COVID-19 pandemic period and adult cardiac arrest: Analysis of clinical and epidemiological changes before and after the pandemic

Abstract

This study aimed to investigate the impact of the COVID-19 pandemic on the management and outcomes of adult cardiac arrest patients by assessing the incidence, patient outcomes, and influence of comorbidities during the pandemic. This retrospective cross-sectional study analyzed the clinical data of 500 patients who experienced cardiac arrest in the Emergency Department of Esenyurt Necmi Kadioğlu State Hospital between September 1, 2018, and August 31, 2024. Patient data were obtained from the hospital’s electronic records and included variables such as age, sex, arrest location, etiology, initial rhythm, intervention time, and outcomes. Data analysis was performed using SPSS version 26. Chi-square tests were used for categorical variables, while independent sample t tests and Mann–Whitney U tests were used for continuous data. The incidence of cardiac arrest increased during the pandemic. COVID-19-positive patients had a lower return of spontaneous circulation (ROSC) rates (30%) compared with negative patients (50%) and suspected cases (40%). Mortality was higher in COVID-19-positive patients (70%) and their discharge rates were lower (20%). Ventricular fibrillation as the initial rhythm was associated with better ROSC rates. Comorbidities such as chronic obstructive pulmonary disease, cancer, and heart failure were associated with lower ROSC rates and higher mortality rates. In conclusion, the COVID-19 pandemic has increased the number of cardiac arrest cases and worsened patient outcomes. Comorbidities significantly affected the prognosis. Future preparedness should focus on reducing intervention time, optimizing resource management, and implementing targeted care plans for high-risk patient groups.

1. Introduction

The COVID-19 pandemic has significantly impacted global healthcare systems, influencing both the delivery of healthcare services and treatment of various diseases, including acute and critical care conditions.^[1,2] Acute coronary syndrome is a critical clinical issue requiring timely intervention and assessment, and the pandemic presents unique challenges for its management. During this period, acute coronary syndrome and other cardiac emergencies were managed in both hospital and out-of-hospital settings, reflecting developments and adaptations in the healthcare systems.^[3]

Several barriers and challenges to the management of cardiac arrest during pandemics have been identified. These include increased response times due to the donning of personal protective equipment, healthcare providers’ concerns about infection during patient assessment and management, and modifications to the layout of emergency and intensive care units to accommodate COVID-19 patients.^[4] Field response teams also face logistical and operational difficulties. Pandemic-related measures, such as social distancing, lockdowns, and reduced hospital admissions, further hinder cardiac arrest patients’ access to emergency care.^[5,6]

The effects of the pandemic have also led to changes in clinical practice trends and the characteristics of patients with cardiac arrest. Conditions such as myocardial infarction, arrhythmias, and thromboembolic events have been observed to contribute to cardiac arrest during the pandemic, particularly in patients with preexisting comorbidities and vascular risk factors.^[7] However, these effects are not yet fully understood and warrant further investigation.

At this stage, it is crucial to examine the epidemiology of adult cardiac arrest during the COVID-19 pandemic. Understanding how healthcare systems manage cardiac arrest, along with evaluating resuscitation protocols and intervention measures, is vital for improving outcomes. This study aimed to expand the knowledge on the effects of the COVID-19 pandemic on the presentation, management, and outcomes of adult cardiac arrest patients. Insights from this study may benefit clinicians, policymakers, and healthcare systems by developing appropriate strategies for managing future pandemics and disasters.^[8,9]

2. Methods

This retrospective cross-sectional study analyzed the clinical data of 500 patients who presented with cardiac arrest or developed cardiac arrest during follow-up in the Emergency Department of State Hospital between September 1, 2018, and August 31, 2024. The study was conducted in accordance with the Declaration of Helsinki and was approved by the relevant ethics committee.

The study population included patients who presented with cardiac arrest or cardiac arrest during follow-up in the emergency department. The inclusion criteria were as follows: patients aged 18 years and older, those diagnosed with cardiac arrest in the Emergency Department of State Hospital during the study period, and all cardiac arrest cases, regardless of whether resuscitation was performed. The exclusion criteria were incomplete or insufficient medical records, patients who died from primary causes other than cardiac arrest, and pediatric or adolescent patients (under 18 years of age).

Patient data were retrospectively obtained from the hospital’s electronic medical records and files. The analyzed parameters included demographic information (age, sex); cardiac arrest characteristics (location of cardiac arrest: in-hospital or out-of-hospital; etiology of arrest: cardiac, respiratory, traumatic, etc; initial rhythm: ventricular fibrillation (VF), pulseless ventricular tachycardia, asystole, pulseless electrical activity); resuscitation details (duration and success rate of resuscitation attempts, response time to initial intervention), patient outcomes (return of spontaneous circulation [ROSC], hospital discharge, and mortality); COVID-19 status (presence or suspicion of COVID-19 diagnosis); and comorbidities such as hypertension, diabetes mellitus, chronic obstructive pulmonary disease (COPD), chronic kidney disease, congestive heart failure, malignancies, other cardiovascular diseases, obesity, and neurological disorders (stroke, epilepsy, etc).

