Johan Engdahl

Factors associated with survival to hospital discharge among patients hospitalised alive after out of hospital cardiac arrest: change in outcome over 20 years in the community of Göteborg, Sweden

Objective: To describe the change in survival and factors associated with survival during a 20 year period among patients suffering from out of hospital cardiac arrest and being hospitalised alive. Patients: All patients hospitalised alive in the community of Göteborg after out of hospital cardiac arrest between 1 October 1980 and 1 October 2000 were included. Methods: Patient data were prospectively computerised with regard to factors at resuscitation. Data on medical history and hospitalisation were retrospectively recorded. Patients were divided into two groups (the first and second 10 year periods). Setting: Community of Göteborg, Sweden. Results: 5505 patients suffered from cardiac arrest during the time of the survey. Among them 1310 patients (24%) were hospitalised alive. Survival (discharged alive) was 37.5% during the first part and 35.1% during the second part (NS). The following were independent predictors of an increased chance of survival: ventricular fibrillation/tachycardia as the first recorded rhythm (odds ratio (OR) 3.46, 95% confidence interval (CI) 2.36 to 5.07); witnessed arrest (OR 2.50, 95% CI 1.52 to 4.10); bystander initiated cardiopulmonary resuscitation (OR 2.00, 95% CI 1.42 to 2.80); the patient being conscious on admission to hospital (OR 6.43, 95% CI 3.61 to 11.45); sinus rhythm on admission to hospital (OR 1.53, 95% CI 1.12 to 2.10); and treatment with lidocaine in the emergency department (OR 1.64, 95% CI 1.16 to 2.31). The following were independent predictors of a low chance of survival: age > 70 years (median) (OR 0.65, 95% CI 0.47 to 0.88); atropine required in the emergency department (OR 0.35, 95% CI 0.16 to 0.75); and chronic treatment with diuretics before hospital admission (OR 0.59, 95% CI 0.43 to 0.81). Conclusion: There was no improvement in survival over time among initial survivors of out of hospital cardiac arrest during a 20 year period. Major indicators for an increased chance of survival were initial ventricular fibrillation/tachycardia, bystander cardiopulmonary resuscitation, arrest being witnessed, and the patient being conscious on admission. Major indicators for a lower chance were high age, requirement for atropine in the emergency department, and chronic treatment with diuretics before cardiac arrest.

The epidemiology of out-of-hospital 'sudden' cardiac arrest.

It is difficult to assemble data from an out-of-hospital cardiac arrest since there is often lack of objective information. The true incidence of sudden cardiac death out-of-hospital is not known since far from all of these patients are attended by emergency medical services. The incidence of out-of-hospital cardiac arrest increases with age and is more common among men. Among patients who die, the probability of having a fatal event outside hospital decreases with age; i. e. younger patients tend to more often die unexpectedly and outside hospital. Among the different initial arrhythmias, ventricular fibrillation is the most common among patients with cardiac aetiology. The true distribution of initial arrhythmias is not known since several minutes most often elapse between collapse and rhythm assessment. Most patients with out-of-hospital cardiac arrest have a cardiac aetiology. Out-of-hospital cardiac arrests most frequently occur in the patients home, but the prognosis is shown to be better when they occur in a public place. Witnessed arrest, ventricular fibrillation as initial arrhythmia and cardiopulmonary resuscitation are important predictors for immediate survival. In the long-term perspective, cardiac arrest in connection with acute myocardial infarction, high left ventricular ejection fraction, moderate age, absence of other heart failure signs and no history of myocardial infarction promotes better prognosis. Still there is much to learn about time trends, the influence of patient characteristics, comorbidity and hospital treatment among patients with prehospital cardiac arrest.

