Seroprevalence of SARS-CoV-2 antibodies in social housing areas in Denmark.

BACKGROUND: COVID-19 is thought to be more prevalent among ethnic minorities and individuals with low socioeconomic status. We aimed to investigate the prevalence of SARS-CoV-2 antibodies during the COVID-19 pandemic among citizens 15 years or older in Denmark living in social housing (SH) areas. METHODS: We conducted a study between January 8th and January 31st, 2021 with recruitment in 13 selected SH areas. Participants were offered a point-of-care rapid SARS-CoV-2 IgM and IgG antibody test and a questionnaire concerning risk factors associated with COVID-19. As a proxy for the general Danish population we accessed data on seroprevalence from Danish blood donors (total Ig ELISA assay) in same time period. RESULTS: Of the 13,279 included participants, 2296 (17.3%) were seropositive (mean age 46.6 (SD 16.4) years, 54.2% female), which was 3 times higher than in the general Danish population (mean age 41.7 (SD 14.1) years, 48.5% female) in the same period (5.8%, risk ratios (RR) 2.96, 95% CI 2.78-3.16, p > 0.001). Seropositivity was higher among males (RR 1.1, 95% CI 1.05-1.22%, p = 0.001) and increased with age, with an OR seropositivity of 1.03 for each 10-year increase in age (95% CI 1.00-1.06, p = 0.031). Close contact with COVID-19-infected individuals was associated with a higher risk of infection, especially among household members (OR 5.0, 95% CI 4.1-6.2 p < 0,001). Living at least four people in a household significantly increased the OR of seropositivity (OR 1.3, 95% CI 1.0-1.6, p = 0.02) as did living in a multi-generational household (OR 1.3 per generation, 95% CI 1.1-1.6, p = 0.003). Only 1.6% of participants reported not following any of the national COVID-19 recommendations. CONCLUSIONS: Danish citizens living in SH areas of low socioeconomic status had a three times higher SARS-CoV-2 seroprevalence compared to the general Danish population. The seroprevalence was significantly higher in males and increased slightly with age. Living in multiple generations households or in households of more than four persons was a strong risk factor for being seropositive. Results of this study can be used for future consideration of the need for preventive measures in the populations living in SH areas.

Hypothetical interventions on emergency ambulance and prehospital acetylsalicylic acid administration in myocardial infarction patients presenting without chest pain.

BACKGROUND: Myocardial infarction (MI) patients presenting without chest pain are a diagnostic challenge. They receive suboptimal prehospital management and have high mortality. To elucidate potential benefits of improved management, we analysed expected outcome among non-chest pain MI patients if hypothetically they (1) received emergency ambulances/acetylsalicylic acid (ASA) as often as observed for chest pain patients, and (2) all received emergency ambulance/ASA. METHODS: We sampled calls to emergency and non-emergency medical services for patients hospitalized with MI within 24 h and categorized calls as chest pain/non-chest pain. Outcomes were 30-day mortality and a 1-year combined outcome of re-infarction, heart failure admission, and mortality. Targeted minimum loss-based estimation was used for all statistical analyses. RESULTS: Among 5418 calls regarding MI patients, 24% (1309) were recorded with non-chest pain. In total, 90% (3689/4109) of chest pain and 40% (525/1309) of non-chest pain patients received an emergency ambulance, and 73% (2668/3632) and 37% (192/518) of chest pain and non-chest pain patients received prehospital ASA. Providing ambulances to all non-chest pain patients was not associated with improved survival. Prehospital administration of ASA to all emergency ambulance transports of non-chest pain MI patients was expected to reduce 30-day mortality by 5.3% (CI 95%: [1.7%;9%]) from 12.8% to 7.4%. No significant reduction was found for the 1-year combined outcome (2.6% CI 95% [- 2.9%;8.1%]). In comparison, the observed 30-day mortality was 3% among ambulance-transported chest pain MI patients. CONCLUSIONS: Our study found large differences in the prehospital management of MI patients with and without chest pain. Improved prehospital ASA administration to non-chest pain MI patients could possibly reduce 30-day mortality, but long-term effects appear limited. Non-chest pain MI patients are difficult to identify prehospital and possible unintended effects of ASA might outweigh the potential benefits of improving the prehospital management. Future research should investigate ways to improve the prehospital recognition of MI in the absence of chest pain.

International initiation and termination of resuscitation practices: Protocol of a cross-sectional survey.

