The ARREST Trial - Dr Malik Explains

Dr Malik was part of a UK study recently published in the Science Journal THE LANCET. It was presented at The European Society of Cardiology Meeting on Sunday 27th August 2023. Dr Malik provides an overview of the study and its key findings.

About the trial

The ARREST Trial looked at the treatment of patients who have an Out Of Hospital Cardiac Arrest (OOHCA) and return or spontaneous circulation (ROSC) at the scene. If we got a pulse back.

London Ambulance Service (LAS) does an amazing job of restarting the heart and getting patients to hospital.

BUT- which hospital? That was the propose of the study.

What does cardiac arrest mean?

A cardiac arrest means that the heart stops. This can be for many reasons, including heart attack, (or acute myocardial infarction) when a major blood vessel is blocked to the heart and the heart rhythm is disturbed.

Types of OOHCA include:

  1. Ventricular Fibrillation (VF): when an electric shock could reset the heartbeat and start the heart- this is the most survivable OOHCA
  2. Pulseless Electrical Activity (PEA): when the electrics are working but the pump has no forward flow
  3. Asystole: where there is NO electrical activity in the heart

Summary of the ARREST trial

This trial looked at whether transporting to a major heart centre rather than the nearest A+E (ER) department would help the patient AFTER they had a return of a pulse.

These patients did NOT have an ECG that suggested a heart attack as the cause of the OOHCA- those patients still come to the Heart Attack Centers, such as the one Dr Malik helped set up and run at Hammersmith Hospital, London.

It did NOT seem to help to transfer such patients to specialist heart attack centres- BUT it also did no harm to do so. The transport time is longer, and unless there is a benefit, LAS might be better dropping the patient to a closer hospital, and getting to the next urgent case they need to help.

It seems that in the cardiac centre, more tests and diagnostics were carried out, e.g. angiograms, time on ITU, kidney support, etc., but it seems to not improve survival.

What is clear is how serious a condition it is. Even those that survived to hospital, had an over 60% chance of dying by 1 month. Thus prevention is much better than cure.

How do I prevent having a cardiac arrest?

Firstly, if you are healthy with no chest pain, breathing issues or palpitations- the risk is low.

If there are people in your family who have had a cardiac arrest, especially if under the age of 60, you should get assessed.

The commonest cause in adults is coronary artery disease- and it is the condition we know most about and are most able to prevent.

To prevent cardiac arrest, it is advised to focus on not smoking, taking regular exercise, losing weight if you are overweight, and treating high blood pressure and diabetes.

What if I am worried about my risk?

Please come and see me or one of our specialists at OneWelbeck Heart Health. We can do a battery of tests to ensure that your risk of cardiac arrest is as low as possible.

These can include an ECG, Echocardiogram, blood tests and a CT coronary angiogram or cardiac MRI scan.

Details of the ARREST trial

If you're looking for more information, you can view the full article here: Expedited transfer to a cardiac arrest centre for non-ST-elevation out-of-hospital cardiac arrest (ARREST): a UK prospective, multicentre, parallel, randomised clinical trial

Summary of the trial

862 patients were enrolled, but 20 participants withdrew from the cardiac arrest centre group and 19 from the standard care group, leaving 411 participants in the cardiac arrest centre group and 412 in the standard care group.

CPR was done in almost all the patients- and I suspect it is part of the reason that they had ROSC and made it alive to the hospital- despite a time of about 10 minutes before circulation was restored.

Over half had a rhythm that could have a shock (VF), but a lot had other less survivable types of OOHCA

The primary endpoint of 30-day mortality occurred in 258 (63%) of 411 participants in the cardiac arrest centre group and in 258 (63%) of 412 in the standard care group (unadjusted risk ratio for survival 1·00, 95% CI 0·90–1·11; p=0·96).

Eight (2%) of 414 patients in the cardiac arrest centre group and three (1%) of 413 in the standard care group had serious adverse events, none of which were deemed related to the trial intervention.

Written by Dr Iqbal Malik

Dr Iqbal Malik is a consultant cardiologist and Medical Director of OneWelbeck Heart Health, specialising in coronary artery disease and structural heart disease including PFO, ASD and the TAVI procedure.