Carolina Malta Hansen

Association of national initiatives to improve cardiac arrest management with rates of bystander intervention and patient survival after out-of-hospital cardiac arrest

IMPORTANCE Out-of-hospital cardiac arrest is a major health problem associated with poor outcomes. Early recognition and intervention are critical for patient survival. Bystander cardiopulmonary resuscitation (CPR) is one factor among many associated with improved survival. OBJECTIVE To examine temporal changes in bystander resuscitation attempts and survival during a 10-year period in which several national initiatives were taken to increase rates of bystander resuscitation and improve advanced care. DESIGN, SETTING, AND PARTICIPANTS Patients with out-of-hospital cardiac arrest for which resuscitation was attempted were identified between 2001 and 2010 in the nationwide Danish Cardiac Arrest Registry. Of 29,111 patients with cardiac arrest, we excluded those with presumed noncardiac cause of arrest (n = 7390) and those with cardiac arrests witnessed by emergency medical services personnel (n = 2253), leaving a study population of 19,468 patients. MAIN OUTCOMES AND MEASURES Temporal trends in bystander CPR, bystander defibrillation, 30-day survival, and 1-year survival. RESULTS The median age of patients was 72 years; 67.4% were men. Bystander CPR increased significantly during the study period, from 21.1% (95% CI, 18.8%-23.4%) in 2001 to 44.9% (95% CI, 42.6%-47.1%) in 2010 (P < .001), whereas use of defibrillation by bystanders remained low (1.1% [95% CI, 0.6%-1.9%] in 2001 to 2.2% [95% CI, 1.5%-2.9%] in 2010; P = .003). More patients achieved survival on hospital arrival (7.9% [95% CI, 6.4%-9.5%] in 2001 to 21.8% [95% CI, 19.8%-23.8%] in 2010; P < .001). Also, 30-day survival improved (3.5% [95% CI, 2.5%-4.5%] in 2001 to 10.8% [95% CI, 9.4%-12.2%] in 2010; P < .001), as did 1-year survival (2.9% [95% CI, 2.0%-3.9%] in 2001 to 10.2% [95% CI, 8.9%-11.6%] in 2010; P < .001). Despite a decrease in the incidence of out-of-hospital cardiac arrests during the study period (40.4 to 34.4 per 100,000 persons in 2001 and 2010, respectively; P = .002), the number of survivors per 100,000 persons increased significantly (P < .001). For the entire study period, bystander CPR was positively associated with 30-day survival, regardless of witnessed status (30-day survival for nonwitnessed cardiac arrest, 4.3% [95% CI, 3.4%-5.2%] with bystander CPR and 1.0% [95% CI, 0.8%-1.3%] without; odds ratio, 4.38 [95% CI, 3.17-6.06]). For witnessed arrest the corresponding values were 19.4% (95% CI, 18.1%-20.7%) vs 6.1% (95% CI, 5.4%-6.7%); odds ratio, 3.74 (95% CI, 3.26-4.28). CONCLUSIONS AND RELEVANCE In Denmark between 2001 and 2010, an increase in survival following out-of-hospital cardiac arrest was significantly associated with a concomitant increase in bystander CPR. Because of the co-occurrence of other related initiatives, a causal relationship remains uncertain.

Bleeding after Initiation of Multiple Antithrombotic Drugs, Including Triple Therapy, in Atrial Fibrillation Patients Following Myocardial Infarction and Coronary Intervention: A Nationwide Cohort Study