BACKGROUND: Substantial variation in survival following out-of-hospital cardiac arrest (OHCA) is described both internationally and nationally. The Utstein factors account for half of the variation, but the remaining is not fully understood. Local regulations or guidelines concerning the withholding and termination of resuscitation may influence the reporting of cardiac arrests when comparing outcomes between different Emergency Medical Service systems. METHOD: We have developed an online cross-sectional mixed-methods explanatory design survey aimed at describing the international and national variations in the initiation, the termination of resuscitation, and the refraining from resuscitation of adult patients (>18 years of age) suffering from non-traumatic OHCA. The respondents will be national experts and the questionnaire will be distributed among members of European Prehospital Research Alliance, the International Liaison Committee of Resuscitation, the European Resuscitation Council, and the Resuscitation Academy. Each invited country will have to identify at least two national experts with special expertise in prehospital resuscitation practices. We exclude countries with less than two respondents. RESULTS: The survey will provide both quantitative and qualitative data. Quantitative data will be presented as frequencies and proportions. Qualitative data will be analyzed using content analysis. CONCLUSION: This survey could be of importance in understanding the multiple factors leading to the substantial variation in survival found following OHCA. Furthermore, the interpretation of future studies on OHCA from different settings may be improved to further increase survival following OHCA.

SARS-CoV-2 antibody prevalence among homeless people and shelter workers in Denmark: a nationwide cross-sectional study.

BACKGROUND: People experiencing homelessness (PEH) and associated shelter workers may be at higher risk of infection with "Severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2). The aim of this study was to determine the prevalence of SARS-CoV-2 among PEH and shelter workers in Denmark. DESIGN AND METHODS: In November 2020, we conducted a nationwide cross-sectional seroprevalence study among PEH and shelter workers at 21 recruitment sites in Denmark. The assessment included a point-of-care test for antibodies against SARS-CoV-2, followed by a questionnaire. The seroprevalence was compared to that of geographically matched blood donors considered as a proxy for the background population, tested using a total Ig ELISA assay. RESULTS: We included 827 participants in the study, of whom 819 provided their SARS-CoV-2 antibody results. Of those, 628 were PEH (median age 50.8 (IQR 40.9-59.1) years, 35.5% female) and 191 were shelter workers (median age 46.6 (IQR 36.1-55.0) years and 74.5% female). The overall seroprevalence was 6.7% and was similar among PEH and shelter workers (6.8% vs 6.3%, p = 0.87); and 12.2% among all participants who engaged in sex work. The overall participant seroprevalence was significantly higher than that of the background population (2.9%, p < 0.001). When combining all participants who reported sex work or were recruited at designated safe havens, we found a significantly increased risk of seropositivity compared to other participants (OR 2.23, 95%CI 1.06-4.43, p = 0.02). Seropositive and seronegative participants reported a similar presence of at least one SARS-CoV-2 associated symptom (49% and 54%, respectively). INTERPRETATIONS: The prevalence of SARS-CoV-2 antibodies was more than twice as high among PEH and associated shelter workers, compared to the background population. These results could be taken into consideration when deciding in which phase PEH are eligible for a vaccine, as part of the Danish national SARS-CoV-2 vaccination program rollout. FUNDING: TrygFonden and HelseFonden.

Early ICD implantation in cardiac arrest survivors with acute coronary syndrome - predictors of implantation, ICD-therapy and long-term survival.

Objectives. Implantable cardioverter defibrillator (ICD) implantation in patients resuscitated from out-of-hospital cardiac arrest (OHCA) due to acute myocardial infarction (AMI) is controversial. Design. Consecutive OHCA-survivors due to AMI from two Danish tertiary heart centers from 2007 to 2011 were included. Predictors of ICD-implantation, ICD-therapy and long-term survival (5 years) were investigated. Patients with and without ICD-implantation during the index hospital admission were included (later described as early ICD-implantation). Patients with an ICD after hospital discharge were censored from further analyses at time of implantation. Results. We identified 1,457 consecutive OHCA-patients, and 292 (20%) of the cohort met the inclusion criteria. An ICD was implanted during hospital admission in 78 patients (27%). STEMI and successful revascularization were inversely and independently associated with ICD-implantation (ORSTEMI = 0.37, 95% CI: 0.14-0.94, ORrevasc = 0.11, 0.03-0.36) whereas age, sex, LVEF <35%, comorbidity burden or shockable first OHCA-rhythm were not associated with ICD-implantation. Appropriate ICD-shock therapy during the follow-up period was noted in 15% of patients (n = 12). Five-year mortality-rate was significantly lower in ICD-patients (18% vs. 28%, plogrank = 0.02), which was persistent after adjustment for prognostic factors (HR = 0.44 (95% CI: 0.23-0.88)). This association was no longer found when using first event (death or appropriate shock whatever came first) as outcome variable (plogrank = 0.9). Conclusions. Mortality after OHCA due to AMI was significantly lower in patients with early ICD-implantation after adjustment for prognostic factors. When using appropriate shock and death as events, ICD-patients had similar outcome as patients without an ICD, which may suggest a survival benefit due to appropriate device therapy.

