Comparison of out-of-hospital cardiac arrest occurring before and after paramedic arrival: Epidemiology, survival to hospital discharge and 12-month functional recovery

Changes in the neurological status from 30 to 90 days post-cardiac arrest by age: A nationwide retrospective observational study

Introduction

Few studies have investigated the changes in the neurological status after 30 days post-arrest in out-of-hospital cardiac arrest (OHCA) patients according to the patient age. The aim of this study was to investigate the differences in the mid-term (from 30 days to 90 days) neurological changes after CA according to the age group.

Methods

We retrospectively analysed the data of all OHCA patients aged ≥1 year who showed return of spontaneous circulation and survived until 30 days after CA. We compared the proportions of patients who showed neurological deterioration from 30 to 90 days post-CA by age group (1-17, 18-39, 40-64, 65-79, ≥80 years). The neurological outcome was assessed by the Cerebral Performance Category (CPC) or Pediatric Cerebral Performance Category (PCPC) scale.

Results

Of the 68,110 registered patients, we analysed the data of a total of 2,663 patients. The neurological deterioration rate and improvement rate from 30 to 90 days after CA in each age group were as follows: 1-17 years: 11.6% (8/69)/7.2% (5/69); 18-39 years: 8.3% (15/181)/6.1% (11/181); 40-64 years: 7.3% (72/982)/7.0% (69/982); 65-79 years: 13.5% (130/965)/8.1% (78/965); and ≥ 80 years: 24.2% (113/466)/4.9% (23/466). Multivariable logistic regression analysis showed a higher likelihood of mid-term neurological deterioration in patients aged ≥ 80 years than in those aged 1-17 years.

Conclusions

Most OHCA patients, irrespective of age, showed no change of the neurological status from 30 to 90 days after OHCA. However, a relatively large percentage of patients aged ≥80 years old showed significant neurological deterioration after 30 days post-OHCA.

Cricothyroidotomy in out-of-hospital cardiac arrest: An observational study

Aim

To describe the incidence, characteristics, success rates, and outcomes of out-of-hospital cardiac arrest (OHCA) patients receiving cricothyroidotomy.

Methods

Over an 18-year period, we retrospectively analysed patient care records and cardiac arrest registry data for cricothyroidotomy cases. Multivariable logistic regression analysis was used to examine associations between study characteristics and cricothyroidotomy success.

Results

We identified 80 cricothyroidotomies, 56 of which occurred in OHCA. The incidence of cricothyroidotomy in OHCA was 1.1 per 1,000 attempted resuscitations and increased over the study period (incidence rate ratio [IRR] = 1.13, 95 % confidence interval [CI]: 1.02-1.25, p = 0.023). The overall success rate was 68.8 % (n = 55/80), with lower success in cardiac arrest (n = 33/56, 58.9 %) than non-cardiac arrest patients (n = 22/24, 91.7 %). In OHCA, success rates were higher for surgical compared to needle techniques (88.2 % vs. 54.6 %, p = 0.003). Cardiac arrest (odds ratio [OR] 0.09, 95 % CI 0.16-0.51) and needle techniques (OR 0.11, 95 % CI 0.02-0.56) were independently associated with lower odds of procedural success, while male sex (OR 10.06, 95 % CI 2.00-50.62) was associated with higher odds. Return of spontaneous circulation occurred in 44.6 % (n = 22/56), with 35.7 % (n = 20/56) surviving to hospital and 7.1 % (n = 4/56) surviving to hospital discharge. Procedural complications included cardiac arrest (n = 6/56, 10.7 %), minor bleeding (n = 5/56, 8.9 %), surgical emphysema (n = 3/56, 5.4 %), and major bleeding (n = 2/56, 3.6 %).

Conclusion

We found cricothyroidotomy in OHCA to be associated with low rates of procedural success and high mortality rates. Further studies are required to assess the role and potential benefits of cricothyroidotomy in cardiac arrest.