Background— Uncertainty remains over optimal antithrombotic treatment of patients with atrial fibrillation presenting with myocardial infarction and/or undergoing percutaneous coronary intervention. We investigated the risk and time frame for bleeding following myocardial infarction/percutaneous coronary intervention in patients with atrial fibrillation according to antithrombotic treatment. Methods and Results— Patients with atrial fibrillation and admitted with myocardial infarction or for percutaneous coronary intervention between 2000 and 2009 (11 480 subjects, mean age 75.6 years [SD ±10.3], males 60.9%) were identified by individual level linkage of nationwide registries in Denmark. Fatal or nonfatal (requiring hospitalization) bleeding was determined according to antithrombotic treatment regimen: triple therapy (TT) with vitamin K antagonist (VKA)+aspirin+clopidogrel, VKA+antiplatelet, and dual antiplatelet therapy with aspirin+clopidogrel. We calculated crude incidence rates and adjusted hazard ratios by Cox regression models. Within 1 year, 728 bleeding events were recorded (6.3%); 79 were fatal (0.7%). Within 30 days, rates were 22.6, 20.3, and 14.3 bleeding events per 100 person-years for TT, VKA+antiplatelet, and dual antiplatelet therapy, respectively. Both early (within 90 days) and delayed (90–360 days) bleeding risk with TT exposure in relation to VKA+antiplatelet was increased; hazard ratio 1.47 (1.04;2.08) and 1.36 (0.95;1.95), respectively. No significant difference in thromboembolic risk was observed for TT versus VKA+antiplatelet; hazard ratio, 1.15 (0.95;1.40). Conclusions— High risk of bleeding is immediately evident with TT after myocardial infarction/percutaneous coronary intervention in patients with atrial fibrillation. A continually elevated risk associated with TT indicates no safe therapeutic window, and TT should only be prescribed after thorough bleeding risk assessment of patients.

Association of Bystander and First-Responder Intervention With Survival After Out-of-Hospital Cardiac Arrest in North Carolina, 2010-2013

IMPORTANCE Out-of-hospital cardiac arrest is associated with low survival, but early cardiopulmonary resuscitation (CPR) and defibrillation can improve outcomes if more widely adopted. OBJECTIVE To examine temporal changes in bystander and first-responder resuscitation efforts before arrival of the emergency medical services (EMS) following statewide initiatives to improve bystander and first-responder efforts in North Carolina from 2010-2013 and to examine the association between bystander and first-responder resuscitation efforts and survival and neurological outcome. DESIGN, SETTINGS, AND PARTICIPANTS We studied 4961 patients with out-of-hospital cardiac arrest for whom resuscitation was attempted and who were identified through the Cardiac Arrest Registry to Enhance Survival (2010-2013). First responders were dispatched police officers, firefighters, rescue squad, or life-saving crew trained to perform basic life support until arrival of the EMS. EXPOSURES Statewide initiatives to improve bystander and first-responder interventions included training members of the general population in CPR and in use of automated external defibrillators (AEDs), training first responders in team-based CPR including AED use and high-performance CPR, and training dispatch centers in recognition of cardiac arrest. MAIN OUTCOMES AND MEASURES The proportion of bystander and first-responder resuscitation efforts, including the combination of efforts between bystanders and first responders, from 2010 through 2013 and the association between these resuscitation efforts and survival and neurological outcome. RESULTS The combination of bystander CPR and first-responder defibrillation increased from 14.1% (51 of 362; 95% CI, 10.9%-18.1%) in 2010 to 23.1% (104 of 451; 95% CI, 19.4%-27.2%) in 2013 (P < .01). Survival with favorable neurological outcome increased from 7.1% (82 of 1149; 95% CI, 5.8%-8.8%) in 2010 to 9.7% (129 of 1334; 95% CI, 8.2%-11.4%) in 2013 (P = .02) and was associated with bystander-initiated CPR. Adjusting for age and sex, bystander and first-responder interventions were associated with higher survival to hospital discharge. Survival following EMS-initiated CPR and defibrillation was 15.2% (30 of 198; 95% CI, 10.8%-20.9%) compared with 33.6% (38 of 113; 95% CI, 25.5%-42.9%) following bystander-initiated CPR and defibrillation (odds ratio [OR], 3.12; 95% CI, 1.78-5.46); 24.2% (83 of 343; 95% CI, 20.0%-29.0%) following bystander CPR and first-responder defibrillation (OR, 1.70; 95% CI, 1.06-2.71); and 25.2% (109 of 432; 95% CI, 21.4%-29.6%) following first-responder CPR and defibrillation (OR, 1.77; 95% CI, 1.13-2.77). CONCLUSIONS AND RELEVANCE Following a statewide educational intervention on rescusitation training, the proportion of patients receiving bystander-initiated CPR and defibrillation by first responders increased and was associated with greater likelihood of survival. Bystander-initiated CPR was associated with greater likelihood of survival with favorable neurological outcome.

