Rationale and design of: A Randomized tRial of Expedited transfer to a cardiac arrest center for non-ST elevation out-of-hospital cardiac arrest: The ARREST randomized controlled trial.

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) is a global public health issue. There is wide variation in both regional and inter-hospital survival rates from OHCA and overall survival remains poor at 7%. Regionalization of care into cardiac arrest centers (CAC) improves outcomes following cardiac arrest from ST elevation myocardial infarction (STEMI) through concentration of services and greater provider experience. The International Liaison Committee on Resuscitation (ILCOR) recommends delivery of all post-arrest patients to a CAC, but that randomized controlled trials are necessary in patients without ST elevation (STE). METHODS/DESIGN: Following completion of a pilot randomized trial to assess safety and feasibility of conducting a large-scale randomized controlled trial in patients following OHCA of presumed cardiac cause without STE, we present the rationale and design of A Randomized tRial of Expedited transfer to a cardiac arrest center for non-ST elevation OHCA (ARREST). In total 860 patients will be enrolled and randomized (1:1) to expedited transfer to CAC (24/7 access to interventional cardiology facilities, cooling and goal-directed therapies) or to the current standard of care, which comprises delivery to the nearest emergency department. Primary outcome is 30-day all-cause mortality and secondary outcomes are 30-day and 3-month neurological status and 3, 6 and 12-month mortality. Patients will be followed up for one year after enrolment. CONCLUSION: Post-arrest care is time-critical, requires a multi-disciplinary approach and may be more optimally delivered in centers with greater provider experience. This trial would help to demonstrate if regionalization of post-arrest care to CACs reduces mortality in patients without STE, which could dramatically reshape emergency care provision.

Intra-Aortic Balloon Pump Counterpulsation in the Post-Resuscitation Period is Associated with Improved Functional Outcomes in Patients Surviving an Out-of-Hospital Cardiac Arrest: Insights from a Dedicated Heart Attack Centre.

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.

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.

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.

High incidence of acute coronary occlusion in patients without protocol positive ST segment elevation referred to an open access primary angioplasty programme.

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.

The influence of biological age and sex on long-term outcome after percutaneous coronary intervention for ST-elevation myocardial infarction.

BACKGROUND: Outcome following ST-segment elevation myocardial infarction (STEMI) is thought to be worse in women than in age-matched men. We assessed whether such differences occur in the UK Pan-London dataset and if age, and particularly menopause, influences upon outcome. METHODS: We undertook an observational cohort study of 26,799 STEMI patients (20,633 men, 6,166 women) between 2005-2015 at 8 centres across London, UK. Patient details were recorded at the time of the procedure into local databases using the British Cardiac Intervention Society (BCIS) PCI dataset. Primary outcome was all-cause mortality at a median follow-up of 4.1 years (IQR: 2.2-5.8 years). RESULTS: Kaplan-Meier analysis demonstrated a higher mortality rate in women versus men (15.6% men vs. 25.3% women, P<0.0001). Univariate Cox analysis revealed that female sex was a predictor of all-cause mortality (HR: 1.69 95% CI: 1.59-1.82). However, after multivariate adjustment, this effect of female sex diminished (HR: 1.05 95% CI: 0.90-1.25). In a sub-group analysis, we compared the sexes separated by age into the ≤55 and the >55 year olds. Age-stratified Cox analysis revealed that female sex was a univariate predictor of all-cause mortality (HR: 1.60 95% CI: 1.25-2.05) in the ≤55 group and in the >55 group (HR: 1.38 95% CI: 1.28-1.47). However, after regression adjustment incorporating the propensity score into a proportional hazard model as a covariate, whilst female sex was not a significant predictor of all-cause mortality in the ≤55 group it was a predictor in the >55 group. Moreover, whilst age did not influence outcome in <55 group, this effect in the >55 group was correlated with age. CONCLUSIONS: Overall women have a worse all-cause mortality following primary PCI for STEMI compared to men. However, this effect was driven predominantly by women >55 years of age since after adjusting for co-morbidities the risk in younger women did not differ significantly from that in men. These observations support the view that as women advance past the menopausal years their risk of further events following revascularization increases substantially and we suggest that routine assessment of hormonal status may improve clinical decision-making and ultimately outcome for women post-PCI.

