Early versus Later Rhythm Analysis in Patients with Out-of-Hospital Cardiac Arrest

Background In a departure from the previous strategy of immediate defibrillation, the 2005 resuscitation guidelines from the American Heart Association–International Liaison Committee on Resuscitation suggested that emergency medical service (EMS) personnel could provide 2 minutes of cardiopulmonary resuscitation (CPR) before the first analysis of cardiac rhythm. We compared the strategy of a brief period of CPR with early analysis of rhythm with the strategy of a longer period of CPR with delayed analysis of rhythm. Methods We conducted a cluster-randomized trial involving adults with out-of-hospital cardiac arrest at 10 Resuscitation Outcomes Consortium sites in the United States and Canada. Patients in the early-analysis group were assigned to receive 30 to 60 seconds of EMS-administered CPR and those in the later-analysis group were assigned to receive 180 seconds of CPR, before the initial electrocardiographic analysis. The primary outcome was survival to hospital discharge with satisfactory functional status (a modified Rankin scale score of ≤3, on a scale of 0 to 6, with higher scores indicating greater disability). Results We included 9933 patients, of whom 5290 were assigned to early analysis of cardiac rhythm and 4643 to later analysis. A total of 273 patients (5.9%) in the later-analysis group and 310 patients (5.9%) in the early-analysis group met the criteria for the primary outcome, with a cluster-adjusted difference of −0.2 percentage points (95% confidence interval, −1.1 to 0.7; P=0.59). Analyses of the data with adjustment for confounding factors, as well as subgroup analyses, also showed no survival benefit for either study group. Conclusions Among patients who had an out-of-hospital cardiac arrest, we found no difference in the outcomes with a brief period, as compared with a longer period, of EMS-administered CPR before the first analysis of cardiac rhythm. (Funded by the National Heart, Lung, and Blood Institute and others; ROC PRIMED ClinicalTrials.gov number, NCT00394706.

Evaluation of pre-hospital administration of adrenaline (epinephrine) by emergency medical services for patients with out of hospital cardiac arrest in Japan: controlled propensity matched retrospective cohort study

Objectives To evaluate the effectiveness of pre-hospital adrenaline (epinephrine) administered by emergency medical services to patients with out of hospital cardiac arrest.Design Controlled propensity matched retrospective cohort study, in which pairs of patients with or without (control) adrenaline were created with a sequential risk set matching based on time dependent propensity score.Setting Japan’s nationwide registry database of patients with out of hospital cardiac arrest registered between January 2007 and December 2010.Participants Among patients aged 15-94 with out of hospital cardiac arrest witnessed by a bystander, we created 1990 pairs of patients with and without adrenaline with an initial rhythm of ventricular fibrillation or pulseless ventricular tachycardia (VF/VT) and 9058 pairs among those with non-VF/VT.Main outcome measures Overall and neurologically intact survival at one month or at discharge, whichever was earlier.Results After propensity matching, pre-hospital administration of adrenaline by emergency medical services was associated with a higher proportion of overall survival (17.0% v 13.4%; unadjusted odds ratio 1.34, 95% confidence interval 1.12 to 1.60) but not with neurologically intact survival (6.6% v 6.6%; 1.01, 0.78 to 1.30) among those with VF/VT; and higher proportions of overall survival (4.0% v 2.4%; odds ratio 1.72, 1.45 to 2.04) and neurologically intact survival (0.7% v 0.4%; 1.57, 1.04 to 2.37) among those with non-VF/VT.Conclusions Pre-hospital administration of adrenaline by emergency medical services improves the long term outcome in patients with out of hospital cardiac arrest, although the absolute increase of neurologically intact survival was minimal

Implantable cardioverter defibrillators for the treatment of arrhythmias and cardiac resynchronisation therapy for the treatment of heart failure: systematic review and economic evaluation