Vascular Disease and Stroke Risk in Atrial Fibrillation: A Nationwide Cohort Study

BACKGROUND Vascular disease (including myocardial infarction and peripheral artery disease) has been proposed as a less well-validated risk factor for stroke in patients with atrial fibrillation. We investigated whether vascular disease is an independent risk factor of stroke/thromboembolism in atrial fibrillation and whether adding vascular disease improves Congestive heart failure, Hypertension, Age 75 years, Diabetes, previous Stroke (CHADS(2)) risk stratification. METHODS By using nationwide Danish registers, we identified all patients discharged with atrial fibrillation and not treated with vitamin K antagonist or heparin between 1997 and 2008. The rate of stroke/thromboembolism in patients with atrial fibrillation with and without vascular disease was determined, and the risk associated with vascular disease was estimated in Cox regression analyses. The value of adding vascular disease to the CHADS(2) score was evaluated by Net Reclassification Improvement and Integrated Discrimination Improvement. RESULTS We included 87,202 patients with non-valvular atrial fibrillation; of these, 15,212 (17.4%) had vascular disease, 11,750 (77.2%) had myocardial infarction, 2503 (16.5%) had peripheral artery disease, and 959 (6.3%) had both. In patients with a CHADS(2) score=0, the rate of stroke/thromboembolism at 1-year follow-up was 2.31 (1.63-3.26) and 1.52 (1.34-1.73) per 100 person-years in patients with and without vascular disease, respectively. Vascular disease increased the risk of stroke/thromboembolism in both univariate (hazard ratio [HR] 1.26; confidence interval [CI], 1.18-1.35) and multivariate (HR, 1.12; CI, 1.05-1.21) analyses. The risk of stroke/thromboembolism associated with peripheral artery disease alone (HR, 1.93; CI, 1.70-2.19) was greater than the risk with myocardial infarction alone (HR, 1.12; CI, 1.04-1.21), and vascular disease significantly improved the predictive ability of the CHADS(2) score (Net Reclassification Improvement 0.032, P<.001). CONCLUSIONS Vascular disease is an independent predictor of stroke/thromboembolism in atrial fibrillation and improves the predictive ability of the CHADS(2) score.

Automated External Defibrillators Inaccessible to More Than Half of Nearby Cardiac Arrests in Public Locations During Evening, Nighttime, and Weekends

Background— Despite wide dissemination, use of automated external defibrillators (AEDs) in community settings is limited. We assessed how AED accessibility affected coverage of cardiac arrests in public locations. Methods and Results— We identified cardiac arrests in public locations (1994–2011) in terms of location and time and viewed them in relation to the location and accessibility of all AEDs linked to the emergency dispatch center as of December 31, 2011, in Copenhagen, Denmark. AED coverage of cardiac arrests was defined as cardiac arrests within 100 m (109.4 yd) of an AED and further categorized according to AED accessibility at the time of cardiac arrest. Daytime, evening, and nighttime were defined as 8 AM to 3:59 PM, 4 to 11:59 PM, and midnight to 7:59 AM, respectively. Of 1864 cardiac arrests in public locations, 61.8% (n=1152) occurred during the evening, nighttime, or weekends. Of 552 registered AEDs, 9.1% (n=50) were accessible at all hours, and 96.4% (n=532) were accessible during the daytime on all weekdays. Regardless of AED accessibility, 28.8% (537 of 1864) of all cardiac arrests were covered by an AED. Limited AED accessibility decreased coverage of cardiac arrests by 4.1% (9 of 217) during the daytime on weekdays and by 53.4% (171 of 320) during the evening, nighttime, and weekends. Conclusions— Limited AED accessibility at the time of cardiac arrest decreased AED coverage by 53.4% during the evening, nighttime, and weekends, which is when 61.8% of all cardiac arrests in public locations occurred. Thus, not only strategic placement but also uninterrupted AED accessibility warrant attention if public-access defibrillation is to improve survival after out-of-hospital cardiac arrest.