Strategies to Handle Increased Demand in the COVID-19 Crisis: A Coronavirus EMS Support Track and a Web-Based Self-Triage System.

BACKGROUND: In emergencies, such as the COVID-19 pandemic, there is an increased need for contact with emergency medical services (EMS), and call volume might surpass capacity. The Copenhagen EMS operates two telephone line the 1-1-2 emergency number and the 1813 medical helpline. A separate coronavirus support track was implemented on the 1813 medical helpline and a web-based self-triage (web triage) system was created to reduce non-emergency call volume. The aim of this paper is to present call volume and the two measures implemented to handle the increased call volume to the Copenhagen EMS. METHODS: This is a cross sectional observational study. Call volume and queue time is presented in the first month of the COVID-19 pandemic (27th of February 2020 to 27th of march) and compared to the equivalent month from the year before (2019). Descriptive statistics are conducted on call volumes and queue times and spearman's rank correlation test are performed to test correlation between web triage and call volume. RESULTS: Total EMS call volume increase by 23.3% between 2019 and 2020 (92.670 vs. 114,250). The 1-1-2 emergency line total call volume increase by 4.4% (8,4942 vs. 8,870) and the 1813 medical helpline increased by 25.1% (84.176 vs. 105.380). The coronavirus support track handled 21,063 calls. The 1813 medical helpline queue time was a mean of 02 minutes and 23 seconds (CI: 2.22-2.25) in 2019 and 12 minutes and 2 seconds (CI 11:55-12:09) in 2020 (P < 0.001). The web triage was used 10,894 times. No correlation between call volume and web triage usage was seen. CONCLUSIONS: In the first month of the ongoing COVID-19 pandemic a significant increase in call volume was observed in the 1813 medical helpline compared to 2019. A large number of calls were handled by the additional coronavirus track and diverted away from the regular tracks of the 1813 medical helpline. This likely contributed to mitigating increased call volumes and queue times. The web triage was widely used but no significant correlation was seen with 1813 medical helpline call volume. Other EMS organizations can learn from this to enhance capacity in a future epidemics.

Socioeconomic inequality in telephone triage on triage response, hospitalization and 30-day mortality.

We investigated socioeconomic inequality (measured by the indicators highest attained education level and household income) in telephone triage on triage response (face-to-face contact), hospitalization and 30-day mortality among Danish citizens calling the medical helpline 1813 between 23 January and 9 February 2017. The analysis included 6869 adult callers from a larger prospective cohort study and showed that callers with low socioeconomic status (SES) were less often triaged to a face-to-face contact and had higher 30-day mortality than callers with high SES.

Assessment of breathing in cardiac arrest: a randomised controlled trial of three teaching methods among laypersons.

BACKGROUND: The aim of this trial was to compare a video- and a simulation-based teaching method to the conventional lecture-based method, hypothesizing that the video- and simulation-based teaching methods would lead to improved recognition of breathing patterns during cardiac arrest. METHODS: In this Danish, investigator-initiated, stratified, randomised controlled trial, adult laypersons (university students, military conscripts and elderly retirees) participating in European Resuscitation Council Basic Life Support courses were randomised to receive teaching on how to recognise breathing patterns using a lecture- (usual practice), a video-, or a simulation-based teaching method. The primary outcome was recognition of breathing patterns in nine videos of actors simulating normal breathing, no breathing, and agonal breathing (three of each). We analysed outcomes using logistic regression models and present results as odds ratios (ORs) with 95% confidence intervals (CIs) and P-values from likelihood ratio tests. RESULTS: One hundred fifty-three participants were included in the analyses from February 2, 2018 through May 21, 2019 and recognition of breathing patterns was statistically significantly different between the teaching methods (P = 0.013). Compared to lecture-based teaching (83% correct answers), both video- (90% correct answers; OR 1.77, 95% CI: 1.19-2.64) and simulation-based teaching (88% correct answers; OR 1.48; 95% CI: 1.01-2.17) led to significantly more correct answers. Video-based teaching was not statistically significantly different compared to simulation-based teaching (OR 1.20; 95% CI: 0.78-1.83). CONCLUSION: Video- and simulation-based teaching methods led to improved recognition of breathing patterns among laypersons participating in adult Basic Life Support courses compared to the conventional lecture-based teaching method.

Live video from bystanders' smartphones to medical dispatchers in real emergencies.