Bypassing Emergency Service: Decoding the Drivers of Self-Referral During Acute Myocardial Infarction on Rural Areas in Sachsen-Anhalt, Germany

Background/Objectives: the timely and effective management of acute myocardial infarction (AMI) is crucial to improve patient outcomes. 'Self-Referral' is defined as instances either where patients arrive at the hospital by their own means or are transported by someone else, rather than through professional emergency medical services. This approach can lead to treatment delays and potentially worsen outcomes. This study aims to identify the factors associated with the choice of self-referral among patients with AMI in Saxony-Anhalt, Germany. Methods: We used the data from the Regional Myocardial Infarction Registry of Saxony-Anhalt (RHESA), which included 4044 patients with confirmed acute myocardial infarction (AMI), including 48.7% from urban areas (city of Halle) and 51.3% from rural areas (Altmark). The gender distribution was 65% male and 35% female, covering an age range from 25 to over 80 years. Multivariable logistic regression identified factors associated with self-referral and its impact on reaching a hospital with percutaneous coronary intervention (PCI) capability. Results: Rural residents were more likely to self-refer compared to those in urban settings (adjusted odds ratio 2.43 [95% CI: 2.00-2.94]). Odds of self-referral decreased with age, while metabolic factors, including hypertension, high body mass index (BMI), and diabetes, as well as sex were not associated with self-referral. Self-referral did not increase the odds of arriving in a hospital without PCI capability. (Adjusted odds ratio 1.12 [95% CI: 0.85-1.47]). Furthermore, in cases of self-referral, women did not have a disadvantage in reaching a hospital with PCI (0.91; 0.59-1.41) compared to men. However, in medically attended transports, women were at a disadvantage (odds ratio: 1.33; 95% CI: 1.06-1.67). Conclusions: These findings highlight the need for public education on self-referral and for medical personnel training to prevent gender bias in AMI transport to PCI-capable hospitals.

Do differences in emergency medical services (EMS) response time to an arrest account for the survival differences between EMS-witnessed and bystander-witnessed out of hospital cardiac arrest?

Introduction

Out-of-hospital cardiac arrests (OHCA) witnessed by Emergency Medical Services (EMS) are reported to have more favourable survival than bystander-witnessed arrests, even after adjusting for patient and arrest factors known to be associated with increased OHCA survival. This study aims to determine whether the survival advantage in EMS-witnessed arrests can be attributed to differences in the EMS response time to the arrest.

Methods

Using registry data we conducted a retrospective, population-based cohort study of bystander- and EMS-witnessed OHCAs of medical aetiology who received an EMS resuscitation attempt in Western Australia between 2018-2021. EMS response time to arrest was assumed to be zero for EMS-witnessed arrests. Multivariable logistic regression was used to compare 30-day OHCA survival by witness and bystander CPR (B-CPR) status, adjusting for EMS response time to arrest, and patient and arrest characteristics.

Results

Of 2,130 OHCA cases, 510 (23.9%) were EMS-witnessed and 1620 were bystander-witnessed: 1318/1620 (81.4%) with B-CPR, and 302/1620 (18.6%) with no B-CPR. The median EMS response time to bystander-witnessed arrests who received B-CPR was 9.9 [Q1,Q3: 7.4, 13.3] minutes. After adjusting for the EMS response time and patient and arrest factors, 30-day survival remained significantly lower in both the bystander-witnessed group with B-CPR (aOR 0.56; 95% CI 0.34 - 0.91) and bystander-witnessed group without B-CPR (aOR 0.23; 95% CI 0.11 - 0.46).

Conclusion

An increased EMS response time does not fully account for the higher OHCA survival in EMS-witnessed arrests compared to bystander-witnessed arrests.

The association of depression and patient and resuscitation characteristics with survival after out-of-hospital cardiac arrest: a cohort study

AIMS

Out-of-hospital cardiac arrest (OHCA) is a leading cause of death worldwide, with cardiovascular disease (CVD) being a key risk factor. This study aims to investigate disparities in patient/OHCA characteristics and survival after OHCA among patients with vs. without depression.