Prognosis Among Healthy Individuals Discharged With a Primary Diagnosis of Syncope

OBJECTIVES This study sought to examine the risk of major cardiac adverse events and death in a nationwide cohort of patients without previous comorbidity admitted for syncope. BACKGROUND Syncope is a common clinical event, but knowledge of prognosis is not fully elucidated in healthy individuals. METHODS Patients without previous comorbidity admitted for syncope in Denmark from 2001 to 2009 were identified in nationwide administrative registries and matched by sex and age with 5 control subjects from the Danish population. The risk of death or recurrent syncope, implantation of pacemaker or implantable cardioverter-defibrillator, and cardiovascular hospitalization were analyzed with multivariable Cox proportional hazard models. RESULTS We identified 37,017 patients with a first-time diagnosis of syncope and 185,085 control subjects; their median age was 47 years (interquartile range, 32 to 63 years) and 47% were male. A total of 3,023 (8.2%) and 14,251 (7.1%) deaths occurred in the syncope and the control population, respectively, yielding an event rate of 14.3 per 1,000 person-years (PY) in the syncope population. Multivariable Cox regression analysis demonstrated a significantly increased risk of all-cause mortality (hazard ratio [HR]: 1.06; 95% confidence interval [CI]: 1.02 to 1.10), cardiovascular hospitalization event rate of 26.5 per 1,000 PY (HR: 1.74; 95% CI: 1.68 to 1.80), recurrent syncope event rate of 45.1 per 1,000, stroke event rate of 6.8 per 1,000 PY (HR: 1.35; 95% CI: 1.27 to 1.44), and pacemaker or implantable cardioverter-defibrillator event rate of 4.2 per 1,000 PY (HR: 5.52; 95% CI: 4.67 to 5.73; p < 0.0001). CONCLUSIONS The first admission for syncope among healthy individuals significantly predicts the risk of all-cause mortality, stroke, cardiovascular hospitalization, device implantation, and recurrent syncope.

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.)

Temporal Trends in Coverage of Historical Cardiac Arrests Using a Volunteer-Based Network of Automated External Defibrillators Accessible to Laypersons and Emergency Dispatch Centers

Background— Although increased dissemination of automated external defibrillators (AEDs) has been associated with more frequent AED use, the trade-off between the number of deployed AEDs and coverage of cardiac arrests remains unclear. We investigated how volunteer-based AED dissemination affected public cardiac arrest coverage in high- and low-risk areas. Methods and Results— All public cardiac arrests (1994–2011) and all registered AEDs (2007–2011) in Copenhagen, Denmark, were identified and geocoded. AED coverage of cardiac arrests was defined as historical arrests ⩽100 m from an AED. High-risk areas were defined as those with ≥1 arrest every 2 years and accounted for 1.0% of the total city area. Of 1864 cardiac arrests, 18.0% (n=335) occurred in high-risk areas throughout the study period. From 2007 to 2011, the number of AEDs and the corresponding coverage of cardiac arrests increased from 36 to 552 and from 2.7% to 32.6%, respectively. The corresponding increase for high-risk areas was from 1 to 30 AEDs and coverage from 5.7% to 51.3%, respectively. Since the establishment of the AED network (2007–2011), few arrests (n=55) have occurred ⩽100 m from an AED with only 14.5% (n=8) being defibrillated before the arrival of emergency medical services. Conclusions— Despite the lack of a coordinated public access defibrillation program, the number of AEDs increased 15-fold with a corresponding increase in cardiac arrest coverage from 2.7% to 32.6% over a 5-year period. The highest increase in coverage was observed in high-risk areas (from 5.7% to 51.3%). AED networks can be used as useful tools to optimize AED placement in community settings.

