Higher chances of survival to hospital admission after out-of-hospital cardiac arrest in patients with previously diagnosed heart disease

AimThis study aimed to determine whether patients suffering from out-of-hospital cardiac arrest (OHCA) with a pre-OHCA diagnosis of heart disease have higher survival chances than patients without such a diagnosis and to explore possible underlying mechanisms.MethodsA retrospective cohort study in 3760 OHCA patients from the Netherlands (2010–2016) was performed. Information from emergency medical services, treating hospitals, general practitioner, resuscitation ECGs and civil registry was used to assess medical histories and the presence of pre-OHCA diagnosis of heart disease. We used multivariable regression analysis to calculate associations with survival to hospital admission or discharge, immediate causes of OHCA (acute myocardial infarction (AMI) vs non-AMI) and initial recorded rhythm.ResultsOverall, 48.1% of OHCA patients had pre-OHCA heart disease. These patients had higher odds to survive to hospital admission than patients without pre-OHCA heart disease (OR 1.25 (95%CI 1.05 to 1.47)), despite being older and more often having cardiovascular risk factors and some non-cardiac comorbidities. These patients also had higher odds of shockable initial rhythm (SIR) (OR 1.60 (1. 36 to 1.89)) and a lower odds of AMI as immediate cause of OHCA (OR 0.33 (0.25 to 0.42)). Their chances of survival to hospital discharge were not significantly larger (OR 1.16 (0.95 to 1.42)).ConclusionHaving pre-OHCA diagnosed heart disease is associated with better odds to survive to hospital admission, but not to hospital discharge. This is associated with higher odds of a SIR and in a subgroup with available diagnosis a lower proportion of AMI as immediate cause of OHCA.

Abstract 11488: Ventilation Rate and Sustained Return of Spontaneous Circulation in In-Hospital Cardiac Arrest: Is More Better?

Introduction: Current consensus holds that CPR must balance chest compressions and ventilation rate (VR), with a low VR being essential for venous return and cardiac output. AHA guidelines recommend a VR of 10 ventilations per minute (vpm) after advanced airway placement. We sought to examine VR adherence and its impact on end-tidal CO 2 (ETCO 2 ) and ROSC >20 minutes. Methods: This is a retrospective analysis of data from AWARE II, a multicenter prospective observational study of adult in-hospital cardiac arrest (IHCA) outcomes at 14 US and UK sites. Inclusion criteria were: 1) adult patient in CA, 2) advanced airway already in place or placed during the CA, and 3) at least one minute of VR and ETCO 2 data available after removal of the last minute of CPR in subjects achieving ROSC (due to the rise of ETCO 2 just prior to ROSC). Results: A total of 563 subjects were enrolled in the parent study. Of these, 225 had ETCO 2 and VR tracings available, and 201 had sufficient data for inclusion. Mean age was 69.3 (range 18-100), patients were 63.7% male, and 16.4% had a shockable initial rhythm. A total of 116 subjects (57.7%) achieved ROSC, which was sustained in 76 (37.8%), leading to survival to hospital discharge with favorable neurological outcomes in 9 (4.5%). Mean VR was 16.3 vpm, with 171 (85.1%) subjects being ventilated in excess of guidelines; only 16 (8.0%) subjects received 8-10 vpm. Higher VR had a weak but significant association with increased mean ETCO 2 (linear R 2 = 0.11, p < 1x10 -6 ) and sustained ROSC (OR 1.05; 95% CI: 1.01-1.11; p = 0.02). Patients with sustained ROSC had a significantly higher VR at 17.7 vpm than those without sustained ROSC at 15.6 vpm (p = 0.007). Patients receiving a VR close to AHA guidelines (6-12 vpm) had a significantly lower rate of sustained ROSC (26.1%, n = 46) than patients receiving >12 vpm (42.0%, n = 148) (OR 2.30; 95% CI: 1.08-4.89; p = 0.031 using a multivariate model including patient age, shockable initial rhythm, known cardiac disease, witnessed IHCA, and use of mechanical compressions). Conclusions: VR within AHA guidelines is rare during IHCA. However, ventilation in excess of current guidelines may increase rates of sustained ROSC, an essential predicate to survival. AHA guidelines on VR in CPR with an advanced airway may not yet be optimized.

