Risultati per: Le linfoadenopatie vaccino COVID-19 correlate: ruolo della POCUS in Medicina Generale

Circulation, Volume 150, Issue Suppl_1, Page A4141333-A4141333, November 12, 2024. Background:COVID-19 is a multiorgan disease characterized by a prothrombotic state and increased risk of venous thromboembolism (VTE), especially in hospitalized patients. Although prior studies have attempted to identify predictors of VTE, restricted sample size and use of administrative claims data have limited such analyses. We conducted a multivariable analysis to identify predictors of VTE in hospitalized patients with COVID-19 in a multicenter patient-level registry.Methods:We utilized data from the CORONA-VTE Network, a US multicenter registry of 10,420 adult (≥18 years) patients with PCR-confirmed COVID-19 of whom 3,844 were hospitalized. The primary outcome was time-to-first-event for a composite of adjudicated pulmonary embolism and deep vein thrombosis (e.g. lower extremity, mesenteric, gonadal vein, etc.) during 90-day follow-up. The candidate variables were selected by a priori clinical consensus. The variables with ≥20% missing data were excluded, whereas those with missing data

Circulation, Volume 150, Issue Suppl_1, Page A4113573-A4113573, November 12, 2024. Introduction/Background:Cardiovascular and neurological diseases develop in a significant proportion of COVID-19 patients. Minimally invasive tools to predict outcome after SARS-CoV-2 infection would enable personalized healthcare, potentially easing the disease burden. We showed that blood levels of the long noncoding RNA lymphoid enhancer-binding factor-1 antisense 1 (LEF1-AS1) predict COVID-19 in-hospital mortality.Hypothesis:LEF1-AS1 is associated with long-term clinical outcomes of COVID-19.Aim:Test the capacity of LEF1-AS1 to predict neuro-cardio-vascular outcomes post-SARS-CoV-2 infection.Methods/Approach:We enrolled 104 primo-infected COVID-19 patients aged 18+ recruited from April to December 2020 in the PrediCOVID national cohort for which 12-month follow-up data were available (Ethics Committee approvals 202003/07 and 202310/02-SU-202003/07). Whole blood samples were collected at baseline and expression levels of LEF1-AS1 were assessed by quantitative PCR.Results/Data:Of the 104 patients, 35 had at least one neurological symptom and one cardiovascular symptom at month 12. Levels of LEF1-AS1 at baseline were lower (p=0.019) in patients who developed neurological and cardiovascular symptoms as compared to patients who did not. Lower LEF1-AS1 was associated with symptoms development with an odds ratio of 0.48 (95% CI 0.28-0.83) from logistic regression model adjusted for age, sex, comorbidities and disease severity at baseline. Addition of LEF1-AS1 to a clinical model including age, sex, comorbidities and baseline severity yielded an incremental predictive value as attested by an increased AUC from 0.79 to 0.83 (likelihood ratio test p=0.005), a net reclassification index of 0.54 (p=0.007) and an integrated discrimination improvement of 0.08 (p=0.009).Conclusion:Blood levels of LEF1-AS1 predict 12-month neurological and cardiovascular outcomes of COVID-19 patients. This needs to be validated in larger populations.

