Prehospital Predictors of Initial Shockable Rhythm in Out-of-Hospital Cardiac Arrest: Findings From the Taichung Sudden Unexpected Death Registry (THUNDER)

Time Is Life: Golden Ten Minutes on Scene-EuReCa_Serbia 2014-2023

Background and Objectives: This study analyzed the frequency of factors influencing the course and outcomes of out-of-hospital cardiac arrest (OHCA) in Serbia and the prediction of pre-hospital outcomes and survival. Materials and Methods: Data were collected during the period from 1 October 2014, to 31 September 2023, according to the protocol of the EuReCa_One study (clinical trial ID number NCT02236819). Results: Overall 9303 OHCA events were registered with a median age of 71 (IQR 61-81) years and 59.7% of them being males. The annual OHCA incidence was 85.60 ± 20.73/100,000. Within all bystander-witnessed cases, bystander-initiated cardiopulmonary resuscitation in 15.3%. Within the resuscitation-initiated group, return-of-spontaneous circulation (ROSC) on scene (any ROSC) was present in 1037/4053 cases (25.6%) and ROSC on admission to the nearest hospital in 792/4053 cases (19.5%), while 201/4053 patients survived to hospital discharge (5.0%). Predictive potential on pre-hospital outcomes was shown by several factors. Also, of all patients having any ROSC, 89.2% were admitted to the hospital alive. The probability of any ROSC dropped below 50% after 17 min passed after the emergency call and 10 min after the EMS scene arrival. These time intervals were significantly associated with survival to hospital discharge (p < 0.001). Five-minute time intervals between both emergency calls and any ROSC and EMS scene arrival and any ROSC also had a significant predictive potential for survival to hospital discharge (p < 0.001, HR 1.573, 95% CI 1.303-1.899 and p = 0.017, HR 1.184, 95% CI 1.030-1.361, respectively). Conclusions: A 10-min time on scene to any ROSC is a crucial time-related factor for achieving any ROSC, and indirectly admission ROSC and survival to hospital discharge, and represents a golden time interval spent on scene in the management of OHCA patients. A similar effect has a time interval of 17 min from an emergency call. Further investigations should be focused on factors influencing these time intervals, especially time spent on scene.

Role of low-density lipoprotein electronegativity and sexual dimorphism in contributing early ventricular tachyarrhythmias following ST-elevation myocardial infarction

Background

Early ventricular tachycardia/fibrillation (VT/VF) in patients with ST-elevation myocardial infarction (STEMI) has higher morbidity and mortality. This study examines gender-differentiated risk factors and underlying mechanisms for early onset VT/VF in STEMI.

Methods

We analyzed data from 2,964 consecutive STEMI patients between January 1, 2008 and December 31, 2021. Early VT/VF was defined as occurrence of spontaneous VT/VF of ≥30 s or requirement of immediate cardioversion/defibrillation within the first 48 h after symptoms. An ex vivo ischemic-reperfusion experiments were conducted in 8-week-old ApoE-/- mice fed a high-fat diet to explore the underlying mechanisms of early VT/VF.

Results

In 255 of out 2,964 STEMI patients who experienced early VT/VF, the age was younger (58.6 ± 13.8 vs. 61.0 ± 13.0 years old, P = 0.008) with a male predominance. The plasma levels of L5, the most electronegative subclass of low-density lipoprotein, was higher in early VT/VF patients compared to those without early VT/VF (n = 21, L5: 14.1 ± 22.6% vs. n = 46, L5: 4.3 ± 9.9%, P = 0.016). In the experimental setup, all male mice (n = 4) developed VT/VF post sham operation, whereas no such incidence was observed in the female mice (n = 3). Significantly, male mice exhibited considerably slower cardiac conduction velocity as compared to their female counterparts in whole heart preparations (25.01 ± 0.93 cm/s vs.42.32 ± 5.70 cm/s, P < 0.001), despite analogous action potential durations. Furthermore, isolated ventricular myocytes from male mice showed a distinctly lower sodium current density (-29.20 ± 3.04 pA/pF, n = 6) in comparison to female mice (-114.05 ± 6.41 pA/pF, n = 6, P < 0.001). This decreased sodium current density was paralleled by a reduced membrane expression of Nav1.5 protein (0.38 ± 0.06 vs. 0.89 ± 0.09 A.U., P < 0.001) and increased cytosolic Nav1.5 levels (0.59 ± 0.06 vs. 0.29 ± 0.04 A.U., P = 0.001) in male mice. Furthermore, it was observed that the overall expressions of sorting nexin 27 (SNX27) and vacuolar protein sorting 26 (VPS26) were significantly diminished in male mice as compared to female littermates (0.91 ± 0.15 vs. 1.70 ± 0.28, P = 0.02 and 0.74 ± 0.09 vs. 1.57 ± 0.13, P < 0.01, respectively).