METHODS AND RESULTS

This is a retrospective cohort study using data from the AmsteRdam REsuscitation Studies (ARREST) registry from 2008 to 2018. History of comorbidities, including depression, was obtained from the patient's general practitioner. Out-of-hospital cardiac arrest survival was defined as survival at 30 days post-OHCA or hospital discharge. Logistic regression models were used to obtain crude and adjusted odds ratios (ORs) for the association between depression and OHCA survival and possible effect modification by age, sex, and comorbidities. The potential mediating effects of initial heart rhythm and provision of bystander cardiopulmonary resuscitation were explored. Among 5594 OHCA cases, 582 individuals had pre-existing depression. Patients with depression had less favourable patient and OHCA characteristics and lower odds of survival after adjustment for age, sex, and comorbidities [OR 0.65, 95% confidence interval (CI) 0.51-0.82], with similar findings by sex and age groups. The association remained significant among the Utstein comparator group (OR 0.63, 95% CI 0.45-0.89) and patients with return of spontaneous circulation (OR 0.60, 95% CI 0.42-0.85). Initial rhythm and bystander cardiopulmonary resuscitation partially mediated the observed association (by 27 and 7%, respectively).

CONCLUSION

Out-of-hospital cardiac arrest patients with depression presented more frequently with unfavourable patient and OHCA characteristics and had reduced chances of survival. Further investigation into potential pathways is warranted.

Does time heal fatigue, psychological, cognitive and disability problems in people who experience an out-of-hospital cardiac arrest? Results from the DANCAS survey study

AIMS

Out-of-hospital cardiac arrest (OHCA) survivors may suffer short-term fatigue, psychological, cognitive and disability problems, but we lack information on the proportion of survivors with these problems in the long-term. Hence, we investigated these problems in survivors 1-5 years post-OHCA and whether the results are different at different time points post-OHCA.

METHODS

All adults who survived an OHCA in Denmark from 2016 to 2019 were identified using the Danish Cardiac Arrest Registry and invited to participate in a survey between October 2020 and March 2021. The survey included the Modified Fatigue Impact Scale, Hospital Anxiety and Depression Scale, "Two simple questions" (everyday activities and mental recovery), and the 12-item World Health Organisation Disability Assessment Schedule 2.0. To investigate results at different time points, survivors were divided into four time-groups (12-24, 25-36, 37-48 and 49-56 months post-OHCA). Differences between time-groups were determined using the Kruskall-Wallis test for the mean scores and Chi-square test for the proportion of survivors with symptoms.

RESULTS

Total eligible survey population was 2116, of which 1258 survivors (60 %) responded. Overall, 29 % of survivors reported fatigue, 20 % anxiety, 15 % depression, and 27 % disability. When survivors were sub-divided by time since OHCA, no significant difference was found on either means scores or proportion between time groups (p = 0.28 to 0.88).

CONCLUSION

Up to a third of survivors report fatigue, anxiety, depression, reduced mental function and disability 1-5 years after OHCA. This proportion is the same regardless of how much time has passed supporting early screening and tailored post-OHCA interventions to help survivors adapt to their new situation.

A Qualitative Analysis of the Experiences of EMS Clinicians in Recognizing and Treating Witnessed Cardiac Arrests

BACKGROUND

Survival from out of hospital cardiac arrest (OHCA) increases when effective cardiopulmonary resuscitation (CPR) and defibrillation are performed early. Patients who suffer OHCA in front of emergency medical services (EMS) clinicians have greater likelihood of survival, but little is known about how EMS clinicians think about and experience those events. We sought to understand how EMS clinicians assessed patients who devolved to cardiac arrest in their presence and uncover the perceived barriers and facilitators associated with recognizing and treating witnessed OHCAs.

METHODS

EMS clinicians who had attended an EMS-witnessed OHCA and consented to participate were interviewed within 72 hours of the index case. Transcripts of the interviews were coded through the consolidated framework for implementation research to understand enabling and constraining factors involved and the predictability and anticipation of OHCA and subsequent management of patient care. Utstein data points, interventions, and associated times were extracted from the medical records.

