Heart 'start-up' kits for home: new research reports on whether all heart attack survivors should have one

Published by Ather for University of Leicester in Health

University of Leicester-led research in the UK centred at University Hospitals of Leicester NHS Trust

A cardiac arrest study across seven countries, led in the UK by a Leicester medical and academic heart expert, has announced new findings that could impact on how patients are treated.

It sought to assess whether giving home defibrillator machines to patients who had previously suffered a heart attack could improve their chances of survival compared with simply training partners to perform CPR in the event of a cardiac arrest.

The defibrillator delivers an electric shock, which may be sufficient to restore the heart to its normal rhythm. The incidence of out-of-hospital cardiac arrest in the UK is estimated to be between 70,000 and 80,000 cases per annum and the majority of these events occur in the home.

The results of the Home Automated Defibrillator Trial (‘HAT’) were presented at the Annual Scientific Sessions of the American College of Cardiology in Chicago. The results were published on-line simultaneously in the New England Journal of Medicine.

Supported by the US National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health, the researchers report that although the safe and easy-to-use devices are effective for certain type of patients, they were underused at home.

The study was led in the UK by Dr William Toff, Senior Lecturer in Cardiology at the University of Leicester. University Hospitals of Leicester NHS Trust was the host institution for the study in the UK, where 1,024 patients were enrolled between 23 centres.

The trial was conducted in the US, Canada, Australia, New Zealand and the UK, and also included a few patients in Germany and the Netherlands.

In the trial, 7,001 patients with a history of anterior myocardial infarction, and their partners, were randomly assigned to receive either an Automated External Defibrillator (AED) for home use or training to call the emergency services and perform CPR in the event of a cardiac arrest occurring at home. Those in the AED for home use group also received training to call emergency services and to perform CPR, though they were instructed to use the AED first.

After an average of just over three years of follow-up, researchers found no differences in survival rates between the two groups and also found that only 39 percent of sudden cardiac arrests were witnessed events occurring at home.

Dr Toff said: “Overall, survival and successful resuscitation after cardiac arrest was the same in both study groups.

“This suggests that the routine provision of an AED for home use in this group of patients would not be a useful intervention over and above conventional training to call an ambulance and perform CPR. However, the study did show that the use of an AED in the home by lay people with minimal training is feasible, safe and effective.

"The overall number of deaths and cardiac arrests in the study was much lower than anticipated. This probably reflects the effectiveness of the modern treatments that are now routinely recommended after a heart attack and the high level of use in the study patients. This is good news for heart attack survivors and should encourage them to take their prescribed medication.

"In both study groups, the overall survival after cardiac arrest occurring at home was several times greater than is usually observed. This highlights the importance of training and prompt action to deal with a cardiac arrest, whether it be calling the emergency services and performing CPR or using an AED if one is available."

"We should redouble our efforts to ensure that all members of the public know how to recognise and respond to a cardiac arrest. Ideally, the education process should start in school and be included in the national curriculum, as it is in some other countries.”

Dr Toff was Principal Investigator for the UK and also the lead investigator for Leicester in the study. He is based in the University of Leicester’s Department of Cardiovascular Sciences at Glenfield Hospital.

UHL NHS Trust was the host institution for the study in the UK, where 1,024 patients were enrolled between 23 centres. The UK sites included the first (Russells Hall Hospital, Dudley – 292 patients) and third (UHL NHS Trust – 232 patients) highest recruiters of the 178 centres worldwide.

ENDS

Press release issued 2 April.