Mass Screening for Untreated Atrial Fibrillation The STROKESTOP Study

Background— The aims of the present study were to define the prevalence of untreated atrial fibrillation (AF) in a systematic screening program using intermittent ECG recordings among 75- to 76-year-old individuals and to study the feasibility of initiating protective oral anticoagulant (OAC) treatment. Methods and Results— Half of the 75- to 76-year-old population in 2 Swedish regions were invited to a screening program for AF. Participants without a previous diagnosis of AF underwent intermittent ECG recordings over 2 weeks. If AF was detected, participants were offered OAC. During the 28-month inclusion period, 13 331 inhabitants were invited. Of these, 7173 (53.8%) participated. Of the participants, 218 (3.0%; 95% confidence interval [CI], 2.7–3.5) were found to have previously unknown AF, and of these, AF was found in 37 (0.5% of the screened population) on their first ECG. The use of intermittent ECGs increased new AF detection 4-fold. A previous diagnosis of AF was known in 9.3% (n=666; 95% CI, 8.6–10.0). Total AF prevalence in the screened population was 12.3%. Of participants with known AF, 149 (2.1%; 95% CI, 1.8–2.4) had no OAC treatment. In total, 5.1% (95% CI, 4.6–5.7) of the screened population had untreated AF; screening resulted in initiation of OAC treatment in 3.7% (95% CI, 3.3–4.2) of the screened population. More than 90% of the participants with previously undiagnosed AF accepted initiation of OAC treatment. Conclusions— Mass screening for AF in a 75- to 76-year-old population identifies a significant proportion of participants with untreated AF. Initiation of stroke prophylactic treatment was highly successful in individuals with newly diagnosed AF. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01593553.

Stepwise Screening of Atrial Fibrillation in a 75-Year-Old Population Implications for Stroke Prevention

Background— Atrial fibrillation (AF) is a frequent source of cardiac emboli in patients with ischemic stroke. AF may be asymptomatic and therefore undiagnosed. Screening for silent AF seems suitable in risk populations, however little is known on the yield and cost-effectiveness of such screening. Methods and Results— All inhabitants in the municipality of Halmstad, Sweden aged 75 to 76 years were invited to a stepwise screening program for AF. As a first step, participants recorded a 12-lead ECG and reported their relevant medical history. Those with sinus rhythm on 12-lead ECG, no history of AF, and ≥2 risk factors according to CHADS2 were invited to a 2-week recording period using a hand-held ECG and asked to record 20 or 30 seconds twice daily and if palpitations occurred. One thousand, three hundred thirty inhabitants were invited, of whom 848 (64%) participated. Previously undiagnosed silent AF was found in 10 (1%) among 848 individuals who recorded 12-lead ECG. Among 81 patients with known AF, 35 (43%) were not on oral anticoagulation treatment. Among 403 persons with ≥2 risk factors for stroke, who completed the hand-held ECG event recording, 30 (7.4%) were diagnosed with paroxysmal AF. Thus 75/848 (9%) of the screened population were candidates for new oral anticoagulation treatment, of those 57 actually started oral anticoagulation treatment. Conclusions— Stepwise risk factor–stratified AF screening in a 75-year-old population yields a large share of candidates for oral anticoagulation treatment on AF indication.

Factors affecting short- and long-term prognosis among 1069 patients with out-of-hospital cardiac arrest and pulseless electrical activity

AIMS To describe the epidemiology, resuscitation factors and prognosis among a consecutive population of patients suffering from out-of-hospital cardiac arrest (OHCA) where pulseless electrical activity (PEA) was the first arrhythmia recorded on emergency medical services (EMS) arrival. METHODS Analysis of data collected prospectively on all patients regardless of age succumbing to OHCA during 1980-1997 in the community of Gothenburg where EMS initiated resuscitative measures. RESULTS 4662 patients with OHCA were attended by the EMS during the study period. Of these, 1069 (23%) were judged as having PEA as the first recorded arrhythmia; 158 (15%) of these were admitted alive to hospital and 26 (2.4%) were discharged alive. Survivors to discharge had a significantly larger share of bystander cardiopulmonary resuscitation (CPR) (28 vs. 8%, P=0.008), significantly higher levels of consciousness (8% awake vs. 0%, P<0.001) and higher median systolic blood pressure (145 vs. 106 mmHg, P<0.001) on arrival at hospital. No patient with unwitnessed cardiac arrest and PEA over 80 years old survived. CONCLUSION Survival among patients suffering from OHCA and PEA is poor, especially among the elderly unwitnessed cases and those who do not receive bystander CPR. The latter seems to be of utmost importance among these patients.