BACKGROUND: Medical dispatchers have limited information to assess the appropriate emergency response when citizens call the emergency number. We explored whether live video from bystanders' smartphones changed emergency response and was beneficial for the dispatcher and caller. METHODS: From June 2019 to February 2020, all medical dispatchers could add live video to the emergency calls at Copenhagen Emergency Medical Services, Denmark. Live video was established with a text message link sent to the caller's smartphone using GoodSAM®. To avoid delayed emergency response if the video transmission failed, the medical dispatcher had to determine the emergency response before adding live video to the call. We conducted a cohort study with a historical reference group. Emergency response and cause of the call were registered within the dispatch system. After each video, the dispatcher and caller were given a questionnaire about their experience. RESULTS: Adding live video succeeded in 838 emergencies (82.2% of attempted video transmissions) and follow-up was possible in 700 emergency calls. The dispatchers' assessment of the patients' condition changed in 51.1% of the calls (condition more critical in 12.9% and less critical in 38.2%), resulting in changed emergency response in 27.5% of the cases after receiving the video (OR 1.58, 95% CI: 1.30-1.91) compared to calls without video. Video was added more frequently in cases with sick children or unconscious patients compared with normal emergency calls. The dispatcher recognized other or different disease/trauma in 9.9% and found that patient care, such as the quality of cardiopulmonary resuscitation, obstructed airway or position of the patient, improved in 28.4% of the emergencies. Only 111 callers returned the questionnaire, 97.3% of whom felt that live video should be implemented. CONCLUSIONS: It is technically feasible to add live video to emergency calls. The medical dispatcher's perception of the patient changed in about half of cases. The odds for changing emergency response were 58% higher when video was added to the call. However, use of live video is challenging with the existing dispatch protocols, and further implementation science is necessary.

Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden.

Bystander Efforts and 1-Year Outcomes in Out-of-Hospital Cardiac Arrest.

BACKGROUND: The effect of bystander interventions on long-term functional outcomes among survivors of out-of-hospital cardiac arrest has not been extensively studied. METHODS: We linked nationwide data on out-of-hospital cardiac arrests in Denmark to functional outcome data and reported the 1-year risks of anoxic brain damage or nursing home admission and of death from any cause among patients who survived to day 30 after an out-of-hospital cardiac arrest. We analyzed risks according to whether bystander cardiopulmonary resuscitation (CPR) or defibrillation was performed and evaluated temporal changes in bystander interventions and outcomes. RESULTS: Among the 2855 patients who were 30-day survivors of an out-of-hospital cardiac arrest during the period from 2001 through 2012, a total of 10.5% had brain damage or were admitted to a nursing home and 9.7% died during the 1-year follow-up period. During the study period, among the 2084 patients who had cardiac arrests that were not witnessed by emergency medical services (EMS) personnel, the rate of bystander CPR increased from 66.7% to 80.6% (P<0.001), the rate of bystander defibrillation increased from 2.1% to 16.8% (P<0.001), the rate of brain damage or nursing home admission decreased from 10.0% to 7.6% (P<0.001), and all-cause mortality decreased from 18.0% to 7.9% (P=0.002). In adjusted analyses, bystander CPR was associated with a risk of brain damage or nursing home admission that was significantly lower than that associated with no bystander resuscitation (hazard ratio, 0.62; 95% confidence interval [CI], 0.47 to 0.82), as well as a lower risk of death from any cause (hazard ratio, 0.70; 95% CI, 0.50 to 0.99) and a lower risk of the composite end point of brain damage, nursing home admission, or death (hazard ratio, 0.67; 95% CI, 0.53 to 0.84). The risks of these outcomes were even lower among patients who received bystander defibrillation as compared with no bystander resuscitation. CONCLUSIONS: In our study, we found that bystander CPR and defibrillation were associated with risks of brain damage or nursing home admission and of death from any cause that were significantly lower than those associated with no bystander resuscitation. (Funded by TrygFonden and the Danish Heart Foundation.).

Bystander cardiopulmonary resuscitation and long-term outcomes in out-of-hospital cardiac arrest according to location of arrest.