Abstract 8875: Early Compared to Late Administration of Epinephrine in Adults With Shockable Initial Rhythm Out-of-Hospital Cardiac Arrest

Introduction: The optimal timing of epinephrine administration in shockable initial rhythm out-of-hospital cardiac arrest (OHCA) is unclear. Hypothesis: Early compared to late epinephrine following first electrical defibrillation attempt is associated with better outcomes in shockable initial rhythm OHCA. Methods: We conducted a retrospective study in adults with shockable initial rhythm OHCA from 2011-2015 in North America. We used multivariable logistic regression to assess associations between timing of epinephrine and prehospital return of spontaneous circulation (ROSC), survival to hospital discharge, and hospital discharge with favorable neurological outcome (modified Rankin Scale score≤3). We used propensity-score-matching and subgroup analyses to assess robustness of associations. Results: Of 6416 patients, median age was 64 (IQR: 54-74) years, 5136 (80%) were men, 2226 (35%) received epinephrine within four minutes after first defibrillation, 5119 (80%), 1237 (19%), and 996 (16%) had prehospital ROSC, survival to hospital discharge, and favorable neurological outcome at discharge respectively. Adjusted for confounders, we observed lower odds of prehospital ROSC (OR=0.95, 95%CI 0.94-0.96; p<0.001), survival to hospital discharge (OR=0.91, 95%CI 0.89-0.92; p<0.001), and favorable neurological outcomes at discharge (OR=0.92, 95%CI 0.90-0.93; p<0.001) per minute later epinephrine administration. Compared to epinephrine administration within four minutes following first defibrillation attempt, later epinephrine was associated with lower odds of prehospital ROSC (OR=0.58, 95%CI 0.51-0.68; p<0.001), survival to hospital discharge (OR=0.50, 95%CI 0.43-0.58; p<0.001), and favorable neurological outcome at discharge (OR=0.51, 95%CI 0.43-0.59; p<0.001). Associations remained significant in a well-balanced propensity score matched cohort and subgroup analyses by witness status, EMS response time, and total epinephrine dose. Conclusion: In shockable initial rhythm OHCA, early compared to late epinephrine administration following first defibrillation attempt was associated with better odds of prehospital ROSC, survival to hospital discharge, and hospital discharge with favorable neurological outcome.

Abstract 9774: Shockable Rhythms Are Common First Rhythms in Cardiac Arrests Involving Patient with Heart Failure with Preserved Ejection Fraction

Introduction: Sudden cardiac death (SCD) is responsible from 25% of the total mortality in patients with heart failure with preserved ejection fraction (HFpEF). Whether SCD in HFpEF is due to shockable or unshockable rhythms is unknown. Hypothesis: Cardiac arrests in HFpEF are due to ventricular tachycardia/ventricular fibrillation (VT/VF). Methods: We determined the initial rhythm in 286 consecutive in-hospital cardiac arrests at the Minneapolis VA Health Care system from 2011 through 2020. Clinical and survival information were obtained from electronic health records. According to their heart failure history, we categorized the patients as HFpEF, heart failure with reduced ejection fraction (HFrEF) or no heart failure (NoHF). Results: Of the 286 patients (mean age 70.2±9.0 years old and 97.5% male), 51 (17.8%) had HFpEF, 77 (26.9%) had HFrEF and 158 (55.2%) had NoHF. The initial rhythm was VT/VF in 47.1%, 39.0% and 22.2% of patients with HFpEF, HFrEF and NoHF respectively (p<0.001) (Figure). Return of spontaneous circulation (ROSC) after VT/VF arrest was similar amongst the three groups (66.7%, 73.3% and 74.3%, respectively; p=0.8) but the 30-day survival trended higher in HFpEF (54.2%) and NoHF (48.6%) when compared with HFrEF (26.7%) (p=0.08)(Figure). Among patients with HFpEF, 30-day survival was lower after cardiac arrests due to PEA/Asystole when compared to those due to VT/VF (18.5% vs. 54.2%, respectively, p=0.03). Conclusion: VT/VF was the initial rhythm in 47% of patients with HFpEF who had in-hospital cardiac arrest. The proportion of VT/VF and ROSC after in-hospital cardiac arrest was similar in HFpEF and HFrEF. These data provide one more piece of evidence that SCD could be a therapeutic target in HFpEF.

Abstract 13013: Survival After In-Hospital Cardiopulmonary Resuscitation for Cardiac Arrest in Patients With COVID-19: An Updated Meta-Analysis