Sub30: Protocol for the Sub30 feasibility study of a pre-hospital Extracorporeal membrane oxygenation (ECMO) capable advanced resuscitation team at achieving blood flow within 30 ​min in patients with refractory out-of-hospital cardiac arrest.

BACKGROUND: Out-of-hospital cardiac arrest carries a poor prognosis with survival less than 10% in many patient cohorts. Survival is inversely associated with duration of resuscitation as external chest compressions do not provide sufficient blood flow to prevent irreversible organ damage during a prolonged resuscitation. Extracorporeal membrane oxygenation (ECMO) instituted during cardiac arrest can provide normal physiological blood flows and is termed Extracorporeal Cardio-Pulmonary Resuscitation (ECPR). ECPR may improve survival when used with in-hospital cardiac arrests. This possible survival benefit has not been replicated in trials of out-of-hospital cardiac arrests, possibly because of the additional time it takes to transport the patient to hospital and initiate ECPR. Pre-hospital ECPR may shorten the time between cardiac arrest and physiological blood flows, potentially improving survival. It may also mitigate some of the neurological injury that many survivors suffer. METHODS: Sub30 is a prospective six patient feasibility study. The primary aim is to test whether it is possible to institute ECPR within 30 ​min of collapse in adult patients with refractory out of hospital cardiac arrest (OHCA). The secondary aims are to gather preliminary data on clinical outcomes, resource utilisation, and health economics associated with rapid ECPR delivery in order to plan any subsequent clinical investigation or clinical service. On study days a dedicated fast-response vehicle with ECPR capability will be tasked to out-of-hospital cardiac arrests in an area of London served by Barts Heart Centre. If patients suffer a cardiac arrest refractory to standard advanced resuscitation and meet eligibility criteria, ECPR will be started in the pre-hospital environment. DISCUSSION: Delivering pre-hospital ECPR within 30 ​min of an out-of-hospital cardiac arrest presents significant ethical, clinical, governance and logistical challenges. Prior to conducting an efficacy study of ECPR the feasibility of timely and safe application must be demonstrated first. Extensive planning, multiple high-fidelity multiagency simulations and a unique collaboration between pre-hospital and in-hospital institutions will allow us to test the feasibility of this intervention in London. The study has been reviewed, refined and endorsed by the International ECMO Network (ECMONet). TRIAL REGISTRATION: Clinicaltrials. gov NCT03700125, prospectively registered October 9, 2018.

Complete Versus Culprit only Revascularisation in Patients with Cardiogenic Shock Complicating Acute Myocardial Infarction: Incidence and Outcomes from the London Heart Attack Group.

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.

Achieving routine sub 30 minute door-to-balloon times in a high volume 24/7 primary angioplasty center with autonomous ambulance diagnosis and immediate catheter laboratory access.

BACKGROUND: In primary angioplasty (primary percutaneous coronary intervention [PPCI]) for acute myocardial infarction, institutional logistical delays can increase door-to-balloon times, resulting in increased mortality. METHODS: We moved from a thrombolysis (TL) service to 24/7 PPCI for direct access and interhospital transfer in April 2004. Using autonomous ambulance diagnosis with open access to the myocardial infarction center catheter laboratory, we compared reperfusion times and clinical outcomes for the final 2 years of TL with the first 3 years of PPCI. RESULTS: Comparison was made between TL (2002-2004, n = 185) and PPCI (2004-2007, n = 704); all times are medians in minutes (interquartile range): for TL, symptom to needle 153 (85-225), call to needle 58 (49-73), first professional contact (FPC) to needle 47 (39-63), door to needle 18 (12-30) (mortality: 7.6% at 30 days, 9.2% at 1 year); for interhospital transfer PPCI (n = 227), symptom to balloon 226 (175-350), call to balloon 135 (117-188), FPC to balloon 121 (102-166), first door-to-balloon 100 (80-142) (mortality: 7.0% at 30 days, 12.3% at 1 year); for direct-access PPCI (n = 477), symptom to balloon 142 (101-238), call to balloon 79 (70-93), FPC to balloon 69 (59-82), door to balloon 20 (16-29) (mortality: 4.6% at 30 days, 8.6% at 1 year). There was no difference between direct-access PPCI and TL times for symptom to needle/balloon. Direct-access PPCI was significantly quicker for the group than in-hospital thrombolysis for door to needle/balloon times due to the lack of any long wait patients (P < .001). CONCLUSIONS: Interhospital transfer remains slow even with rapid institutional door-to-balloon times. With autonomous ambulance diagnosis and open access direct to the catheter laboratory, a median door-to-balloon time of <30 minutes day and night was achieved, and >95% of patients were reperfused within 1 hour.