Aims: Bystander cardiopulmonary resuscitation (CPR) has increased in several countries following nationwide initiatives to facilitate bystander resuscitative efforts in out-of-hospital cardiac arrest (OHCA). We examined the importance of public or residential location of arrest on temporal changes in bystander CPR and outcomes. Methods and results: From the nationwide Danish Cardiac Arrest Registry, all OHCAs from 2001 to 2014 of presumed cardiac cause and between 18 and 100 years of age were identified. Arrests witnessed by emergency medical services personnel were excluded. Of 25 505 OHCAs, 26.4% (n = 6738) and 73.6% (n = 18 767) were in public and residential locations, respectively. Bystander CPR increased during 2001-2014 in both locations: from 36.4% [95% confidence interval (CI) 30.6-42.6%] to 83.1% (95% CI 80.0-85.8%) in public (P < 0.001) and from 16.0% (95% CI 13.2-19.3%) to 61.0% (95% CI 58.7-63.2%) in residential locations (P < 0.001). Concurrently, 30-day survival increased in public from 6.4% (95% CI 4.0-10.0%) to 25.2% (95% CI 22.1-28.7%) (P < 0.001), and in residential from 2.9% (95% CI 1.8-4.5%) to 10.0% (95% CI 8.7-11.4%) (P < 0.001). Among 2281 30-day survivors, 1-year risk of anoxic brain damage/nursing home admission during 2001-2014 decreased from 18.8% (95% CI 6.6-43.0%) to 6.8% (95% CI 3.9-11.8%) in public (P < 0.001), whereas the corresponding change was insignificant in residential locations from 11.8% (95% CI 3.3-34.3) to 17.6% (95% CI 12.7-23.9%) (P = 0.52). Conclusion: During 2001-2014, bystander CPR and 30-day survival more than doubled in both public and residential OHCA locations. A significant decrease in anoxic brain damage/nursing home admission was observed among 30-day survivors in public, but not among survivors from residential OHCAs.

The Effects of Public Access Defibrillation on Survival After Out-of-Hospital Cardiac Arrest: A Systematic Review of Observational Studies.

BACKGROUND: Despite recent advances, the average survival after out-of-hospital cardiac arrest (OHCA) remains <10%. Early defibrillation by an automated external defibrillator is the most important intervention for patients with OHCA, showing survival proportions >50%. Accordingly, placement of automated external defibrillators in the community as part of a public access defibrillation program (PAD) is recommended by international guidelines. However, different strategies have been proposed on how exactly to increase and make use of publicly available automated external defibrillators. This systematic review aimed to evaluate the effect of PAD and the different PAD strategies on survival after OHCA. METHODS: PubMed, Embase, and the Cochrane Library were systematically searched on August 31, 2015 for observational studies reporting survival to hospital discharge in OHCA patients where an automated external defibrillator had been used by nonemergency medical services. PAD was divided into 3 groups according to who applied the defibrillator: nondispatched lay first responders, professional first responders (firefighters/police) dispatched by the Emergency Medical Dispatch Center (EMDC), or lay first responders dispatched by the EMDC. RESULTS: A total of 41 studies were included; 18 reported PAD by nondispatched lay first responders, 20 reported PAD by EMDC-dispatched professional first responders (firefighters/police), and 3 reported both. We identified no qualified studies reporting survival after PAD by EMDC-dispatched lay first responders. The overall survival to hospital discharge after OHCA treated with PAD showed a median survival of 40.0% (range, 9.1-83.3). Defibrillation by nondispatched lay first responders was associated with the highest survival with a median survival of 53.0% (range, 26.0-72.0), whereas defibrillation by EMDC-dispatched professional first responders (firefighters/police) was associated with a median survival of 28.6% (range, 9.0-76.0). A meta-analysis of the different survival outcomes could not be performed because of the large heterogeneity of the included studies. CONCLUSIONS: This systematic review showed a median overall survival of 40% for patients with OHCA treated by PAD. Defibrillation by nondispatched lay first responders was found to correlate with the highest impact on survival in comparison with EMDC-dispatched professional first responders. PAD by EMDC-dispatched lay first responders could be a promising strategy, but evidence is lacking.

Association between socioeconomic factors and ICD implantation in a publicly financed health care system: a Danish nationwide study.

