Mark Whitbread

Increases in survival from out-of-hospital cardiac arrest: A five year study

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 Services 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.

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 Services 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.

Culprit Vessel Versus Multivessel Intervention at the Time of Primary Percutaneous Coronary Intervention in Patients With ST-Segment–Elevation Myocardial Infarction and Multivessel Disease: Real-World Analysis of 3984 Patients in London

Background—It is estimated that up to two thirds of patients presenting with ST-segment–elevation myocardial infarction have multivessel disease. The optimal strategy for treating nonculprit disease is currently under debate. This study provides a real-world analysis comparing a strategy of culprit-vessel intervention (CVI) versus multivessel intervention at the time of primary percutaneous coronary intervention in patients with ST-segment–elevation myocardial infarction. Methods and Results—We compared CVI versus multivessel intervention in 3984 patients with multivessel disease undergoing primary percutaneous coronary intervention between 2004 and 2011 at all 8 tertiary cardiac centers in London. Multivariable-adjusted models were built to determine independent predictors for in-hospital major adverse cardiovascular events (MACEs) and all-cause mortality at 1 year. To reduce confounding and bias, propensity score methods were used. CVI was associated with reduced in-hospital MACE (4.6% versus 7.2%; P=0.010) and mortality at 1 year (7.4% versus 10.1%; P=0.031). CVI was an independent predictor for reduced in-hospital MACE (odds ratio, 0.49; 95% confidence interval [CI], 0.32–0.75; P<0.001) and survival at 1 year (hazard ratio, 0.65; 95% CI, 0.47–0.91; P=0.011) in the complete cohort; and in 2821 patients in propensity-matched cohort (in-hospital MACE: odds ratio, 0.49; 95% CI, 0.32–0.76; P=0.002; and 1-year survival: hazard ratio, 0.64; 95% CI, 0.45–0.90; P=0.010). Inverse probability treatment weighted analyses also confirmed CVI as an independent predictor for reduced in-hospital MACE (odds ratio, 0.38; 95% CI, 0.15–0.96; P=0.040) and survival at 1 year (hazard ratio, 0.44; 95% CI, 0.21–0.93; P=0.033). Conclusions—In this observational analysis of patients with ST-segment–elevation myocardial infarction undergoing primary percutaneous coronary intervention, CVI was associated with increased survival at 1 year. Acknowledging the limitations with observational analyses, our findings support current recommended practice guidelines.

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. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00535106.

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.

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.

Resuscitation training for medical students

This paper describes the systematic training of undergraduate medical students in resuscitation skills, aimed at overcoming the well known deficiencies in the resuscitation skills of junior doctors. This training can be integrated with the medical curriculum, but takes a considerable commitment in teaching time. To give each of our 240 medical students 36 h of resuscitation training, including an advanced life support (ALS) course for all students, 2442 h of teachers time is required each year. It is important that teaching is continued on the wards as part of the training of pre-registration house officers. The amount of teaching time required justifies the appointment of Medical School Resuscitation Officers, dedicated to teaching medical students, dental students and pre-registration house officers.

Out-of-hours primary percutaneous coronary intervention for ST-elevation myocardial infarction is not associated with excess mortality: a study of 3347 patients treated in an integrated cardiac network

Objectives Timely delivery of primary percutaneous coronary intervention (PPCI) is the treatment of choice for ST-segment elevation myocardial infarction (STEMI). Optimum delivery of PPCI requires an integrated network of hospitals, following a multidisciplinary, consultant-led, protocol-driven approach. We investigated whether such a strategy was effective in providing equally effective in-hospital and long-term outcomes for STEMI patients treated by PPCI within normal working hours compared with those treated out-of-hours (OOHs). Design Observational study. Setting Large PPCI centre in London. Participants 3347 STEMI patients were treated with PPCI between 2004 and 2012. The follow-up median was 3.3 years (IQR: 1.2–4.6 years). Primary and secondary outcome measures The primary endpoint was long-term major adverse cardiac events (MACE) with all-cause mortality a secondary endpoint. Results Of the 3347 STEMI patients, 1299 patients (38.8%) underwent PPCI during a weekday between 08:00 and 18:00 (routine-hours group) and 2048 (61.2%) underwent PPCI on a weekday between 18:00 and 08:00 or a weekend (OOHs group). There were no differences in baseline characteristics between the two groups with comparable door-to-balloon times (in-hours (IHs) 67.8 min vs OOHs 69.6 min, p=0.709), call-to-balloon times (IHs 116.63 vs OOHs 127.15 min, p=0.60) and procedural success. In hospital mortality rates were comparable between the two groups (IHs 3.6% vs OOHs 3.2%) with timing of presentation not predictive of outcome (HR 1.25 (95% CI 0.74 to 2.11). Over the follow-up period there were no significant differences in rates of mortality (IHs 7.4% vs OFHs 7.2%, p=0.442) or MACE (IHs 15.4% vs OFHs 14.1%, p=0.192) between the two groups. After adjustment for confounding variables using multivariate analysis, timing of presentation was not an independent predictor of mortality (HR 1.04 95% CI 0.78 to 1.39). Conclusions This large registry study demonstrates that the delivery of PPCI with a multidisciplinary, consultant-led, protocol-driven approach provides safe and effective treatment for patients regardless of the time of presentation.

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.

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.