In this study, missing data management strategies were used to deal with missing data to increase the precision of data analyses. First, the randomness of the missing data was checked to determine whether it was due to a specific cause. When there was no apparent structure in the missing data, the mean substitution procedure was employed to handle the missing data; that is, missing values were replaced by the mean of the corresponding variable.

When the missing data structure was complex, a regression substitution procedure was employed. In this approach, missing values were imputed using regression equations with other explanatory variables. This method is particularly recommended for variables with <10% of missing data. Missing data values were imputed properly to maintain the quality of the data and the results of the analysis.

In addition, to avoid the false-positive rate in multiple comparisons made in the study, Bonferroni correction was used. This method tightens the significance threshold by dividing the alpha level by the number of tests to set a more conservative threshold. With this correction, for all the statistical analyses performed in this study, the significance level (P value) was determined as α/n, and the findings were analyzed in light of this. This helped to avoid false-positive results and thus made the findings more credible.

All methods discussed were used systematically in this study to make the study more transparent and statistically sound.

Data were analyzed using the Statistical Package for Social Sciences (SPSS) version 26 (IBM Corp., Armonk). Continuous variables are reported as means, standard deviations (SDs), medians, and interquartile ranges (IQRs), while categorical variables are expressed as frequencies and percentages. The impact of comorbidities on cardiac arrest outcomes was assessed using chi-square or Fisher exact tests. Independent sample t tests or Mann–Whitney U tests were used for continuous variables. Comparisons were made between patients with and without COVID-19 regarding comorbidity distribution and clinical outcomes. Statistical significance was set at P < .05.

2.1. Ethical approval

This study was conducted in accordance with the principles of the Declaration of Helsinki. Ethical approval was obtained from the Istanbul Medipol University Non-Interventional Clinical Research Ethics Committee (approval no 1369, date: December 26, 2024).

As this study involved a retrospective analysis of anonymized patient data collected from the hospital’s electronic records, the requirement for informed consent was waived by the ethics committee. No direct patient intervention was performed in this study. All data were handled with strict confidentiality, ensuring compliance with institutional and national regulations for data protection and patient privacy.

3. Results

This retrospective cross-sectional study analyzed the clinical data of 500 patients who presented with cardiac arrest or developed cardiac arrest during follow-up in the Emergency Department of Esenyurt Necmi Kadioğlu State Hospital between September 1, 2018, and August 31, 2024. The study was conducted in accordance with the Declaration of Helsinki and was approved by the relevant ethics committee.

Descriptive analysis revealed the following results. The mean age of the patients was 60.4 years with a SD of 15.2. The median age was 61 years, and the IQR was 52 to 70 years. The mean time to intervention was 12.3 minutes with a SD of 6.5 minutes. The median intervention time was 12 minutes, and the IQR was 8 to 16 minutes. Regarding sex distribution, 58.2% of the patients were male and 41.8% were female. In terms of cardiac arrest location, 46% of the cases occurred in-hospital, whereas 54% occurred out-of-hospital. The etiology of cardiac arrest was cardiac arrest in 50.8% of the cases, respiratory arrest in 24.6%, traumatic arrest in 15.2%, and other causes in 9.4%. The initial rhythm observed during cardiac arrest included VF in 22.0% of cases, ventricular tachycardia in 15.4%, asystole in 34.8%, and pulseless electrical activity in 27.8%. ROSC was achieved in 42% of the patients, while 58% did not achieve ROSC. The COVID-19 status was positive in 30.2% of cases, negative in 55.8%, and suspected in 14.0%. The most common comorbidities were hypertension (45.4%), diabetes mellitus (32.0%), COPD (19.6%), chronic kidney disease (12.4%), heart failure (23.2%), cancer (9.8%), obesity (28.0%), and neurological disorders, such as stroke and epilepsy (8.6%).

The comparison of prepandemic and postpandemic periods was performed. For categorical variables, no significant difference in sex distribution was observed between the periods (P > .05). However, there was a statistically significant difference in the distribution of arrest locations between the prepandemic and postpandemic periods (P < .05). A significant increase in the frequency of cardiac arrest cases was observed in the postpandemic period (P < .01). Regarding initial rhythms, the rate of VF rhythm significantly increased in the postpandemic period compared with the prepandemic period (P < .01), whereas no significant changes were observed in other rhythm types (P > .05). For continuous variables, the mean age of the patients was 58.4 years (SD = 14.8) in the prepandemic period and 50.6 years (SD = 12.3) in the postpandemic period. This represented a statistically significant increase in cardiac arrest rates among the younger age groups in the postpandemic period (P < .01). The mean time to intervention was 10.8 minutes (SD = 5.4) in the prepandemic period and 13.6 minutes (SD = 6.8) in the postpandemic period, indicating a significant increase in intervention times (P < .01). These results suggest a significant increase in cardiac arrest cases during the postpandemic period, particularly in younger age groups with longer intervention times and increased rates of VF rhythm.

