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Background: Despite advances in treatment for out-of-hospital cardiac arrest (OHCA), a subgroup of patients remain in refractory ventricular fibrillation (RVF) during resuscitation. Recent evidence suggests that double sequential defibrillation (DSD), where two shocks are delivered to the patient in quick succession, may provide an effective therapy for RVF. This study describes the characteristics and survival outcomes of OHCA patients treated by ambulance clinicians using a local DSD protocol in an attempt to resolve RVF.Methods: This is a retrospective, observational analysis of patients who received DSD by the London Ambulance Service from 1st July 2015 to 31st December 2016. A comparator group of patients who received more than six consecutive standard shocks (not DSD) for persistent VF was also identified. Outcomes included pre-hospital return of spontaneous circulation (ROSC), ROSC sustained to hospital, and survival to hospital discharge. DSD patients who survived to hospital discharge are reported in further detail.Results: During the 18-month study period, 45 patients were treated with DSD: a third obtained a pre-hospital ROSC and 7% survived to hospital discharge. We observed similar ROSC and survival rates amongst those who received standard defibrillation only.Conclusion: Our observational study did not find any clear benefit of DSD use by EMS in the treatment of RVF. However, we find that 3 patients, who were treated with DSD following unsuccessful single shocks, had their VF terminated. Prospective randomised clinical trials are urgently needed to investigate the potential value of DSD in the pre-hospital setting. [ABSTRACT FROM AUTHOR]

Background: Despite advances in technology, patients with Cardiogenic Shock (CS) presenting with ST-segment myocardial infarction (STEMI) still have a poor prognosis with high mortality rates. A large proportion of these patients have multi-vessel coronary artery disease, the treatment of which is still unclear. We aimed to assess the trends in management of CS patients with multi-vessel disease (MVD), particularly looking at the incidence and outcomes of complete revascularisation compared to culprit vessel only.Methods and Results: We undertook an observational cohort study of 21,210 STEMI patients treated between 2005 and 2015 at the 8 Heart Attack Centres in London, UK. Patients' details were recorded prospectively into local databases using the British Cardiac Intervention Society (BCIS) PCI dataset. 1058 patients presented with CS and MVD. Primary outcome was all-cause mortality. Patients were followed-up for a median of 4.1 years (IQR range: 2.2-5.8 years). 497 (47.0%) patients underwent complete revascularisation during primary PCI for CS with stable rates seen over time. These patients were more likely to be male, hypertensive and more likely to have poor LV function compared to the culprit vessel intervention group. Although crude, in hospital major adverse cardiac events (MACE) rates were similar (40.8% vs. 36.0%, p = 0.558) between the two groups. Kaplan-Meier analysis demonstrated no significant differences in mortality rates between the two groups (53.8% complete revascularisation vs. 46.8% culprit vessel intervention, p = 0.252) during the follow-up period. After multivariate cox analysis (HR 0.69 95% CI (0.44-0.98)) and the use of propensity matching (HR: 0.81 95% CI: 0.62-0.97) complete revascularisation was associated with reduced mortality. A number of co-variates were included in the model, including age, gender, diabetes, hypertension, hypercholesterolaemia, previous PCI, previous MI, chronic renal failure, Anterior infarct, number of treated vessels, pre-procedure TIMI flow, procedural success and GP IIb/IIIA use.Conclusion: In a contemporary observational series of CS patients with MVD, complete revascularisation appears to be associated with better outcomes compared to culprit vessel only intervention. This supports on-going clinical trials in this area and provides further evidence of the association of complete revascularisation in STEMI with good outcomes. [ABSTRACT FROM AUTHOR]