Conclusions

Our findings reveal that male STEMI patients with early VT/VF are associated with elevated L5 levels. The gender-based discrepancy in early VT/VF predisposition might be due to compromised sodium channel trafficking, possibly linked with increased LDL electronegativity.

Statement from the Asia Summit: Current state of arrhythmia care in Asia

On May 27, 2022, the Asia Pacific Heart Rhythm Society and the Heart Rhythm Society convened a meeting of leaders from different professional societies of healthcare providers committed to arrhythmia care from the Asia Pacific region. The overriding goals of the meeting were to discuss clinical and health policy issues that face each country for providing care for patients with electrophysiologic issues, share experiences and best practices, and discuss potential future solutions. Participants were asked to address a series of questions in preparation for the meeting. The format of the meeting was a series of individual country reports presented by the leaders from each of the professional societies followed by open discussion. The recorded presentations from the Asia Summit can be accessed at https://www.heartrhythm365.org/URL/asiasummit-22. Three major themes arose from the discussion. First, the major clinical problems faced by different countries vary. Although atrial fibrillation is common throughout the region, the most important issues also include more general issues such as hypertension, rheumatic heart disease, tobacco abuse, and management of potentially life-threatening problems such as sudden cardiac arrest or profound bradycardia. Second, there is significant variability in the access to advanced arrhythmia care throughout the region due to differences in workforce availability, resources, drug availability, and national health policies. Third, collaboration in the area already occurs between individual countries, but no systematic regional method for working together is present.

Prevalence and factors associated with initial and subsequent shockable cardiac arrest rhythms and their association with patient outcomes in dogs and cats undergoing cardiopulmonary resuscitation: A RECOVER registry study

OBJECTIVE

To report the prevalence of initial shockable cardiac arrest rhythms (I-SHKR), incidence of subsequent shockable cardiac arrest rhythms (S-SHKR), and factors associated with I-SHKRs and S-SHKRs and explore their association with return of spontaneous circulation (ROSC) rates in dogs and cats undergoing CPR.

DESIGN

Multi-institutional prospective case series from 2016 to 2021, retrospectively analyzed.

SETTING

Eight university and eight private practice veterinary hospitals.

ANIMALS

A total of 457 dogs and 170 cats with recorded cardiac arrest rhythm and event outcome reported in the Reassessment Campaign on Veterinary Resuscitation CPR registry.

MEASUREMENTS AND MAIN RESULTS

Logistic regression was used to evaluate association of animal, hospital, and arrest variables with I-SHKRs and S-SHKRs and with patient outcomes. Odds ratios (ORs) were generated, and significance was set at P < 0.05. Of 627 animals included, 28 (4%) had I-SHKRs. Odds for I-SHKRs were significantly higher in animals with a metabolic cause of arrest (OR 7.61) and that received lidocaine (OR 17.50) or amiodarone (OR 21.22) and significantly lower in animals experiencing arrest during daytime hours (OR 0.22), in the ICU (OR 0.27), in the emergency room (OR 0.13), and out of hospital (OR 0.18) and that received epinephrine (OR 0.19). Of 599 initial nonshockable rhythms, 74 (12%) developed S-SHKRs. Odds for S-SHKRs were significantly higher in animals with higher body weight (OR 1.03), hemorrhage (OR 2.85), or intracranial cause of arrest (OR 3.73) and that received epinephrine (OR 11.36) or lidocaine (OR 18.72) and significantly decreased in those arresting in ICU (OR 0.27), emergency room (OR 0.29), and out of hospital (OR 0.38). Overall, 171 (27%) animals achieved ROSC, 81 (13%) achieved sustained ROSC, and 15 (2%) survived. Neither I-SHKRs nor S-SHKRs were significantly associated with ROSC.

