Anneli Strömsöe

Improved outcome in Sweden after out-of-hospital cardiac arrest and possible association with improvements in every link in the chain of survival

AIMS To describe out-of-hospital cardiac arrest (OHCA) in Sweden from a long-term perspective in terms of changes in outcome and circumstances at resuscitation. METHODS AND RESULTS All cases of OHCA (n = 59,926) reported to the Swedish Cardiac Arrest Register from 1992 to 2011 were included. The number of cases reported (n/100,000 person-years) increased from 27 (1992) to 52 (2011). Crew-witnessed cases, cardiopulmonary resuscitation prior to the arrival of the emergency medical service (EMS), and EMS response time increased (P < 0.0001). There was a decrease in the delay from collapse to calling for the EMS in all patients and from collapse to defibrillation among patients found in ventricular fibrillation (P < 0.0001). The proportion of patients found in ventricular fibrillation decreased from 35 to 25% (P < 0.0001). Thirty-day survival increased from 4.8 (1992) to 10.7% (2011) (P < 0.0001), particularly among patients found in a shockable rhythm and patients with return of spontaneous circulation (ROSC) at hospital admission. Among patients hospitalized with ROSC in 2008-2011, 41% underwent therapeutic hypothermia and 28% underwent percutaneous coronary intervention. Among 30-day survivors in 2008-2011, 94% had a cerebral performance category score of 1 or 2 at discharge from hospital and the results were even better if patients were found in a shockable rhythm. CONCLUSION From a long-term perspective, 30-day survival after OHCA in Sweden more than doubled. The increase in survival was most marked among patients found in a shockable rhythm and those hospitalized with ROSC. There were improvements in all four links in the chain of survival, which might explain the improved outcome.

Validity of reported data in the Swedish Cardiac Arrest Register in selected parts in Sweden

AIM To describe differences and similarities between reported and non-reported data in the Swedish Cardiac Arrest Register in selected parts in Sweden. METHODS Prospective and retrospective data for treated OHCA patients in Sweden, 2008-2010, were compared in the Swedish Cardiac Arrest Register. Data were investigated in three Swedish counties, which represented one third of the population. The recording models varied. Prospective data are those reported by the emergency medical service (EMS) crews, while retrospective data are those missed by the EMS crews but discovered afterwards by cross-checking with the local ambulance register. RESULT In 2008-2010, the number of prospectively (n=2398) and retrospectively (n=800) reported OHCA cases was n=3198, which indicates a 25% missing rate. When comparing the two groups, the mean age was higher in patients who were reported retrospectively (69 years vs. 67 years; p=0.003). There was no difference between groups with regard to gender, time of day and year of OHCA, witnessed status or initial rhythm. Bystander cardiopulmonary resuscitation (CPR) was more frequent among patients who were reported prospectively (65% vs. 60%; p=0.023), whereas survival to one month was higher among patients who were reported retrospectively (9.2% vs. 11.9%; p=0.035). CONCLUSION Among 3198 cases of OHCA in three counties in Sweden, 800 (25%) were not reported prospectively by the EMS crews but were discovered retrospectively as missing cases. Patients who were reported retrospectively differed from prospectively reported cases by being older, having less frequently received bystander CPR but having a higher survival rate. Our data suggest that reports on OHCA from national quality registers which are based on prospectively recorded data may be influenced by selection bias.

Association between population density and reported incidence, characteristics and outcome after out–of–hospital cardiac arrest in Sweden

AIM To describe the reported incidence of out of hospital cardiac arrest (OHCA) and the characteristics and outcome after OHCA in relation to population density in Sweden. METHODS All patients participating in the Swedish Cardiac Arrest Register between 2008 and 2009 in (a) 20 of 21 regions (n=6457) and in (b) 165 of 292 municipalities (n=3522) in Sweden, took part in the survey. RESULTS The regional population density varied between 3 and 310 inhabitants per km(2) in 2009. In 2008-2009, the number of reported cardiac arrests varied between 13 and 52 per 100,000 inhabitants and year. Survival to 1 month varied between 2% and 14% during the same period in different regions. With regard to population density, based on municipalities, bystander CPR (p=0.04) as well as cardiac etiology (p=0.002) were more frequent in less populated areas. Ambulance response time was longer in less populated areas (p<0.0001). There was no significant association between population density and survival to 1 month after OHCA or incidence (adjusted for age and gender) of OHCA. CONCLUSION There was no significant association between population density and survival to 1 month after OHCA or incidence (adjusted for age and gender) of OHCA. However, bystander CPR, cardiac etiology and longer response times were more frequent in less populated areas.

