The relationship of large city out-of-hospital cardiac arrests and the prevalence of COVID-19

Abstract

Background: Though variable, many major metropolitan cities reported profound and unprecedented increases in out-of-hospital cardiac arrest (OHCA) in early 2020. This study examined the relative magnitude of those increases and their relationship to COVID-19 prevalence.

Methods: EMS (9-1-1 system) medical directors for 50 of the largest U.S. cities agreed to provide the aggregate, de-identified, pre-existing monthly tallies of OHCA among adults (age >18 years) occurring between January and June 2020 within their respective jurisdictions. Identical comparison data were also provided for corresponding time periods in 2018 and 2019. Equivalent data were obtained from the largest cities in Italy, United Kingdom and France, as well as Perth, Australia and Auckland, New Zealand.

Findings: Significant OHCA escalations generally paralleled local prevalence of COVID-19. During April, most U.S. cities (34/50) had >20% increases in OHCA versus 2018-2019 which reflected high local COVID-19 prevalence. Thirteen observed 1·5-fold increases in OHCA and three COVID-19 epicenters had >100% increases (2·5-fold in New York City). Conversely, cities with lesser COVID-19 impact observed unchanged (or even diminished) OHCA numbers. Altogether (n = 50), on average, OHCA cases/city rose 59% during April (p = 0·03). By June, however, after mitigating COVID-19 spread, cities with the highest OHCA escalations returned to (or approached) pre-COVID OHCA numbers while cities minimally affected by COVID-19 during April (and not experiencing OHCA increases), then had marked OHCA escalations when COVID-19 began to surge locally. European, Australian, and New Zealand cities mirrored the U.S. experience.

Interpretation: Most metropolitan cities experienced profound escalations of OHCA generally paralleling local prevalence of COVID-19. Most of these patients were pronounced dead without COVID-19 testing.

Funding: No funding was involved. Cities provided de-identified aggregate data collected routinely for standard quality assurance functions.

Fig. 1

Comparing the total monthly numbers of out-of-hospital cardiac arrest (OHCA) for March, April, May and June 2020 to the average of the corresponding monthly totals for the prior two years (2018–2019), the percent change in monthly totals of OHCA cases from those prior years (y-axis) are displayed for each of 50 major U.S. cities (x-axis) during the months of March through June, respectively. Deviations of greater than 10% from prior years were deemed significant, both statistically and operationally. The red lines delineate cities with greater than 20% increases in OHCA over prior years.

Fig. 1

Comparing the total monthly numbers of out-of-hospital cardiac arrest (OHCA) for March, April, May and June 2020 to the average of the corresponding monthly totals for the prior two years (2018–2019), the percent change in monthly totals of OHCA cases from those prior years (y-axis) are displayed for each of 50 major U.S. cities (x-axis) during the months of March through June, respectively. Deviations of greater than 10% from prior years were deemed significant, both statistically and operationally. The red lines delineate cities with greater than 20% increases in OHCA over prior years.

Fig. 2

Examples of the percent change in the total monthly frequency of out-of-hospital cardiac arrest (OHCA) cases that were reported for March, April, May and June 2020, respectively, when compared to the averaged corresponding totals for previous two years. The colored horizontal lines, scaled on left y-axis, represent the overall averaged percent increase for each of the entire respective months. The overlay of the concurrent number of daily new COVID-19 cases (vertical black lines, scaled on right y-axis) helps to illustrate how the month by month increases or decreases in the numbers of OHCA cases in 2020 paralleled the prevalence of COVID-19 cases using four sample cities; two with a high prevalence of COVID-19 in March and April (New York City, Detroit) accompanied by a corresponding increase in OHCA that later diminished as the local prevalence of COVID-19 dissipated; and two other cities with late surges in OHCA that occurred along with corresponding increases in COVID-19 cases in late June 2020 (Charleston, Madison).

Fig. 2

Examples of the percent change in the total monthly frequency of out-of-hospital cardiac arrest (OHCA) cases that were reported for March, April, May and June 2020, respectively, when compared to the averaged corresponding totals for previous two years. The colored horizontal lines, scaled on left y-axis, represent the overall averaged percent increase for each of the entire respective months. The overlay of the concurrent number of daily new COVID-19 cases (vertical black lines, scaled on right y-axis) helps to illustrate how the month by month increases or decreases in the numbers of OHCA cases in 2020 paralleled the prevalence of COVID-19 cases using four sample cities; two with a high prevalence of COVID-19 in March and April (New York City, Detroit) accompanied by a corresponding increase in OHCA that later diminished as the local prevalence of COVID-19 dissipated; and two other cities with late surges in OHCA that occurred along with corresponding increases in COVID-19 cases in late June 2020 (Charleston, Madison).

Fig. 3

Month by month percent change in the total number of out-of-hospital cardiac arrest (OHCA) cases (y-axis) occurring in March, April, May and June 2020, respectively, when compared to the corresponding month by month average for the previous two years in several non-U.S. cities (x-axis).