Aims: For patients surviving out-of-hospital cardiac arrest (OHCA) with a shockable rhythm, implantable cardioverter defibrillator (ICD) is recommended for non-reversible causes of arrest. We aimed to determine factors associated with implantation of ICD and survival in patients surviving non-AMI OHCA in a nationwide register covering all OHCAs in Denmark. Methods and results: We identified 36 950 OHCAs between 2001 and 2012, 1700 of whom were ICD naïve, ≥18 years, of non-AMI cardiac aetiology and surviving until discharge. Six hundred fifty eight patients had ICD implanted during index admission. Association to ICD implantation during index admission was analysed in logistic regression, survival was assessed using Cox regression. Implantable cardioverter defibrillator implantation increased during the study period [odds ratio (OR) 1-year increase: 1.04, 95% confidence intervals (95% CI): 1.00-1.08, P = 0.03]. Non-shockable rhythm and age ≥70 years were associated with lower odds of ICD implantation (ORnon-shockable: 0.27, 95% CI: 0.19-0.37, P < 0.001, OR70-79 years: 0.71, 95% CI: 0.52-0.98, P = 0.04, OR≥80 years: 0.13, 95% CI: 0.07-0.22, P < 0.001). Non-AMI ischaemic heart disease, highest income tertile and chronic heart failure were associated with higher odds (ORIHD: 2.51, 95% CI: 1.77-3.60, P < 0.001, ORhighest income tertile: 1.58, 95% CI: 1.06-2.23, P = 0.02, ORHF: 1.77, 95% CI: 1.35-2.32, P < 0.001). Implantable cardioverter defibrillator implantation was associated with a lower risk of mortality (HR: 0.70, 95% CI: 0.53-0.92, P = 0.01). Conclusion: Implantable cardioverter defibrillator implantation rates increased over the study period. CHF, previous IHD and high income were associated with ICD implantation, while older age and non-shockable rhythm was associated with lower odds of ICD implantation. Implantable cardioverter defibrillator implantation was associated with higher survival rates.

Refractory out-of-hospital cardiac arrest with ongoing cardiopulmonary resuscitation at hospital arrival - survival and neurological outcome without extracorporeal cardiopulmonary resuscitation.

BACKGROUND: The prognosis in refractory out-of-hospital cardiac arrest (OHCA) with ongoing cardiopulmonary resuscitation (CPR) at hospital arrival is often considered dismal. The use of extracorporeal cardiopulmonary resuscitation (eCPR) for perfusion enhancement during resuscitation has shown variable results. We aimed to investigate outcome in refractory OHCA patients managed conservatively without use of eCPR. METHODS: We included consecutive OHCA patients with refractory arrest or prehospital return of spontaneous circulation (ROSC) in the Copenhagen area in 2002-2011. RESULTS: A total of 3992 OHCA patients with resuscitation attempts were included; in 2599, treatment was terminated prehospital, and 1393 (35%) were brought to the hospital either with ROSC (n = 1285, 92%) or with refractory OHCA (n = 108, 8%). Of patients brought in with refractory OHCA, 56 (52%) achieved ROSC in the emergency department. There were no differences between patients with refractory OHCA or prehospital ROSC with regard to age, sex, comorbidities, or etiology of OHCA. Time to emergency medical services (EMS) arrival was similar, whereas time to ROSC (when ROSC was achieved) was longer in refractory OHCA patients (EMS, 6 (5-9] vs. 7 [5-10] min, p = 0.8; ROSC, 15 [9-22] vs. 27 [20-41] min, p < 0.001). Independent factors associated with transport with refractory OHCA instead of prehospital termination of therapy were OHCA in public (OR, 3.6 [95% CI, 2.2-5.8]; p < 0.001), witnessed OHCA (OR, 3.7 [2.0-7.1]; p < 0.001), shockable rhythm (OR, 3.0 [1.9-4.7]; p < 0.001), younger age (OR, 1.2 [1.1-1.2]; p < 0.001), and later calendar year (OR, 1.4 [1.2-1.6]; p < 0.001). Thirty-day survival was 20% in patients with refractory OHCA compared with 42% in patients with prehospital ROSC (p < 0.001). Four of 28 refractory OHCA patients with duration of resuscitation > 60 min achieved ROSC. No difference in favorable neurological outcome in patients surviving to discharge was found (prehospital ROSC 84% vs. refractory OHCA 86%; p = 0.7). CONCLUSIONS: Survival after refractory OHCA with ongoing CPR at hospital arrival was significantly lower than among patients with prehospital ROSC. Despite a lower survival, the majority of survivors with both refractory OHCA and prehospital ROSC were discharged with a similar degree of favorable neurological outcome, indicating that continued efforts in spite of refractory OHCA are not in vain and may still lead to favorable outcome even without eCPR.

Use of renal replacement therapy after out-of-hospital cardiac arrest in Denmark 2005-2013.