CONCLUSIONS

I-SHKRs and S-SHKRs occur infrequently in dogs and cats undergoing CPR and are not associated with increased ROSC rates.

Global disparities in arrhythmia care: Mind the gap

Delivery of comprehensive arrhythmia care requires the simultaneous presence of many resources. These include complex hospital infrastructure, expensive implantable equipment, and expert personnel. In many low- and middle-income countries (LMICs), at least 1 of these components is often missing, resulting in a gap between the demand for arrhythmia care and the capacity to supply care. In addition to this treatment gap, there exists a training gap, as many clinicians in LMICs have limited access to formal training in cardiac electrophysiology. Given the progressive increase in the burden of cardiovascular diseases in LMICs, these patient care and clinical training gaps will widen unless further actions are taken to build capacity. Several strategies for building arrhythmia care capacity in LMICs have been described. Medical missions can provide donations of both equipment and clinical expertise but are only intermittently present and therefore are not optimized to provide the longitudinal support needed to create self-sustaining infrastructure. Use of donated or reprocessed equipment (eg, cardiac implantable electronic devices) can reduce procedural costs but does not address the need for infrastructure, including diagnostics and expert personnel. Collaborative efforts involving multiple stakeholders (eg, professional organizations, government agencies, hospitals, and educational institutions) have the potential to provide longitudinal support of both patient care and clinician education in LMICs.

Prognostic value of early and late spontaneous conversion into a shockable rhythm for patients with out-of-hospital cardiac arrest

BACKGROUND

The prognostic significance of conversion into a shockable rhythm in patients who experienced out-of-hospital cardiac arrest (OHCA) with an initially nonshockable rhythm is controversial, perhaps due to the timing of rhythm conversion not being considered previously. We aimed to compare the different prognoses of patients with OHCA and early and late conversion of their rhythm into a shockable rhythm.

METHODS

This was a single-centre retrospective cohort study. We enrolled patients with OHCA who were sent to a medical centre in central Taiwan from 2016 to 2020. Patients <18 years old, those with cardiac arrest due to trauma or a circumstantial cause, and those for whom resuscitation was not attempted were excluded. Patients were divided into two groups in accordance with presentation with an initially shockable rhythm. Those with an initially nonshockable rhythm were divided into three subgroups: early-conversion, late-conversion, and nonconversion groups. The primary outcome was the neurological functional status upon discharge from hospital.

RESULTS

A total of 1645 patients with OHCA were included: initially shockable rhythm group, 339; early conversion group, 68; late-conversion group, 166; and nonconversion group, 1072. After adjustment, multivariate logistic regression revealed that a favourable neurological outcome was more common in the early conversion group than the nonconversion group (odds ratio [OR] 2.4; 95% confidence interval [CI], 1.1-5.3; p = 0.035), whereas the late-conversion group did not significantly differ from the nonconversion group (OR 0.5; 95% CI, 0.1-1.5; p = 0.211). The proportions of sustained return of spontaneous circulation and survival to discharge were also higher in the early conversion group than the late-conversion group (OR 2.9 95% CI 1.6-5.5, p = 0.001 and OR 4.5, 1.8-11.0, p = 0.001, respectively).

CONCLUSION

In patients who experience OHCA and have an initially nonshockable rhythm, early conversion into a shockable rhythm resulted in a better prognosis, whereas late conversion was not significantly different from nonconversion.

Using QRS loop descriptors to characterize the risk of sudden cardiac death in patients with structurally normal hearts