Repeated adrenaline doses and survival from an out-of-hospital cardiac arrest.

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.

Contemporary trends in cardiogenic shock: Incidence, intra-aortic balloon pump utilisation and outcomes from the London Heart Attack Group.

BACKGROUND: Cardiogenic shock remains a major cause of morbidity and mortality in patients with ST-segment elevation myocardial infarction. We aimed to assess the current trends in cardiogenic shock management, looking specifically at the incidence, use of intra-aortic balloon pump therapy and outcomes in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention. METHODS AND RESULTS: We undertook an observational cohort study of 21,210 ST-segment elevation myocardial infarction patients treated between 2005-2015 at the eight Heart Attack Centres in London, UK. Patients' details were recorded at the time of the procedure into local databases using the British Cardiac Intervention Society percutaneous coronary intervention dataset. There were 1890 patients who presented with cardiogenic shock. The primary outcome was all-cause mortality at a median follow-up of 4.1 years (interquartile range: 2.2-5.8 years). Increasing rates of cardiogenic shock were seen over the course of the study with consistently high mortality rates of 45-70%. A total of 685 patients underwent intra-aortic balloon pump insertion during primary percutaneous coronary intervention for cardiogenic shock with decreasing rates over time. Those patients undergoing intra-aortic balloon pump therapy were younger, more likely to have poor left ventricular function and less likely to have had previous percutaneous coronary intervention compared to the control group. Procedural success rates were similar (86.0% vs 87.1%, p=0.292) although crude, in-hospital major adverse cardiac event rates were higher (43.8% vs 33.7%, p<0.0001) in patients undergoing intra-aortic balloon pump therapy. Kaplan-Meier analysis demonstrated significantly higher mortality rates in patients receiving intra-aortic balloon pump therapy (50.9% intra-aortic balloon pump vs 39.9% control, p<0.0001) during the follow-up period. After multivariate Cox analysis (hazard ratio 1.04, 95% confidence interval 0.62-1.89) and the use of propensity matching (hazard ratio: 1.29, 95% confidence interval: 0.68-1.45) intra-aortic balloon pump therapy was not associated with mortality. CONCLUSION: Cardiogenic shock treated by percutaneous coronary intervention is increasing in incidence and remains a condition associated with high mortality and limited treatment options. Intra-aortic balloon pump therapy was not associated with a long-term survival benefit in this cohort and may be associated with increased early morbidity.

Double sequential defibrillation therapy for out-of-hospital cardiac arrests: The London experience.

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.

A Randomised tRial of Expedited transfer to a cardiac arrest centre for non-ST elevation ventricular fibrillation out-of-hospital cardiac arrest: The ARREST pilot randomised trial.

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.

Inter-hospital transfer for primary angioplasty: delays are often due to diagnostic uncertainty rather than systems failure and universal time metrics may not be appropriate.

