Cardiac arrest survival rates in urban areas 40% higher than rural settings, research finds

Out of more than 18,000 cardiac arrests examined, just in excess of 1,000 patients survived to hospital discharge

The highest cardiac arrest survival rate – 30 per cent – is among patients who get defibrillation from bystanders, who are often the first to arrive on the scene. Photograph: Alamy/PA
The highest cardiac arrest survival rate – 30 per cent – is among patients who get defibrillation from bystanders, who are often the first to arrive on the scene. Photograph: Alamy/PA

Having a cardiac arrest in an urban area in Ireland increases your chances of survival by 40 per cent compared to it happening in a rural setting, according to new research.

The overall chances of surviving out-of-hospital cardiac arrests are low – at under 6 per cent – but they are increasing, thanks in part to the wider availability of defibrillation, an analysis of eight years of data shows.

More than 18,000 cardiac arrests occurring between 2012 and 2020 were examined in the analysis by scientists at UCD, UCC and University of Galway. Just over 1,000 of these patients survived to hospital discharge.

Although the survival rate is average in international terms, the research shows it is increasing, by 14 per cent year on year.

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The Covid-19 pandemic, increasing patient age and longer emergency call response times were all associated with lower survival rates. Urban location was associated with higher survival rates.

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The highest survival rate – 30 per cent – was among patients who received defibrillation from bystanders, who are often the first to arrive on the scene. However, these cases accounted for only 6.8 per cent of all patients treated. One-quarter of defibrillation was given by emergency personnel, with a survival rates of 12.4 per cent in such cases.

Just 1 per cent of patients who did not have any defibrillation survived – but almost 70 per cent of the heart attacks reviewed were in this category.

The pandemic was associated with decreased survival even after account was taken of the disruption it caused to care provided by bystanders and emergency medical staff.

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Further research is called for to understand and address the discrepancy between urban and rural survival rates. “One issue that could be explored in follow-up research is whether reduced rural access to specialist out-of-hospital cardiac-arrest treatments is a driver of outcomes,” according to the study published in Resuscitation Plus journal.

One-third of all cardiac arrest callouts occur in rural areas. “The figures highlight the crucial importance of early defibrillation in treating patients in all areas, but particular in rural areas where it can take longer for emergency services to arrive,” said Prof Andrew Murphy of the department of general practice in University of Galway.

Emergency medical services were reconfigured in 2015/2016, when multiple regional control centres were amalgamated into a single National Emergency Operations Centre. Training of first responders and public education has also been stepped up.

The authors say they do not believe the centralisation of emergency services alone was the principal driver of the improvement in survival rates seen over the period.

The Covid-19 period was associated with a 39 per cent reduced odds of survival, the study estimates.

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The survival rate improved by 23 per cent when cardiac arrests occurred from Monday to Friday. With 30 per cent of callouts occurring at weekends, the authors say consideration should be given as to whether there is a “weekend effect” in terms of survival.

The single most significant factor improving survival rates was the administration of amiodarone, a drug that steadies the heart rhythm, which raised the odds almost threefold. Only advanced paramedics can administer this medication, but not all emergency medical service resources responding to heart attacks are crewed by advanced paramedics, co-authors Prof Murphy and Prof Tomás Barry point out.

They suggest further examination of whether and how amiodarone can be made available to all patients.

In 2021, there were almost 3,000 attempts to resuscitate people suffering cardiac arrest; only 6.1 per cent of these patients survived to hospital discharge.

Patient story: ‘In situations like this, every second counts’

While out enjoying a New Year’s Day, Nada Kanj and her husband Finn passed some of the defibrillators that she and her fellow community first responders were responsible for maintaining. What neither of them knew was that, less than 24 hours later, one of these defibrillators would save Finn’s life.

They checked the machines and continued on their walk. The next day, Finn was due to travel to Denmark for work – he had been commuting there from Dublin for six years. Nada, who came from Lebanon to Ireland 18 years ago, was at work in Sandyford when a call came through from a garda.

“He explained that Finn had collapsed on the street with a cardiac arrest and that they were giving him CPR and would be taking him to St James’s Hospital. I raced out of the office and got in my car. I don’t know how I got there but I arrived at the scene seven minutes later and saw the ambulance there – I just screamed,” said Nada.

Fortunately, other community first responders were already on the scene and a doctor happened to be passing by.

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Finn effectively died for two minutes before he was revived, she explained. “He was lucky that the two people that came along had training in CPR. Others won’t be as lucky. In situations like this, every second counts,” said Nada, who encourages people to train as a community first responder.

Finn spent time in intensive care and underwent a long and slow rehabilitation. “Finn is in his mid-50s and was otherwise fit and healthy,” Nada said. “He did have a very stressful job in Denmark and he has decided not to go back to it. We were very lucky – it was a miracle. Not many people get this lucky. We will take time finding him something less stressful.”

Paul Cullen

Paul Cullen

Paul Cullen is a former heath editor of The Irish Times.