RESULTS

We interviewed 29 EMS clinicians who attended 27 EMS-witnessed OHCAs. Twenty-six (96.3%) of the EMS-witnessed OHCAs were preceded by prodromal symptoms and were classified as predictable. Of the predictable cases, clinicians anticipated 53.8% of them and attributed the prodromes of other cases to serious but not peri-arrest etiologies. Participants described various environmental, crew, and intrapersonal enabling and constraining factors associated with recognizing and treating EMS-witnessed OHCAs. Environmental elements included issues of safety and physical locations, crew elements included familiarity with their partners and working with them in the past, and intrapersonal elements included abilities to collect information and stress associated with responding to and managing the calls.

CONCLUSION

Recognition and treatment of EMS-witnessed OHCAs are influenced by numerous environmental, crew, and intrapersonal factors. Future training and education on OHCA should include diverse locations, situations, and crew make-up, along with nontraditional patient complaints to broaden experiences associated with cardiac arrest management.

Out-of-hospital cardiac arrest with onset witnessed by emergency medical services: Implications for improvement in overall survival

Out-of-hospital cardiac arrest (OHCA) remains a major public health problem. Even in high-income countries, survival rates have plateaued in the range of ten percent, stimulating an ongoing interest in developing novel approaches to resuscitation. Emergency Medical Services (EMS)-witnessed OHCAs constitute a subgroup of overall OHCA that occur after the arrival of EMS, leading to rapid initiation of resuscitation and significantly improved survival. In this narrative review we summarize and interpret recent developments in knowledge of EMS-witnessed OHCA regarding prevalence, demographics, location, circumstances, survival outcomes and clinical profile. We examine the possibility of informing novel resuscitation approaches and enhancing mechanistic knowledge by studying EMS-witnessed OHCA, with the goal of improving overall survival from OHCA.

Global variation in the incidence and outcome of emergency medical services witnessed out-of-hospital cardiac arrest: A systematic review and meta-analysis

AIM OF THE REVIEW

To examine global variation in the incidence and outcomes of emergency medical services (EMS) witnessed out-of-hospital cardiac arrest (OHCA).

DATA SOURCES

We systematically reviewed four electronic databases for studies between 1990 and 5th April 2021 reporting EMS-witnessed OHCA populations. Studies were included if they reported sufficient data to calculate the primary outcome of survival to hospital discharge or 30-day survival. Random-effects models were used to pool incidence and survival outcomes, and meta-regression was used to examine sources of heterogeneity. Study quality was appraised using the Joanna Briggs Institute critical appraisal tools.

RESULTS

The search returned 1178 non-duplicate titles of which 66 articles comprising 133,981 EMS-witnessed patients treated by EMS across 33 countries were included. All but one study was observational and only 12 studies (18%) were deemed to be at low risk of bias. The pooled incidence of EMS-treated cases was 4.1 per 100,000 person-years (95% CI: 3.5, 4.7), varying almost 4-fold across continents. The pooled proportion of survivors to hospital discharge or 30-days was 20% overall (95% CI: 18%, 22%; I² = 98%), 43% (95% CI: 37%, 49%; I² = 94%) for initial shockable rhythms and 6% (95% CI: 5%, 8%; I² = 79%) for initial non-shockable rhythms. In the meta-regression analysis, only region and aetiology were significantly associated with survival. When compared to studies from North America, pooled survival was significantly higher in studies from Europe (14% vs. 26%; p = 0.04) and Australasia (14% vs. 31%, p < 0.001).

CONCLUSION

We identified significant global variation in the incidence and survival outcome of EMS-witnessed OHCA. Further research is needed to understand the factors contributing to these variations.

Outcomes following out-of-hospital cardiac arrest in the aeromedical retrieval population of the remote Top End of the Northern Territory, Australia

OBJECTIVE

Out-of-hospital cardiac arrest is an event with an extremely poor prognosis. There is limited literature on the outcomes for regional Australia, with none specifically addressing remote populations. We aimed to assess out-of-hospital cardiac arrest outcomes in the aeromedical retrieval population of the Top End Medical Retrieval Service.