Background This assessment updates and expands on two previous technology assessments that evaluated implantable cardioverter defibrillators (ICDs) for arrhythmias and cardiac resynchronisation therapy (CRT) for heart failure (HF). Objectives To assess the clinical effectiveness and cost-effectiveness of ICDs in addition to optimal pharmacological therapy (OPT) for people at increased risk of sudden cardiac death (SCD) as a result of ventricular arrhythmias despite receiving OPT; to assess CRT with or without a defibrillator (CRT-D or CRT-P) in addition to OPT for people with HF as a result of left ventricular systolic dysfunction (LVSD) and cardiac dyssynchrony despite receiving OPT; and to assess CRT-D in addition to OPT for people with both conditions. Data sources Electronic resources including MEDLINE, EMBASE and The Cochrane Library were searched from inception to November 2012. Additional studies were sought from reference lists, clinical experts and manufacturers’ submissions to the National Institute for Health and Care Excellence. Review methods Inclusion criteria were applied by two reviewers independently. Data extraction and quality assessment were undertaken by one reviewer and checked by a second. Data were synthesised through narrative review and meta-analyses. For the three populations above, randomised controlled trials (RCTs) comparing (1) ICD with standard therapy, (2) CRT-P or CRT-D with each other or with OPT and (3) CRT-D with OPT, CRT-P or ICD were eligible. Outcomes included mortality, adverse events and quality of life. A previously developed Markov model was adapted to estimate the cost-effectiveness of OPT, ICDs, CRT-P and CRT-D in the three populations by simulating disease progression calculated at 4-weekly cycles over a lifetime horizon. Results A total of 4556 references were identified, of which 26 RCTs were included in the review: 13 compared ICD with medical therapy, four compared CRT-P/CRT-D with OPT and nine compared CRT-D with ICD. ICDs reduced all-cause mortality in people at increased risk of SCD, defined in trials as those with previous ventricular arrhythmias/cardiac arrest, myocardial infarction (MI) > 3 weeks previously, non-ischaemic cardiomyopathy (depending on data included) or ischaemic/non-ischaemic HF and left ventricular ejection fraction ≤ 35%. There was no benefit in people scheduled for coronary artery bypass graft. A reduction in SCD but not all-cause mortality was found in people with recent MI. Incremental cost-effectiveness ratios (ICERs) ranged from £14,231 per quality-adjusted life-year (QALY) to £29,756 per QALY for the scenarios modelled. CRT-P and CRT-D reduced mortality and HF hospitalisations, and improved other outcomes, in people with HF as a result of LVSD and cardiac dyssynchrony when compared with OPT. The rate of SCD was lower with CRT-D than with CRT-P but other outcomes were similar. CRT-P and CRT-D compared with OPT produced ICERs of £27,584 per QALY and £27,899 per QALY respectively. The ICER for CRT-D compared with CRT-P was £28,420 per QALY. In people with both conditions, CRT-D reduced the risk of all-cause mortality and HF hospitalisation, and improved other outcomes, compared with ICDs. Complications were more common with CRT-D. Initial management with OPT alone was most cost-effective (ICER £2824 per QALY compared with ICD) when health-related quality of life was kept constant over time. Costs and QALYs for CRT-D and CRT-P were similar. The ICER for CRT-D compared with ICD was £27,195 per QALY and that for CRT-D compared with OPT was £35,193 per QALY. Limitations Limitations of the model include the structural assumptions made about disease progression and treatment provision, the extrapolation of trial survival estimates over time and the assumptions made around parameter values when evidence was not available for specific patient groups. Conclusions In people at risk of SCD as a result of ventricular arrhythmias and in those with HF as a result of LVSD and cardiac dyssynchrony, the interventions modelled produced ICERs of < £30,000 per QALY gained. In people with both conditions, the ICER for CRT-D compared with ICD, but not CRT-D compared with OPT, was < £30,000 per QALY, and the costs and QALYs for CRT-D and CRT-P were similar. A RCT comparing CRT-D and CRT-P in people with HF as a result of LVSD and cardiac dyssynchrony is required, for both those with and those without an ICD indication. A RCT is also needed into the benefits of ICD in non-ischaemic cardiomyopathy in the absence of dyssynchrony. Study registration This study is registered as PROSPERO number CRD42012002062. Funding The National Institute for Health Research Health Technology Assessment programme

Management of Refractory Ventricular Fibrillation with Double Sequential Defibrillation