Circulation, Volume 150, Issue Suppl_1, Page A4143488-A4143488, November 12, 2024. Background:Patients with acute decompensated heart failure (ADHF) often require admission to the Cardiac Care Unit (CCU). Clinical examination alone may be inadequate for management, leading to suboptimal diuretic regimens and prolonged hospital stays. The use of Point-of-care ultrasound (POCUS) to evaluate the lungs for pulmonary edema and inferior vena cava (IVC) for size and collapsibility can enhance volume status evaluation.Aim:Reduce the average duration of IV diuresis by 20% among patients admitted to the CCU for ADHF in 1 yearMethods:An algorithm for POCUS guided diuretic regimen escalation was implemented across three Plan-Do-Study-Act (PDSA) cycles. Patients who were intubated, on dialysis, or with isolated RV failure were excluded. PDSA-1 introduced the algorithm and provided training to a team of 5 residents. PDSA-2 included weekly reminders and recruitment of 14 residents to increase buy-in. PDSA-3 focused on incorporating POCUS assessments into nighttime care to facilitate early morning decision-making.Results:Process Measure: Quarterly compliance rates using the number of POCUS orders that were completed- Baseline (0%, n=23), PDSA-1 (0%, n=35), PDSA-2 (19%, n=15), PDSA-3 (31%, n=46).Outcome Measure: The average duration of IV diuresis progressively decreased through the year: Baseline (5 days), PDSA-1 (5.3 days), PDSA-2 (4.4 days), PDSA-3 (3.5 days). There was an increase of 6% in PDSA-1 compared to baseline, but PDSA-2 and 3 showed a progressive reduction of 12% and 30% respectively.Balancing Measure: The mean potassium supplementation showed variation throughout the year: Baseline (63.3 mg), PDSA-1 (141 mg), PDSA-2 (151.7 mg), PDSA-3 (75.7 mg), reflecting no significant negative impact from the intervention.Equity Lens: The duration of IV diuresis, which at baseline ranged from 3 to 8 days across different races, standardized to approximately 5 days for all races by PDSA-3.Conclusion:We progressively reduced the duration of IV diuresis using POCUS-guided lung and IVC assessments with a structured diuretic regimen. This demonstrated improved patient care from early decongestion and symptomatic relief. Additionally, we demonstrate that POCUS plays a crucial role in promoting health equity by providing an objective assessment of volume status across diverse racial groups. This integration promises optimized heart failure management and potential cost reductions from reduced length of stay, highlighting the value of POCUS in clinical practice.

Circulation, Volume 150, Issue Suppl_1, Page A4137878-A4137878, November 12, 2024. Background:The COVID-19 pandemic in 2020 was marked by a sharp decrease in out-of-hospital cardiac arrest (OHCA) survival. Whether OHCA survival has recovered to pre-pandemic levels, and whether changes in OHCA survival are similar across communities of different racial and ethnic composition, is unknown.Methods:We included adult patients with non-traumatic OHCA from 2015-2022 in the Cardiac Arrest Registry to Enhance Survival registry. Using hierarchical multivariable regression, we calculated risk-adjusted rates of survival to hospital discharge during 2015-2019 (reference period) and compared this to survival rates during 2020, 2021, and 2022. We also examined whether the trajectory of survival over this period differed based on the racial/ethnic composition of the community served by the emergency medical service (EMS) agency, defined as predominantly White ( >80% White residents), majority Black or Hispanic ( >50% Black or Hispanic residents), or integrated (neither).Results:Of 485,079 patients with OHCA, mean age was 61.9 years; 64% were male, and 22% were of Black race with 7% of Hispanic ethnicity. Overall, risk-adjusted survival rates to hospital discharge for OHCA decreased from 10.1% in 2015-2019 to 8.4% in 2020 (P

Circulation, Volume 150, Issue Suppl_1, Page A4139661-A4139661, November 12, 2024. Introduction:Troponin-defined myocardial injury or N-terminal pro-B-type natriuretic peptide (NT-proBNP) elevation frequently coincides with coronavirus disease 2019 (COVID-19). Our prior study (COVID-MI Registry Cohort-1) confirmed that high-sensitive troponin I (HsTnI) and NT-proBNP effectively stratified mortality risk. However, variants of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) change rapidly, and it remains unclear whether these biomarkers are consistently effective in predicting prognosis of COVID-19 patients irrespective of epidemic periods.Research Questions:Can HsTnI or NT-proBNP stratify mortality risk in recent COVID-19 cohorts?Aims:To assess the potential of HsTnI and NT-proBNP levels for risk stratification in the recent COVID-19 waves.Methods:In the COVID-MI Registry Cohort-2, we enrolled 1115 consecutive COVID-19 patients admitted between October 2021 and October 2022, during the Omicron variant endemic. We collected data of HsTnI or NT-proBNP levels from hospital charts or using the samples in our hospital’s serum/plasma bank if the data were not available. The primary outcome measure was all-cause mortality.Results:On admission, more than one-third of patients were classified as having severe COVID-19. HsTnI and NT-proBNP levels were available for 427 and 414 patients, respectively. The median HsTnI and NT-proBNP levels were 16 (interquartile range [IQR]: 5-57) ng/L and 524 (IQR: 140-2056) pg/mL, respectively. We stratified the patients into three groups by HsTnI level:

Circulation, Volume 150, Issue Suppl_1, Page A4137782-A4137782, November 12, 2024. Background:Fibrinogen-to-albumin ratio (FAR) has been proposed as a readily available inflammatory biomarker associated with coronary artery disease (CAD). However, its association with CAD severity and prognosis has predominantly been assessed in patients with acute coronary syndromes (ACS). The Leiden score is a validated comprehensive measure of CAD incorporating stenosis proximity, severity, and plaque type that independently predicts cardiovascular events. Whether FAR is associated with Leiden score or high-risk plaque features on coronary computed tomographic angiography (CCTA) in stable outpatients is unknown.Methods:Adult outpatients undergoing clinically indicated CCTA were enrolled (5/2021-9/2023) in a prospective study assessing the relationship of plaque to immune markers and provided same-day pre-scan peripheral venous blood samples. CCTAs were post-processed and analyzed by the consensus of two expert readers blinded to clinical data using a 17-segment model to determine coronary artery calcium (CAC), Leiden score, and high-risk plaque features. Patients were grouped by FAR (quartiles), Leiden score (20), and CAC score (0, >0-100, >100-300, >300-1000, >1000). Numerical variables were compared via Wilcoxon and Kruskal-Willis tests. Spearman correlation was calculated between FAR and Leiden score.Results:Of 284 patients, 53.8% were male, 86.7% were white, and 58.8% were on a statin (Table 1). Median FAR was 70.3 mg/g, 64.0% had a non-zero CAC score, and 25.0% had at least one segment with one high-risk plaque feature. Across quartiles of FAR, there was no difference in Leiden score (5.8 (IQR: 0.0-18.5), 12.4 (3.1-20.7), 8.0 (0.0-19.9), 6.8 (0.0-21.1), p=0.50) or probability of having at least one segment with at least one (29.6%, 23.9%, 23.9%, 22.5%, p=0.69) or two (18.3%, 14.1%, 12.7%, 15.5%, p=0.66) high-risk plaque features. There was no correlation between FAR and Leiden score (R=0.03, p=0.66). There was no difference in FAR when stratified by Leiden score (Table 1, p=0.53), CAC score (Table 2, p=0.50), or number of segments with at least one high-risk plaque feature (Table 3, p=0.18).Conclusion:In a prospective cohort of adult outpatients across a wide spectrum of CAD burden with high rates of baseline statin use, FAR was not associated with CAD or presence of high-risk plaque features on CCTA. Further evaluation of its role as an inflammatory biomarker in larger populations, particularly patients without ACS, is required.

Circulation, Volume 150, Issue Suppl_1, Page A4146890-A4146890, November 12, 2024. Background:COVID-19 has introduced new complexities in the management of patients undergoing the transcatheter edge-to-edge repair (TEER) procedure of the mitral valve. This study compares outcomes of mitral valve TEER in patients with and without COVID-19, utilizing data from the National Inpatient Sample (2020-2021).Methods:We conducted a retrospective cohort study on 23,465 patients without COVID-19 and 85 patients with COVID-19 undergoing mitral valve TEER. Multivariate logistic regression was employed to compare outcomes, adjusting for potential confounders. Primary outcomes included mortality and major complications, while secondary outcomes encompassed specific procedural complications.Results:Patients with COVID-19 were younger (mean age: 73.176 vs. 76.178 years, p-value