DESIGN

We retrospectively identified all cardiac arrests, deaths and patients who had cardiopulmonary resuscitation within the aeromedical retrieval database for a 5-year period from January 2012 to December 2016.

SETTING

Retrieval patients across the Top End of the Northern Territory, Australia.

PARTICIPANTS

All patients within the cohort with a non-traumatic out-of-hospital cardiac arrest.

MAIN OUTCOME MEASURES

Data were collected on outcomes as per Utstein definitions, along with patient demographics, retrieval timings and interventions.

RESULTS

Seventy-five patients suffering cardiac arrest were identified, with 58 having a non-traumatic arrest in an out-of-hospital setting. The median age of the cohort was 40 years, and 53% had an initial shockable rhythm. Return of spontaneous circulation was achieved in 55% and 43% survived to hospital. The survival to hospital discharge and 28 days were 31% and 29%, respectively.

CONCLUSIONS

Although the study has a small sample size and limitations on generalisability due to the restricted nature of the cohort selection, the results suggest a 28-day survival rate is potentially comparable to other regions of Australia and the rest of the world. Further research needs to be undertaken in out-of-hospital cardiac arrest in remote regions to establish a true population-based cohort and ascertain where improvements can be made.

Cardiac arrests in general practice clinics or witnessed by emergency medical services: a 20-year retrospective study

OBJECTIVE

To compare the frequency and outcomes of cardiac arrests in general practice clinics with those of paramedic-witnessed cardiac arrests.

DESIGN, SETTING

Retrospective study; analysis of Victorian Ambulance Cardiac Arrest Registry data, 1 January 2000 - 30 December 2019.

PARTICIPANTS

Patients with non-traumatic cardiac arrests whom emergency medical services staff attempted to resuscitate.

MAIN OUTCOME MEASURES

Survival to hospital discharge.

RESULTS

6363 cases of cardiac arrest were identified: 216 in general practice clinics (3.4%) and 6147 witnessed by paramedics (96.6%). The proportion of patients presenting with initial shockable rhythms was larger in clinic (126 patients, 58.3%) than paramedic-witnessed cases (1929, 31.4%). The proportion of general practice clinic cases in which defibrillation was provided in the clinic increased from 2 of 37 in 2000-2003 (5%) to 19 of 57 patients in 2016-2019 (33%); survival increased from 7 of 37 (19%) to 23 of 57 patients (40%). For patients with initial shockable rhythms, 57 of 126 in clinic cases (45%) and 1221 of 1929 people in paramedic-witnessed cases (63.3%) survived to hospital discharge; of 47 general practice patients defibrillated by clinic staff, 27 survived (57%). For patients with initial shockable rhythms, the odds of survival were greater following paramedic-witnessed events (adjusted odds ratio [aOR], 3.39; 95% CI, 2.08-5.54) or general clinic arrests with defibrillation by clinic staff (aOR, 2.23; 95% CI, 1.03-4.83) than for general practice clinic arrests in which arriving paramedics provided defibrillation.

CONCLUSION

Emergency medical services should be alerted as soon as possible after people experience heart attack warning symptoms. Automated external defibrillators should be standard equipment in general practice clinics, enabling prompt defibrillation, which may substantially reduce the risk of death for people in cardiac arrest.

Effect of awareness time interval for out-of-hospital cardiac arrest on outcomes: A nationwide observational study

PURPOSE

Awareness of out-of-hospital cardiac arrest (OHCA) is critically important for bystanders to receive early instruction of dispatch-assisted cardiopulmonary resuscitation (DA-CPR) as well as to call for ambulance services. This study aimed to determine the association between awareness time interval and outcomes.

METHODS

EMS-treated, witnessed, adult (≥18 years old) OCHAs with presumed cardiac etiology between 2012 and 2017 were analyzed, excluding patients with unknown awareness time factors and outcomes. The main exposure was awareness time interval (ATI), defined as the time from the witnessed event to calling for ambulance. Patients were categorized into five groups according to ATI: Group 1 (0-1 min), Group 2 (2-3 min), Group 3 (4-5 min), Group 4 (6-30 min) and Group 5 (31-60 min). The primary outcome was good neurological recovery defined as cerebral performance category 1 or 2 (good CPC). Multivariable logistic regression analysis was performed to calculate adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for outcomes by ATI group (reference = Group 1) and by one-minute delay. We compared the effect size of ATI on outcomes across three witness groups (Layperson, Family, and Unknown).