Introduction: Several small studies have reported variable outcomes following in-hospital cardiac arrest (IHCA) in patients with COVID-19. A clear estimate is important in prognostication and guiding resuscitation efforts and policies for these patients. Methods: A search of PubMed, Embase, and Scopus databases was conducted to identify studies reporting outcomes after IHCA in adult patients with confirmed COVID-19. The cumulative characteristics of the patients were described. The primary outcome studied was survival at 30 days or at hospital discharge (short term survival). Additional outcomes of interest were proportional prevalence of the initial rhythm at arrest, return of spontaneous circulation (ROSC), and neurological recovery (defined as Cerebral Performance Category Score of 1-2 ). Metanalysis of proportions was performed utilizing the Metaprop command. A random effects model was chosen to account for interstudy variance. Results: A total of 13 eligible studies were identified and included in the analyses. Out of all the hospitalized patients with COVID-19, 1,618 underwent advanced cardiac resuscitation after an IHCA. Patients who had a cardiac arrest had a median age between 50-69 years. IHCA occurred predominantly in men, and in the ICU setting. Shockable rhythms were identified in 8% (95% CI 5-10%, I2; 56%) and non-shockable rhythms in 89% (95% CI 85-94% I2; 84%) of patients (Fig. 1a). ROSC was achieved in 40% (95% CI 31-48% I2; 90%) (Fig. 1b). Only 7 % ( 95% CI 3-12% I2; 86%) of patients survived at 30 days/hospital discharge (Fig. 1c). Neurological recovery was seen in 5% (95% CI 3-9% I2; 67%) of patients who suffered a IHCA (Fig. 1d). Conclusions: Our meta-analysis demonstrates the majority of the cardiac arrests in patients with COVID-19 have non-shockable rhythms. Survival rate in these patients is low, and neurological recovery is unfavorable. This study provides further insight in guiding resuscitation efforts in these patients.

Abstract 9899: Sex-Related Differences in Severe Cerebral Edema Development in Comatose Cardiac Arrest Patients

Introduction: Previous studies have shown that women have poorer neurological outcomes than men following out-of-hospital cardiac arrest (OHCA). However, those studies focused on survival, a measure that may be confounded by withdrawal of life-sustaining therapy (WLST) decisions. We sought to assess sex differences in severe cerebral edema development following cardiac arrest. Methods: Data from adult OHCA patients presenting between 2007-2019 were retrospectively analyzed. Patients with multiple concomitant acute neurologic dysfunctions were excluded. Severe cerebral edema was classified as herniation or more than minimal ventricular effacement in MRI or CT radiology reports. Arrest types were categorized as shockable (VT/VF) or non-shockable (PEA, asystole). Poor outcomes were defined as Cerebral Performance Category > 3 at discharge. Multivariable backward stepwise logistic regression was performed. Results: 359 patients met our inclusion criteria. Demographics, imaging and clinical outcomes are summarized in Table 1. Women were more likely than men to have a non-shockable initial rhythm (P=0.003) and develop severe cerebral edema (P=0.005). Backwards stepwise logistic regression of an initial model including age, sex, rhythm, witnessed arrest and TTM-treatment, produced a final model that showed younger age (P<0.001), female sex (P=0.01), and non-shockable rhythm (P<0.001) as significant predictors of severe cerebral edema development. Patients with severe cerebral edema had worse outcomes (89/91 vs 176/268, P<0.001), and greater in-hospital mortality (82/91 vs 166/268, P<0.001), with a higher proportion of deaths due to brain death (15/82 vs 3/166 P<0.001). Conclusion: For OHCA patients who are initially comatose, women are more likely than men to have non-shockable rhythms and severe cerebral brain edema. These differences may be responsible for the poorer discharge outcomes that have been observed by other studies.

Abstract 10611: Variation in Out-of-Hospital Cardiac Arrest Survival Across EMS Agencies

Background: Although some studies have reported variation in out-of-hospital cardiac arrest (OHCA) survival by neighborhood and geographic region, little is known about variation in OHCA survival at the level of EMS agencies—which, unlike neighborhoods and regions, may have modifiable resuscitation practices. Methods: Within the national Cardiac Arrest Registry to Enhance Survival, we identified 258,320 non-traumatic OHCAs from 764 EMS agencies with ≥10 OHCAs annually between 2015-2019. Using multivariable hierarchical logistic regression, we computed risk-adjusted rates of survival to hospital admission for each EMS agency. We quantified the extent of variation in survival with the median odds ratios (MOR) and assessed the extent to which variation in survival was explained by two EMS agency resuscitation practices: time from 911 call to EMS arrival and the proportion of OHCAs at each EMS agency with termination of resuscitation (TOR) without meeting TOR futility criteria. Results: Of 258,320 persons with OHCA, mean age was 62.2 ± 17.0 years and 36.1% were female. Overall, 85.0% were of presumed cardiac etiology, 82.3% occurred at home, 44.0% were witnessed by a bystander, and ~75% were due to a non-shockable initial rhythm. Across the 764 EMS agencies, the median risk-adjusted rate of survival to hospital admission was 27.4% (IQR, 24.5% - 30.2%). The adjusted MOR was 1.35 (95% CI: 1.32, 1.39), suggesting that the odds of survival to hospital admission after an OHCA varied by 35% in two identical patients in one randomly selected EMS agency vs. another. EMS agencies in the lowest quartile of risk-adjusted survival had a mean EMS response time of 12.0 ± 3.4 minutes, whereas those in the highest quartile had a mean EMS response time of 9.0 ± 2.6 minutes ( P <0.001). The mean proportion of OHCA cases where CPR was terminated in the field without meeting TOR futility criteria was 27.9% ±16.1% in quartile 1 and 18.9% ±11.4% in quartile 4 ( P <0.001). Adjustment for the EMS-level variation in both resuscitation practices attenuated the MOR to 1.30 (95% CI: 1.27, 1.33). Conclusions: Rates of survival to hospital admission for OHCA vary significantly by EMS agency, and some of this variation in survival is explained by differences in EMS arrival time and TOR practice patterns.

