Circumstances of out of hospital cardiac arrest in patients with ischaemic heart disease

Sudden Cardiac Death at Home: Potential Lives Saved With Fully Automated External Defibrillators

Sudden cardiac death from ventricular arrhythmia kills about 350,000 people annually in the United States. This number has not improved since the widespread public availability of semi-automated external defibrillators (AEDs) and the teaching of nonbreathing cardiopulmonary resuscitation (CPR) procedures. When an out-of-hospital cardiac arrest occurs in a public space, lay witnesses do CPR in 40% of the cases and use AEDs on only 7.4% of the victims before emergency medical services (EMS) arrive. About 70% of sudden cardiac death occurs at home, where an AED is usually unavailable until EMS appears. The time from a 911 call to shock averages approximately 7 minutes in urban areas and is more than 14.5 minutes in rural environments. Because arrest onset is often not observed, arrest onset to shock times maybe even longer. Survival from cardiac arrest decreases by approximately 7 to 10% per minute of ventricular arrhythmia. A prearrest protocol is proposed for the at-home use of fully automated external defibrillators in select cardiac patients, which should reduce the arrest-to-shock interval to under 1 minute and may eliminate the need for CPR in some cases.

Warning symptoms associated with imminent sudden cardiac arrest: a population-based case-control study with external validation

BACKGROUND

Sudden cardiac arrest is a global public health problem with a mortality rate of more than 90%. Prearrest warning symptoms could be harnessed using digital technology to potentially improve survival outcomes. We aimed to estimate the strength of association between symptoms and imminent sudden cardiac arrest.

METHODS

We conducted a case-control study of individuals with sudden cardiac arrest and participants without sudden cardiac arrest who had similar symptoms identified from two US community-based studies of patients with sudden cardiac arrest in California state, USA (discovery population; the Ventura Prediction of Sudden Death in Multi-Ethnic Communities [PRESTO] study), and Oregon state, USA (replication population; the Oregon Sudden Unexpected Death Study [SUDS]). Participant data were obtained from emergency medical services reports for people aged 18-85 years with witnessed sudden cardiac arrest (between Feb 1, 2015, and Jan 31, 2021) and an inclusion symptom. Data were also obtained from corresponding control populations without sudden cardiac arrest who were attended by emergency medical services for similar symptoms (between Jan 1 and Dec 31, 2019). We evaluated the association of symptoms with sudden cardiac arrest in the discovery population and validated our results in the replication population by use of logistic regression models.

FINDINGS

We identified 1672 individuals with sudden cardiac arrest from the PRESTO study, of whom 411 patients (mean age 65·7 [SD 12·4] years; 125 women and 286 men) were included in the analysis for the discovery population. From a total of 76 734 calls to emergency medical services, 1171 patients (mean age 61·8 [SD 17·3] years; 643 women, 514 men, and 14 participants without data for sex) were included in the control group. Patients with sudden cardiac arrest were more likely to have dyspnoea (168 [41%] of 411 vs 262 [22%] of 1171; p<0·0001), chest pain (136 [33%] vs 296 [25%]; p=0·0022), diaphoresis (50 [12%] vs 90 [8%]; p=0·0059), and seizure-like activity (43 [11%] vs 77 [7%], p=0·011). Symptom frequencies and patterns differed significantly by sex. Among men, chest pain (odds ratio [OR] 2·2, 95% CI 1·6-3·0), dyspnoea (2·2, 1·6-3·0), and diaphoresis (1·7, 1·1-2·7) were significantly associated with sudden cardiac arrest, whereas among women, only dyspnoea was significantly associated with sudden cardiac arrest (2·9, 1·9-4·3). 427 patients with sudden cardiac arrest (mean age 62·2 [SD 13·5]; 122 women and 305 men) were included in the analysis for the replication population and 1238 patients (mean age 59·3 [16·5] years; 689 women, 548 men, and one participant missing data for sex) were included in the control group. Findings were mostly consistent in the replication population; however, notable differences included that, among men, diaphoresis was not associated with sudden cardiac arrest and chest pain was associated with sudden cardiac arrest only in the sex-stratified multivariable analysis.

INTERPRETATION

The prevalence of warning symptoms was sex-specific and differed significantly between patients with sudden cardiac arrest and controls. Warning symptoms hold promise for prediction of imminent sudden cardiac arrest but might need to be augmented with additional features to maximise predictive power.

FUNDING

US National Heart Lung and Blood Institute.

Myocardial scarring and recurrence of ventricular arrhythmia in patients surviving an out-of-hospital cardiac arrest

INTRODUCTION

Prediction of recurrent ventricular arrhythmia (VA) in survivors of an out-of-hospital cardiac arrest (OHCA) is important, but currently difficult. Risk of recurrence may be related to presence of myocardial scarring assessed with late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Our study aims to characterize myocardial scarring as defined by LGE-CMR in survivors of a VA-OHCA and investigate its potential role in the risk of new VA events.

METHODS

Between 2015 and 2022, a total of 230 VA-OHCA patients without ST-segment elevation myocardial infarction had CMR before implantable cardioverter-defibrillator implantation for secondary prevention at Copenhagen University Hospital, Rigshospitalet, and Hospital Clínic, University of Barcelona, of which n = 170 patients had a conventional (no LGE protocol) CMR and n = 60 patients had LGE-CMR (including LGE protocol). Scar tissue including core, border zone (BZ) and BZ channels were automatically detected by specialized investigational software in patients with LGE-CMR. The primary endpoint was recurrent VA.

RESULTS

After exclusion, n = 52 VA-OHCA patients with LGE-CMR and a mean left ventricular ejection fraction of 49 ± 16% were included, of which 18 (32%) patients reached the primary endpoint of VA. Patients with recurrent VA in exhibited greater scar mass, core mass, BZ mass, and presence of BZ channels compared with patients without recurrent VA. The presence of BZ channels identified patients with recurrent VA with 67% sensitivity and 85% specificity (area under the ROC curve (AUC) 0.76; 95% CI: 0.63-0.89; p < .001) and was the strongest predictor of the primary endpoint.

CONCLUSIONS

The presence of BZ channels was the strongest predictor of recurrent VA in patients with an out of-hospital cardiac arrest and LGE-CMR.

Effect of a national awareness campaign on ambulance attendances for chest pain and out-of-hospital cardiac arrest

AIM

Awareness of heart attack symptoms may enhance health-seeking behaviour and prevent premature deaths from out-of-hospital cardiac arrest (OHCA). We sought to investigate the impact of a national awareness campaign on emergency medical service (EMS) attendances for chest pain and OHCA.