The role of bystanders, first responders, and emergency medical service providers in timely defibrillation and related outcomes after out-of-hospital cardiac arrest: Results from a statewide registry

AIM Defibrillation by bystanders and first responders has been associated with increased survival, but limited data are available from non-metropolitan areas. We examined time from 911-call to defibrillation (according to who defibrillated patients) and survival in North Carolina. METHODS Through the Cardiac Arrest Registry to Enhance Survival, we identified 1732 defibrillated out-of-hospital cardiac arrests from counties with complete case capture (population 2.7 million) from 2010 to 2013. RESULTS Most patients (60.9%) were defibrillated in > 10 min. A minority (8.0%) was defibrillated < 5 min; most of these patients were defibrillated by first responders (51.8%) and bystanders (33.1%), independent of location of arrest (residential or public). Bystanders initiated cardiopulmonary resuscitation (CPR) in 49.0% of cases and defibrillated 13.4% of those. Survival decreased with increasing time to defibrillation (< 2 min: 59.1%; 2 to < 5 min: 38.5%; 5-10 min: 33.1%; > 10 min: 13.2%). Odds of survival with favorable neurologic outcome adjusted for age, sex, and bystander CPR improved with faster defibrillation (<2 min: OR 7.73 [95% CI 3.19-18.73]; 2 to < 5 min: 3.78 [2.45-5.84]; 5-10 min: 3.16 [2.42-4.12]; > 10 min: reference). CONCLUSION Bystanders and first responders were mainly responsible for defibrillation within 5 min, independent of location of arrest. Bystanders initiated CPR in half of the cardiac arrest cases but only defibrillated a minority of those. Timely defibrillation and defibrillation by bystanders and/or first responders were strongly associated with increased survival. Strategic efforts to increase bystander and first-responder defibrillation are warranted to increase survival after out-of-hospital cardiac arrest.

Out-of-hospital cardiac arrests in children and adolescents: Incidences, outcomes, and household socioeconomic status

BACKGROUND There is insufficient knowledge of out-of-hospital cardiac arrest (OHCA) in the very young. OBJECTIVES This nationwide study sought to examine age-stratified OHCA characteristics and the role of parental socioeconomic differences and its contribution to mortality in the young population. METHODS All OHCA patients in Denmark, ≤21 years of age, were identified from 2001 to 2010. The population was divided into infants (<1 year); pre-school children (1-5 years); school children (6-15 years); and high school adolescents/young adults (16-21 years). Multivariate logistic regression analyses were used to investigate associations between pre-hospital factors and study endpoints: return of spontaneous circulation and survival. RESULTS A total of 459 individuals were included. Overall incidence of OHCA was 3.3 per 100,000 inhabitants per year. The incidence rates for infants, pre-school children, school children and high school adolescents were 11.5, 3.5, 1.3 and 5.3 per 100,000 inhabitants. Overall bystander CPR rate was 48.8%, and for age groups: 55.4%, 41.2%, 44.9% and 63.0%, respectively. Overall 30-day survival rate was 8.1%, and for age groups: 1.4%, 4.5%, 16.1% and 9.3%, respectively. High parental education was associated with improved survival after OHCA (OR 3.48, CI 1.27-9.41). Significant crude difference in survival (OR 3.18, CI 1.22-8.34) between high household incomes vs. low household incomes was found. CONCLUSION OHCA incidences and survival rates varied significantly between age groups. High parental education was found to be associated with improved survival after OHCA.