Circulation, Volume 150, Issue Suppl_1, Page A4140703-A4140703, November 12, 2024. Background:The mRNA vaccines against COVID-19 are highly effective but have been associated with a rare non-infective form of myocarditis, particularly in young males after receiving the second dose. Understanding the mediators of this adverse effect is crucial to enhance the safety of future mRNA vaccines.Hypothesis:Myocardial injury following COVID-19 mRNA vaccination is mediated by overproduced cytokines, and estrogens have a protective effect on this adverse effect.Approach:Candidate cytokine mediators were identified through analysis of proteomics data from plasma samples of vaccinated individuals. Human iPSC-derived macrophages and cardiomyocytes were used to model cytokine-induced effects. An in vivo mouse model of cytokine-induced myocardial injury was employed to assess the impact of the cytokine cocktail and estrogens.Results:CXCL10 and IFN-γ were consistently upregulated in vaccinated individuals on day 1 and further elevated in patients with myocarditis following mRNA vaccination. Consistently, iPSC-derived macrophages exposed to COVID-19 mRNA vaccines produced these cytokines. Next, iPSC-derived cardiomyocytes exposed to these cytokines showed impaired contractility, arrhythmogenicity, and pro-inflammatory gene expression. The phytoestrogen genistein mitigated these effects in vitro, reducing cytokine-induced proteasomal degradation of cardiac proteins and preserving contractile function. In vivo, genistein significantly decreased cardiac injury markers and immune cell infiltration in a mouse model of cytokine-induced myocardial injury.Conclusion:CXCL10 and IFN-γ are key mediators of myocardial injury post-mRNA vaccination. Genistein shows potential as a therapeutic agent to mitigate associated cardiovascular risks.

Circulation, Volume 150, Issue Suppl_1, Page A4141859-A4141859, November 12, 2024. Background:Field activation of patients with ST-segment elevation myocardial infarction (STEMI) by Emergency Medical Services (EMS) during the COVID-19 (COVID) pandemic era involved a change in policy whereby patients underwent COVID-19 testing in the emergency department (ED) prior to Percutaneous Coronary Intervention (PCI) versus bypassing the ED to the Catheterization (Cath) Lab.Research Question:We aimed to compare In-Hospital Mortality and other performance metrics of field activated STEMI patients at a large rural health system during the COVID era to pre and post pandemic periods.Methods:Retrospective single-center (Essentia Health, Duluth, MN, USA) cohort study of consecutive patients with STEMI activation identified in the field by EMS prior to the COVID era (5/27/2018–3/26/2020), during the 22 months of the COVID testing policy (3/27/2020–1/25/2022), and post-COVID when ED bypass resumed (1/ 26/2022–11/26/2023). The main outcomes of this study were in-hospital mortality and common STEMI system performance metrics.Results:A total of 373 consecutive field activated STEMI cases were included (pre COVID [N =132], COVID [N = 104], post COVID [N = 137]). Pre COVID, 40.9% of EMS activated STEMI cases stopped in the ED prior to the Cath Lab, 97.1% during the COVID era, and 51.1% in the post-COVID era (p