METHODS

Between January 2005 and December 2017, we included registry data for 97,860 EMS-attended OHCA cases from 3 Australian regions and dispatch data for 1,631,217 EMS attendances for chest pain across 5 Australian regions. Regions were exposed to between 11 and 28 months of television, radio, and print media activity. Multivariable negative binomial models were used to explore the effect of campaign activity on the monthly incidence of EMS attendances for chest pain and OHCA.

RESULTS

Months with campaign activity were associated with an 8.8% (IRR 1.09, 95% CI: 1.07, 1.11) increase in the incidence of EMS attendances for chest pain and a 5.6% (IRR 0.94, 95% CI: 0.92, 0.97) reduction in OHCA attendances. Larger intervention effects were associated with increasing months of campaign activity, increasing monthly media spending and media exposure in 2013. In stratified analyses of OHCA cases, the largest reduction in incidence during campaign months was observed for unwitnessed arrests (IRR 0.93, 95% CI: 0.90, 0.96), initial non-shockable arrests (IRR 0.93, 95% CI: 0.90, 0.97) and arrests occurring in private residences (IRR 0.95, 95% CI: 0.91, 0.98).

CONCLUSION

A national awareness campaign targeting knowledge of heart attack symptoms was associated with an increase in EMS use for chest pain and a reduction in OHCA incidence and may serve as an effective primary prevention strategy for OHCA.

Reducing patient delay in acute coronary syndrome: Randomized controlled trial testing effect of behaviour change intervention on intentions to seek help

OBJECTIVES

The aim of this study was to evaluate the efficacy of a behaviour change intervention to reduce patient delay with symptoms of acute coronary syndrome.

DESIGN

A 3-arm web-based, parallel randomized controlled trial.

METHODS

The intervention comprised 12 behaviour change techniques (BCTs) embedded in a text-only or text+visual narrative (the techniques were systematically identified through systematic review and a consensus exercise). Between February and November 2017, n = 145 people who had recently experienced acute coronary syndrome were randomly allocated to intervention ('text+visual' or 'text-only') or control. Intentions to phone an ambulance immediately for acute coronary syndrome symptoms were assessed before and after the intervention using symptom scenarios, and the change in intention was compared across the three groups.

RESULTS

Significant increases in intention to phone an ambulance immediately for ACS symptoms were seen following the 'text+visual' intervention but not following 'text-only' or control. However, the study was underpowered to detect any significant changes in intention between the 3 groups. There were no unintended effects on intentions for non-urgent symptoms.

CONCLUSIONS

A 'text+visual' BCT-based intervention may significantly increase intention to phone an ambulance with symptoms of ACS. Further testing of the effect of the intervention on actual behaviour is required.

Long-term outcome of myocardial scarring and deformation with cardiovascular magnetic resonance in out of hospital cardiac arrest survivors

AIMS

Cardiovascular magnetic resonance (CMR) is increasingly recognized as a diagnostic and prognostic tool in out of hospital cardiac arrest (OHCA) survivors. After assessing CMR findings early after ventricular fibrillation (VF) OHCA, we sought to explore the long-term outcome of myocardial scarring and deformation.

METHODS AND RESULTS

We included 121 consecutive VF OHCA survivors (82% male, median 62 years) undergoing CMR within 2 weeks from cardiac arrest. Late gadolinium-enhancement (LGE) was quantified using the full width at half maximum method and tissue tracking analysis software was used to assess myocardial deformation. LGE was found in 71% of patients (median LGE mass 6.2% of the left ventricle, LV), mainly with an ischaemic pattern. Myocardial deformation was overall impaired and showed a significant correlation with LGE presence and extent (P < 0.001). A composite end-point of all-cause mortality and appropriate ICD discharge/anti-tachycardia pacing was met in 24% of patients. Patients meeting the end-point had significantly greater LGE extent (8.6% of LV myocardium vs. 4.1%, P = 0.02), while there was no difference with regards to myocardial deformation. Survival rate was significantly lower in patients with LGE (P = 0.05) and LGE mass >4.4% of the LV identified a group of patients at higher risk of adverse events (P = 0.005).

CONCLUSIONS

We found a high prevalence of LGE, early after OHCA, and an overall impaired myocardial deformation. On long-term follow-up both LGE presence and extent showed a significant association with recurrent adverse events, while LV ejection fraction and myocardial deformation did not identify patients with an unfavourable outcome.

Development of a Novel Framework to Propose New Strategies for Automated External Defibrillators Deployment Targeting Residential Out-Of-Hospital Cardiac Arrests: Application to the City of Milan

Public Access Defibrillation (PAD) is the leading strategy in reducing time to first defibrillation in cases of Out-Of-Hospital Cardiac Arrest (OHCA), but PAD programs are underperforming considering their potentiality. Our aim was to develop an analysis and optimization framework, exploiting georeferenced information processed with Geographic Information Systems (GISs), specifically targeting residential OHCAs. The framework, based on an historical database of OHCAs, location of Automated External Defibrillators (AEDs), topographic and demographic information, proposes new strategies for AED deployment focusing on residential OHCAs, where performance assessment was evaluated using AEDs “catchment area” (area that can be reached within 6 min walk along streets). The proposed framework was applied to the city of Milan, Lombardy (Italy), considering the OHCA database of four years (2015–2018), including 8152 OHCA, of which 7179 (88.06%) occurred in residential locations. The proposed strategy for AEDs deployment resulted more effective compared to the existing distribution, with a significant improvement (from 41.77% to 73.33%) in OHCAs’ spatial coverage. Further improvements were simulated with different cost scenarios, resulting in more cost-efficient solutions. Results suggest that PAD programs, either in brand-new territories or in further improvements, could significantly benefit from a comprehensive planning, based on mathematical models for risk mapping and on geographical tools.

Effectiveness of a community based out-of-hospital cardiac arrest (OHCA) interventional bundle: Results of a pilot study

BACKGROUND

70% of Out-of-hospital cardiac arrests (OHCA) in Singapore occur in residential areas, and are associated with poorer outcomes. We hypothesized that an interventional bundle consisting of Save-A-life (SAL) initiative (cardiopulmonary resuscitation (CPR)/automated external defibrillator (AED) training and public-housing AED installation), dispatcher-assisted CPR (DA-CPR) program and myResponder (mobile application) will improve OHCA survival.

METHODS

This is pilot data from initial implementation of a stepped-wedge, before-after, real-world interventional bundle in six selected regions. Under the SAL initiative, 30,000 individuals were CPR/AED trained, with 360 AEDs installed. Data was obtained from Singapore's national OHCA Registry. We included all adult patients who experienced OHCA in Singapore from 2011 to 2016 within study regions, excluding EMS-witnessed cases and cases due to trauma/drowning/ electrocution. Cases occurring before and after intervention were allocated as control and intervention groups respectively. Survival was assessed via multivariable logistic regression.