RESULTS

A total of 36,809 OHCAs were analyzed. The AOR (95% CI) by one-minute ATI delay was 0.91 (0.90-0.92) for good CPC. The AORs (95% CIs) for outcomes compared with Group 1 were 0.98 (0.88-1.09) for Group 2, 0.64 (0.56-0.74) for Group 3, 0.30 (0.26-0.35) for Group 4, and 0.10 (0.05-0.20) for Group 5. In the Family bystander group, AORs (95% CIs) compared with Group 1 were significantly decreased by delay of ATI; 1.04 (0.88-1.11) for Group 2, 0.63 (0.81-0.83) for Group 3, and 0.31 (0.31-0.40) for Group 4 and 5. In Layperson-witnessed OHCAs, however, the AORs were significantly higher in the delayed awareness groups (Group 2 and Group 3).

CONCLUSION

A longer ATI in witnessed adult OHCAs was associated with poor neurological recovery. A one-minute delay in ATI was associated with a 9% decrease of good neurological recovery, and the effect was significantly increased in Family-witnessed OHCAs.

The timing of testing influences skill retention after basic life support training: a prospective quasi-experimental study

BACKGROUND

Proper basic life support (BLS) is key in improving the survival of out-of-hospital cardiac arrest. BLS skills deteriorate in three to 6 months after training. One method to improve skill retention may be using the "testing effect" to test skills at the end of a BLS course. The aim of our study was to investigate whether either testing or the timing of such testing after BLS training have any influence on skill retention.

METHODS

This was a post-test only, partial coverage, prospective quasi-experimental study designed to evaluate a BLS training course among 464 fifth year medical students at Semmelweis University in the first semester of 2013/2014. Groups were systematically but non-randomly assigned to either a control group that took no exam or one of two experimental groups that took an exam (N = 179, NoExam group; N = 165, EndExam group - exam at the end of the BLS training; N = 120, 3mExam group - exam 3 months after the BLS training). The ability to perform ten prescribed essential BLS steps was evaluated during a skill retention assessment 2 months after the course in the NoExam, 2 months after the course (and the exam) in the EndExam and 5 months after the course (2 months after the exam) in the 3mExam group to measure skill retention and the effect of our intervention. Scores were calculated for each BLS step, and also summed up as a total score. We used Kruskal-Wallis test to assess differences in skill retention.

RESULTS

Overall, NoExam and EndExam groups showed similar skill retention. The mean total score (and many of the sub-scores) of students was significantly higher in the 3mExam group compared to both the NoExam and the EndExam groups, and there was no difference in the total score (and many of the sub-scores) of the latter two groups. The 3mExam group had less variability in total scores (and many of the sub-scores) than the other two groups.

CONCLUSION

Our study provides evidence that testing these skills 3 months after BLS training may be more effective than either testing immediately at the end of the course or no testing at all.

Improvement in Non-Traumatic, Out-Of-Hospital Cardiac Arrest Survival in Detroit From 2014 to 2016