Circulation, Volume 150, Issue Suppl_1, Page A4142337-A4142337, November 12, 2024. Background:We previously demonstrated a significantly increased inpatient mortality of COVID-19 infection-induced male Takotsubo (TTS) patients during the early pandemic period. Since then, our management of COVID-19 prevention and treatment have evolved significantly, reducing both hospitalization and mortality rates. With these advancements, we have analyzed the clinical characteristics and outcomes of reported COVD-19-associated TTS patients since the initial pandemic.Research Question:What are the clinical characteristics and mortality outcomes of COVID-19-associated TTS patients especially in the context of improved prevention and treatment?Aims:To identify clinical characteristics and outcome correlates in patients with COVID-19-associated TTS.Methods:We completed a systematic review of 191 patients with TTS from 95 published case reports, 13 case series, and 4 observational cross-sectional/cohort studies published from April 1, 2020 to May 1, 2024 (PubMed). We performed clustering analysis using the clinical, imaging, and inpatient mortality data of 78 patients, which categorized groups of patients based on how closely associated or similar they are relative to other groups. Following this, we applied feature analysis to identify which features contributed the most to the clustering results.Results:Of all TTS cases, the mean age was 64.2±16.1 with 32.9% males. A total of 122 (63.9%) had COVID-19 infection, 21 (11.0%) had COVID-19 vaccination, and 50 (26.2%) patients had other triggers (2 patients had both COVID-19 infection and a non-infectious trigger). In-hospital mortality was 28.6% (16 of 56) for males and 13.2% (15 of 114) for females (p-value = 0.01). There was no association between COVID-19 vaccine administration and in-hospital mortality (0%, 0 of 21). There were notable differences in the clinical and demographic characteristics of TTS patients before and after September 2021 based on clustering analysis. Feature analysis indicated that COVID-19-induced TTS strongly correlated with in-hospital mortality and long-term adverse outcome in male patients.Conclusion:More male TTS patients were found during the pandemic than is expected of the traditional TTS archetype. A triad of “male, COVID-19 infection and TTS” appears to predict higher inpatient mortality. Compared to our prior study, inpatient mortality rates for TTS COVID patients have declined for all groups. Vaccine-induced TTS is associated with a benign clinical phenotype.

Circulation, Volume 150, Issue Suppl_1, Page A4141276-A4141276, November 12, 2024. Introduction:Aortic valve stenosis (AVS) is a degenerative disease characterized by progressive calcification and stenosis, driven by a multifactorial inflammatory process. Oxidized phospholipids (OxPL) have been implicated in this process, yet their presence in aortic valve tissue remains unexplored. This study aims to fill this gap by developing a sensitive method to identify and quantify OxPL in the plasma and tissue of patients with severe AVS.Methods:We obtained aortic valve tissue from 70 patients undergoing aortic valve replacement surgery. The tissue samples were subjected to derivatization with DNPH, followed by LC/MS/MS analysis, enabling the identification and quantification of 60 individual OxPL across five different phospholipid classes.Results:Our analysis identified 34 OxPL species across five phospholipid classes in human valvular tissue, including oxidized phosphatidylcholine (OxPC), phosphatidylethanolamine (OxPE), phosphatidylinositol (OxPI), and phosphatidylserine (OxPS). OxPC was the most abundant class, with PONPC being the most prevalent molecule, constituting 35% of total OxPL. We observed a significant increase (p