RESULTS

1241 patients were included for analysis (Intervention: 361; Control: 880). The intervention group had higher mean age (70 vs 67 years), survival (3.3% [12/361] vs. 2.2% [19/880]), pre-hospital return of spontaneous circulation (ROSC) (9.1% [33/361] vs 5.1% [45/880]), bystander CPR (63.7% [230/361] vs 44.8% [394/880]) and bystander AED application (2.8% [10/361] vs 1.1% [10/880]). After adjusting for age, gender, race and significant covariates, the intervention was associated with increased odds ratio (OR) for survival (OR 2.39 [1.02-5.62]), pre-hospital ROSC (OR 1.94 [1.15-3.25]) and bystander CPR (OR 2.29 [1.77-2.96]).

CONCLUSION

The OHCA interventional bundle (SAL initiative, DA-CPR, myResponder) significantly improved survival and is being scaled up as a national program.

One in four major ischaemic heart disease events are fatal and 60% are pre-hospital deaths: a national data-linkage study (ANZACS-QI 8)

Aims

The aim of this study is to determine proportions of major ischaemic heart disease (IHD) events that are fatal and where they occur, in an era of rapidly falling IHD mortality.

Methods and Results

Individual person linkage of national data sets identified all IHD hospitalizations and deaths in New Zealand from December 2008 to November 2010. Outcome measures were proportions of people: (i) hospitalized with IHD and alive at 28 days; (ii) hospitalized with IHD and died within 28 days; (iii) hospitalized for a non-IHD cause and died from IHD within 28 days; and (iv) not hospitalized and died from IHD. Three event definitions were used [broad-balanced: IHD deaths and IHD hospitalizations, unbalanced: IHD deaths and myocardial infarction (MI) hospitalizations, and narrow-balanced: MI deaths and MI hospitalizations]. About 37 867 IHD hospitalizations and 9409 IHD deaths were identified using the broad IHD definition. Approximately one-quarter of IHD events were fatal: 4% were deaths within 28 days of an IHD hospitalization, 6% were IHD deaths within 28 days of a non-IHD hospitalization, and 14% were non-hospitalized IHD deaths. Using different event definitions, overall case fatality varied from 24–25% (broad and narrow balanced) to 37–39% (unbalanced), whereas the proportion of all deaths that were non-hospitalized was approximately 60%. Forty per cent of deaths were first-ever events that manifested as non-hospitalized IHD deaths.

Conclusion

About one-quarter of IHD are fatal, although the proportion is dependent on disease definitions and age. About 60% of all IHD deaths occur out of hospital, and of these 60% are in people not previously hospitalized for IHD.

Impact Of Ambulance Diversion: Black Patients With Acute Myocardial Infarction Had Higher Mortality Than Whites

This study investigated whether emergency department crowding affects blacks more than their white counterparts and the mechanisms behind which this might occur. Using a nonpublic database of patients in California with acute myocardial infarction between 2001 and 2011 and hospital-level data on ambulance diversion, we found that hospitals treating a high share of black patients with acute myocardial infarction were more likely to experience diversion and that black patients fared worse compared to white patients experiencing the same level of emergency department crowding as measured by ambulance diversion. The ninety-day and one-year mortality rates among blacks exposed to high diversion levels were 2.88 and 3.09 percentage points higher, respectively, relative to whites, representing a relative increase of 19 percent and 14 percent for ninety-day and one-year death, respectively. Interventions that decrease the need for diversion in hospitals serving a high volume of blacks could reduce these disparities.

Impact of a public awareness campaign on out-of-hospital cardiac arrest incidence and mortality rates

Aims

Increased public awareness of the warning signs of a heart attack and the importance of early medical intervention may help to prevent premature deaths from out-of-hospital cardiac arrest (OHCA). We sought to investigate the impact of the Heart Foundation's public awareness campaigns on the monthly incidence of, and deaths from, OHCA in Melbourne, Australia.

Methods and results

Between July 2005 and June 2015, we included registry data for 25 060 OHCA of presumed cardiac aetiology. Time series models with distributed lags were used to explore the effect of campaign activity on OHCA outcomes. A sensitivity analysis involving segmented regression of the pre-intervention, intervention, and post-intervention time segments was also performed. The mean monthly incidence of, and deaths from, OHCA was 207 and 189 events respectively. After adjustment for temporal trends, campaign activity was associated with a 6.0% [95% confidence interval (CI): 2.8-9.0%; P < 0.001] reduction in the monthly incidence of OHCA, or 11.7% (95% CI: 7.7-15.5%, P < 0.001) with the addition of residual effects in two additional lag months. Similarly, the rate of deaths from OHCA reduced by 6.4% (95% CI: 2.8-10.0%; P = 0.001) during months with campaign activity. Campaign activity had a greater effect in males and patients aged ≥65 years, and reduced the incidence of OHCA in unwitnessed and initial non-shockable arrests. In the segmented regression analysis, the intervention period was associated with a 15.2% (95% CI: 9.2-20.9%; P < 0.001) reduction in the mean monthly incidence and a 16.6% (95% CI: 9.9-22.7%; P < 0.001) reduction in deaths from OHCA.

Conclusion

A comprehensive mass media campaign targeting the community's awareness of heart attack symptoms was associated with a substantial reduction in the incidence of OHCA and associated deaths.

Acute myocardial infarction hospital admissions and deaths in England: a national follow-back and follow-forward record-linkage study

BACKGROUND

Little information is available on how primary and comorbid acute myocardial infarction contribute to the mortality burden of acute myocardial infarction, the share of these deaths that occur during or after a hospital admission, and the reasons for hospital admission of those who died from acute myocardial infarction. Our aim was to fill in these gaps in the knowledge about deaths and hospital admissions due to acute myocardial infarction.

METHODS

We used individually linked national hospital admission and mortality data for England from 2006 to 2010 to identify all primary and comorbid diagnoses of acute myocardial infarction during hospital stay and their associated fatality rates (during or within 28 days of being in hospital). Data were obtained from the UK Small Area Health Statistics Unit and supplied by the Health and Social Care Information Centre (now NHS Digital) and the Office of National Statistics. We calculated event rates (reported as per 100 000 population for relevant age and sex groups) and case-fatality rate for primary acute myocardial infarction diagnosed during the first physician encounter or during subsequent encounters, and acute myocardial infarction diagnosed only as a comorbidity. We also calculated what proportion of deaths from acute myocardial infarction occurred in people who had been in hospital on or within the 28 days preceding death, and whether acute myocardial infarction was one of the recorded diagnoses in such admissions.