Background: Adrenaline is the primary drug of choice for resuscitation from out-of-hospital cardiac arrest (OHCA). Although adrenaline may increase the chance of achieving return of spontaneous circulation (ROSC), there is limited evidence that repeated doses of adrenaline improves overall survival, and increasing evidence of a detrimental effect on neurological function in survivors. This paper reports the relationship between repeated doses of adrenaline and survival in a cohort of patients attended by the London Ambulance Service in the United Kingdom.Methods: A retrospective review of OHCA treated by the London Ambulance Service over a one year period. Patients aged ≥18 years who received one or more doses of adrenaline (1 mg bolus) during resuscitation were included in the analyses. Outcomes described are survival to hospital discharge and survival to one year post-arrest.Results: Over the one year study period, 3151 patients received adrenaline during OHCA. A significant inverse relationship was found between increasing cumulative doses of adrenaline and survival both to hospital discharge and one year post-arrest. No patients survived after receiving more than ten adrenaline doses.Conclusion: Our study indicates that repeated doses of adrenaline are associated with decreasing odds of survival. There were no survivors amongst patients requiring more than 10 doses of adrenaline. [ABSTRACT FROM AUTHOR]

Background: Wide variation exists in inter-hospital survival from out-of-hospital cardiac arrest (OHCA). Regionalisation of care into cardiac arrest centres (CAC) may improve this. We report a pilot randomised trial of expedited transfer to a CAC following OHCA without ST-elevation. The objective was to assess the feasibility of performing a large-scale randomised controlled trial.Methods: Adult witnessed ventricular fibrillation OHCA of presumed cardiac cause were randomised 1:1 to either: (1) treatment: comprising expedited transfer to a CAC for goal-directed therapy including access to immediate reperfusion, or (2) control: comprising current standard of care involving delivery to the geographically closest hospital. The feasibility of randomisation, protocol adherence and data collection of the primary (30-day all-cause mortality) and secondary (cerebral performance category (CPC)) and in-hospital major cardiovascular and cerebrovascular events (MACCE) clinical outcome measures were assessed.Results: Between November 2014 and April 2016, 118 cases were screened, of which 63 patients (53%) met eligibility criteria and 40 of the 63 patients (63%) were randomised. There were no protocol deviations in the treatment arm. Data collection of primary and secondary outcomes was achieved in 83%. There was no difference in baseline characteristics between the groups: 30-day mortality (Intervention 9/18, 50% vs. Control 6/15, 40%; P=0.73), CPC 1/2 (Intervention: 9/18, 50% vs. Control 7/14, 50%; P>0.99) or MACCE (Intervention: 9/18, 50% vs. Control 6/15, 40%; P=0.73).Conclusions: These findings support the feasibility and acceptability of conducting a large-scale randomised controlled trial of expedited transfer to CAC following OHCA to address a remaining uncertainty in post-arrest care. [ABSTRACT FROM AUTHOR]

Background: Despite advances in cardiopulmonary resuscitation, functional survival remains low after out-of-hospital cardiac arrest (OOHCA). Intra-aortic balloon pump (IABP) therapy has recently been shown to augment cerebral blood flow. Whether IABP therapy in the post-resuscitation period improves functional outcomes is unknown.Methods: We analysed 174 consecutive patients who were successfully resuscitated from an OOHCA between 2011-2013 at Harefield Hospital, London. We analysed functional status at discharge and mortality up to one year.Results: A total of 55 patients (32.1%) received IABP therapy. Comparing those receiving IABP with those not receiving IABP, there was no difference in favourable functional status at discharge (49.1% vs. 57.1%, p=0.321); and mortality at one year (45.5% vs. 35.5%, p=0.164). Multivariable analyses identified IABP therapy as a strong independent predictor for favourable functional status at discharge (OR=7.51, 95% CI: 2.15-26.14, p=0.002) and this association was maintained in propensity-score adjusted analyses (OR=9.90, 95% CI: 2.11-46.33, p=0.004) and inverse probability treatment weighted analyses (OR=10.84, 95% CI: 2.75-42.69, p<0.001). However, IABP therapy was not an independent predictor for mortality at one year (HR=0.93, 95% CI: 0.52-1.65, p=0.810) and this was confirmed in both propensity-score adjusted and inverse probability treatment weighted analyses.Conclusions: In this observational analysis of patients surviving an OOHCA, the use of IABP therapy in the post-resuscitation period was associated with improved functional outcomes. This warrants further evaluation in larger prospective studies. [ABSTRACT FROM AUTHOR]