OBJECTIVES: Renal replacement therapy (RRT) is used to treat acute kidney injury as part of multi organ failure. Use and prognostic implications after out-of-hospital cardiac arrest (OHCA) is not well known. This study aims to assess incidence and use of RRT and whether RRT post-arrest was associated with 30-day mortality in Denmark in the years 2005-2013. METHODS: The Danish Cardiac Arrest Registry holds information on all OHCA patients in Denmark from 2005 to 2013. We identified 3,012 one-day survivors of OHCA ≥18 years, with presumed cardiac aetiology of arrest, admitted to ICU without previous RRT. Change in use of RRT during the study period was assessed using competing risk analysis. Mortality was assessed with Cox regression. RESULTS: On average, RRT was performed in 6% of the patient population with an average annual 1% increase, HR: 1.01, CI: 0.95-1.07, p = .69. Hazard of RRT was lower in patients receiving bystander cardiopulmonary resuscitation (CPR) (p < .001), patients with a shockable primary rhythm (p = .009) and elderly patients (p = .03). Socioeconomic factors did not influence hazard of RRT, but patients admitted to tertiary centres had higher hazard of RRT (p = .009). Use of RRT was associated with increased mortality in multivariate Cox regression (HR: 1.28, CI: 1.06-1.55, p = .01). CONCLUSION: Use of RRT as part of post resuscitation care following OHCA did not increase from 2005 to 2013; use was more common in tertiary centres and in patients with negative prehospital predictors (no bystander CPR, non-shockable rhythm). RRT was associated with increased mortality.

Distance to invasive heart centre, performance of acute coronary angiography, and angioplasty and associated outcome in out-of-hospital cardiac arrest: a nationwide study.

AIMS: To evaluate whether the distance from the site of event to an invasive heart centre, acute coronary angiography (CAG)/percutaneous coronary intervention (PCI) and hospital-level of care (invasive heart centre vs. local hospital) is associated with survival in out-of-hospital cardiac arrest (OHCA) patients. METHODS AND RESULTS: Nationwide historical follow-up study of 41 186 unselected OHCA patients, in whom resuscitation was attempted between 2001 and 2013, identified through the Danish Cardiac Arrest Registry. We observed an increase in the proportion of patients receiving bystander CPR (18% in 2001, 60% in 2013, P < 0.001), achieving return of spontaneous circulation (ROSC) (10% in 2001, 29% in 2013, P < 0.001) and being admitted directly to an invasive centre (26% in 2001, 45% in 2013, P < 0.001). Simultaneously, 30-day survival rose from 5% in 2001 to 12% in 2013, P < 0.001. Among patients achieving ROSC, a larger proportion underwent acute CAG/PCI (5% in 2001, 27% in 2013, P < 0.001). The proportion of patients undergoing acute CAG/PCI annually in each region was defined as the CAG/PCI index. The following variables were associated with lower mortality in multivariable analyses: direct admission to invasive heart centre (HR 0.91, 95% CI: 0.89-0.93), CAG/PCI index (HR 0.33, 95% CI: 0.25-0.45), population density above 2000 per square kilometre (HR 0.94, 95% CI: 0.89-0.98), bystander CPR (HR 0.97, 95% CI: 0.95-0.99) and witnessed OHCA (HR 0.87, 95% CI: 0.85-0.89), whereas distance to the nearest invasive centre was not associated with survival. CONCLUSION: Admission to an invasive heart centre and regional performance of acute CAG/PCI were associated with improved survival in OHCA patients, whereas distance to the invasive centre was not. These results support a centralized strategy for immediate post-resuscitation care in OHCA patients.

Association of Bystander Cardiopulmonary Resuscitation and Survival According to Ambulance Response Times After Out-of-Hospital Cardiac Arrest.

BACKGROUND: Bystander-initiated cardiopulmonary resuscitation (CPR) increases patient survival after out-of-hospital cardiac arrest, but it is unknown to what degree bystander CPR remains positively associated with survival with increasing time to potential defibrillation. The main objective was to examine the association of bystander CPR with survival as time to advanced treatment increases. METHODS: We studied 7623 out-of-hospital cardiac arrest patients between 2005 and 2011, identified through the nationwide Danish Cardiac Arrest Registry. Multiple logistic regression analysis was used to examine the association between time from 911 call to emergency medical service arrival (response time) and survival according to whether bystander CPR was provided (yes or no). Reported are 30-day survival chances with 95% bootstrap confidence intervals. RESULTS: With increasing response times, adjusted 30-day survival chances decreased for both patients with bystander CPR and those without. However, the contrast between the survival chances of patients with versus without bystander CPR increased over time: within 5 minutes, 30-day survival was 14.5% (95% confidence interval [CI]: 12.8-16.4) versus 6.3% (95% CI: 5.1-7.6), corresponding to 2.3 times higher chances of survival associated with bystander CPR; within 10 minutes, 30-day survival chances were 6.7% (95% CI: 5.4-8.1) versus 2.2% (95% CI: 1.5-3.1), corresponding to 3.0 times higher chances of 30-day survival associated with bystander CPR. The contrast in 30-day survival became statistically insignificant when response time was >13 minutes (bystander CPR vs no bystander CPR: 3.7% [95% CI: 2.2-5.4] vs 1.5% [95% CI: 0.6-2.7]), but 30-day survival was still 2.5 times higher associated with bystander CPR. Based on the model and Danish out-of-hospital cardiac arrest statistics, an additional 233 patients could potentially be saved annually if response time was reduced from 10 to 5 minutes and 119 patients if response time was reduced from 7 (the median response time in this study) to 5 minutes. CONCLUSIONS: The absolute survival associated with bystander CPR declined rapidly with time. Yet bystander CPR while waiting for an ambulance was associated with a more than doubling of 30-day survival even in case of long ambulance response time. Decreasing ambulance response time by even a few minutes could potentially lead to many additional lives saved every year.