FINDINGS

Acute myocardial infarction was diagnosed in the first physician encounter in 307 496 (69%) of 446 744 admissions with a diagnosis of acute myocardial infarction, in the second or later physician encounter in 52 374 (12%) admissions, and recorded only as a comorbidity in 86 874 (19%) admissions. Patients with comorbid diagnoses of acute myocardial infarction had two to three times the case-fatality rate of patients in whom acute myocardial infarction was a primary diagnosis. 135 950 deaths were recorded as being caused by acute myocardial infarction as the underlying cause of death, of which 66 490 (49%) occurred in patients who were in hospital on the day of death or in the 28 days preceding death. AMI was the primary diagnosis in 32 695 (49%) of these 66 490 patients (27 678 [42%] diagnosed in the first physician encounter and 5017 [8%] in a second or subsequent encounter), was a comorbid diagnosis in 12 118 (18%), and was not mentioned at all in the remaining 21 677 (33%). The most common causes of admission in people who did not have an acute myocardial infarction diagnosis but went on to die of acute myocardial infarction as the underlying cause of death were other circulatory conditions (7566 [35%] of 21 677 deaths), symptomatic diagnoses including non-specific chest pain, dyspnoea and syncope (1368 [6%] deaths), and respiratory disorders (2662 [12%] deaths), mainly pneumonia and chronic obstructive airways disease.

INTERPRETATION

As many acute myocardial infarction deaths occurring within 28 days of being in hospital follow a non-acute myocardial infarction admission as follow an acute myocardial infarction admission. These people are often diagnosed with other circulatory disorders or symptoms of circulatory disturbance. Further investigation is needed to establish whether there are symptoms and information that can be used to predict the risk of a fatal acute myocardial infarction in such patients, which can contribute to reducing the mortality burden of acute myocardial infarction.

FUNDING

Wellcome Trust, Medical Research Council, Public Health England, National Institute for Health Research.

Geographic Discordance Between Patient Residence and Incident Location in Emergency Medical Services Responses

STUDY OBJECTIVE

The location of a patient's residence is often used for emergency medical services (EMS) system planning. Our objective is to evaluate the association between patient residence and emergency incident zip codes for 911 calls.

METHODS

We used data from the 2013 National Emergency Medical Services Information System (NEMSIS) Public-Release Research Dataset. We studied all 911 calls with a valid complaint by dispatch, identifying zip codes for both the residence and incident locations (n=12,376,784). The primary outcomes were geographic and distance discordances between patient residence and incident zip codes. We used a multivariate logistic regression model to determine geographic discordance between residence and incident zip codes by dispatch complaint, age, and sex. We also measured distances between locations with geospatial processing.

RESULTS

The overall proportion of geographic discordance for all 911 calls was 27.7% (95% confidence interval [CI] 27.7% to 27.8%) and the median distance discordance was 11.5 miles (95% CI 11.5 to 11.5 miles). Lower geographic discordance rates were found among patients aged 65 to 79 years (20.2%; 95% CI 20.1% to 20.2%) and 80 years and older (14.5%; 95% CI 14.5% to 14.6%). Motor vehicle crashes (63.5%; 95% CI 63.5% to 63.6%), industrial accidents (59.3%; 95% CI 58.0% to 60.6%), and mass casualty incidents (50.6%; 95% CI 49.6% to 51.5%) were more likely to occur outside a patient's residence zip code. Median network distance between home and incident zip centroid codes ranged from 8.6 to 23.5 miles.

CONCLUSION

In NEMSIS, there was geographic discordance between patient residence zip code and call location zip code in slightly more than one quarter of EMS responses records. The geographic discordance rates between residence and incident zip codes were associated with dispatch complaints and age. Although a patient's residence might be a valid proxy for incident location for elderly patients, this relationship holds less true for other age groups and among different complaints. Our findings have important implications for EMS system planning, resource allocation, and injury surveillance.

Ethnic differences in case fatality following an acute ischaemic heart disease event in New Zealand: ANZACS-QI 13

BACKGROUND

The aim of this study was to investigate ischaemic heart disease (IHD) case fatality in high-risk ethnic populations in New Zealand.

DESIGN

This is a national data-linkage study using anonymised hospitalisation and mortality data.

METHODS

Linked individual patient data were used to identify 35-84-year-olds who experienced IHD events (acute IHD hospitalisations and/or deaths) in 2009-2010. Subjects were classified as: (i) hospitalised with IHD and alive at 28 days post-event; (ii) hospitalised with IHD and died within 28 days; (iii) hospitalised with a non-IHD diagnosis and died from IHD within 28 days; or (iv) died from IHD but not hospitalised. Multinomial logistic regression was used to estimate the proportion of people in each group, as well as overall 28-day case fatality, adjusted for ethnic differences in demographic and comorbidity profiles.

RESULTS

A total of 26,885 people experienced IHD events (11.3% Māori, 4.0% Pacific and 2.5% Indian); 3.3% of people died within 28 days of IHD hospitalisations, 5.1% died of IHD within 28 days of non-IHD hospitalisations and 13.0% died of IHD without any recent hospitalisation. Overall adjusted case fatality was 12.6% in Indian, 20.5% in European, 26.0% in Pacific and 27.6% in Māori people. Compared to Europeans, the adjusted odds of death were approximately 50% higher in Māori and Pacific people and 50% lower in Indians, regardless of whether they were hospitalised.

CONCLUSIONS

Major ethnic inequalities in IHD case fatality occur with and without associated hospitalisations. Improvements in both primary prevention and hospital care will be required to reduce inequalities.

Presumed Regional Incidence Rate of Out-of-Hospital Cardiac Arrest in Korea

The regional incidence rates of out-of-hospital cardiac arrest (OHCA) were traditionally calculated with the residential population as the denominator. The aim of this study was to estimate the true incidence rate of OHCA and to investigate characteristics of regions with overestimated and underestimated OHCA incidence rates. We used the national OHCA database from 2006 to 2010. The nighttime residential and daytime transient populations were investigated from the 2010 Census. The daytime population was calculated by adding the daytime influx of population to, and subtracting the daytime outflow from, the nighttime residential population. Conventional age-standardized incidence rates (CASRs) and daytime corrected age-standardized incidence rates (DASRs) for OHCA per 100,000 person-years were calculated in each county. A total of 97,291 OHCAs were eligible. The age-standardized incidence rates of OHCAs per 100,000 person-years were 34.6 (95% CI: 34.3-35.0) in the daytime and 24.8 (95% CI: 24.5-25.1) in the nighttime among males, and 14.9 (95% CI: 14.7-15.1) in the daytime, and 10.4 (95% CI: 10.2-10.6) in the nighttime among females. The difference between the CASR and DASR ranged from 35.4 to -11.6 in males and from 6.1 to -1.0 in females. Through the Bland-Altman plot analysis, we found the difference between the CASR and DASR increased as the average CASR and DASR increased as well as with the larger daytime transient population. The conventional incidence rate was overestimated in counties with many OHCA cases and in metropolitan cities with large daytime population influx and nighttime outflow, while it was underestimated in residential counties around metropolitan cities.