Out-of-hospital cardiac arrest in the elderly: A large-scale population-based study☆

BACKGROUND There is little information on elderly people who suffer from out-of-hospital cardiac arrest (OHCA). AIM To determine 30-day mortality and neurological outcome in elderly patients with OHCA. METHODS OHCA patients ≥ 70 years of age who were registered in the Swedish Cardiopulmonary Resuscitation Register between 1990 and 2013 were included and divided into three age categories (70-79, 80-89, and ≥ 90 years). Multiple logistic regression analyses were performed to identify independent predictors of 30-day survival. RESULTS Altogether, 36,605 cases were included in the study. Thirty-day survival was 6.7% in patients aged 70-79 years, 4.4% in patients aged 80-89 years, and 2.4% in those over 90 years. For patients with witnessed OHCA of cardiac aetiology found in a shockable rhythm, survival was higher: 20%, 15%, and 11%, respectively. In 30-day survivors, the distribution according to the cerebral performance categories (CPC) score at discharge from hospital was similar in the three age groups. In multivariate analysis, in patients over 70 years of age, the following factors were associated with increased chance of 30-day survival: younger age, OHCA outside the home, witnessed OHCA, CPR before arrival of EMS, shockable first-recorded rhythm, and short emergency response time. CONCLUSIONS Advanced age is an independent predictor of mortality in OHCA patients over 70 years of age. However, even in patients above 90 years of age, defined subsets with a survival rate of more than 10% exist. In survivors, the neurological outcome remains similar regardless of age.

Improvements in logistics could increase survival after out-of-hospital cardiac arrest in Sweden.

In a review based on estimations and assumptions, to report the estimated number of survivors after out‐of‐hospital cardiac arrest (OHCA) in whom cardiopulmonary resuscitation (CPR) was started and to speculate about possible future improvements in Sweden.

Improving Survival and Neurologic Function for Younger Age Groups After Out-of-Hospital Cardiac Arrest in Sweden: A 20-Year Comparison.

Objective: To describe changes in the epidemiology of out-of-hospital cardiac arrest in Sweden with the emphasis on the younger age groups. Design: Prospective observational study. Setting: Sweden. Patients: Patients were recruited from the Swedish Registry of Cardiopulmonary Resuscitation from 1990 to 2012. Only non–crew-witnessed cases were included. Intervention: Cardiopulmonary resuscitation. Measurement and Main Results: The endpoint was 30-day survival. Cerebral function among survivors was estimated according to the cerebral performance category scores. In all, 50,879 patients in the survey had an out-of-hospital cardiac arrest, of which 1,321 (2.6%) were 21 years old or younger and 1,543 (3.0%) were 22–35 years old. On the basis of results from 2011 and 2012, we estimated that there are 4.9 cases per 100,000 person-years in the age group 0–21 years. The highest survival was found in the 13- to 21-year age group (12.6%). Among patients 21 years old or younger, the following were associated with an increased chance of survival: increasing age, male gender, witnessed out-of-hospital cardiac arrest, ventricular fibrillation, and a short emergency medical service response time. Among patients 21 years old or younger , there was an increase in survival from 6.2% in 1992–1998 to 14.0% in 2007–2012. Among 30-day survivors, 91% had a cerebral performance category score of 1 or 2 (good cerebral performance or moderate cerebral disability) at hospital discharge. Conclusions: In Sweden, among patients 21 years old or younger, five out-of-hospital cardiac arrests per 100,000 person-years occur and survival in this patient group has more than doubled during the past two decades. The majority of survivors have good or relatively good cerebral function.

Higher survival rates in exercise-related out-of-hospital cardiac arrests, compared to non-exercise-related – a study from the Swedish Register of Cardiopulmonary Resuscitation

Background Despite the positive effects of physical activity, the risk of sudden cardiac arrest is transiently increased during and immediately after exercise. The purpose of this study was to assess the incidence of exercise-related out-of-hospital cardiac arrest in the general population and to compare characteristics and prognosis of these cardiac arrests with non-exercise-related out-of-hospital cardiac arrests. Methods Data from all cases of treated out-of-hospital cardiac arrest outside of home reported to the Swedish Register of Cardiopulmonary Resuscitation from 2011–2015 in three counties of Sweden were investigated (population 2.1 m). This registry captures almost 100% of all out-of-hospital cardiac arrests in Sweden. Results Of 1825 out-of hospital cardiac arrests, 137 (7.5%) were exercise-related, resulting in an incidence of 1.2 per 100,000 person-years. The 30-day survival rate was significantly higher among exercise-related out-of hospital cardiac arrests compared to non-exercise-related out-of-hospital cardiac arrests (54.3 % vs 19.4%, p < 0.0001). Patients suffering an exercise-related out-of-hospital cardiac arrest were on average 10 years younger than those who had a non-exercise-related out-of-hospital cardiac arrest, 56.4 years compared to 67.2 years. Exercise-related out-of-hospital cardiac arrests were more often witnessed (89.4% vs 78.6%, p = 0.002), had higher rates of bystander cardiopulmonary resuscitation (80.3% vs 61.0%, p < 0.0001) and were more frequently connected to an automated external defibrillator (20.4% vs 4.6%, p < 0.0001). Conclusions Cardiac arrests that occur in relation to exercise have a significantly better prognosis and outcome than non-exercise-related cardiac arrests. This may be explained by favourable circumstances but may also reflect that these persons experience a sudden cardiac arrest at a lower degree of coronary artery disease, due to their younger age and to exercise being a trigger.

