Registered prodromal symptoms of out-of-hospital cardiac arrest among patients calling the medical helpline services.

Background Early identification of warning symptoms among out-of-hospital cardiac arrest (OHCA) patients remains challenging. Thus, we examined the registered prodromal symptoms of patients who called medical helpline services within 30-days before OHCA. Methods Patients unwitnessed by emergency medical services (EMS) aged ≥18 years during their OHCA were identified from the Danish Cardiac Arrest Registry (2014-2018) and linked to phone records from the 24-h emergency helpline (1-1-2) and out-of-hours medical helpline (1813-Medical Helpline) in Copenhagen before the arrest. The registered symptoms were categorized into chest pain; breathing problems; central nervous system (CNS)-related/unconsciousness; abdominal/back/urinary; psychiatric/addiction; infection/fever; trauma/exposure; and unspecified (diverse from the beforementioned categories). Analyses were divided by the time-period of calls (0-7 days/8-30 days preceding OHCA) and call type (1-1-2/1813-Medical Helpline). Results Of all OHCA patients, 18% (974/5442) called helpline services (males 56%, median age 76 years[Q1-Q3:65-84]). Among these, 816 had 1145 calls with registered symptoms. The most common symptom categories (except for unspecified, 33%) were breathing problems (17%), trauma/exposure (17%), CNS/unconsciousness (15%), abdominal/back/urinary (12%), and chest pain (9%). Most patients (61%) called 1813-Medical Helpline, especially for abdominal/back/urinary (17%). Patients calling 1-1-2 had breathing problems (24%) and CNS/unconsciousness (23%). Nearly half of the patients called within 7 days before their OHCA, and CNS/unconsciousness (19%) was the most registered. The unspecified category remained the most common during both time periods (32%;33%) and call type (24%;39%). Conclusions Among patients who called medical helplines services up to 30-days before their OHCA, besides symptoms being highly varied (unspecified (33%)), breathing problems (17%) were the most registered symptom-specific category.

Contacts With the Health Care System Before Out-of-Hospital Cardiac Arrest.

Background It remains challenging to identify patients at risk of out-of-hospital cardiac arrest (OHCA). We aimed to examine health care contacts in patients before OHCA compared with the general population that did not experience an OHCA. Methods and Results Patients with OHCA with a presumed cardiac cause were identified from the Danish Cardiac Arrest Registry (2001-2014) and their health care contacts (general practitioner [GP]/hospital) were examined up to 1 year before OHCA. In a case-control study (1:9), OHCA contacts were compared with an age- and sex-matched background population. Separately, patients with OHCA were examined by the contact type (GP/hospital/both/no contact) within 2 weeks before OHCA. We included 28 955 patients with OHCA. The weekly percentages of patient contacts with GP the year before OHCA were constant (25%) until 1 week before OHCA when they markedly increased (42%). Weekly percentages of patient contacts with hospitals the year before OHCA gradually increased during the last 6 months (3.5%-6.6%), peaking at the second week (6.8%) before OHCA; mostly attributable to cardiovascular diseases (21%). In comparison, there were fewer weekly contacts among controls with 13% for GP and 2% for hospital contacts (P<0.001). Within 2 weeks before OHCA, 57.8% of patients with OHCA had a health care contact, and these patients had more contacts with GP (odds ratio [OR], 3.17; 95% CI, 3.09-3.26) and hospital (OR, 2.32; 95% CI, 2.21-2.43) compared with controls. Conclusions The health care contacts of patients with OHCA nearly doubled leading up to the OHCA event, with more than half of patients having health care contacts within 2 weeks before arrest. This could have implications for future preventive strategies.

Regional variation in out-of-hospital cardiac arrest: Incidence and survival - A nationwide study of regions in Denmark.