Ambulance diversion associated with reduced access to cardiac technology and increased one-year mortality

Ambulance diversion, which occurs when a hospital emergency department (ED) is temporarily closed to incoming ambulance traffic, is an important system-level interruption that causes delays in treatment and potentially lower quality of care. There is little empirical evidence investigating the mechanisms through which ambulance diversion might affect patient outcomes. We investigated whether ambulance diversion affects access to technology, likelihood of treatment, and ultimately health outcomes for Medicare patients with acute myocardial infarction in twenty-six California counties. We found that patients whose nearest hospital ED had significant ambulance diversions experienced reduced access to hospitals with cardiac technology. This led to a 4.6 percent decreased likelihood of revascularization and a 9.8 percent increase in one-year mortality compared to patients who did not experience diversion. Policy makers may wish to consider creating a policy to specifically manage certain time-sensitive conditions that require technological intervention during periods of ambulance diversion.

Primary prevention of sudden cardiac death - Challenge the guidelines

Primary Prevention of Sudden Cardiac death in post-infarction patients especially those with ejection fraction less than 35% is best achieved by implantable defibrillator. However, the cost of Quality Adjusted Life Years saved is $ 50,000-70,000, makes implantable defibrillators not an easily acceptable option when preventing SCD in a significant number of patients with low ejection fraction of 35 percent. In, addition excessive dependence on ejection fraction, excludes a large number of postinfarction patients with ejection fraction more than 35 percent, or patients with existing but not known heart disease. The two complementary strategies based on Public Health approach and Home AED approach and strengthening the program of Bystander CPR and AED application of publically available AED may be a better way for Primary Prevention of SCD in more number of patients. These approaches may be considered seriously to reduce sudden cardiac death in India, however, it needs to be proven.

Risky locations for out-of-hospital cardiopulmonary arrest in a typical urban city

Background:

The aim of this study is to clarify the circumstances including the locations where critical events resulting in out-of-hospital cardiopulmonary arrest (OHCPA) occur.

Materials and Methods:

Subjects of this population-based observational case series study were the clinical records of patients with nontraumatic and nonneck-hanging OHCPA.

Results:

Of all 1546 cases, 10.3% occurred in a public place (shop, restaurant, workplace, stations, public house, sports venue, and bus), 8.3% on the street, 73.4% in a private location (victim's home, the homes of the victims’ relatives or friends or cheap bedrooms, where poor homeless people live), and 4.1% in residential institutions. In OHCPA occurring in private locations, the frequency of asystole was higher and the outcome was poorer than in other locations. A total of 181 OHCPA cases (11.7%) took place in the lavatory and 166 (10.7%) in the bathroom; of these, only 7 (3.9% of OHCPA in the lavatory) and none in the bath room achieved good outcomes. The frequencies of shockable initial rhythm occurring in the lavatory and in bath room were 3.7% and 1.1% (lower than in other locations, P = 0.011 and 0.002), and cardiac etiology in OHCPA occurring in these locations were 46.7% and 78.4% (the latter higher than in other locations, P < 0.001).

Conclusions:

An unignorable population suffered from OHCPA in private locations, particularly in the lavatory and bathroom; their initial rhythm was usually asystole and their outcomes were poor, despite the high frequency of cardiac etiology in the bathroom. We should try to treat OHCPA victims and to prevent occurrence of OHCPA in these risky spaces by considering their specific conditions.

Implications for public access defibrillation placement by non-traumatic out-of-hospital cardiac arrest occurrence in Singapore

INTRODUCTION

The American Heart Association recommends automated external defibrillator placement in public areas with a high probability (>1) of out-of-hospital cardiac arrest (OHCA) occurring in 5 years. We aimed to determine the incidence rate of OHCA for different location categories in Singapore.

METHODS

Cardiac arrest incidence was obtained from a national registry. Denominators for the actual number of sites per location category were obtained from public accessible sources, government officers and purchased statistics. Analysis was performed and expressed in terms of the corresponding 95% confidence interval (CI).

RESULTS

From 1 October 2001 to 14 October 2004, 2254 non-trauma OHCA cases were included. Mean age for arrests was 62.2 years, with 67.5% men. The location category with the highest incidence of cardiac arrests per site per 5 years was Port/Airport/Immigration Checkpoints (5.24 CI [3.66-7.20]). Top individual site with high average incidence of cardiac arrests per 5 years was Changi Airport (25.0 CI [16.18-36.90]). Seventy-one per cent of arrests occurred in residential areas. The postal sector with the highest average incidence per 100 000 population was Bedok Reservoir (54.89), whereas that with the highest population density was Bukit Merah/Alexandra with 348.14 population per 100 km(2) .

CONCLUSION

In this study, we found the categories and individual sites that clearly fulfilled the American Heart Association criteria of at least 1 OHCA per site per 5 years. This study provides a model of how cardiac arrest registry data can be used to guide local health policy on automated external defibrillator deployment.

Prodromal symptoms and health care consumption prior to out-of-hospital cardiac arrest in patients without previously known ischaemic heart disease

AIMS

To describe prodromal symptoms and health care consumption prior to an out-of-hospital cardiac arrest (OHCA) in patients without previously known ischaemic heart disease (IHD).

BACKGROUND

The most common lethal event of cardiovascular disease is sudden cardiac death, and the majority occur outside hospital. Little is known about prodromal symptoms and health care consumption associated with OHCAs.

DESIGN

Case-crossover study.

METHODS

Medical records of 403 OHCA cases without previously known IHD, age 25-74 years in the MONICA myocardial registry in Norrbotten County 2000-2008, were reviewed. Presenting symptoms and emergency visits at public primary care facilities and internal medicine clinics in Norrbotten County were analyzed from the week prior to the OHCA and from the same week one year previously, which served as a control week. Unlike most studies we included unwitnessed arrests and those where no cardiopulmonary resuscitation (CPR) was attempted.