Can we define patients with no and those with some chance of survival when found in asystole out of hospital

We describe the epidemiology, prognosis, and circumstances at resuscitation among a consecutive population of patients with out-of-hospital cardiac arrest (OHCA) with asystole as the arrhythmia first recorded by the Emergency Medical Service (EMS), and identify factors associated with survival. We included all patients in the municipality of Göteborg, regardless of age and etiology, who experienced an OHCA between 1981 and 1997. There were a total of 4,662 cardiac arrests attended by the EMS during the study period. Of these, 1,635 (35%) were judged as having asystole as the first-recorded arrhythmia: 156 of these patients (10%) were admitted alive to hospital, and 32 (2%) were discharged alive. Survivors were younger (median age 58 vs 68 years) and had a witnessed cardiac arrest more often than nonsurvivors (78% vs 50%). Survivors also had shorter intervals from collapse to arrival of ambulance (3.5 vs 6 minutes) and the mobile coronary care unit (MCCU) (5 vs 10 min), and they received atropine less often on scene. There were also a greater proportion of survivors with noncardiac etiologies of cardiac arrest (48% vs 27%). Survivors to discharge also displayed higher degrees of consciousness on arrival to the emergency department in comparison to nonsurvivors. Multivariate analysis among all patients with asystole indicated age (p = 0.01) and witnessed arrest (p = 0.03) as independent predictors of an increased chance of survival. Multivariate analysis among witnessed arrests indicated short time to arrival of the MCCU (p < 0.001) and no treatment with atropine (p = 0.05) as independent predictors of survival. Fifty-five percent of patients discharged alive had none or small neurologic deficits (cerebral performance categories 1 or 2). No patients > 70 years old with unwitnessed arrests (n = 211) survived to discharge.

Screening for Atrial Fibrillation A Report of the AF-SCREEN International Collaboration

Approximately 10% of ischemic strokes are associated with atrial fibrillation (AF) first diagnosed at the time of stroke. Detecting asymptomatic AF would provide an opportunity to prevent these strokes by instituting appropriate anticoagulation. The AF-SCREEN international collaboration was formed in September 2015 to promote discussion and research about AF screening as a strategy to reduce stroke and death and to provide advocacy for implementation of country-specific AF screening programs. During 2016, 60 expert members of AF-SCREEN, including physicians, nurses, allied health professionals, health economists, and patient advocates, were invited to prepare sections of a draft document. In August 2016, 51 members met in Rome to discuss the draft document and consider the key points arising from it using a Delphi process. These key points emphasize that screen-detected AF found at a single timepoint or by intermittent ECG recordings over 2 weeks is not a benign condition and, with additional stroke factors, carries sufficient risk of stroke to justify consideration of anticoagulation. With regard to the methods of mass screening, handheld ECG devices have the advantage of providing a verifiable ECG trace that guidelines require for AF diagnosis and would therefore be preferred as screening tools. Certain patient groups, such as those with recent embolic stroke of uncertain source (ESUS), require more intensive monitoring for AF. Settings for screening include various venues in both the community and the clinic, but they must be linked to a pathway for appropriate diagnosis and management for screening to be effective. It is recognized that health resources vary widely between countries and health systems, so the setting for AF screening should be both country- and health system-specific. Based on current knowledge, this white paper provides a strong case for AF screening now while recognizing that large randomized outcomes studies would be helpful to strengthen the evidence base.

Factors at resuscitation and outcome among patients suffering from out of hospital cardiac arrest in relation to age.

