ORBITA-FIRE
Research type
Research Study
Full title
ORBITA-FIRE: Finding the invasive haemodynamic threshold for symptom relief in stable angina
IRAS ID
304700
Contact name
Rasha Al-Lamee
Contact email
Sponsor organisation
Joint Research Compliance Office, Imperial College London
Duration of Study in the UK
2 years, 11 months, 26 days
Research summary
Angina is a symptom of chest pain that is thought to be caused by a reduction in blood flow, and therefore oxygen, to the heart’s muscle. The most common cause of angina is narrowing in the arteries supplying the heart.
Current clinical guidelines recommend if a narrowing is causing a reduction in blood flow of 20% or more through an artery, this is likely to cause angina, and patients should be offered a treatment called coronary angioplasty. This is where a balloon is used to stretch open the narrow artery and a metal stent (acting like a scaffold) is left in place permanently to allow blood to flow more freely.
An important question that remains unanswered however, is whether all patients develop pain at the same level, as this 20% threshold has never been tested before in a clinical study for the purpose of symptom relief. New data suggests not all patients get pain in the same way, and therefore it is likely the use of a single 20% cut-point for the whole population may be an oversimplification.
In this study we will, for the first time, investigate exactly what percentage reduction in blood flow is required to cause chest pain for each patient under experimental conditions following angioplasty. We will do this by progressively inflating a tiny balloon inside the recently deployed stent until the patient reports pain and then measure the corresponding reduction in blood flow.
If successful, this study will help us understand more accurately the relationship between blood flow and chest pain, the variability to expect between patients, and with exercise (when a patient typically gets angina) rather than rest. If significant variability is observed, this suggests a more individualised and patient-tailored approach is more favourable to improve procedural outcomes rather than a single threshold for everyone.REC name
London - Central Research Ethics Committee
REC reference
22/LO/0308
Date of REC Opinion
9 Jun 2022
REC opinion
Further Information Favourable Opinion