RESULTS

Emergency visits were more common during the week prior to the OHCA than during the control week, both for visits to primary care (29 vs. 6, p<0.001) and to internal medicine clinics (16 vs. 0, p<0.001). Symptoms were more prevalent during the week prior to the OHCA (36.7 vs. 6.7%, p<0.001). The most prevalent symptoms were chest pain (14.6 vs. 0%, p<0.001), gastrointestinal symptoms (7.7 vs. 1.2%, p<0.001) and dyspnoea/peripheral oedema (6.9 vs. 0.2%, p<0.001).

CONCLUSIONS

Patients who suffer an OHCA seek health care and present prodromal symptoms significantly more often the week prior to the event than the same week one year earlier.

Marital status and ischemic heart disease incidence and mortality in women: a large prospective study

BACKGROUND

Being married has been associated with a lower mortality from ischemic heart disease (IHD) in men, but there is less evidence of an association for women, and it is unclear whether the associations with being married are similar for incident and for fatal IHD. We examined the relation between marital status and IHD incidence and mortality in the Million Women Study.

METHODS

A total of 734,626 women (mean age 60 years) without previous heart disease, stroke or cancer, were followed prospectively for hospital admissions and deaths. Adjusted relative risks (RRs) for IHD were calculated using Cox regression in women who were married or living with a partner versus women who were not. The role of 14 socio-economic, lifestyle and other potential confounding factors was investigated.

RESULTS

81% of women reported being married or living with a partner and they were less likely to live in deprived areas, to smoke or be physically inactive, but had a higher alcohol intake than women who were not married or living with a partner. During 8.8 years of follow-up, 30,747 women had a first IHD event (hospital admission or death) and 2,148 died from IHD. Women who were married or living with a partner had a similar risk of a first IHD event as women who were not (RR = 0.99, 95% confidence interval (CI) 0.96 to 1.02), but a significantly lower risk of IHD mortality (RR = 0.72, 95% CI 0.66 to 0.80, P <0.0001). This lower risk of IHD death was evident both in women with and without a prior IHD hospital admission (respectively: RR = 0.72, 95% CI 0.60 to 0.85, P <0.0001, n = 683; and 0.70, 95% CI 0.62 to 0.78, P <0.0001, n = 1,465). These findings did not vary appreciably between women of different socio-economic groups or by lifestyle and other factors.

CONCLUSIONS

After adjustment for socioeconomic, lifestyle and other factors, women who were married or living with a partner had a similar risk of developing IHD but a substantially lower IHD mortality compared to women who were not married or living with a partner.

Association between ambulance diversion and survival among patients with acute myocardial infarction

CONTEXT

Ambulance diversion, a practice in which emergency departments (EDs) are temporarily closed to ambulance traffic, might be problematic for patients experiencing time-sensitive conditions, such as acute myocardial infarction (AMI). However, there is little empirical evidence to show whether diversion is associated with worse patient outcomes.

OBJECTIVE

To analyze whether temporary ED closure on the day a patient experiences AMI, as measured by ambulance diversion hours of the nearest ED, is associated with increased mortality rates among patients with AMI. DESIGN, STUDY, AND PARTICIPANTS: A case-crossover design of 13,860 Medicare patients with AMI from 508 zip codes within 4 California counties (Los Angeles, San Francisco, San Mateo, and Santa Clara) whose admission date was between 2000 and 2005. Data included 100% Medicare claims data that covered admissions between 2000 and 2005, linked with date of death until 2006, and daily ambulance diversion logs from the same 4 counties. Among the hospital universe, 149 EDs were identified as the nearest ED to these patients.

MAIN OUTCOME MEASURES

The percentage of patients with AMI who died within 7 days, 30 days, 90 days, 9 months, and 1 year from admission (when their nearest ED was not on diversion and when that same ED was exposed to <6, 6 to <12, and ≥12 hours of diversion out of 24 hours on the day of admission).

RESULTS

Between 2000 and 2006, the mean (SD) daily diversion duration was 7.9 (6.1) hours. Based on analysis of 11,625 patients admitted to the ED between 2000 and 2005, and whose nearest ED had at least 3 diversion exposure levels (3541, 3357, 2667, and 2060 patients for no exposure, exposure to <6, 6 to <12, and ≥12 hours of diversion, respectively), there were no statistically significant differences in mortality rates between no diversion and exposure to less than 12 hours of diversion. Exposure to 12 or more hours of diversion was associated with higher 30-day mortality vs no diversion status (unadjusted mortality rate, 392 patients [19%] vs 545 patients [15%]; regression adjusted difference, 3.24 percentage points; 95% confidence interval [CI], 0.60-5.88); higher 90-day mortality (537 patients [26%] vs 762 patients [22%]; 2.89 percentage points; 95% CI, 0.13-5.64); higher 9-month mortality (680 patients [33%] vs 980 patients [28%]; 2.93 percentage points; 95% CI, 0.15-5.71); and higher 1-year mortality (731 patients [35%] vs 1034 patients [29%]; 3.04 percentage points; 95% CI, 0.33-5.75).

CONCLUSION

Among Medicare patients with AMI in 4 populous California counties, exposure to at least 12 hours of diversion by the nearest ED was associated with increased 30-day, 90-day, 9-month, and 1-year mortality.

Educational polymorphisms of basic life support algorithms

BACKGROUND

A systematic review of the pooled effect of articles presenting current basic life support (BLS) algorithms for the treatment of cardiac arrest has never been carried.

AIMS

We aimed to record and classify potential inherent factors influencing simplicity negatively in teaching, learning and retention of cardiopulmonary resuscitation (CPR) delivered by health care providers or lay persons.

METHODS

We performed a search of the relevant literature exploring MEDLINE, COCHRANE LIBRARY and SCOPUS databases. Potential inhibitory factors in the structure of available algorithms influencing simplicity in teaching, learning and retention of BLS were recorded and stratified accordingly. In a second phase of this study, we tested the hypothesis that different options of a BLS algorithm might influence CPR retention negatively, by asking 348 health care provider participants of our CPR seminars to describe their predicted response in an emergency to: (1) a real-time model implicating the various victims and rescuers; and (2) a hypothetical challenging 'all-in-one' BLS algorithm model.

RESULTS

Fifteen articles presenting current BLS algorithms evidenced 163 suggestions that produced 23 different CPR options: five contrasting algorithms (21.8%); three two-option models (13%); six vague technical or scientific suggestions (26%); and nine multiple choices of action (39.1%). Identified references contributed differently in the development of educationally polymorphic BLS options in each of the four categories (P < 0.0001) and were all brought about by variants of victims and rescuers. Participants of CPR seminars answered that in an emergency they could remember the hypothetical BLS model (90%, P = 0.007) rather than a current BLS algorithm for adults (42.2%) or children (36%).