Circulation, Volume 150, Issue Suppl_1, Page ASa807-ASa807, November 12, 2024. Background:Despite the lack of evidence supporting the use of chest compression-only cardiopulmonary resuscitation (CO-CPR) emphasizing the importance of rescue breathing for pediatric out-of-hospital cardiac arrest (OHCA), prehospital CO-CPR is increasing. The COVID-19 pandemic may have led more bystanders to perform CO-CPR, even for pediatric OHCA. However, studies on the dissemination of CO-CPR and outcomes in pediatric OHCA are limited.Hypothesis:Spread of CO-CPR led to increased mortality in pediatric OHCA.Aims:Investigate the mortality of nationwide pediatric OHCA patients with the dissemination of CO-CPR pre- and post-COVID-19.Methods:We conducted a retrospective study using a Utstein-Style population cohort database (Japanese National Registry). Pediatric OHCA patients (≤17 years old) with bystander resuscitation attempts registered between the pre-COVID-19 era (2017-2019) and the post-COVID-19 era (2020-2021) were included. The primary outcome was 30-day mortality after OHCA. The secondary outcome was 30-day poor neurological outcomes, defined as Cerebral Performance Category scores of 3, 4, or 5. We used Poisson regression with robust variance to estimate adjusted risk ratio (aRR) with 95% confidence interval (CI) and the population attributable fraction (PAF, %) with a focus on the post-COVID-19 period.Results:A total of 3,352 pediatric OHCA, 2,023 pre-COVID-19, and 1,329 post-COVID-19 patients received bystander CPR and were registered in the database. CO-CPR was more common than CPR with rescue breathing (RB-CPR) during the pre- and post-COVID-19 periods [pre-COVID-19: 1,356 (67.0%) vs. 667 (33.0%), post-COVID-19: 1,048 (78.9%) vs. 281 (21.1%)]. Comparison of CO-CPR vs. RB-CPR showed increased 30-day mortality in both periods [pre-COVID-19: 1,081/1,356 (79.7%) vs. 420/667 (63.0%), post-COVID-19: 841/1,048 (80.2%) vs. 181/281 (64.4%)]. In the overall cohort, mortality increased with CO-CPR (aRR: 1.16, 95% CI: 1.09-1.23, PAF:1.60%). Due to the increased number of patients receiving CO-CPR, we estimated 21.2 excess deaths over the two-year post-COVID-19 period. Similar results were observed for poor neurological outcome (aRR: 1.10, 95% CI: 1.05-1.16, PAF: 1.10%, excess poor outcome: 14.6]).Conclusion:With the spread of CO-CPR for pediatric OHCA, an estimated 10.6 excess deaths per year attributed to CO-CPR may have occurred in the post-COVID-19 period compared to the pre-COVID-19 period in Japan.

Circulation, Volume 150, Issue Suppl_1, Page A4144997-A4144997, November 12, 2024. Introduction:Myocardial injury in patients hospitalized with acute on chronic heart failure concurrent with index SARS-CoV-2 (CoV-2) infection is well described, though studies incorporating pre- and post-acute COVID-19 (PAC) are lacking. We address this gap by estimating intensity of acutely decompensated heart failure (ADHF) using time-series pro-BNP levels across hospitalizations pre- vs. respectively index and initial readmission (PAC1).Hypothesis:Case time series analysis will reveal association (p

Circulation, Volume 150, Issue Suppl_1, Page A4141946-A4141946, November 12, 2024. INTRODUCTION:Mechanisms contributing to the post-acute sequelae of SARS-CoV-2 (PASC, aka Long COVID) and associated functional limitations are unclear.RESEARCH QUESTION:Determine cardiovascular, autonomic and exercise physiology among patients with Long COVID.METHODS:Twenty-one Long COVID patients (16 females, 41±12yrs) underwent cardiovascular assessment during head-up tilt at supine, 30oand 60o, a 10-minute upright standing orthostatic challenge and cardiopulmonary exercise testing (CPET). Baroreceptor sensitivity was determined with Valsalva maneuver. Heart rate (HR) and blood pressure (BP) were monitored continuously. Plasma norepinephrine (NE) was monitored during tilt.RESULTS:During tilt, HR increased with transition from supine to 30oand 60o(72±12 v. 80±14 v. 90±15bpm, P