We conducted an analysis to determine the impact of COVID-19 on patient outcomes. ROSC rates were significantly lower among COVID-19-positive patients (30%) than among negative patients (50%) and suspected cases (40%) (P < .01). Mortality rates were highest in COVID-19-positive patients (70%), compared with 45% in negative cases and 55% suspected cases (P < .01). Discharge rates were lower in COVID-19-positive patients (20%) than in negative patients (40%) and suspected cases (35%) (P < .05). Among the continuous variables, the mean age of COVID-19 positive patients was 65 years, which was significantly higher than negative patients (58 years) and suspected cases (60 years) (P < .05). The average time to intervention was longer in COVID-19-positive patients (15 minutes) than in negative patients (10 minutes) and suspected cases (12 minutes) (P < .01). These findings suggest worse outcomes in COVID-19-positive patients, including lower ROSC rates, higher mortality rates, longer intervention times, and lower discharge rates.

The impact of comorbidities on cardiac arrest outcomes was also analyzed. Regarding ROSC rates, COPD (P < .05) and cancer (P < .01) were associated with significantly lower ROSC rates, whereas no significant differences were found for hypertension, diabetes, chronic kidney disease, heart failure, obesity, or neurological disorders (P > .05). Mortality was significantly higher in patients with COPD (P < .05), chronic kidney disease (P < .05), heart failure (P < .01), and cancer (P < .01). The discharge rates were significantly lower among patients with COPD (P < .05), heart failure (P < .05), and cancer (P < .01). For continuous variables, significant age differences were observed for patients with hypertension, diabetes, COPD, chronic kidney disease, heart failure, and cancer (P < .05), whereas no significant differences were observed for obesity and neurological disorders (P > .05). No significant differences were found in the time to intervention for any comorbidity (P > .05). These results emphasize the negative impact of comorbidities, particularly COPD, heart failure, and cancer, on ROSC, mortality, and discharge rates.

Multivariate analysis revealed several predictors of cardiac arrest outcomes. COVID-19 positivity, out-of-hospital arrest, and longer intervention times were associated with significantly lower ROSC rates (P < .01). The VF rhythm was a positive predictor of ROSC (P < .01). For discharge rates, COVID-19 positivity, cancer, and longer intervention times were significant negative predictors (P < .01), whereas cardiac arrest etiology was a positive predictor (P < .05). Mortality was significantly higher among COVID-19-positive patients, those with COPD, older patients, and those with out-of-hospital arrests (P < .01). These findings suggest that COVID-19 positivity, comorbidities, and prolonged intervention times were associated with worse outcomes, whereas VF rhythm and cardiac etiology were associated with better outcomes.

A time trend analysis of cardiac arrest incidence revealed a monthly average of 24.7 cases prepandemic, which increased to 35.6 cases during the pandemic period and slightly decreased to 33.2 cases in the postpandemic period. The highest monthly case count was recorded in January 2021, with 42 cases. Seasonal analysis showed consistently higher cases during winter months, with January averaging 38 cases and July averaging 30. The onset of the pandemic caused a sharp increase in cases from 28 to 40 months in early 2020, stabilizing at 33 to 36 cases in the postpandemic period. Residual analysis showed greater variability during the pandemic period than during the prepandemic period. These findings indicate a sustained increase in postpandemic cardiac arrest cases, with persistent seasonal effects and higher winter case counts.

4. Discussion

The COVID-19 pandemic has had significant clinical and epidemiological effects on the management and outcomes of cardiac arrest. The results of this study demonstrate that the pandemic not only affected the patient population but also challenged the capacity of healthcare systems to meet increased demands during the crisis.

There was a noticeable increase in the frequency of cardiac arrest cases during the pandemic. Several key factors have been implicated in this rise, including the direct cardiovascular impacts of COVID-19, such as myocardial infarction, arrhythmias, and thromboembolic events.^[3] Additionally, delays or shortcomings in medical care management during the pandemic and the reluctance of individuals to seek hospital care due to fear of infection further contributed to this increase. This was particularly evident during the early phase of the pandemic when a surge in caseload emphasized the importance of restructuring healthcare systems to better handle such crises.