CONCLUSIONS

Educational polymorphisms of BLS algorithms could build unpredictable barriers between rescuers and cardiac arrest victims and might seriously limit instructors' educational effectiveness. These findings might support an alternative trial hypothesis of a simple 'all-in-one algorithm' educational approach in future.

Trends in Out-of-Hospital Deaths Due to Coronary Heart Disease in Sweden (1991 to 2006)

Background—

Case fatality associated with a first coronary event is often underestimated when only those who survive to reach a hospital are considered. Few studies have examined long-term trends in case fatality associated with a major coronary event that occurs out of the hospital.

Methods and Results—

Record linkage documented all case subjects 35 to 84 years of age in Sweden during 1991 to 2006 with a first major coronary event (out-of-hospital coronary death or hospitalization for acute myocardial infarction). Of the 384 597 cases identified, 111 319 (28.9%) died out of the hospital, and another 36 552 (9.5%) died in the hospital or within 28 days of hospitalization. From 1991 to 2006, out-of hospital deaths as a proportion of all major coronary events declined from 30.5% to 25.6% (adjusted mean annual decrease 2.2%, 95% confidence interval 2.1% to 2.4%), however, with a larger decline in 28-day case fatality in hospitalized cases (adjusted mean annual decrease 5.8%, 95% confidence interval 5.5% to 6.0%). As a result of the faster decline in in-hospital deaths, the relative contribution of out-of-hospital deaths to overall case fatality increased, particularly among younger individuals (eg, among those 35 to 54 years of age, no more than 10.8% of all deaths occurred in hospitalized cases during 2003–2006). Although female sex (odds ratio 0.85, 95% confidence interval 0.83 to 0.87) and older age (odds ratio 0.972, 95% confidence interval 0.971 to 0.974 per year) were associated with lower risk for initial out-of-hospital death, each successive calendar year was associated with increased risk (odds ratio 1.041, 95% confidence interval 1.038 to 1.044).

Conclusions—

The great majority of all fatal coronary events occur outside the hospital, and this proportion is increasing, particularly among younger individuals.

Differences between out-of-hospital cardiac arrest in residential and public locations and implications for public-access defibrillation

BACKGROUND

The majority of out-of-hospital cardiac arrests (OHCAs) occur in residential locations, but knowledge about strategic placement of automated external defibrillators in residential areas is lacking. We examined whether residential OHCA areas suitable for placement of automated external defibrillators could be identified on the basis of demographic characteristics and characterized individuals with OHCA in residential locations.

METHODS AND RESULTS

We studied 4828 OHCAs in Copenhagen between 1994 and 2005. The incidence and characteristics of OHCA were examined in every 100 x 100-m (109.4 x 109.4-yd) residential area according to its underlying demographic characteristics. By combining > or =2 demographic characteristics, it was possible to identify 100 x 100-m (109.4 x 109.4-yd) areas with at least 1 arrest every 5.6 years (characterized by >300 persons per area and lowest income) to 1 arrest every 4.3 years (characterized by >300 persons per area, lowest income, low education, and highest age). These areas covered 9.0% and 0.8% of all residential OHCAs, respectively. Individuals with OHCA in residential locations differed from public ones in that the patients were older (70.6 versus 60.6 years; P<0.0001), the ambulance response interval was longer (6.0 versus 5.0 minutes; P<0.0001), arrests occurred more often at night (21.2% versus 11.2%; P<0.0001), the patients had ventricular fibrillation less often (12.8% versus 38.1%; P<0.0001), and the patients had a worse 30-day survival rate (3.2% versus 13.9%; P<0.0001).

CONCLUSIONS

On the basis of simple demographic characteristics of a city center, we could identify residential areas suitable for automated external defibrillator placement. Individuals with OHCA in residential locations were more likely to have characteristics associated with poor outcome compared with public arrests.

Advanced Cardiac Resuscitation Evaluation (ACRE): a randomised single-blind controlled trial of peer-led vs. expert-led advanced resuscitation training

Background

Advanced resuscitation skills training is an important and enjoyable part of medical training, but requires small group instruction to ensure active participation of all students. Increases in student numbers have made this increasingly difficult to achieve.

Methods

A single-blind randomised controlled trial of peer-led vs. expert-led resuscitation training was performed using a group of sixth-year medical students as peer instructors. The expert instructors were a senior and a middle grade doctor, and a nurse who is an Advanced Life Support (ALS) Instructor.

A power calculation showed that the trial would have a greater than 90% chance of rejecting the null hypothesis (that expert-led groups performed 20% better than peer-led groups) if that were the true situation. Secondary outcome measures were the proportion of High Pass grades in each groups and safety incidents.

The peer instructors designed and delivered their own course material. To ensure safety, the peer-led groups used modified defibrillators that could deliver only low-energy shocks.

Blinded assessment was conducted using an Objective Structured Clinical Examination (OSCE). The checklist items were based on International Liaison Committee on Resuscitation (ILCOR) guidelines using Ebel standard-setting methods that emphasised patient and staff safety and clinical effectiveness.

The results were analysed using Exact methods, chi-squared and t-test.

Results

A total of 132 students were randomised: 58 into the expert-led group, 74 into the peer-led group. 57/58 (98%) of students from the expert-led group achieved a Pass compared to 72/74 (97%) from the peer-led group: Exact statistics confirmed that it was very unlikely (p = 0.0001) that the expert-led group was 20% better than the peer-led group.

There were no safety incidents, and High Pass grades were achieved by 64 (49%) of students: 33/58 (57%) from the expert-led group, 31/74 (42%) from the peer-led group. Exact statistics showed that the difference of 15% meant that it was possible that the expert-led teaching was 20% better at generating students with High Passes.

Conclusions

The key elements of advanced cardiac resuscitation can be safely and effectively taught to medical students in small groups by peer-instructors who have undergone basic medical education training.

Effect of listening to Nellie the Elephant during CPR training on performance of chest compressions by lay people: randomised crossover trial

OBJECTIVES

To determine whether listening to music during cardiopulmonary resuscitation (CPR) training increases the proportion of lay people delivering chest compressions of 100 per minute.

DESIGN

Prospective randomised crossover trial.

SETTING

Large UK university.

PARTICIPANTS

130 volunteers (81 men) recruited on an opportunistic basis. Exclusion criteria included age under 18, trained health professionals, and cardiopulmonary resuscitation (CPR) training within the past three months.