Circulation, Volume 150, Issue Suppl_1, Page A4139757-A4139757, November 12, 2024. Background:The COVID-19 pandemic has significantly exacerbated sleep problems. Pandemic-related lockdowns and drastic changes in daily life have disrupted sleep patterns, resulting in a marked increase in sleep disturbances.Research questions:This study aims to investigate the primary factors contributing to the increase in sleep disturbances during the COVID-19 pandemic in Korea. By utilizing nationally representative data encompassing various variables, this study seeks to identify COVID-19-related factors associated with sleep disturbances during the pandemic.Method:We analyzed data from the nationally representative Korea Community Health Survey conducted in 2020, including 216,809 adults. Changes in daily life due to COVID-19 were assessed by asking participants to score their current situation compared to their pre-pandemic situation, ranging from 100 (no change) to 0 (complete cessation of daily activities). COVID-19 concerns were assessed with five questions: 1) fear of contracting the virus; 2) fear of mortality if infected; 3) fear of blame from others; 4) concerns about the health of vulnerable family members; and 5) concerns about economic impacts. Sleep disturbances were defined as sleeping 5 hours or less per night on average. Logistic regression analyses with a complex sample design were performed to examine the relationship between COVID-19-related factors and sleep disturbances, adjusting for socioeconomic and health-related variables.Results:A high level of lifestyle changes due to COVID-19 (OR = 1.15, 95% CI = 1.11–1.19) and high COVID-19 concerns (OR = 1.04, 95% CI = 1.01–1.08) were associated with an increased likelihood of sleep disturbances. Conversely, resting during COVID-19 symptoms (OR = 0.81, 95% CI = 0.76–0.87), having support during quarantine (OR = 0.93, 95% CI = 0.89–0.97), and trust in the government and neighbors (OR = 0.92, 95% CI = 0.89–0.96) were associated with a decreased likelihood of sleep disturbances.Conclusion:These findings suggest that sleep disturbances during the COVID-19 pandemic were mediated by lifestyle disruptions and high levels of concern. Social support and trust mitigated the impact of COVID-19-related risk factors. As part of preparedness, improving the environment to facilitate adequate rest during illness, ensuring strong social support, and fostering high levels of trust in the government and neighbors may be important to protect sleep health during future public health emergencies.

Circulation, Volume 150, Issue Suppl_1, Page ASa907-ASa907, November 12, 2024. Background:Different from the negative impact of COVID-19 pandemic on outcomes after out-of-hospital cardiac arrest (OHCA) collapsed before emergency medical service (EMS) arrival, there was a report suggested that COVID-19 pandemic did not affect outcomes after OHCA witnessed by EMS personnel. However, no large-scale studies have examined the impact of COVID-19 pandemic after EMS-witnessed OHCA, focusing on favorable neurological outcomes.Research Questions:Does COVID-19 pandemic affect favorable neurological outcomes after EMS-witnessed OHCA?Aims:To assess COVID-19’s impact on favorable neurological outcomes after EMS-witnessed OHCA.Methods:We performed an interrupted time series analysis (ITSA) with a prospective, nationwide, population-based registry in Japan to assess trends of incidence and favorable neurological outcome (Cerebral Performance Category 1 or 2) at 30 days with adult EMS-witnessed OHCA between pre-pandemic (January 2016-March 2020) and pandemic (April 2020-December 2021) periods. Subgroup analyses were performed by stratifying regions by infection spread status defined by whether a state of emergency has been declared. To assess whether there are differences in trends between areas with and without COVID-19 spread, we performed a controlled ITSA between the two areas.Results:We identified 58,315 patients with adult EMS-witnessed OHCA, 41,112 during the pre-pandemic period and 17,203 during the pandemic period. There was no significant increase in the incidence of EMS-witnessed OHCA during the pandemic period (0.03 per 100,000 person-years; 95% confidence interval [CI], –0.02 to 0.08; p = 0.21). Favorable neurological outcome significantly decreased (relative risk [RR], 0.80; 95% CI, 0.71 to 0.91; p < 0.01). In subgroup analysis, favorable neurological outcome significantly decreased in areas with COVID-19 spread (RR, 0.67; 95% CI, 0.56 to 0.81; p < 0.01), while there was no significant difference in areas without COVID-19 spread (RR, 0.91; 95% CI, 0.77 to 1.07; p = 0.24). A controlled ITSA showed that favorable neurological outcome significantly decreased in areas with COVID-19 spread compared to without COVID-19 spread (RR, 0.77; 95% CI, 0.60 to 0.98; p = 0.04).Conclusion:Unlike previous studies, our research with a nationwide, population-based registry showed that COVID-19 pandemic influenced favorable neurological outcome in EMS-witnessed OHCA. This trend appears to be more pronounced in areas with widespread infection.