Long delays in ambulances reaching patients with the most serious type of heart attack are putting lives at risk, according to a new investigation.

The Healthcare Safety Investigation Branch (HSIB) said not enough people were getting prompt treatment after an attack, while some patients are sent paramedic cars instead of an ambulance that could transfer them to hospital.

The HSIB examined in detail the most serious form of heart attack known as ST-elevated myocardial infarction (Stemi), which affects about 31,000 people every year.

It followed a complaint made by a man and his family over long delays in transferring him to hospital for a procedure to open up his arteries after he suffered a Stemi.

The NHS recommends that people with Stemi undergo primary percutaneous coronary intervention (PPCI) – in which stents are inserted into arteries to relieve blockages, also known as angioplasty – and that PPCI is most effective if carried out within 1.5 hours of a patient being diagnosed.

Yet the HSIB said “there has been a decreasing ability for ambulance services to ensure that patients are transferred to a PPCI centre and undergo PPCI within timescales set out in national guidance”.

A Myocardial Infarction National Audit Project (Minap) report last year found that the median 999 call-to-procedure time in England “has increased each year from 117 minutes in 2015/16 to 125 minutes in 2018/19,” the HSIB reported.

It added: “In 2018/19, 31% of patients with Stemi did not receive PPCI within 150 minutes of their call for help.

Our investigation highlights that the reduced ability of the ambulance services to provide pre-hospital treatment places even more emphasis on patients arriving within a crucial time window

“The percentage of cases that have not met the 150-minute treatment time has increased year-on-year since 2015/16 when 25% of patients failed to receive PPCI within the 150-minute target.”

While there are suggestions of improvements in the few months leading up to February 2020, patients still waited a median time of 132 minutes, with 10% of
cases averaging at least 179 minutes, the HSIB said.

It argues that “timely treatment of heart attack is needed to avoid further damage to the heart”, while delays increase the risk of death.

Experts examined in detail the case of “Phil”, who was aged 61 at the time of his heart attack.

He had been cycling with friends and helping with their house renovations in the days leading up to his attack, which happened at half past midnight.

He woke up with chest pains and was breathless and sweating. He contacted a friend, a retired GP, who recognised he was having a heart attack and called 999.

The call was listed by NHS staff as Category 2, which means that on average a suitable ambulance should arrive with the patient within 18 minutes.

A rapid response vehicle (RRV), crewed by a solo paramedic, was dispatched to Phil and arrived 67 minutes after the 999 call.

But this paramedic knew he would not be able to transfer Phil to hospital and made several calls for an ambulance to attend the scene.

An ambulance was eventually dispatched but arrived more than two hours (130 minutes) after the initial 999 call was made.

Ambulance services will review these recommendations, building on the fast and effective services they deliver

Phil finally underwent PPCI in hospital just under four hours after the initial 999 call. He survived, though he has reduced physical activity levels and ongoing medical needs.

The HSIB has made three safety recommendations: two to NHS England and one to the Association of Ambulance Chief Executives (AACE).

They focus on reviewing current guidance on timescales, clarifying information on Stemi treatment and addressing why delays occur.

Dr Stephen Drage, director of investigations at HSIB, said: “Delays in emergency response to Stemi and the impact this could have on treatment is a patient safety issue seen across England.

“Our investigation highlights that the reduced ability of the ambulance services to provide pre-hospital treatment places even more emphasis on patients arriving within a crucial time window to receive PPCI.

“Data cited in our report suggests that the longer the delay, the poorer the outcome could be even if patients survive the heart attack and the procedure that follows.

“Our safety recommendations focus on ensuring national clarity and consistency for paramedics dealing with Stemi transfers, and on building further understanding of the factors that influence ambulance response times and how this might contribute to delays.”

An NHS spokesperson said: “Ambulance services will review these recommendations, building on the fast and effective services they deliver.

“This includes providing resuscitation on scene and preparing the patient for their procedure once they have arrived at hospital, which regularly save lives of cardiac arrest sufferers.

“Paramedics and other ambulance and NHS staff have also developed other initiatives which help more people get immediate care, including through rollout of a national network of community first responders and defibrillators, which will also enhance response times for out of hospital cardiac arrest.”