AIM To describe various factors at resuscitation and outcome among patients suffering from out-of-hospital cardiac arrest in relation to age. PATIENTS All patients included in the Swedish Cardiac Arrest Registry during the period 1990-1999. The registry covers about 60% of all ambulance organisations in Sweden. METHODS All patients reached by the ambulance crew and in whom resuscitative efforts were attempted. Crew witnessed cases were excluded. Only patients aged over 18 years were included. Patients were divided into three age groups: less than 65 years (n=7810), 65-75 years (n=7261) and over 75 years (n=8390). RESULTS The proportion of cases with a cardiac aetiology increased with increasing age (P<0.0001). The proportion of witnessed cases increased with increasing age among those with a non-cardiac aetiology (P<0.0001) and decreased with increasing age among cases with a cardiac aetiology (P=0.02). The proportion of patients exposed to bystander CPR decreased with increasing age (P<0.0001). The proportion of patients found in ventricular fibrillation (VF) decreased with increasing age among patients with a cardiac aetiology (P<0.0001) but was not related to age in those with a non-cardiac aetiology. The proportion of patients being alive after 1 month in the three age groups (youngest first) were: 4.5, 3.2 and 2.5% (P<0.0001). The corresponding figures for patients with a cardiac aetiology found in VF were: 10.7, 7.6 and 6.6% (P<0.0001). After multiple regression analysis controlling for other factors increasing age was still associated with decreased survival to 1 month (odds ratio 0.85; 95% confidence limits 0.80-0.91). CONCLUSION Among patients suffering from out-of-hospital cardiac arrest various factors at resuscitation, including initial rhythm, aetiology and bystander CPR, are strongly related to age. The chance of survival diminishes with increasing age. When correcting for the dissimilarities in terms of factors at resuscitation, age is still significantly associated with survival, being lower among the elderly.

Characteristics and outcome among patients having out of hospital cardiac arrest at home compared with elsewhere

Objective: To describe the characteristics and outcome of patients who have a cardiac arrest at home compared with elsewhere out of hospital. Patients: Subjects were patients included in the Swedish cardiac arrest registry between 1990 and 1999. The registry covers about 60% of all ambulance organisations in Sweden. Methods: The study sample comprised patients reached by the ambulance crew and in whom resuscitation was attempted out of hospital. There was no age limit. Crew witnessed cases were excluded. The patients were divided into two groups: cardiac arrest at home and cardiac arrest elsewhere. Results: Among a study population of 24 630 patients the event took place at home in 16 150 (65.5%). Those in whom the arrest took place at home differed from the remainder in that they were older, were more often women, less often had a witnessed cardiac arrest, were less often exposed to bystander cardiopulmonary resuscitation (CPR), were less often found in ventricular fibrillation, and had a longer interval between collapse and call for ambulance, arrival of ambulance, start of CPR, and first defibrillation. Of patients in whom the arrest took place at home, 11.3% were admitted to hospital alive, v 19.4% in the elsewhere group (p < 0.0001); corresponding figures for survival after one month were 1.7% v 6.2% (p < 0.0001). The adjusted odds ratio for survival after one month (at home v not at home; considering age, sex, initial arrhythmia, bystander CPR, aetiology, and whether the arrest was witnessed) was 0.40 (95% confidence interval 0.33 to 0.49; p < 0.0001). Conclusions: Sixty five per cent of out of hospital cardiac arrests in Sweden occur at home. The patients differed greatly from those with out of hospital cardiac arrests elsewhere, and fewer than 2% were alive after one month. Having an arrest at home was a strong independent predictor of adverse outcome. Further research is needed to identify the reasons for this.

There is a difference in characteristics and outcome between women and men who suffer out of hospital cardiac arrest.

OBJECTIVE To evaluate whether there is a difference in characteristics and outcome in relation to gender among patients who suffer out of hospital cardiac arrest. DESIGN Observational study. SETTING The community of Göteborg. PATIENTS All patients in the community of Göteborg who suffered out of hospital cardiac arrest between 1980 and 1996, and in whom cardiopulmonary resuscitation (CPR) was initiated. MAIN OUTCOME MEASURES Factors at resuscitation and the proportion of patients being hospitalized and discharged from hospital. P values were corrected for age. RESULTS The women were older than the men (median of 73 vs. 69 years; P < 0.0001), they received bystander-CPR less frequently (11 vs. 15%; P = 0.003), they were found in ongoing ventricular fibrillation less frequently (28 vs. 44%; P < 0.0001), and their arrests were judged to be of cardiac origin less frequently. In a multivariate analysis considering age, gender, arrest being due to a cardiac etiology, initial arrhythmia and by-stander initiated CPR, female gender appeared as an independent predictor for patients being brought to hospital alive (odds ratio 1.37; P = 0.001) but not for patients being discharged from hospital. CONCLUSION Among patients who suffer out of hospital cardiac arrest with attempted CPR women differ from men being older, receive bystander CPR less frequently, have a cardiac etiology less frequently and are found in ventricular fibrillation less frequently. Finally female gender is associated with an increased chance of arriving at hospital alive.