AIMS: We aimed to investigate why many patients with ST-segment elevation myocardial infarction (STEMI) initially present to non-primary percutaneous coronary intervention (PPCI) equipped hospitals in a region that offers a 24-hour direct access Heart Attack Centre. METHODS AND RESULTS: A retrospective stratified consecutive case analysis was performed for 180 inter-hospital transfer (IHT) and 201 direct access PPCI patients. IHT and direct patients had similar age (61±1.8 years vs. 62±1.9 years, p=0.42), gender (76% vs. 78% male, p=0.64), and cardiovascular risk profile (hypertension 53% vs. 46%, p=0.18; hypercholesterolaemia 32% vs. 25%, p=0.22; and smoking 38% vs. 35%, p=0.56), though there were more diabetic patients in the IHT group (15% vs. 8%, p<0.05). The IHT group had longer symptom-call times 104 mins (42 mins-195 mins) vs. 46 mins (19 mins-114 mins), p<0.0001), lower ECG ST-elevation scores (3.0 mm [1.0-6.0] vs. 5.0 mm [3.0-9.0], p<0.0001), and more protocol negative ECGs at presentation (31.6% vs. 9.4%, p<0.0001). Peak CK was similar for the two groups (628 IU/L [191-1,144] vs. 603 IU/L [280-1,238], p=0.61), as was in-hospital (1.7% vs. 1.5%, p=0.89) and 30-day mortality (2.8% vs. 2.0%, p=0.61). CONCLUSIONS: This study suggests that reperfusion delays in PPCI due to IHT are not always simply "system failures". IHT patients appear to be a different patient cohort in which symptoms and early ECG changes may be less clear. In many cases, initial triage to a non-PPCI centre may be justifiable due to diagnostic uncertainty, and guideline time metrics should be amended appropriately.

Predictors of survival and favorable functional outcomes after an out-of-hospital cardiac arrest in patients systematically brought to a dedicated heart attack center (from the Harefield Cardiac Arrest Study).

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. We analyzed (1) all-cause mortality and (2) functional status using a modified Rankin scale (mRS 0 to 6, where mRS0-3(+) = 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.

Manual Thrombus Aspiration Is Not Associated With Reduced Mortality in Patients Treated With Primary Percutaneous Coronary Intervention: An Observational Study of 10,929 Patients With ST-Segment Elevation Myocardial Infarction From the London Heart Attack Group.

OBJECTIVES: This study aimed to assess the impact of thrombus aspiration on mortality in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention (PCI). BACKGROUND: The clinical effect of routine intracoronary thrombus aspiration before primary PCI in patients with ST-segment elevation myocardial infarction is uncertain. METHODS: We undertook an observational cohort study of 10,929 ST-segment elevation myocardial infarction patients from January 2005 to July 2011 at 8 centers across London, United Kingdom. Patients' details were recorded at the time of the procedure into local databases using the British Cardiac Intervention Society PCI dataset. Primary outcome was all-cause mortality at a median follow-up of 3.0 years (interquartile range: 1.2 to 4.6 years). RESULTS: In our cohort, 3,572 patients (32.7%) underwent thrombus aspiration during primary PCI. Patients who had thrombus aspiration were younger, had lower rates of previous myocardial infarction but were more likely to have poor left ventricular function. Procedural success rates were higher (90.9% vs. 89.2%; p=0.005) and in-hospital major adverse cardiac event rates were lower (4.4% vs. 5.5%; p=0.012) in patients undergoing thrombus aspiration. However, Kaplan-Meier analysis demonstrated no significant difference in mortality rates between patients with and without thrombus aspiration (14.8% aspiration vs. 15.3% PCI only; p=0.737) during the follow-up period. After multivariate Cox analysis (hazard ratio [HR]: 0.89, 95% confidence interval [CI]: 0.65 to 1.23) and the addition of propensity matching (HR: 0.85 95% CI: 0.60 to 1.20) thrombus aspiration was still not associated with decreased mortality. CONCLUSIONS: In this cohort of nearly 11,000 patients, routine thrombus aspiration was not associated with a reduction in long-term mortality in patients undergoing primary PCI, although procedural success and in-hospital major adverse cardiac event rates were improved.

Time-trend analyses of bleeding and mortality after primary percutaneous coronary intervention during out of working hours versus in-working hours: an observational study of 11 466 patients.