Background In 2002, the out-of-hospital cardiac arrest ( OHCA ) survival rate in Detroit was the lowest in the nation. Concerted efforts sought to improve the city's chain of survival with a focus on emergency medical services ( EMS ). This study assesses the impact on OHCA survival rates and describe factors associated with survival. Methods and Results Data for non-traumatic OHCA cases in Detroit from 2014 to 2016 were extracted from CARES (Cardiac Arrest Registry to Enhance Survival). Chi-squared tests, non-parametric tests, and a multivariable logistic regression analysis were employed to examine the associations between overall survival and its covariates. A total of 2359 non-traumatic OHCA cases were examined. The overall survival rate increased from 3.7% in 2014 to 5.4% in 2015, and 6.4% in 2016 ( P<0.01), reflecting a 73% improvement in survival over the 3-year period. EMS median on-scene time decreased over the study period, while the rate at which EMS initiated cardiopulmonary resuscitation and applied an automated external defibrillator (AED) greatly increased ( P<0.001). The factors significantly associated with survival were female sex (odds ratio=1.70, P<0.05), a public setting (odds ratio=2.31, P<0.01), an EMS witness (odds ratio=6.18, P<0.01), and the presence of an initial shockable rhythm (odds ratio=1.88, P<0.05). Conclusions From 2014 to 2016, the overall survival rate for OHCA patients in Detroit, MI significantly improved. Our results suggest that an improved chain of survival may explain this progress. This study is an example of how OHCA data analysis and EMS improvement can improve end OHCA outcomes in a resource-limited urban setting.

Impact of a public awareness campaign on out-of-hospital cardiac arrest incidence and mortality rates

Aims

Increased public awareness of the warning signs of a heart attack and the importance of early medical intervention may help to prevent premature deaths from out-of-hospital cardiac arrest (OHCA). We sought to investigate the impact of the Heart Foundation's public awareness campaigns on the monthly incidence of, and deaths from, OHCA in Melbourne, Australia.

Methods and results

Between July 2005 and June 2015, we included registry data for 25 060 OHCA of presumed cardiac aetiology. Time series models with distributed lags were used to explore the effect of campaign activity on OHCA outcomes. A sensitivity analysis involving segmented regression of the pre-intervention, intervention, and post-intervention time segments was also performed. The mean monthly incidence of, and deaths from, OHCA was 207 and 189 events respectively. After adjustment for temporal trends, campaign activity was associated with a 6.0% [95% confidence interval (CI): 2.8-9.0%; P < 0.001] reduction in the monthly incidence of OHCA, or 11.7% (95% CI: 7.7-15.5%, P < 0.001) with the addition of residual effects in two additional lag months. Similarly, the rate of deaths from OHCA reduced by 6.4% (95% CI: 2.8-10.0%; P = 0.001) during months with campaign activity. Campaign activity had a greater effect in males and patients aged ≥65 years, and reduced the incidence of OHCA in unwitnessed and initial non-shockable arrests. In the segmented regression analysis, the intervention period was associated with a 15.2% (95% CI: 9.2-20.9%; P < 0.001) reduction in the mean monthly incidence and a 16.6% (95% CI: 9.9-22.7%; P < 0.001) reduction in deaths from OHCA.

Conclusion

A comprehensive mass media campaign targeting the community's awareness of heart attack symptoms was associated with a substantial reduction in the incidence of OHCA and associated deaths.

Establishing the Aus-ROC Australian and New Zealand out-of-hospital cardiac arrest Epistry

INTRODUCTION

Out-of-hospital cardiac arrest (OHCA) is a global health problem with low survival. Regional variation in survival has heightened interest in combining cardiac arrest registries to understand and improve OHCA outcomes. While individual OHCA registries exist in Australian and New Zealand ambulance services, until recently these registries have not been combined. The aim of this protocol paper is to describe the rationale and methods of the Australian Resuscitation Outcomes Consortium (Aus-ROC) OHCA epidemiological registry (Epistry).

METHODS AND ANALYSIS

The Aus-ROC Epistry is designed as a population-based cohort study. Data collection started in 2014. Six ambulance services in Australia (Ambulance Victoria, SA Ambulance Service, St John Ambulance Western Australia and Queensland Ambulance Service) and New Zealand (St John New Zealand and Wellington Free Ambulance) currently contribute data. All OHCA attended by ambulance, regardless of aetiology or patient age, are included in the Epistry. The catchment population is approximately 19.3 million persons, representing 63% of the Australian population and 100% of the New Zealand population. Data are collected using Utstein-style definitions. Information incorporated into the Epistry includes demographics, arrest features, ambulance response times, treatment and patient outcomes. The primary outcome is 'survival to hospital discharge', with 'return of spontaneous circulation' as a key secondary outcome.