The predictive value of non-invasive electrocardiographic examination findings for the risk of sudden cardiac death (SCD) in populations with structurally normal hearts remains unclear. This study aimed to investigate the characteristics of the QRS vectorcardiography of surface electrocardiography in patients with structurally normal hearts who experienced SCD. We consecutively enrolled patients who underwent vectorcardiography between March 2017 and December 2018 in a tertiary referral medical center. These patients didn’t have structural heart diseases, histories of congestive heart failure, or reduced ejection fraction, and they were classified into SCD (with aborted SCD history and cerebral performance category score of 1) and control groups (with an intervention for atrioventricular node reentrant tachycardia and without SCD history). A total of 162 patients (mean age, 54.3±18.1 years; men, 75.9%), including 59 in the SCD group and 103 in the control group, underwent propensity analysis. The baseline demographic variables, underlying diseases, QRS loop descriptors (the percentage of the loop area, loop dispersion, and inter-lead QRS dispersion), and other electrocardiographic parameters were compared between the two groups. In the univariate and multivariate analyses, a smaller percentage of the loop area (odds ratio, 0.0003; 95% confidence interval, 0.00–0.02; p<0.001), more significant V4-5 dispersion (odds ratio, 1.04; 95% confidence interval, 1.02–1.07; p = 0.002), and longer QRS duration (odds ratio, 1.05; 95% confidence interval, 1.00–1.10; p = 0.04) were associated with SCD. In conclusion, the QRS loop descriptors of surface electrocardiography could be used as non-invasive markers to identify patients experiencing aborted SCD from a healthy population. A decreased percentage of loop area and elevated V4-5 QRS dispersion values assessed using vectorcardiography were associated with an increased risk of SCD in patients with structurally normal hearts.

Association of dispatcher-assisted cardiopulmonary resuscitation with initial shockable rhythm and survival after out-of-hospital cardiac arrest

BACKGROUND AND IMPORTANCE

Bystander cardiopulmonary resuscitation (CPR) and initial shockable rhythm are crucial predictors of survival after out-of-hospital cardiac arrest (OHCA). However, the relationship between dispatcher-assisted CPR (DA-CPR) and initial shockable rhythm is not completely elucidated.

OBJECTIVE

To examine the association of DA-CPR with initial shockable rhythm and outcomes.

DESIGN, SETTING AND PARTICIPANTS

This nationwide population-based observational study conducted in Japan included 59 688 patients with witnessed OHCA of cardiac origin after excluding those without bystander CPR. Patients were divided into DA-CPR (n = 42 709) and CPR without dispatcher assistance (unassisted CPR, n = 16 979) groups.

OUTCOME MEASURES AND ANALYSIS

The primary outcome measure was initial shockable rhythm, and secondary outcome measures were 1-month survival and neurologically intact survival. A Cox proportional hazards model adjusted for collapse-to-first-rhythm-analysis time and multivariable logistic regression models were used after propensity score (PS) matching to compare the incidence of initial shockable rhythm and outcomes, respectively.

MAIN RESULTS

Among all patients (mean age 76.7 years), the rates of initial shockable rhythm, 1-month survival and neurologically intact survival were 20.8, 10.7 and 7.0%, respectively. The incidence of initial shockable rhythm in the DA-CPR group (20.4%, 3462/16 979) was significantly higher than that in the unassisted CPR group (18.5%, 3133/16 979) after PS matching (P < 0.0001). However, no significant differences were found between the two groups with respect to the incidence of initial shockable rhythm in the Cox proportional hazards model [adjusted hazard ratio of DA-CPR for initial shockable rhythm compared with unassisted CPR, 0.99; 95% confidence interval (CI), 0.97-1.02, P = 0.56]. No significant differences were observed in the survival rates in the two groups after PS matching [10.8% (1833/16 979) vs. 10.3% (1752/16 979), P = 0.16] and neurologically intact survival rates [7.3% (1233/16 979) vs. 6.8% (1161/16 979), P = 0.13]. The multivariable logistic regression model showed no significant differences between the groups with regard to survival (adjusted odds ratio of DA-CPR compared with unassisted CPR: 1.00; 95% CI, 0.89-1.13, P = 0.97) and neurologically intact survival (adjusted odds ratio: 1.12; 95% CI, 0.98-1.29, P = 0.14).

CONCLUSION

DA-CPR after OHCA had the same independent association with the likelihood of initial shockable rhythm and 1-month meaningful outcome as unassisted CPR.

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

Aim

This 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.

Methods

A 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.

Results

Overall, 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)).

Conclusion

Having 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.

