key: cord-0735327-40gpn8hm
authors: Khan, Sadiya S.; Furmanchuk, Al'ona; Seegmiller, Laura E.; Ahmad, Faraz S.; Black, Bernard S.; O'Leary, Kevin J.
title: Divergent Trends in Emergency Department Presentations Amidst the Novel Coronavirus Disease 2019 Pandemic in Chicago, Illinois
date: 2021-10-08
journal: J Card Fail
DOI: 10.1016/j.cardfail.2021.09.011
sha: a382e2ac0a1cae6f503e44b11891d6766e37e7d5
doc_id: 735327
cord_uid: 40gpn8hm

Excess deaths during the COVID-19 pandemic have been largely attributed to cardiovascular disease (CVD); however, patterns in CVD hospitalizations following the first surge of the pandemic have not well-documented. Our brief report, examining trends in healthcare avoidance documents that CVD hospitalizations declined in Chicago prior to significant burden of COVID-19 cases or deaths and normalized during the first COVID-19 surge. These data may help inform healthcare systems responses in the coming months while mobilizing vaccinations to the population at-large.

The pandemic caused by the novel coronavirus disease 2019 (COVID-19) has led to over 600,000 deaths in the United States (US) as of August 2021. In addition to the direct burden of COVID-19, substantial indirect burden as a result of the pandemic has been reported in terms of excess deaths in the US and across many European countries. Specifically, mortality due to cardiovascular disease (CVD) has been identified as the leading cause of these excess deaths, not directly attributed to COVID-19 during the pandemic. 1 This may be, in part, due to health systems being overwhelmed or fear of COVID-19 infection and changes in behavior related to lockdown measures leading to avoidance of healthcare. While many studies have identified declines in patients presenting to the Emergency Department (ED) since the declaration of a national emergency by the US on March 13 th , 2020, these have been focused on the early phase of the pandemic and have not examined the potential "rebound" effect of delayed care. 2, 3 Additionally, differences in utilization of telehealth services to better manage certain CVD conditions remotely (e.g., heart failure [HF] compared with myocardial infarction [MI]) may have led to greater declines in these CVD subtypes. Lastly, it is not known if trends in ED presentations in cities that experienced a high burden of COVID-19 temporally later in the pandemic differ. Therefore, we sought to describe trends in the number of ED presentations for CVD and across subtypes (HF, hypertension, MI, and stroke) at an integrated, multi-site health system during the first 26 weeks of 2020 and 2019 and compare with COVID-19 cases in Chicago, Illinois over the same period.

We analyzed data from the Northwestern Medicine Enterprise Data Warehouse (NMEDW), a comprehensive electronic repository across 10 hospitals, which houses demographic, laboratory, and claims data on all inpatient and outpatient encounters. 4 The NMEDW reflects data across 10 hospital systems, which represent a single [I10-I16]). We described inflection points in weekly counts during the first 26 weeks of 2020 using a piecewise linear regression model. 5 We displayed data as scatterplots with overlaid nonparametric smoothed curves generated with a locally weighted scatterplot smoothing (LOWESS) method and estimated the percentage change in average weekly ED visits between 2019 and 2020. We repeated the analysis for all hospital admissions with a principal diagnosis of CVD over this same time period. A p<0.05 was considered statistically significant. Lastly, we qualitatively examined COVID-19 cases in Chicago. Analyses were performed in SAS v9.4 and MATLAB R2016b. The study was approved by the Institutional Review Board at Northwestern University Feinberg School of Medicine.

Of 1,943 patients who presented to the ED for CVD in 2020 with mean age 53±19.1 years, 25% were Black adults and 48% were female. There were no significant differences in age, sex, race, or history of obesity or diabetes in patients who presented in 2020 compared with 2019 (n=2480, p>0.23 for all). We identified two significant inflection points: 3/4/20 and 3/18/20 (Figure 1) . Between 1/1 to 3/4, weekly counts for CVD presentations in ED were similar between 2019 and 2020. However, a significant decline in CVD counts was observed between 3/4/20 and 3/18/20 (-49.5% [-37.4, -61.5]). During this same period, cumulative COVID-19 cases were low in Chicago in early March with the decline in ED visits preceding the rise in COVID-19 cases; the rebound in ED visits began after lockdown measures were instituted nationally but prior to the peak in local COVID-19 activity.