Despite advances in cardiopulmonary resuscitation (CPR), survival remains low after out-of-hospital cardiac arrest (OOHCA). Acute coronary ischemia is the predominating precipitant, and prompt delivery of patients to dedicated facilities may improve outcomes. Since 2011, all patients experiencing OOHCA in London,where a cardiac etiology is suspected, are systematically brought to heart attack centers (HACs). We determined the predictors for survival and favorable functional outcomes in this setting. We analyzed 174 consecutive patients experiencing OOHCA from 2011 to 2013 brought to Harefield Hospital—a designated HAC in London. Weanalyzed (1) all-cause mortality and (2) functional status using amodified Rankin scale (mRS 0 to 6, wheremRS0-3+ = favorable functional status). The overall survival rates were 66.7% (30 days) and 62.1% (1 year); and 54.5% had mRS0-3+ at discharge. Patients with mRS0-3+ had reduced mortality compared to mRS0-3-: 30 days (1.2% vs 72.2%, p <0.001) and 1 year (5.3% vs 77.2%, p <0.001). Multivariate analyses identified lower patient comorbidity, absence of cardiogenic shock, bystander CPR, ventricular tachycardia/ ventricullar fibrillation as initial rhythm, shorter duration of resuscitation, prehospital advanced airway, absence of adrenaline and inotrope use, and intra-aortic balloon pump use as predictors of mRS0-3+. Consistent predictors of increased mortality were the presence of cardiogenic shock, advanced airway use, increased duration of resuscitation, and absence of therapeutic hypothermia. A streamlined delivery of patients experiencing OOHCA to dedicated facilities is associated with improved functional status and survival. Our study supports the standardization of care for such patients with the widespread adoption of HACs. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: The relationship between the neurological status at the time of handover from the ambulance crew to a Heart Attack Centre (HAC) in patients who have achieved return of spontaneous circulation (ROSC) and subsequent outcome, in the context of current treatment standards, is unknown. Methods: A retrospective review of all patients treated by London Ambulance Service (LAS) from 1st April 2011 to 31st March 2013 admitted to a HAC in Greater London was undertaken. Neurological status (A - alert; V - responding to voice; P - responding to pain; U - unresponsive) recorded by the ambulance crew on handover was compared with length of hospital stay and survival to hospital discharge. Results: A total of 475 sequential adult cardiac arrests of presumed cardiac origin, achieving ROSC on admission to a HAC were identified. Outcome data was available for 452 patients, of whom 253 (56.0%) survived to discharge. Level of consciousness on admission to the HAC was a predictor of duration of hospital stay (P <0.0001) and survival to hospital discharge (P <0.0001). Of those presenting with a shockable rhythm, 32.3% (120/371) were ‘A’ or ‘V’, compared with 9.1% (9/99) of those with non-shockable rhythms (P <0.001). Conclusion: Patients with shockable rhythms achieving ROSC are more likely to be conscious (A or V) compared with those with non-shockable rhythms. Most patients who are conscious on admission to the HAC will survive, compared with approximately half of those who are unconscious (P or U), suggesting that critical care is generally appropriate at all levels of consciousness if ROSC has been achieved. [Copyright &y& Elsevier]