The impact on the patient outcomes was also significant. COVID-19-positive patients exhibited lower rates of ROSC and higher mortality rates than non-COVID-19 patients.^[6] In addition, these patients experienced longer intervention times and lower discharge rates. These findings suggest that COVID-19 has had an adverse impact on both the resuscitation process and overall patient outcomes. However, certain factors, such as VF as the initial rhythm, were associated with better outcomes despite the challenges posed by the pandemic.

Comorbidities also play a crucial role in cardiac arrest outcomes. Conditions such as COPD, cancer, and heart failure are associated with lower rates of ROSC and higher mortality rates.^[10] These results indicate that patients with preexisting comorbidities are particularly vulnerable during the pandemic and require targeted management strategies to improve outcomes in such high-risk groups.

A time trend analysis revealed that although there was a partial reduction in cardiac arrest cases in the postpandemic period compared with the peak pandemic phase, the case rates remained higher than the prepandemic levels.^[11] This finding suggests that the healthcare system continues to experience the long-term effects of the pandemic, highlighting the need for sustainable and adaptive strategies to manage the ongoing challenges posed by public health crises.

In this study, multiple methods were used to deal with missing data. First, the randomness of the missing data was examined, and proper missing data analysis was performed accordingly. Because the missing data were randomly missing in most cases, the mean substitution was used to replace missing values in this case. However, for variables with systematic missingness, the regression imputation method was used, in which missing values were imputed using other independent variables.

To avoid the false-positive error rate resulting from multiple comparisons, Bonferroni correction was used.^[12] This method decreases the statistical significance level (P value) by dividing it by the number of tests performed, thereby increasing the threshold for each test. This makes the results statistically sound and prevents false-positive results.

The results of the study showed that missing data management and multiple comparison corrections affected the study results. The analyses were also enhanced in terms of consistency by proper missing data analysis, while the Bonferroni correction was used to avoid false-positive results.^[13] These methodological approaches are essential elements that increased the credibility of our study.

The clinical and policy implications of these findings emphasize the necessity of strengthening healthcare systems to better respond to future outbreaks and other large-scale health emergencies. Efforts to improve intervention times, optimize resource allocation, and develop specific management plans for high-risk patient groups could contribute to better patient outcomes while reducing the strain on the healthcare infrastructure.

Analyzing the seasonal trends in cardiac arrest cases during the prepandemic and pandemic periods revealed a significant effect. For instance, an increase in cases was observed, particularly during the winter months. This is believed to be due to the fact that cold weather is linked with respiratory infections. Cold weather is a known risk factor for myocardial ischemia, which may lead to cardiac arrest. Furthermore, systemic inflammation resulting from influenza and other respiratory infections may worsen heart conditions.

This increase was even more pronounced during the pandemic period. This is mainly because COVID-19 can worsen the condition and increase the risk of cardiac arrest through cardiovascular complications, and the fact that healthcare services are stretched during winter.^[14] In the initial stages of the pandemic, fear of going to the hospital and the overwhelming healthcare system made it difficult to handle the increasing seasonal cardiac arrest rates. These results show that there are seasonal trends in cardiac arrest and that it is important to consider the effects of cold weather and respiratory diseases on the heart. Therefore, it is important for healthcare systems to be better prepared during the winter. In addition, it is important that high-risk individuals should be closely monitored and measures should be taken to prevent overburdening healthcare systems during crises.

The data presented in this study provide valuable insights for both clinical practice and healthcare policy by offering a comprehensive analysis of the influence of the COVID-19 pandemic on adult cardiac arrest. These results can serve as a foundation for developing proactive strategies to minimize the negative impact of similar crises in the future.

5. Conclusion

This study highlights the significant impact of the COVID-19 pandemic on the incidence, management, and outcomes of adult cardiac arrest cases. The findings indicate a notable increase in cardiac arrest cases during the pandemic driven by the direct cardiovascular effects of COVID-19, delayed medical interventions, and healthcare system overload. COVID-19-positive patients had lower ROSC rates, higher mortality rates, and longer intervention times, emphasizing the negative impact of the virus on resuscitation outcomes. Additionally, comorbidities, such as COPD, cancer, and heart failure, further worsen patient prognosis.

Time trend analysis revealed that while postpandemic cardiac arrest rates declined from peak levels, they remained above prepandemic levels, with seasonal variations showing a persistent increase in the winter months. These findings underscore the ongoing burden on healthcare systems.

To mitigate future crises, healthcare strategies should prioritize reducing intervention times, optimizing resource allocation, and implementing targeted care plans for high-risk patients. These insights provide valuable guidance for clinical practice and healthcare policy, aiding the development of more resilient emergency care systems.

Author contributions

Conceptualization: Erkan Boğa.

Data curation: Erkan Boğa.

Methodology: Erkan Boğa.

Project administration: Erkan Boğa.

Software: Erkan Boğa.

Writing—original draft: Erkan Boğa.