Association of a simple SACAF score with bystander witnessed sudden death due to ventricular tachyarrhythmias in a multicenter cohort

Out-of-hospital cardiac arrest (OHCA) remains a major threat to public health worldwide. OHCA patients presenting initial shockable ventricular tachycardia/ventricular fibrillation (VT/VF) rhythm have a better survival rate. We sought to develop a simple SACAF score to discriminate VT/VF from non-VT/VF OHCAs based on the Taiwan multicenter hospital-based registry database. We analyzed the in- and pre-hospital data, including demographics, baseline comorbidities, response times, automated external defibrillator information, and the 12-lead ECG recording closest to the OHCA event in bystander-witnessed OHCA patients. Among the 461 study patients, male sex (OR 2.54, 95% CI = 1.32–4.88, P = 0.005), age ≤ 65 years (OR 2.78, 95% CI = 1.64–4.70, P < 0.001), cardiovascular diseases (OR 2.97, 95% CI = 1.73–5.11, P < 0.001), and atrial fibrillation (AF) (OR 2.36, 95% CI = 1.17–4.76, P = 0.017) were independent risk factors for VT/VF OHCA (n = 81) compared with non-VT/VF OHCA (n = 380). A composite SACAF score was developed (male Sex, Age ≤ 65 years, Cardiovascular diseases, and AF) and compared with the performance of a modified CHA₂DS₂-VASc score (Cardiovascular diseases, Hypertension, Age ≥ 75 years, Diabetes, previous Stroke, Vascular disease, Age 65–74 years, female Sex category). The area under the receiver operating characteristic curve (AUC) of the SACAF was 0.739 (95% CI = 0.681–0.797, P < 0.001), whereas the AUC of the modified CHA₂DS₂-VASc was 0.474 (95% CI = 0.408–0.541, P = 0.464). A SACAF score of ≥ 2 was useful in discriminating VT/VF from non-VT/VF OHCAs with a sensitivity of 0.75 and a specificity of 0.60. In conclusion, the simple SACAF score appears to be useful in discriminating VT/VF from non-VT/VF bystander-witnessed OHCAs and the findings may also shed light on future mechanistic evaluation.

Early blood pH as an independent predictor of neurological outcome in patients with out-of-hospital cardiac arrest: A retrospective observational study

ABSTRACT

Metabolic acidosis is observed in 98% of patients with out-of-hospital cardiac arrest (OHCA). The longer the no-flow or low-flow duration, the more severe is the acidosis in these patients. This study explored whether blood pH in early stages of advanced life support (ALS) was an independent predictor of neurological prognosis in patients with OHCA.We retrospectively enrolled patients with OHCA from January 2012 to June 2018 in a single-medical tertiary hospital in Taiwan. Patients with OHCA whose blood gas analyses within 5 minutes after receiving ALS at the emergency department (ED) were enrolled. Patients younger than 20 years old, with cardiac arrest resulting from traumatic or circumstantial causes, with return of spontaneous circulation (ROSC) before ED arrival, lacking record of initial blood gas analysis, and with do-not-resuscitate orders were excluded. The primary outcome of this study was neurological status at hospital discharge.In total, 2034 patients with OHCA were enrolled. The majority were male (61.89%), and the average age was 67.8 ± 17.0 years. Witnessed OHCA was noted in 571 cases, cardiopulmonary resuscitation was performed before paramedic arrival in 512 (25.2%) cases, and a shockable rhythm was observed in 269 (13.2%). Blood pH from initial blood gas analysis remained an independent predictor of neurological outcome after multivariate regression.Blood pH at early stages of ALS was an independent prognostic factor of post-OHCA neurological outcome. Blood gas analysis on arrival at the ED may provide additional information about the prognosis of patients with OHCA.

Sex and Racial Differences in Autopsy-Defined Causes of Presumed Sudden Cardiac Death

[Figure: see text].

Factors associated with shockable versus non-shockable rhythms in patients with in-hospital cardiac arrest

AIM

To identify factors associated with the initial rhythm in patients with in-hospital cardiac arrest and to assess whether potential differences in outcomes based on the initial rhythm can be explained by patient and event characteristics.

METHODS

Adult patients (≥18 years old) with in-hospital cardiac arrest in 2017 and 2018 were included from the Danish In-Hospital Cardiac Arrest Registry (DANARREST). We used population-based registries to obtain data on comorbidities, cardiac procedures, and medications. Unadjusted and adjusted risk ratios (RRs) for initial rhythm, return of spontaneous circulation (ROSC), and survival were estimated in separate models including an incremental number of prespecified variables.