BACKGROUND: Ventricular fibrillation (VF) waveform properties have been shown to predict defibrillation success and outcomes among patients treated with immediate defibrillation. We postulated that a waveform analysis algorithm could be used to identify VF unlikely to respond to immediate defibrillation, allowing selective initial treatment with cardiopulmonary resuscitation in an effort to improve overall survival. METHODS AND RESULTS: In a multicenter, double-blind, randomized study, out-of-hospital cardiac arrest patients in 2 urban emergency medical services systems were treated with automated external defibrillators using either a VF waveform analysis algorithm or the standard shock-first protocol. The VF waveform analysis used a predefined threshold value below which return of spontaneous circulation (ROSC) was unlikely with immediate defibrillation, allowing selective treatment with a 2-minute interval of cardiopulmonary resuscitation before initial defibrillation. The primary end point was survival to hospital discharge. Secondary end points included ROSC, sustained ROSC, and survival to hospital admission. Of 6738 patients enrolled, 987 patients with VF of primary cardiac origin were included in the primary analysis. No immediate or long-term survival benefit was noted for either treatment algorithm (ROSC, 42.5% versus 41.2%, P=0.70; sustained ROSC, 32.4% versus 33.4%, P=0.79; survival to admission, 34.1% versus 36.4%, P=0.46; survival to hospital discharge, 15.6% versus 17.2%, P=0.55, respectively). CONCLUSIONS: Use of a waveform analysis algorithm to guide the initial treatment of out-of-hospital cardiac arrest patients presenting in VF did not improve overall survival compared with a standard shock-first protocol. Further study is recommended to examine the role of waveform analysis for the guided management of VF. [ABSTRACT FROM AUTHOR]

Background--Ventricular fibrillation (VF) waveform properties have been shown to predict defibrillation success and outcomes among patients treated with immediate defibrillation. We postulated that a waveform analysis algorithm could be used to identify VF unlikely to respond to immediate defibrillation, allowing selective initial treatment with cardiopulmonary resuscitation in an effort to improve overall survival. Methods and Results--In a multicenter, double-blind, randomized study, out-of-hospital cardiac arrest patients in 2 urban emergency medical services systems were treated with automated external defibrillators using either a VF waveform analysis algorithm or the standard shock-first protocol. The VF waveform analysis used a predefined threshold value below which return of spontaneous circulation (ROSC) was unlikely with immediate defibrillation, allowing selective treatment with a 2-minute interval of cardiopulmonary resuscitation before initial defibrillation. The primary end point was survival to hospital discharge. Secondary end points included ROSC, sustained ROSC, and survival to hospital admission. Of 6738 patients enrolled, 987 patients with VF of primary cardiac origin were included in the primary analysis. No immediate or long-term survival benefit was noted for either treatment algorithm (ROSC, 42.5% versus 41.2%, P=0.70; sustained ROSC, 32.4% versus 33.4%, P=0.79; survival to admission, 34.1% versus 36.4%, P=0.46; survival to hospital discharge, 15.6% versus 17.2%, P=0.55, respectively). Conclusions--Use of a waveform analysis algorithm to guide the initial treatment of out-of-hospital cardiac arrest patients presenting in VF did not improve overall survival compared with a standard shock-first protocol. Further study is recommended to examine the role of waveform analysis for the guided management of VF. Clinical Trial Registration--URL: http://www.clinicaltrials.gov. Unique identifier: NCT00535106. [ABSTRACT FROM AUTHOR]

Abstract: Objective: This study reports improvements in survival from out-of-hospital cardiac arrest in London over a five year period from 2007 to 2012 and explores the potential reasons for the very striking increases observed. Methods: Data from the London Ambulance Service's cardiac arrest registry from 2007 to 2012 were analysed retrospectively for all patients who met the Utstein comparator group criteria (an arrest of a presumed cardiac cause that was bystander witnessed with an initial rhythm of VF/VT). Results: We observed an increase in survival from out-of-hospital cardiac arrest during the five year period, with incremental improvements each year from 12% to 32% for the Utstein comparator group of patients. Conclusion: We suggest that a range of important changes made to pre-hospital cardiac care in London over the last five years have contributed to the observed increase in survival over the study period. In addition we advocate a range of further initiatives to continue improving survival from out-of-hospital cardiac arrest. [Copyright &y& Elsevier]

