Observations From the Heart

Improving the UK’s performance on survival after cardiac arrest

BMJ 2013; 347 doi: http://dx.doi.org/10.1136/bmj.f4800 (Published 31 July 2013) Cite this as: BMJ 2013;347:f4800
  1. Aseem Malhotra, interventional cardiology specialist registrar,
  2. Roby Rakhit, consultant cardiologist and clinical director
  1. 1Royal Free Hospital, London
  1. aseem_malhotra{at}hotmail.com, roby.rakhit{at}nhs.net

The evidence base is strong for changing the way we treat people who have had a cardiac arrest outside hospital

On 17 March 2012 the premier league footballer Fabrice Muamba, who played for Bolton, had a cardiac arrest during an FA cup clash against Tottenham Hotspur at White Hart Lane, in north London. Given the estimated resuscitation time of over an hour and his discharge from a London hospital four weeks later with no neurological deficit, it is not surprising that many described his recovery as “miraculous.” Current UK survival rates among people who have a cardiac arrest outside hospital remain extremely poor, varying from 2% to 12%.1 Every year an estimated 60 000 out of hospital cardiac arrests occur in the UK, 30 000 of which are treated by emergency medical services.2 3

Optimal use of the “chain of survival” (the sequence of interdependent treatment actions for cardiac arrest), as occurred with Muamba, is what makes the difference between life and death. Predictors of survival include time to the first emergency response; whether the arrest is witnessed; effective bystander cardiopulmonary resuscitation (CPR); initial shockable rhythm; early defibrillation; and pre-hospital return of spontaneous circulation.4 Although the links within this chain of survival are paramount, early defibrillation is crucial, with a 10% decrease in survival with every minute of delay.5 CPR, when combined with effective defibrillation for shockable rhythms and appropriate post-resuscitation care, results in survival rates that exceed 50%.6 Lessons can be learnt from Seattle, which this year reported the world’s highest rate of survival, at 56%, from witnessed cardiac arrests of cardiac origin with a shockable rhythm (also known as Utstein survival).7 Such a laudable statistic can be attributed to a 30 year history in Seattle and the surrounding King County of CPR being taught in physical education lessons at all schools; over half the population is now fully trained. The American Heart Association recommends that CPR and familiarisation with automated external defibrillators be required as a condition of graduation from all US state secondary schools.6

In comparison, UK surveys show that only one in 13 respondents were confident in their ability to carry out emergency first aid.8 Data from the London Ambulance Service show that the Utstein survival in 2012 was 32%.9 The Oliver King foundation, set up in memory of a 12 year old boy who died after he had a sudden cardiac arrest while swimming at school, succeeded in ensuring the provision of an automated external defibrillator in every primary and secondary school in Liverpool. The foundation’s estimate is that 12-16 young people die from a sudden cardiac arrest every week in the UK.10 The Royal College of Paediatrics and Child Health and the BMA have supported calls for every public building, including schools, sports and fitness centres, and football stadiums, to have an automated external defibrillator.11

Coronary artery disease is responsible for 40-90% of out of hospital cardiac arrests.12 Less common cardiac causes include cardiomyopathies, channelopathies, and acute myocarditis. The pathway for transferral to specialist “heart attack centres” in the UK currently applies only to patients with ECG changes of ST elevation after return of spontaneous circulation, as this group can benefit from primary percutaneous coronary intervention (PCI). However, ambulance crews may occasionally triage patients with return of spontaneous circulation who don’t necessarily fulfil these ECG criteria directly to a heart attack centre in the belief that they will benefit from immediate coronary angiography. A substantial body of evidence of improved outcomes supports such a triage process when the patient has a history of chest pain or cardiac risk factors (or both).13 14 Absence of ST elevation on ECG in patients with cardiac chest pain does not necessarily exclude acute coronary occlusion, and these patients stand to benefit from immediate coronary angiography with a view to PCI.15 16 Input from a multidisciplinary team that includes cardiologists with expertise in intervention and arrhythmia, intensive care physicians, neurologists, specialist nurses, and rehabilitation therapists is crucial in post-resuscitation care to improve morbidity and mortality. Timely institution of therapeutic hypothermia has improved outcomes and survival.17

Londoners who have a cardiac arrest in public are now six times as likely to survive than 10 years ago, and much credit must go to the London Ambulance Service’s improved response times and appropriate post-resuscitation care, including triaging appropriate patients to specialist cardiac centres.18 Pre-hospital return of spontaneous circulation remains the strongest predictor of survival.19 As well as Seattle, we can learn lessons from Norway, where appropriate allocation of resources to this link in the chain of survival has reduced mortality.20 21 The British Heart Foundation should be commended for raising awareness through a national advertising campaign on the importance of CPR.22 Its policy statement calling for the UK governments to ensure the inclusion of emergency life support as a key development skill in all secondary schools should be supported and implemented.23

Scientific evidence to support early defibrillation for cardiac arrest that occurs secondary to ventricular fibrillation or pulseless ventricular tachycardia is overwhelming. Delay from collapse to delivery of the first shock is the most important determinant of survival, and survival rates after prompt defibrillation as high as 75% have been reported.24 Automated external defibrillators are sophisticated, computerised devices that are reliable and simple to operate, and their statutory provision in public places could save thousands of lives. It is perhaps instructive to note that parliamentary premises currently have 16 such devices.25

A better understanding and identification of which patients stand to benefit from subsequent triage to a tertiary cardiac centre beyond those who have acute ST elevation on ECG is imperative. Accurate identification can be effectively implemented only through close liaison between cardiologists and local ambulance services.

Last week the British Heart Foundation said that the number of people dying from cardiac arrests was “unacceptable” and rightly reinforced the message that all schoolchildren should be taught CPR.26 By learning from the tragedy of Oliver King as well as the extraordinary recovery of Fabrice Muamba, we should implement the evidence that will help save thousands of lives.

Notes

Cite this as: BMJ 2013;347:f4800

Footnotes

  • Competing interests: None declared.

  • Commissioning and peer review: Commissioned, externally peer reviewed.

References