Heart attack treatment - RITA-3

The clinical question

A heart attack happens when there is a blockage in one of the coronary arteries that supply blood to the heart. If a complete blockage is suspected – called a ‘STEMI’ heart attack – doctors will usually perform an X-ray procedure called a coronary angiogram to look for blockages. Based on the findings at angiogram, the blocked artery can either be physically opened up with a balloon and stent (angioplasty), or bypassed using pieces of arteries or veins (coronary artery bypass surgery).

However, many people admitted to hospital experiencing chest pain or other symptoms of a heart attack have only a partial blockage or narrowing of the coronary arteries. This is called an ‘NSTEMI’ heart attack. At the time, doctors were unsure if these people should also undergo an urgent angiogram, or whether they should wait to see if medication could work first. BHF Professor Keith Fox and his team at the University of Edinburgh designed the ‘Randomized Intervention Trial of unstable Angina’ (RITA3) trial to find out which treatment gives the best outcome for people experiencing an NSTEMI heart attack.

What did the study involve?

Between 1997 and 2001, the team recruited 1810 people who were experiencing chest pain or other symptoms of an NSTEMI heart attack. The trial took place across 45 UK hospitals. The participants were randomly split into two groups:

• One group was managed with a ‘watch and wait’ approach. They were given medication to treat the heart attack and an angiogram only if their symptoms did not improve or became worse.
• The other ‘actively treated’ group were given medication plus an angiogram as soon as possible (within 3 days of going to hospital).

In both groups, if the angiogram showed a significant blockage, angioplasty or coronary bypass surgery was performed.

What did the study show?

The initial findings of the trial were that, at up to 1 year after treatment:

• Participants in the group that had an urgent angiogram were more likely to have survived than those who were managed conservatively.
• They were also less likely to have had a further heart attack.
• ‘Actively treated’ patients were less likely to have ongoing chest pain.

With further BHF funding, the team followed up participants for several years:

• Participants in the active treatment group, particularly those at high risk of further heart attacks, were more likely to have survived 5 years later.
• Survival rates 10 years after treatment were similar between the two groups. 

Why is the study important?

The RITA3 trial provided evidence that an early coronary angiogram to decide on treatment options should be the standard of care for high-risk NSTEMI heart attack patients. The results changed UK, European and USA treatment guidelines. It is now recommended that high-risk NSTEMI heart attack patients are offered an angiogram, and any appropriate follow on treatments, within 72 hours of first admission to hospital. 

When interviewed by The Lancet in 2013, Professor Fox selected RITA 3 as the study that had “…made the most difference” to the care of people with symptoms of coronary heart disease.

Study details

"Intervention vs conservative treatment strategy in patients with unstable angina or non-ST elevation myocardial infarction (The Third Randomised Intervention Treatment of Angina Trials, RITA-3)"
Award reference: RG/1996001/9075
Principal Investigator: Professor Keith Fox, University of Edinburgh
Trial registration number: ISRCTN07752711

Publication details

Fox KA, Poole-Wilson PA, Henderson RA, et al. Interventional versus conservative treatment for patients with unstable angina or non-ST-elevation myocardial infarction: the British Heart Foundation RITA 3 randomised trial. Randomized Intervention Trial of unstable Angina. Lancet. 2002;360(9335):743-51.