INTERVENTIONS

Volunteers performed three sequences of one minute of continuous chest compressions on a skill meter resuscitation manikin accompanied by no music, repeated choruses of Nellie the Elephant (Nellie), and That's the Way (I like it) (TTW) according to a pre-randomised order.

MAIN OUTCOME MEASURES

Rate of chest compressions delivered (primary outcome), depth of compressions, proportion of incorrect compressions, and type of error.

RESULTS

Median (interquartile range) compression rates were 110 (93-119) with no music, 105 (98-107) with Nellie, and 109 (103-110) with TTW. There were significant differences within groups between Nellie v no music and Nellie v TTW (P<0.001) but not no music v TTW (P=0.055). A compression rate of between 95 and 105 was achieved with no music, Nellie, and TTW for 15/130 (12%), 42/130 (32%), and 12/130 (9%) attempts, respectively. Differences in proportions were significant for Nellie v no music and Nellie v TTW (P<0.001) but not for no music v TTW (P=0.55). Relative risk for a compression rate between 95 and 105 was 2.8 (95% confidence interval 1.66 to 4.80) for Nellie v no music, 0.8 (0.40 to 1.62) for TTW v no music, and 3.5 (1.97 to 6.33) for Nellie v TTW. The number needed to treat for listening to Nellie v no music was 5 (4 to 10)-that is, the number of cardiac arrests required during which lay responders listen to Nellie to facilitate one patient receiving compressions at the correct rate (v no music) would be between four and 10. A greater proportion of compressions were too shallow when participants listened to Nellie v no music (56% v 47%, P=0.022).

CONCLUSIONS

Listening to Nellie the Elephant significantly increased the proportion of lay people delivering compression rates at close to 100 per minute. Unfortunately it also increased the proportion of compressions delivered at an inadequate depth. As current resuscitation guidelines give equal emphasis to correct rate and depth, listening to Nellie the Elephant as a learning aid during CPR training should be discontinued. Further research is required to identify music that, when played during CPR training, increases the proportion of lay responders providing chest compressions at both the correct rate and depth.

Home use of automated external defibrillators for sudden cardiac arrest

BACKGROUND

The most common location of out-of-hospital sudden cardiac arrest is the home, a situation in which emergency medical services are challenged to provide timely care. Consequently, home use of an automated external defibrillator (AED) might offer an opportunity to improve survival for patients at risk.

METHODS

We randomly assigned 7001 patients with previous anterior-wall myocardial infarction who were not candidates for an implantable cardioverter-defibrillator to receive one of two responses to sudden cardiac arrest occurring at home: either the control response (calling emergency medical services and performing cardiopulmonary resuscitation [CPR]) or the use of an AED, followed by calling emergency medical services and performing CPR. The primary outcome was death from any cause.

RESULTS

The median age of the patients was 62 years; 17% were women. The median follow-up was 37.3 months. Overall, 450 patients died: 228 of 3506 patients (6.5%) in the control group and 222 of 3495 patients (6.4%) in the AED group (hazard ratio, 0.97; 95% confidence interval, 0.81 to 1.17; P=0.77). Mortality did not differ significantly in major prespecified subgroups. Only 160 deaths (35.6%) were considered to be from sudden cardiac arrest from tachyarrhythmia. Of these deaths, 117 occurred at home; 58 at-home events were witnessed. AEDs were used in 32 patients. Of these patients, 14 received an appropriate shock, and 4 survived to hospital discharge. There were no documented inappropriate shocks.

CONCLUSIONS

For survivors of anterior-wall myocardial infarction who were not candidates for implantation of a cardioverter-defibrillator, access to a home AED did not significantly improve overall survival, as compared with reliance on conventional resuscitation methods. (ClinicalTrials.gov number, NCT00047411 [ClinicalTrials.gov].).

Where patients with mild to moderate heart failure die: results from the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT)

BACKGROUND

Common locations of death in patients with congestive heart failure (CHF) are unknown. In the SCD-HeFT, mortality of patients with CHF was assessed after randomization to an implantable cardioverter/defibrillator (ICD), amiodarone, or placebo. The aim of this study was to evaluate the location of deaths in SCD-HeFT.

METHODS

Among SCD-HeFT patients whose location of death was identified, we used logistic regression to assess the relationship of randomized treatment arm and other baseline predictors with the location of death. Cause of death was adjudicated by a therapy-blinded events committee.

RESULTS

In SCD-HeFT, 666 (26%) of 2521 patients died. Of the 604 (91%) for whom location of death was known, 58% died in hospital and 29% died at home. Patients randomized to receive an ICD were less likely to die at home than patients randomized to placebo (P = .002). Fewer patients randomized to ICDs died; even fewer randomized to ICDs died at home. Age, sex, etiology of heart failure, left ventricular ejection fraction, and New York Heart Association functional class were not associated with location of death. Sudden cardiac death represented 52% of all out-of-hospital deaths but in hospital deaths exceeded out-of-hospital deaths.

CONCLUSION

Deaths in SCD-HeFT, a well-treated CHF population, were most often in hospital. ICDs were associated with lower total and sudden death rates at home and in hospital. Development of methods to identify which patients will not respond to optimal treatment, including an ICD, remain a challenge.

A Retrospective Study on the Initiation and Maintenance of Therapeutic Hypothermia after Cardiac Arrest. Are Simple Guidelines Easy to Follow?

Background:

Patients surviving a cardiac arrest often suffer debilitating neurological injury as a result of anoxic brain damage. Recent studies have demonstrated improved neurological outcome in cardiac arrest patients undergoing 12–24 hours of mild hypothermia. Reviewing the results from such studies the International Liaison Committee on Resuscitation has issued guidelines on hypothermia treatment in survivors of cardiac arrest.

Aims:

To determine the feasibility of a treatment protocol implementing the International Liaison Committee on Resuscitation guidelines on therapeutic hypothermia after cardiac arrest.

Methods:

A one-year retrospective analysis of cardiac arrest patients assigned to hypothermia treatment in an Intensive Care Unit.

Results:

Fifteen patients were assigned to hypothermia after cardiac arrest. No adverse side effects were observed as a result of the cooling procedure. The length of time to initiate and maintain cooling was the major deviation from the protocol.

Conclusion:

We recommend that hypothermia should be commenced as early as possible by using cold intravenous crystalloids. This is a safe procedure that can be done after the immediate resuscitation.

Reality of out of hospital cardiac arrest

The high mortality rates associated with out of hospital cardiac arrest, particularly those occurring in the home, stress the need for early treatment in the form of publicly accessible external defibrillators.