RESULTS

A total of 3422 patients with in-hospital cardiac arrest were included, of which 639 (19%) had an initial shockable rhythm. Monitored cardiac arrest, witnessed cardiac arrest, and specific cardiac diseases (i.e. ischemic heart disease, dysrhythmias, and valvular heart disease) were associated with initial shockable rhythm. Conversely, higher age, female sex, and specific non-cardiovascular comorbidities (e.g. overweight and obesity, renal disease, and pulmonary cancer) were associated with an initial non-shockable rhythm. Initial shockable rhythm remained strongly associated with increased ROSC (RR = 1.63, 95%CI 1.51-1.76), 30-day survival (RR = 2.31, 95%CI 2.02-2.64), and 1-year survival (RR = 2.36, 95%CI 2.02-2.76) compared to initial non-shockable rhythm in the adjusted analyses.

CONCLUSION

In this study, specific patient and cardiac arrest characteristics were associated with initial rhythm in patients with in-hospital cardiac arrest. However, differences in patient and cardiac arrest characteristics did not fully explain the association with survival for initial shockable rhythm compared to a non-shockable rhythm.

Prognostic value of venous blood analysis at the start of CPR in non-traumatic out-of-hospital cardiac arrest: association with ROSC and the neurological outcome

BACKGROUND

The knowledge of new prognostic factors in out-of-hospital cardiac arrest (OHCA) that can be evaluated since the beginning of cardiopulmonary resuscitation (CPR) manoeuvres could be helpful in the decision-making process of prehospital care. We aim to identify metabolic variables at the start of advanced CPR at the scene that may be associated with two main outcomes of CPR (recovery of spontaneous circulation (ROSC) and neurological outcome).

METHODS

Prospective observational study of all non-traumatic OHCA in patients older than 17 years assisted by emergency medical services (EMS), with doctor and nurse on board, between January 2012 and December 2017. Venous blood gases were sampled upon initially obtaining venous access to determine the initial values of pH, pCO₂, HCO₃^-, base excess (BE), Na⁺, K⁺, Ca²⁺ and lactate. ROSC upon arrival at the hospital and neurological status 30 days later (Cerebral Performance Categories (CPC) scale) were recorded.

RESULTS

We included 1552 patients with OHCA with blood test data in a 6-year period. ROSC was achieved in 906 cases (58.4%), and good neurological recovery at 30 days (CPC I-II) occurred in 383 cases (24.68%). In multivariate analysis, we found a significant relationship between non-recovery of spontaneous circulation (no-ROSC) and low pH levels (adjusted odds ratio (OR) 0.03 (0.002-0.59), p = 0.020), high pCO₂ levels (adjusted OR 1.03 [1.01-1.05], p = 0.008) and high potassium levels (adjusted OR 2.28 [1.43-3.61], p = 0.008). Poor neurological outcomes were associated with low pH levels (adjusted OR 0.06 [0.02-0.18], p < 0.001), high pCO₂ (adjusted OR 1.05 [1.03-1.08], p < 0.001), low HCO₃^- (adjusted OR 0.97 [0.94-0.999], p = 0.044), low BE (adjusted OR 0.96 [0.93-0.98], p < 0.001) and high potassium levels (adjusted OR 1.37 [1.16-1.60], p < 0.001).

CONCLUSION

There is a significant relationship between severe alterations of venous blood-gas variables and potassium at the start of CPR of non-traumatic OHCA and low-ROSC rate and neurological prognosis.

Cardiac arrest and sudden cardiac death registries: a systematic review of global coverage

Background

Sudden cardiac death (SCD) is a major global health problem, accounting for up to 20% of deaths in Western societies. Clinical quality registries have been shown in a range of disease conditions to improve clinical management, reduce variation in care and improve outcomes.

Aim

To identify existing cardiac arrest (CA) and SCD registries, characterising global coverage and methods of data capture and validation.

Methods

Biomedical and public search engines were searched with the terms ‘registry cardio*’; ‘sudden cardiac death registry’ and ‘cardiac arrest registry’. Registries were categorised as either CA, SCD registries or ‘other’ according to prespecified criteria. SCD registry coordinators were contacted for contemporaneous data regarding registry details.