Background Primary percutaneous coronary intervention (PPCI) programmes vary in admission criteria from open referral to acceptance of electrocardiogram (ECG) protocol positive patients only. Rigid criteria may result in some patients with acutely occluded coronary arteries not receiving timely reperfusion therapy. Objective To compare the prevalence of acute coronary occlusion and, in these cases, single time point biomarker estimates of myocardial infarct size between patients presenting with protocol positive ECG changes and those presenting with less diagnostic changes in the primary angioplasty cohort of an open access PPCI programme. Methods We retrospectively performed a single centre cross sectional analysis of consecutive patients receiving PPCI between January and August 2008. Cases were categorised according to presenting ECG--group A: protocol positive (ST segment elevation/left bundle branch block/posterior ST elevation myocardial infarction), group B: ST segment depression or T-wave inversion, or group C: minor ECG changes. Clinical characteristics, coronary flow grades and 12 h postprocedure troponin-I levels were reviewed. Results During the study period there were 513 activations of the PPCI service, of which 390 underwent immediate angiography and 308 underwent PPCI. Of those undergoing PPCI, 221 (72%) were in group A, 41 (13%) in group B and 46 (15%) in group C. Prevalence of coronary occlusion was 75% in group A compared with 73% in group B and 63% in group C. Median 12 h postintervention troponin-I (25th-75th percentile) for those with coronary occlusion was significantly higher in group A patients; 28.9 µg/l (13.2-58.5) versus 18.1 µg/l (6.7-32.4) for group B (p=0.03); and 15.5 µg/l (3.8-22.0) for group C (p<0.001), suggesting greater infarct size in group A. Conclusions A number of patients referred to an open access PPCI programme have protocol negative ECGs but myocardial infarction and acute coronary artery occlusion amenable to angioplasty. [ABSTRACT FROM AUTHOR]

Abstract: Background: The aim of this study was to describe the frequency and characteristics of cardiac arrest patients of 35 years and under attended by the London Ambulance Service NHS Trust between April 2003 and March 2007. Few large studies have described the occurrence, mechanism, resuscitation viability and outcome of this substantial subset of the cardiac arrest population. By documenting over 3000 cardiac arrests in young people we sought to improve understanding, awareness and ultimately survival of a condition notorious for high mortality rates. Methods and results: Data were analysed for 3084 young cardiac arrest patients and reported retrospectively. Patients were categorised by age, gender, aetiology and whether or not resuscitation attempts were made. Over 75% of patients were aged 18–35 years. There were significantly more males in this age group (p <0.001) compared to those aged 17 years or less. The most common cause of cardiac arrest was an underlying cardiac cause (44.9%). Overdoses, hanging and other suicides were found to be major causes of cardiac arrests of non-cardiac origin in young adult males. Sudden Infant Death Syndrome (SIDS) was the most common known cause of death in infants aged less than 1 year. This age group received bystander CPR most often. 5.6% of young cardiac arrest patients who were taken to hospital survived to hospital discharge. Conclusions: Mortality in young cardiac arrest patients remains high. Focus should be placed on tackling social and psychological causes of cardiac arrest as well as cardiac aetiologies. [Copyright &y& Elsevier]

Abstract: Objective: This study reports survival outcomes for patients resuscitated from out-of-hospital cardiac arrest (OHCA) subsequent to ST-elevation myocardial infarction (STEMI), and who were conveyed directly by ambulance clinicians to a specialist Heart Attack Centre for expert cardiology assessment, angiography and possible percutaneous coronary intervention (PCI). Methods: This is a retrospective descriptive review of data sourced from the London Ambulance Service's OHCA registry over a one-year period. Results: We observed excellent survival rates for our cohort of patients with 66% of patients surviving to be discharged from hospital, the majority of whom were still alive after one year. Those who survived tended to be younger, to have had a witnessed arrest in a public place with an initial cardiac rhythm of VF/VT, and to have been transported to the specialist centre more quickly than those who did not. Conclusion: A system allowing ambulance clinicians to autonomously convey OHCA STEMI patients who achieve a return of spontaneous circulation directly to a Heart Attack Centre is highly effective and yields excellent survival outcomes. [Copyright &y& Elsevier]

A response from the authors of the article "Waveform Analysis-Guided Treatment Versus a Standard Shock-First Protocol for the Treatment of Out-of-Hospital Cardiac Arrest Presenting in Ventricular Fibrillation: Results of an International Randomized, Controlled Trial" is presented.