AIM: Regional variation in incidence and survival after out-of-hospital cardiac arrest (OHCA) may be caused by many factors including differences in definitions and reporting. We examined regional differences in Denmark. METHODS: From the Danish Cardiac Arrest Registry we identified adult OHCA patients between 2009-2014 of presumed cardiac cause. Patients were grouped according to the five administrative/geographical regions of Denmark and survival was examined based on all arrest-cases (30-day survival percentage) and number of survivors per 100,000 inhabitants. RESULTS: We included 12,902 OHCAs of which 1550 (12.0 %) were alive 30 days after OHCA. No regional differences were observed in age, sex or comorbidities. Incidence of OHCA ranged from 32.9 to 42.4 per 100,000 inhabitants; 30-day survival percentages ranged from 8.5% to 13.8% and number of survivors per 100,000 inhabitants ranged from 3.5 to 5.9, across the regions. In one of the regions car-manned pre-hospital physicians were discontinued from 2011. Here, the incidence of OHCA per 100,000 inhabitants increased markedly from 37.1 in 2011 to 52.2 in 2014 and 30-day survival percentage decreased from 10.9 % in 2011 to 7.5 % in 2014; while the number of survivors per 100,000 inhabitants stagnated from 4.0 in 2011 to 3.9 in 2014. In comparison, survival increased in the other four regions. CONCLUSION: Differences in incidence and 30-day survival after OHCA were observed between the five regions of Denmark. Comparisons of survival should not only be based on survival percentages, but also on number of survivors of the background population as inclusion bias can influence survival outcomes.

Pre-hospital factors and survival after out-of-hospital cardiac arrest according to population density, a nationwide study.

AIM: This study aimed to examine the impact of population density on bystander cardiopulmonary resuscitation (CPR) and survival after out-of-hospital cardiac arrest (OHCA). METHODS: Through the Danish Cardiac Arrest Registry (2001-2013), OHCAs ≥18 years of presumed cardiac cause were identified, and divided according to the OHCA location in four population density groups (inhabitants/km2) based on urban/rural area-definitions: low (<300/km2), medium (300-1499/km2), high (1500-2999/km2), very high (>3000/km2). The association between population density, bystander cardiopulmonary resuscitation (CPR) and survival was examined using logistic regression, adjusted for age, sex, comorbitidies and calendar-year. RESULTS: 18,248 OHCAs were identified. Patients in areas of high compared to low population density were older, more often female, had more comorbidities, more witnessed arrests (very high: 59.6% versus low: 55.0%), shorter response time (very high: 10 min versus low: 14 min), but less bystander CPR (very high: 34.3% versus low: 45.1%). Thirty-day survival was higher in areas of higher population density (very high: 10.2% vs. low 5.3%), also in best-cases of witnessed arrests with bystander CPR and response time <10 min (very high: 33.6% versus low: 13.8%). The same trends were found in adjusted analyses with lower odds for bystander CPR (odds ratio [OR] 0.55 95% confidence interval [CI] 0.46-0.66) and higher odds for 30-day survival (OR 2.78, 95%CI 1.95-3.96) in the highest population density areas compared to low. CONCLUSIONS: Having an OHCA in higher populated areas were found associated with less bystander CPR, but higher survival. Identification of area-related factors can help target future pre-hospital care.

Data concerning AED registration in the Danish AED Network, and cardiac arrest-related characteristics of OHCAs, including AED coverage and AED accessibility.

The data presented in this article is supplemental data related to the research article entitled "Automated external defibrillator accessibility is crucial for bystander defibrillation and survival: a registry-based study" (Karlsson et al., 2019). We present detailed data concerning: 1) the type of location for deployed and registered automated external defibrillators (AEDs) in the nationwide Danish AED Network; 2) the number of registered AEDs in the nationwide Danish AED Network, and changes in AED registration (according to year and type of AED location); 3) the number of AEDs being withdrawn from the AED network between the years 2007-2016. We also report data on baseline cardiac arrest-related characteristics of out-of-hospital cardiac arrests (OHCAs) that occurred in Copenhagen, Denmark, between 2008 and 2016. Cardiac arrest-related characteristics are further described according to AED accessibility (accessible vs. inaccessible AED at the time of OHCA) for OHCAs covered by an AED (AED ≤200 m route distance of an OHCA). Finally, we report data on distance to the nearest accessible AED for bystander defibrillated OHCAs covered by an AED ≤200 m route distance where the AED was inaccessible at the time of OHCA.

