PREFFIR - Prediction of Recurrent Events With 18F-Fluoride
Research type
Research Study
Full title
Prediction of Recurrent Events with 18F-Fluoride to Identify Ruptured and High-risk Coronary Artery Plaques in Patients with Myocardial Infarction - the PREFFIR study
IRAS ID
167329
Contact name
David E Newby
Contact email
Eudract number
2014-004021-41
Clinicaltrials.gov Identifier
Duration of Study in the UK
4 years, 0 months, 0 days
Research summary
Summary of Research
Heart attacks are caused by a blood clot which stops blood flowing to part of the heart muscle. The blood clots form in areas of blood vessels (arteries) that are damaged (inflamed) by a build up of small fatty lumps (plaques). The fatty lumps can break and cause blood to stick to the wall of the blood vessel. It appears that this process can also occur without causing any symptoms and may put patients at increased risk of heart attacks in the future. It has also been shown that patients with a heart attack often have more than one damaged plaque. Previous research has shown a specialised scanner known as a PET (positron emission tomography) scan can identify these damaged plaques in patients with a recent heart attack. We intend to see if the presence of these plaques can be used to predict heart attacks in the future.
The study will involve patients from 4 hospitals around the UK who have been admitted to hospital with a heart attack. Participants will undergo CT and PET scans at the start of the study to identify the presence and distribution of damaged plaques. They will have ongoing follow up to identify recurrent heart attacks or other vascular events. A second CT scan will be performed 2 years after the first to identify changes or progression of their heart artery disease.Summary of Results
The PREFFIR study was conducted in nine hospitals across four countries between September 2015 and March 2022. The study involved patients aged 50 years or older with multi vessel heart disease and a recent (within 21 days) heart attack.
A heart attack is most often caused by a blood clot, which stops blood flowing to part of the heart muscle. Without a good blood supply and oxygen, the heart muscle is at risk of dying. Blood clots form in areas of blood vessels (arteries) that are damaged by a build up of small fatty lumps (plaques). The fatty lumps can break and cause blood to stick to the wall of the arteries. Whilst we have good treatment for blocked heart arteries, we do not know which fatty lumps will break and cause a heart attack in the future.The PREFFIR study used a special heart scanning technique known as a Positron Emission Tomography (PET). This PET scan allowed us to look at plaques in heart arteries. A ‘tracer’ called 18F-sodium fluoride shows ‘hotspots’ of damage in these plaques. The tracer was given as an injection that is seen by the PET scanner. The aim of the PREFFIR study was to confirm whether this tracer can identify patients who are at risk of having a heart attack or other heart problems in the future.
The study tracked deaths caused by heart problems or nonfatal heart attacks. However, because these events happened less often than expected, the study was adjusted to also include unexpected procedures to restore blood flow to the heart.
704 patients had the PET scan and were included in the study. The average age of the participants was about 64 years, and most of them were male (85%). We found that 60% of the participants had high plaque activity in their arteries. After following up for about 4 years, 20% of the participants experienced serious heart problems: 9 died from a cardiac arrest, 49 had nonfatal heart attacks, and 83 had unscheduled procedures to restore blood flow to the heart.
The results showed that having more active plaque in the arteries did not seem to increase the risk of these heart problems or the need for those procedures compared to having low plaque activity. However, when looking at the original outcomes only (deaths caused by heart problems or nonfatal heart attacks) increased plaque activity was significantly associated. 11.2% of patients with high plaque activity experienced cardiac death or nonfatal heart attacks compared to 6.7% of those with low plaque activity.
The findings in this study suggest that more research is needed to understand if patients with high plaque activity have an increased risk of heart-related death or heart attacks.REC name
Scotland B REC
REC reference
15/SS/0059
Date of REC Opinion
29 Apr 2015
REC opinion
Favourable Opinion