BACKGROUND: Primary percutaneous coronary intervention (PPCI) is the treatment of choice for ST-segment-elevation myocardial infarction. Resources are limited during out of working hours (OWH). Whether PPCI outside working hours is associated with worse outcomes and whether outcomes have improved over time are unknown. METHODS AND RESULTS: We analyzed 11 466 patients undergoing PPCI between 2004 and 2011 at all 8 tertiary cardiac centers in London, United Kingdom. We defined working hours as 9 am to 5 pm (Monday to Friday). We analyzed in-hospital bleeding and all-cause mortality ≤3 years, comparing OWH versus in-working hours. A total of 7494 patients (65.3%) were treated during OWH. Multivariable analyses demonstrated that PPCI during OWH was not a predictor for bleeding (odds ratio, 1.47; 95% confidence interval [CI], 0.97-2.24; P=0.071) or 3-year mortality (hazard ratio, 1.11; 95% CI, 0.94-1.32; P=0.20). This was confirmed in propensity-matched analyses. Time-stratified analyses demonstrated that PPCI during OWH was a predictor for bleeding (odds ratio, 2.00; 95% CI, 1.06-3.80; P=0.034) and 3-year mortality during 2005 to 2008 (hazard ratio, 1.23; 95% CI, 1.00-1.50; P=0.050), but this association was lost during 2009 to 2011. During 2005 to 2008, transradial access was predominantly used during in-working hours and PPCI during OWH was predictive of reduced transradial access use (odds ratio, 0.83; 95% CI, 0.71-0.98; P=0.033), but this association was lost during 2009 to 2011. CONCLUSIONS: In this study of unselected patients with ST-segment-elevation myocardial infarction, PPCI during OWH versus in-working hours had comparable bleeding and mortality. Time-stratified analyses demonstrated a reduction in adjusted bleeding and mortality during OWH over time. This may reflect the improved service provision, but the increased adoption of transradial access during OWH may also be contributory.

Level of consciousness on admission to a Heart Attack Centre is a predictor of survival from out-of-hospital cardiac arrest.

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 1(st) April 2011 to 31(st) 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.

Survival of resuscitated cardiac arrest patients with ST-elevation myocardial infarction (STEMI) conveyed directly to a Heart Attack Centre by ambulance clinicians.

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.

Radial versus femoral access is associated with reduced complications and mortality in patients with non-ST-segment-elevation myocardial infarction: an observational cohort study of 10,095 patients.

BACKGROUND: Compared with transfemoral access, transradial access (TRA) for percutaneous coronary intervention is associated with reduced risk of bleeding and vascular complications. Studies suggest that TRA may reduce mortality in patients with ST-segment-elevation myocardial infarction. However, there are few data on the effect of TRA on mortality, specifically, in patients with non-ST-segment-elevation myocardial infarction. METHODS AND RESULTS: We analyzed 10 095 consecutive patients with non-ST-segment-elevation myocardial infarction treated with percutaneous coronary intervention between 2005 and 2011 in all 8 tertiary cardiac centers in London, United Kingdom. TRA was a predictor for reduced bleeding (odds ratio=0.21; 95% confidence interval [CI]: 0.08-0.57; P=0.002), access-site complications (odds ratio=0.47; 95% CI: 0.23-0.95; P=0.034), and 1-year mortality (hazard ratio [HR]=0.72; 95% CI: 0.54-0.94; P=0.017). Between 2005 and 2007, TRA did not appear to reduce mortality at 1 year (HR=0.81; 95% CI: 0.51-1.28; P=0.376), whereas between 2008 and 2011, TRA conferred survival benefit at 1 year (HR=0.65; 95% CI: 0.46-0.92; P=0.015). The mortality benefit with TRA at 1 year was not seen at the low-volume centers (HR=0.80; 95% CI: 0.47-1.38; P=0.428) but specifically seen in the high volume radial centers (HR=0.70; 95% CI: 0.51-0.97; P=0.031). In propensity-matched analyses, TRA remained a predictor for survival at 1 year (HR=0.60; 95% CI: 0.42-0.85; P=0.005). Instrumental variable analysis demonstrated that TRA conferred mortality benefit at 1-year with an absolute mortality reduction of 5.8% (P=0.039). CONCLUSIONS: In this analysis of patients with non-ST-segment-elevation myocardial infarction, TRA appears to be a predictor for survival. Furthermore, the evolving learning curve, experience, and expertise may be important factors contributing to the prognostic benefit conferred with TRA.