Automated external defibrillator accessibility is crucial for bystander defibrillation and survival: A registry-based study.

AIMS: Optimization of automated external defibrillator (AED) placement and accessibility are warranted. We examined the associations between AED accessibility, at the time of an out-of-hospital cardiac arrest (OHCA), bystander defibrillation, and 30-day survival, as well as AED coverage according to AED locations. METHODS: In this registry-based study we identified all OHCAs registered by mobile emergency care units in Copenhagen, Denmark (2008-2016). Information regarding registered AEDs (2007-2016) was retrieved from the nationwide Danish AED Network. We calculated AED coverage (AEDs located ≤200 m route distance from an OHCA) and, according to AED accessibility, the likelihoods of bystander defibrillation and 30-day survival. RESULTS: Of 2500 OHCAs, 22.6% (n = 566) were covered by a registered AED. At the time of OHCA, <50% of these AEDs were accessible (n = 276). OHCAs covered by an accessible AED were nearly three times more likely to receive bystander defibrillation (accessible: 13.8% vs. inaccessible: 4.8%, p < 0.001) and twice as likely to achieve 30-day survival (accessible: 28.8% vs. inaccessible: 16.4%, p < 0.001). Among bystander-witnessed OHCAs with shockable heart rhythms (accessible vs. inaccessible AEDs), bystander defibrillation rates were 39.8% vs. 20.3% (p = 0.01) and 30-day survival rates were 72.7% vs. 44.1% (p < 0.001). Most OHCAs were covered by AEDs at offices (18.6%), schools (13.3%), and sports facilities (12.9%), each with a coverage loss >50%, due to limited AED accessibility. CONCLUSIONS: The chance of a bystander defibrillation was tripled, and 30-day survival nearly doubled, when the nearest AED was accessible, compared to inaccessible, at the time of OHCA, underscoring the importance of unhindered AED accessibility.

Temporal trends in survival after out-of-hospital cardiac arrest in patients with and without underlying chronic obstructive pulmonary disease.

AIM: Survival after out-of-hospital cardiac arrest (OHCA) has tripled during the past decade in Denmark as a likely result of improvements in cardiac arrest management. This study analyzed whether these improvements were applicable for patients with chronic obstructive pulmonary disease (COPD). METHODS: Patients ≥18 years with OHCA of presumed cardiac cause were identified through the Danish Cardiac Arrest Registry, 2001-2011. Patients with a history of COPD up to ten years prior to arrest were identified from the Danish National Patient Register and compared to non-COPD patients. RESULTS: Of 21,480 included patients, 3056 (14.2%) had history of COPD. Compared to non-COPD patients, COPD patients were older (75 vs. 71 years), less likely male (61.2% vs. 68.5%), had higher prevalence of other comorbidities, and were less likely to have: arrests outside private homes (17.7% vs. 28.3%), witnessed arrests (48.7% vs. 52.9%), bystander cardiopulmonary resuscitation (25.8% vs. 34.8%), and shockable heart rhythm (15.6% vs. 29.9%), all p<0.001; while no significant difference in the time-interval from recognition of arrest to rhythm analysis by ambulance-crew; p=0.24. From 2001 to 2011, survival upon hospital arrival increased in both patient-groups (from 6.8% to 17.1% in COPD patients and from 8.2% to 25.6% in non-COPD patients, p<0.001). However, no significant change was observed in 30-day survival in COPD patients (from 3.7% to 2.1%, p=0.27), in contrast to non-COPD patients (from 3.5% to 13.0%, p<0.001). CONCLUSIONS: Despite generally improved 30-day survival after OHCA over time, no improvement was observed in 30-day survival in COPD patients.