On-Scene and Final Assessments and Their Interrelationship Among Patients Who Use the EMS on Multiple Occasions.

Introduction The use of Emergency Medical Services (EMS) is increasing. A number of patients call repeatedly for EMS. Early studies of frequent callers show that they form a heterogenous group. Problem There is a lack of research on frequent EMS callers. There is furthermore a lack of knowledge about characteristics and the prehospital assessment of the patients who call for EMS on several occasions. Finally, there is a general lack of knowledge with regard to the association between the prehospital assessment by health care providers and the final diagnosis. METHOD Patients in Skaraborg in Western Sweden, who used the EMS at least four times in 2014, were included, excluding transport between hospitals. Information on the prehospital assessment on-scene and the final diagnosis was collected from the EMS and hospital case records. RESULTS In all, 339 individual patients who used the EMS on 1,855 occasions were included, accounting for five percent of all missions. Fifty percent were women. The age range was 10-98 years, but more than 50.0% were in the age range of 70-89 years. The most common emergency signs and symptoms (ESS) codes on the scene were dyspnea, chest pain, and abdominal pain. The most common final diagnosis was chronic obstructive pulmonary disease (eight percent). Thirteen percent of all cases had a final diagnosis defined as a potentially life-threatening condition. Among these, 22.0% of prehospital assessments were retrospectively judged as potentially inappropriate. Forty-nine percent had a defined final diagnosis not fulfilling the criteria for a potentially life-threatening condition. Among these cases, 30.0% of prehospital assessments were retrospectively judged as potentially inappropriate. CONCLUSION Among patients who used EMS on multiple occasions, the most common symptoms on-scene were dyspnea, chest pain, and abdominal pain. The most common final diagnosis was chronic obstructive pulmonary disease. In 13.0%, the final diagnosis of a potentially life-threatening condition was indicated. In a minority of these cases, the assessment on-scene was judged as potentially inappropriate. Tärnqvist J , Dahlén E , Norberg G , Magnusson C , Herlitz J , Strömsöe A , Axelsson C , Andersson Hagiwara M . On-scene and final assessments and their interrelationship among patients who use the EMS on multiple occasions. Prehosp Disaster Med. 2017;32(5):528-535.

Characteristics and outcome among 14,933 adult cases of in-hospital cardiac arrest: A nationwide study with the emphasis on gender and age

Aim To investigate characteristics and outcome among patients suffering in‐hospital cardiac arrest (IHCA) with the emphasis on gender and age. Methods Using the Swedish Register of Cardiopulmonary Resuscitation, we analyzed associations between gender, age and co‐morbidities, etiology, management, 30‐day survival and cerebral function among survivors in 14,933 cases of IHCA. Age was divided into three ordered categories: young (18–49 years), middle‐aged (50–64 years) and older (65 years and above). Comparisons between men and women were age adjusted. Results The mean age was 72.7 years and women were significantly older than men. Renal dysfunction was the most prevalent co‐morbidity. Myocardial infarction/ischemia was the most common condition preceding IHCA, with men having 27% higher odds of having MI as the underlying etiology. A shockable rhythm was found in 31.8% of patients, with men having 52% higher odds of being found in VT/VF. After adjusting for various confounders, it was found that men had a 10% lower chance than women of surviving to 30 days. Older individuals were managed less aggressively than younger patients. Increasing age was associated with lower 30‐day survival but not with poorer cerebral function among survivors. Conclusion When adjusting for various confounders, it was found that men had a 10% lower chance than women of surviving to 30 days after in‐hospital cardiac arrest. Older individuals were managed less aggressively than younger patients, despite a lower chance of survival. Higher age was, however, not associated with poorer cerebral function among survivors.

Corrigendum to “EuReCa ONE—27 Nations, ONE Europe, ONE Registry A prospective one month analysis of out-of-hospital cardiac arrest outcomes in 27 countries in Europe” [Resuscitation 105 (2016) 188–195]

Introduction The aim of the EuReCa ONE study was to determine the incidence, process, and outcome for out of hospital cardiac arrest (OHCA) throughout Europe. Methods This was an international, prospective, multi-centre one-month study. Patients who suffered an OHCA during October 2014 who were attended and/or treated by an Emergency Medical Service (EMS) were eligible for inclusion in the study. Data were extracted from national, regional or local registries. Results Data on 10,682 confirmed OHCAs from 248 regions in 27 countries, covering an estimated population of 174 million. In 7146 (66%) cases, CPR was started by a bystander or by the EMS. The incidence of CPR attempts ranged from 19.0 to 104.0 per 100,000 population per year. 1735 had ROSC on arrival at hospital (25.2%), Overall, 662/6414 (10.3%) in all cases with CPR attempted survived for at least 30 days or to hospital discharge. Conclusion The results of EuReCa ONE highlight that OHCA is still a major public health problem accounting for a substantial number of deaths in Europe. EuReCa ONE very clearly demonstrates marked differences in the processes for data collection and reported outcomes following OHCA all over Europe. Using these data and analyses, different countries, regions, systems, and concepts can benchmark themselves and may learn from each other to further improve survival following one of our major health care events.