Between 3/18/20 and 6/30/20, a significant increase in weekly CVD counts was observed, concurrently with increases in COVID-19 cases in Chicago. Patterns were heterogeneous across CVD subtypes (Figure 2) 

In this retrospective analysis with data from 4,423 patients presenting to the ED at 10 hospitals from an integrated healthcare system, we demonstrate significant declines in patients presenting for acute CVD care in early March 2020 prior to significant COVID-19 burden in Chicago. In contrast with published literature, we observed no change in acute MI presentations, but significant declines in presentations with a principal diagnosis of stroke, HF, or hypertension. Despite increasing COVID-19 cases in Chicago after 3/18/20, we observed normalization (without overcorrection) of ED visits in patients presenting for acute CVD care over this time.

This study confirms and extends prior work identifying dynamic patterns in ED presentations for acute CVD care.

Other studies have focused on high burden areas in the US (e.g., New York City, Boston) that were affected early in the pandemic before there was adequate time for health systems to plan and identify interventions to mitigate healthcare avoidance due to fear of COVID-19. The current study demonstrates similar patterns in early March with declines in patient presentations to the ED at a time when COVID-19 was being recognized on the global scale rather than significant local burden of COVID-19. In contrast, we note increases in ED presentations concurrently with increases in COVID-19 cases locally. The increases following re-opening in early June are consistent with prior work from Norway and Germany that showed similar patterns once restrictions were loosened. 6, 7 Potential explanations may include use of targeted institutional messaging for at-risk patients, local and national media campaigns, and public health messaging focused on mitigating fear to avoid delays in seeking urgent care.

Unlike prior studies, we did not observe a significant difference in patients presenting with acute MI to our ED. 8 However, significant declines in patients with a principal diagnosis of HF or hypertension suggests the potential for greater utilization of remote monitoring and management options when possible. 9 Additionally, it is unclear if lower counts of HF and hypertension presentations represent altered management or a true reduction in incidence, which may be related to changes in dietary intake with lockdown measures (e.g., reduced sodium intake). 10 Unfortunately, studies are emerging that document increases in prevalence of unhealthy behaviors, including greater intake of poor quality diet, higher degree of sedentary behavior, and significant weight gain. 11 These adverse trends are likely to further accelerate pre-pandemic changes observed in declining cardiovascular health. 12 Limitations of the study to note include the retrospective nature with potential for residual confounding and bias.

While we were not able to assess severity at time of presentation, similar patterns in both ED presentations and inpatient hospitalizations for CVD suggest this is unlikely to explain the findings. Additionally, we were unable to assess other health behavior changes that may have occurred and potential for misclassification with use of ICD codes. Our study is ecological in nature and cannot confer causation. However, these data may inform potential strategies to counsel high-risk patients with risk for recurrent surges with novel COVID-19 variants while awaiting herd immunity amidst vaccine hesitancy and limited global vaccine distribution.

Research reported in this publication was supported, in part, by the National Institutes of Health, grant numbers KL2TR001424, P30AG059988; P30DK092939 (SSK). Research reported in this publication was also supported, in part, by the American Heart Association (#19TPA34890060) to SSK.

The authors have no competing interests to declare.

The dashed purple lines with the following symbols *, #, and  reflect the World Health Organization announcement identifying CVD as a high-risk condition for COVID-19 (March 10 th , 2020), Illinois shelter in place order (March 20 th , 2020), and targeted message by the health system to high-risk patients to mitigate fear in seeking urgent care (March 24 th , 2020).

A. Chicago metropolitan area COVID-19 cases * # Y 

Estimation of Excess Deaths Associated With the COVID-19 Pandemic in the United States

Fewer Hospitalizations for Acute Cardiovascular Conditions During the COVID-19 Pandemic

Trends in Emergency Department Visits and Hospital Admissions in Health Care Systems in 5 States in the First Months of the COVID-19 Pandemic in the US

Enabling a Learning Health System through a Unified Enterprise Data Warehouse: The Experience of the Northwestern University Clinical and Translational Sciences (NUCATS) Institute

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Cardiovascular Hospitalizations, Influenza Activity, and COVID-19 Measures. Circulation

Hospital admissions during Covid-19 lock-down in Germany: Differences in discretionary and unavoidable cardiovascular events

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