Abstract 11532: Variation in Coronary Angiography Use in Out-of-Hospital Cardiac Arrest

Introduction: Current patterns of use of coronary angiography (CAG) among out-of-hospital cardiac arrest (OHCA) patients based on ST segment elevation (STE) on post-resuscitation ECG are not well described. Methods: Using data from the Continuous Chest Compressions trial between 2011 and 2016, we identified OHCA patients who survived to hospitalization. We examined rates of CAG across different trial clusters in the overall cohort and among pre-specified subgroups with presumed cardiac etiology of arrest e.g. initial shockable rhythm and STE on presenting ECG. Results: Of 26,148 OHCA patients across 49 trial clusters, 5608 survived to hospital admission. The mean age of patients was 64 years, with 65% men and 43% with initial shockable rhythm. Among patients with initial shockable rhythm 44% had STE on initial ECG compared with 18% of patients with initial non-shockable rhythm. Use of CAG was significantly higher in patients presenting with STE compared with no STE on initial ECG irrespective of initial rhythm: 70% vs. 31%, p<0.001 for initial shockable rhythm and 28% vs. 5%, p<0.001 for initial non-shockable rhythm. In the overall cohort, there was significant variation in CAG use across trial clusters ranging from 4% - 41% of patients within a trial cluster receiving CAG ( Figure ). This variation persisted among pre-specified subgroups with the proportion of patients within a trial cluster receiving CAG ranged from 11% - 75% for patients with initial shockable rhythm, 0% to 19% with initial non-shockable rhythm, 16% - 82% with STE, 2% - 28% without STE and 0% - 63% in patients with initial shockable rhythm and no STE on presenting ECG ( Figure ). Conclusion: There is a higher use of CAG in STE and shockable cardiac arrest, consistent with presumed cardiac etiology of arrest; however, there is large variation in the use of CAG across sites, even among patients with a presumed cardiac etiology of cardiac arrest suggesting challenges with interpretation of current guidelines.

Abstract 10707: The Impact of the COVID-19 Pandemic on Incidence and Outcomes from Out-of-Hospital Cardiac Arrest (OHCA) in Texas

Introduction: Nationally, the COVID-19 pandemic was associated with worse OHCA outcomes. Whether these trends persist or were consistent between states is unclear. Purpose: To determine the impact of COVID-19 on OHCA incidence and outcomes in Texas between 2019-2020. Methods: We analyzed adult OHCAs in Texas from the Cardiac Arrest Registry to Enhance Survival (CARES) during a matched period (March 11-December 31 from 2019 through 2020). We excluded cases witnessed by 9-1-1 responders and arrests occurring at healthcare facilities. Outcomes were rates of BCPR, AED use, sustained ROSC, prehospital termination of resuscitation (TOR), survival to hospital, survival to hospital discharge, good neurological outcomes and Utstein bystander survival. We created a mixed effects logistic regression model analyzing the effect of the pandemic on outcomes, using EMS agency as the random intercept. We adjusted for age, gender, race/ethnicity, witnessed arrest, initial rhythm type and location type. Results: There were 8,070 OHCA cases, with 4,443 (55.1%) in the pandemic period (March 11 - December 31, 2020) and 3,627 (44.5%) from March 11 - December 31 2019, a relative 18.4% increase. There was a significantly decreased odds of BCPR (46.2% v 42.2%, aOR = 0.87, 95% CI 0.79-0.95), AED use (13.0% v 7.3%, aOR = 0.53, 95% CI 0.36-0.78), and sustained ROSC (28.8% v 21.2%, aOR = 0.67, 95% CI 0.60-0.74) during the pandemic. Survival to hospital (27.1% v 20.9%, aOR = 0.72, 95% CI 0.65-0.80) and survival to hospital discharge (10.0% v 7.4%, aOR = 0.71, 95% CI 0.64-0.89) also decreased. Prehospital TOR increased (37.3% v 46.7%, aOR = 1.51, 95% CI 1.35-1.67). The pandemic was associated with a lower Utstein bystander survival rate (58.5% v 52.5%, aOR = 0.79, 95% CI 0.6-0.97). Conclusion: In Texas during the COVID-19 pandemic, there was a greater number of OHCA events, with lower overall survival and increased prehospital TOR.