Survival After Out-of-Hospital Cardiac Arrest in Relation to Age and Early Identification of Patients With Minimal Chance of Long-Term Survival.

BACKGROUND: Survival after out-of-hospital cardiac arrest has increased during the last decade in Denmark. We aimed to study the impact of age on changes in survival and whether it was possible to identify patients with minimal chance of 30-day survival. METHODS AND RESULTS: Using data from the nationwide Danish Cardiac Arrest Registry (2001─2011), we identified 21 480 patients ≥18 years old with a presumed cardiac-caused out-of-hospital cardiac arrest for which resuscitation was attempted. Patients were divided into 3 preselected age-groups: working-age patients 18 to 65 years of age (33.7%), early senior patients 66 to 80 years of age (41.5%), and late senior patients >80 years of age (24.8%). Characteristics in working-age patients, early senior patients, and late senior patients were as follows: witnessed arrest in 53.8%, 51.1%, and 52.1%; bystander cardiopulmonary resuscitation in 44.7%, 30.3%, and 23.4%; and prehospital shock from a defibrillator in 54.7%, 45.0%, and 33.8% (all P<0.05). Between 2001 and 2011, return of spontaneous circulation on hospital arrival increased: working-age patients, from 12.1% to 34.6%; early senior patients, from 6.4% to 21.5%; and late senior patients, from 4.0% to 15.0% (all P<0.001). Furthermore, 30-day survival increased: working-age patients, 5.8% to 22.0% (P<0.001); and early senior patients, 2.7% to 8.4% (P<0.001), whereas late senior patients experienced only a minor increase (1.5% to 2.0%; P=0.01). Overall, 3 of 9499 patients achieved 30-day survival if they met 2 criteria: had not achieved return of spontaneous circulation on hospital arrival and had not received a prehospital shock from a defibrillator. CONCLUSIONS: All age groups experienced a large temporal increase in survival on hospital arrival, but the increase in 30-day survival was most prominent in the young. With the use of only 2 criteria, it was possible to identify patients with a minimal chance of 30-day survival.

Return to Work in Out-of-Hospital Cardiac Arrest Survivors: A Nationwide Register-Based Follow-Up Study.

BACKGROUND: Data on long-term function of out-of-hospital cardiac arrest survivors are sparse. We examined return to work as a proxy of preserved function without major neurologic deficits in survivors. METHODS AND RESULTS: In Denmark, out-of-hospital cardiac arrests have been systematically reported to the Danish Cardiac Arrest Register since 2001. During 2001-2011, we identified 4354 patients employed before arrest among 12 332 working-age patients (18-65 years), of whom 796 survived to day 30. Among 796 survivors (median age, 53 years [quartile 1-3, 46-59 years]; 81.5% men), 610 (76.6%) returned to work in a median time of 4 months [quartile 1-3, 1-19 months], with a median time of 3 years spent back at work. A total of 74.6% (N=455) remained employed without using sick leave during the first 6 months after returning to work. This latter proportion of survivors returning to work increased over time (66.1% in 2001-2005 versus 78.1% in 2006-2011; P=0.002). In multivariable Cox regression analysis, factors associated with return to work with ≥6 months of sustainable employment were as follows: (1) arrest during 2006-2011 versus 2001-2005, hazard ratio (HR), 1.38 (95% CI, 1.05-1.82); (2) male sex, HR, 1.48 (95% CI, 1.06-2.07); (3) age of 18 to 49 versus 50 to 65 years, HR, 1.32 (95% CI, 1.02-1.68); (4) bystander-witnessed arrest, HR, 1.79 (95% CI, 1.17-2.76); and (5) bystander cardiopulmonary resuscitation, HR, 1.38 (95% CI, 1.02-1.87). CONCLUSIONS: Of 30-day survivors employed before arrest, 76.6% returned to work. The percentage of survivors returning to work increased significantly, along with improved survival during 2001-2011, suggesting an increase in the proportion of survivors with preserved function over time.