ETHICS AND DISSEMINATION

Ethics approval was independently sought by each of the contributing registries. Overarching ethics for the Epistry was provided by Monash University HREC (Approval No. CF12/3938-2012001888). A population-based OHCA registry capturing the majority of Australia and New Zealand will allow risk-adjusted outcomes to be determined, to enable benchmarking across ambulance providers, facilitate the identification of system-wide strategies associated with survival from OHCA, and allow monitoring of temporal trends in process and outcomes to improve patient care. Findings will be shared with participating ambulance services and the academic community.

Impact of cardiopulmonary resuscitation duration on survival from paramedic witnessed out-of-hospital cardiac arrests: An observational study

BACKGROUND

Resuscitation guidelines often recommend ongoing cardiopulmonary resuscitation (CPR) efforts to hospital for out-of-hospital cardiac arrests (OHCA) witnessed by emergency medical service (EMS) personnel. In this study, we examine the relationship between EMS CPR duration and survival to hospital discharge in EMS witnessed OHCA patients.

METHODS

Between January 2003 and December 2011, 1035 adult EMS witnessed arrests of presumed cardiac aetiology were included from the Victorian Ambulance Cardiac Arrest Registry. CPR duration was defined as the total sum of prehospital CPR time in minutes. Adjusted logistic regression analyses were used to assess the impact of EMS CPR duration on survival to hospital discharge.

RESULTS

382 (37.3%) patients were discharged alive. The median CPR duration was 12 min (95% CI: 11-13) overall, but was higher in non-survivors compared to survivors (24 min vs. 2 min, p<0.001). The 99th percentile CPR duration in patients surviving to hospital discharge differed by the initial rhythm of arrest: 32 min (95% CI: 27-44) overall, 32 min (95% CI: 23-44) for ventricular fibrillation and pulseless ventricular tachycardia (VF/VT), 34 min (95% CI: 30-34) for pulseless electrical activity (PEA), and 28 min (95% CI: 21-28) for asystole. There were no survivors after 44 min for all rhythms. After adjusting for prehospital confounders, every minute increase in CPR duration was associated with a 13% reduction in the odds of survival to hospital discharge (OR 0.87, 95% CI: 0.84-0.89, p<0.001). The multivariable model predicted no chance of survival at or after a CPR duration of 48 min for VF/VT patients, 47 min for PEA patients and 45 min for asystole patients.

CONCLUSION

Resuscitation efforts exceeding 32 min yielded less than 1% of survivors from EMS witnessed OHCA. On the basis of this data, EMS witnessed OHCA patients may benefit from ongoing CPR efforts up to 48 min in duration.

Incidence of sudden cardiac death in a young active population

BACKGROUND

Little is known about the burden of sudden cardiac death (SCD) among active, presumably healthy persons. We investigated the incidence of SCD among US male career firefighters.

METHODS AND RESULTS

All on-duty SCDs among US male career firefighters between 1998 and 2012 were identified from the US Fire Administration and the US National Institute for Occupational Safety and Health databases. Age-specific incidence rates (IRs) of SCD with 95% CIs were computed. A joinpoint model was fitted to analyze the trend in IR and to help estimate the annual percentage change of SCD rates over the years. The effects of seasonality were assessed through a Poisson regression model. We identified 182 SCDs; based on 99 available autopsy reports, the leading underlying cause of death was coronary heart disease (79%). The overall IR was 18.1 SCDs per 100 000 person-years. The age-specific IRs of SCD ranged between 3.8 (for those aged 18 to 24 years) and 45.2 (for those aged 55 to 64 years) per 100 000 person-years. The annual rate of SCD steadily declined over time (annual percentage change -3.9%, 95% CI -5.8 to -2.0). SCD events were more frequent during January (peak-to-low ratio 1.70; 95% CI 1.09 to 2.65). In addition, the IR was 3 times higher during high-risk duties compared with low-risk duties. IRs among firefighters were lower than those observed among the US general population and US military personnel.

CONCLUSIONS

SCD risk in this active working population is overestimated using statistics from the general population. To address public health questions among these subpopulations, more specific studies of active adults should be conducted.