local COVID-19 severity was a cause of any change.

Using standardized differences, they looked for demographic differences in the people who had heart attacks during this period in 2020 compared to 2019. Black Americans experienced 28% more OHCAs in 2020, while white Americans experienced slightly fewer, a statistically significant difference. In 2019, most OHCAs were at home, but this increased in 2020; OHCAs at work fell by half, from 8.2% of all OHCAs to 3.8%.

As for cardiac outcomes, the results were surprising. Fewer OHCA patients were successfully resuscitated during the pandemic, which is in line with the initial data. However, this trend existed even in counties with low COVID-19 mortality rates. In high COVID death areas, sustained ROSC rates fell between 21-33%. In low COVID death areas, sustained ROSC fell 10-15%. This challenges the original explanation that low ROSC rates were caused by an overwhelmed EMS system. Curiously, survival to discharge rates were only lower in high COVID death areas, where they fell by a third. Overall, incidences of OHCA increased during the pandemic, mostly in high COVID death areas.

What does this mean? In areas with high mortality there were more people reporting heart attacks outside of the hospital and fewer of them lived through discharge. This aligns with the story the earlier New York City data showed. Researchers also found that fewer OHCA patients were successfully resuscitated in both low and high COVID-19 mortality areas, even when controlling for a wide range of possibly confounding variables. Plainly put, cardiac outcomes worsened even before COVID significantly affected an area.

One possible explanation is that some people were afraid of the pandemic and avoided getting preventative care at the hospital, leading to more severe cardiac arrests at home. However, researchers do not consider this explanation to be completely satisfactory. If people were avoiding going to the hospital in lower mortality areas due to COVID fears, then there would be more OHCAs in these areas relative to 2019. This was not really the case, so there must be another explanation. On the other hand, in high COVID areas the researchers did find a spike in OHCAs, but it’s difficult to attribute to any specific cause.

Another possible explanation is that preemptive measures to stop COVID-19 somehow hindered care in these areas. Many of these measures, like limiting number of EMS personnel per call or changing procedures for care that involve the respiratory tract, were meant to help protect frontline workers. Did these measures hurt patients? It’s certainly possible, although more research would be needed to say for certain. However, in low COVID-19 mortality areas, the survival through discharge rate was relatively unchanged, suggesting these preventative measures likely did not meaningfully increase OHCA deaths.

Given the urgency of the early pandemic and the relatively minimal impact these policies had on overall OHCA mortality rates, there’s no reason to think that policymakers made the wrong decision in this instance. However, the study brings a difficult policy question to the foreground: How should policy makers prioritize preventing a potential threat versus effectively dealing with the current problem? COVID is an unprecedented public health crisis, and protecting frontline healthcare workers was prioritized early. If policy makers had waited until COVID-19 cases spiked in a region, perhaps it would have been too late to effectively implement precautions.

Researchers have only just begun investigating the impact of policy response to COVID. The wide ripple effects of policy decisions made swiftly and without a full understanding of what COVID-19 could do will be – and should be – studied for many years to come.

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“Cardiac Arrest: An Important Public Health Issue.” CDC. Accessed March 1, 2021. https://www.cdc.gov/dhdsp/docs/cardiac-arrest-infographic.pdf.

Chan, Paul S. “Outcomes for Out-of-Hospital Cardiac Arrest in the US During the COVID-19 Pandemic.” JAMA Cardiology. JAMA Network, November 14, 2020. https://jamanetwork.com/journals/jamacardiology/fullarticle/2773109.

Lai, Pamela H. “Out-of-Hospital Cardiac Arrests and Resuscitations During COVID-19 Pandemic.” JAMA Cardiology. JAMA Network, October 1, 2020. https://jamanetwork.com/journals/jamacardiology/article-abstract/2767649.