Results

Our search strategy identified 49 CA registries, 15 SCD registries and 9 other registries (ie, epistries). Population coverage of contemporary CA and SCD registries is highly variable with registries densely concentrated in North America and Western Europe. Existing SCD registries (n=15) cover a variety of age ranges and subpopulations, with some enrolling surviving patients (n=8) and family members (n=5). Genetic data are collected by nine registries, with the majority of these (n=7) offering indefinite storage in a biorepository.

Conclusions

Many CA registries exist globally, although with inequitable population coverage. Comprehensive multisource surveillance SCD registries are fewer in number and more challenging to design and maintain. Challenges identified include maximising case identification and case verification.

Trial registration number

CRD42019118910.

Derivation and Validation of the SWAP Score for Very Early Prediction of Neurologic Outcome in Patients With Out-of-Hospital Cardiac Arrest

STUDY OBJECTIVE

For patients with out-of-hospital cardiac arrest who receive cardiopulmonary resuscitation in an emergency department (ED), the early evaluation of their neurologic prognosis is essential for emergency physicians. The aim of this study is to establish a simple and useful assessment tool for rapidly estimating the prognosis of patients with out-of-hospital cardiac arrest after their arrival at an ED.

METHODS

A total of 852 patients admitted from January 1, 2015, to June 30, 2017, were prospectively registered and enrolled in the derivation cohort. Multivariate logistic regression on this cohort identified 4 independent factors associated with unfavorable outcomes: initial nonshockable rhythm (odds ratio [OR] 3.40; 95% confidence interval [CI] 1.58 to 7.32), no witness of collapse (OR 3.19; 95% CI 1.51 to 6.75), older than 60 years (OR 3.65; 95% CI 1.64 to 8.09), and pH less than or equal to 7.00 (OR 3.27; 95% CI 1.42 to 7.54). The shockable rhythm-witness-age-pH (SWAP) score was developed and 1 point was assigned to each predictor.

RESULTS

For a SWAP score of 4, the specificity was 97.14% (95% CI 91.62% to 100%) for unfavorable outcomes in the derivation cohort. For validation, we retrospectively collected data for 859 patients with out-of-hospital cardiac arrest from January 1, 2012, to December 31, 2014. A SWAP score of 4 was 100% specific (95% CI 99.9% to 100%) for unfavorable outcomes in the validation cohort.

CONCLUSION

The SWAP score is a simple and useful predictive model that may provide information for the very early estimation of prognosis for patients with out-of-hospital cardiac arrest. Further research is required to integrate ultrasonographic findings and validate the SWAP score's application in other populations.

Significance of blood pH value and automated external defibrillator shock in determining the outcomes of out-of-hospital cardiac arrest patients

Background:

The prognosis of out-of-hospital cardiac arrest is generally poor. It is known that the survival of out-of-hospital cardiac arrest patients depends on treatments delivered in a very short time frame. Identifying outcome-associated factors may provide valuable information for decision-making in clinical practices.

Aim:

The objective of the present study was to assess the associations between various factors (e.g. serum biomarker levels and prehospital factors) and outcomes in adult, non-traumatic out-of-hospital cardiac arrest patients.

Methods:

Data from 386 consecutive out-of-hospital cardiac arrest patients treated from January 2012 to December 2015 at Taoyuan Chang Gung Memorial Hospital (Taiwan, ROC) were collected. While performing cardiopulmonary resuscitation in the emergency room, the levels of creatinine, aspartate aminotransferase, sodium, potassium, troponin-I, hydrogen bicarbonate and haemoglobin were determined, blood pH and pCO2 were measured and the white blood cell count was calculated. The response time and scene time interval were also recorded.

Results:

Here we found that out-of-hospital cardiac arrest patients with blood pH values of <7.34 had a lower chance of survival to 24 h (Odds Ratio (OR) = 2.77), survival to discharge (OR = 7.06) and a good neurological outcome (OR = 64.59). Moreover, patients without an automated external defibrillator shock had a lower chance of being discharged (OR = 4.27) and enjoying good neurological outcomes (OR = 25.09).

Conclusion:

Our data suggest that the blood pH and an automated external defibrillator shockable rhythm are two easily measurable factors strongly associated with the outcomes of out-of-hospital cardiac arrest patients.