Patients experiencing cardiac arrest are treated according to ACLS protocols, however current protocols lack recommendations for the treatment of refractory Ventricular Fibrillation which persists after more than 3 cycles of CPR and defibrillation. One potential intervention for these cases that is being researched is the use of simultaneous or sequential activation of two defibrillators. This literature review analyzed the results of several studies to determine if double sequential defibrillation (DSD) is a viable treatment to achieve return of spontaneous circulation (ROSC) and improved patient survival. The results of the studies were mixed with some showing positive outcomes, and others showing no significant difference. Although more research is needed, providers should keep this treatment in mind when there are no other options available

Project Retrosight. Understanding the returns from cardiovascular and stroke research: Case Studies

Copyright @ 2011 RAND Europe. All rights reserved. The full text article is available via the link below.This project explores the impacts arising from cardiovascular and stroke research funded 15-20 years ago and attempts to draw out aspects of the research, researcher or environment that are associated with high or low impact. The project is a case study-based review of 29 cardiovascular and stroke research grants, funded in Australia, Canada and UK between 1989 and 1993. The case studies focused on the individual grants but considered the development of the investigators and ideas involved in the research projects from initiation to the present day. Grants were selected through a stratified random selection approach that aimed to include both high- and low-impact grants. The key messages are as follows: 1) The cases reveal that a large and diverse range of impacts arose from the 29 grants studied. 2) There are variations between the impacts derived from basic biomedical and clinical research. 3) There is no correlation between knowledge production and wider impacts 4) The majority of economic impacts identified come from a minority of projects. 5) We identified factors that appear to be associated with high and low impact. This report presents the key observations of the study and an overview of the methods involved. It has been written for funders of biomedical and health research and health services, health researchers, and policy makers in those fields. It will also be of interest to those involved in research and impact evaluation.This study was initiated with internal funding from RAND Europe and HERG, with continuing funding from the UK National Institute for Health Research, the Canadian Institutes of Health Research, the Heart and Stroke Foundation of Canada and the National Heart Foundation of Australia. The UK Stroke Association and the British Heart Foundation provided support in kind through access to their archives

A superfamily of small potassium channel subunits: form and function of the MinK-related peptides (MiRPs).

MinK and MinK-related peptide I (MiRPI) are integral membrane peptides with a single transmembrane span. These peptides are active only when co-assembled with pore-forming K+ channel subunits and yet their role in normal ion channel behaviour is obligatory. In the resultant complex the peptides establish key functional attributes: gating kinetics, single-channel conductance, ion selectivity, regulation and pharmacology. Co-assembly is required to reconstitute channel behaviours like those observed in native cells. Thus, MinK/KvLQT1 and MiRPI/HERG complexes reproduce the cardiac currents called I(Ks) and I(Kr), respectively. Inherited mutations in KCNEI (encoding MinK) and KCNE2(encoding MiRPI) are associated with lethal cardiac arrhythmias. How these mutations change ion channel behaviour has shed light on peptide structure and function. Recently, KCNE3 and KCNE4 were isolated. In this review, we consider what is known and what remains controversial about this emerging superfamily

Case Report: Refractory Ventricular Fibrillation Resolved by Double External Defibrillation and Beta Blockade

Introduction: The mortality rate for refractory ventricular fibrillation (RVF) can be up to 97%. There is no widely accepted treatment plan for this stage of ventricular fibrillation besides the standard combination of defibrillation, amiodarone, and epinephrine. One novel approach that has been documented in a select few cases since 2015 is the combination of double external defibrillation (DED) and esmolol-induced beta blockade. Case Report: We report the case of a 65-year-old man who presented with RVF after collapsing at work. Upon the simultaneous administration of two defibrillators with a combined shock of 400 joules and 35 milligrams of the beta blocker esmolol, the patient regained pulse and began blinking. He was discharged from the hospital after seven days and walked out of the clinic.&nbsp; Conclusion: This case continues the trend of several case reports since 2015 that have featured beta blockade and double external defibrillation as a viable solution to refractory ventricular fibrillation. Since there is limited quantifiable data on the efficacy of this treatment, future studies should aim to evaluate whether the combination of DED and beta blockade has the potential to become the new standard in treating RVF over a broader patient population