Can the GRACE risk score help improve care for NSTEMI heart attack and unstable angina?
The clinical question
People admitted to hospital with an NSTEMI heart attack (where there is a partial blockage or narrowing of the coronary arteries that supply blood to the heart), or with unstable angina (where angina chest pain is not controlled) are at risk of having another cardiovascular event, such as a heart attack or developing heart failure, in the following year. NSTEMI together with unstable angina are known as NSTEACS (Non ST-elevation acute coronary syndrome).
When someone is admitted to hospital with NSTEACS, doctors first establish whether they have had a heart attack and, if so, how severe the heart attack is, and the risk of another cardiovascular event. Based on this risk assessment, they decide what treatments to prescribe - such as giving anti-clotting drugs or opening up a blocked coronary artery with a stent.
Clinical guidelines recommend using scoring systems to more accurately calculate the risk of another cardiovascular event after an NSTEMI heart attack or unstable angina. The GRACE risk score is a tool that can be used by doctors to assess a person's risk, by looking at medical information that is routinely collected during an admission. This includes their heart rate, blood pressure, any signs of heart failure, what the ECG heart trace looks like, and whether there are markers indicating heart muscle damage in their blood. The score has been shown to accurately predict the risk of further cardiovascular events in people with NSTEACS.
But it is not known whether using the GRACE scoring system systematically in hospitals impacts the care that people with NSTEMI or unstable angina receive, and how this affects their outcomes. Professor Chris Gale and colleagues at the University of Leeds conducted the BHF-funded UKGRIS trial to find out.
What did the study involve?
UKGRIS was conducted at 42 hospitals across the UK from 2017 to 2019. These hospitals were chosen because they didn’t normally use the GRACE risk score to assess people with NSTEMI or unstable angina. In total 3050 participants with suspected NSTEMI or unstable angina were recruited into the trial. The hospitals were randomly allocated to one of two groups:
- Hospitals in the first group used the GRACE risk score tool to guide their routine clinical assessment and management of people with NSTEMI or unstable angina. 1440 people admitted to these hospitals agreed to participate, they had their GRACE risk score calculated and the score was used to help decide their treatment.
- Hospitals in the second group continued to follow their current practice. In these hospitals, 1610 participants were given treatment according to usual care.
In both groups, participants completed a general health assessment and a short questionnaire at the start of the study and then again 12 months later to assess their health status and quality of life. Participants’ long-term progress relating to their heart condition was assessed by reviewing electronic medical records.
What did the study show?
- Of the 3050 participants recruited into the trial, 2435 (~80%) participants were diagnosed with NSTEACS, 2037 (~67%) had NSTEMI and 398 (13%) had unstable angina, leaving 615 (~20%) with another diagnosis.
- The team looked at 11 possible diagnostic tests or treatments that guidelines recommend people with NSTEMI or unstable angina should receive based on their level of risk. In total around 76% of patients in the whole trial received the care recommended by guidelines.
- Most people in the trial were prescribed recommended drug treatments, like aspirin and other anti-clotting drugs, as well as medication to prevent another heart attack, such as statins. But only around half of people who - according to guidelines - should have had angiography (an X-ray of the coronary arteries) within 72 hours to see if there was a blockage that needed to be opened, actually had this test in the recommended time period. Overall only two thirds of people in the trial who should have been sent to cardiac rehabilitation got a referral.
- Using the GRACE risk score to direct treatment did not increase the proportion of people who got guideline-recommended care for NSTEACS.
- The chances of having another cardiovascular event (for example, another heart attack or a new episode of heart failure) or of dying of a cardiovascular cause within 12 months of admission were similar in both groups.
- Using the GRACE risk score did not reduce the average number of days that people had to stay in hospital over the 12 month follow up period, or improve health related quality of life measured with a questionnaire.
Why is the study important?
The UKGRIS trial was conducted to find out if using the GRACE risk score in a ‘real world setting’ within the NHS increases guideline-directed treatment and improves prognosis for people admitted to hospital with NSTEACS. The study showed that while many people with NSTEACS received appropriate medications, many are still not getting currently recommended access to timely coronary angiography during their admission (to examine the coronary arteries and insert a stent if required) or being referred for cardiac rehabilitation.
The finding that using the GRACE risk score did not improve adherence to guideline directed management of NSTEACS or reduce cardiovascular events at 12 months compared with standard care replicates the results of a similar study performed in Australia (AGRIS), meaning that the results of the trial are probably not specifically related to how healthcare is provided in the NHS.
It’s possible that doctors are uncertain about the effectiveness of coronary angiography in some groups of patients and that it was not always easy to access heart services, such as cardiac rehabilitation, in the NHS - so some doctors might have overridden the GRACE risk score prompt. It’s also possible that doctors may feel that their clinical estimate of a patient’s risk and the appropriateness of care was of greater importance than an estimate using a risk score.
Professor Chris Gale explained further: “The GRACE risk score has been shown to offer good prediction of a patient’s risk of future events and research has found that objective risk estimation is superior to physician estimation."
Study details
“Effectiveness of the GRACE risk score on the management and outcome of patients hospitalised with non-ST elevation acute coronary syndrome”
Award reference: CS/16/2/32145
Chief Investigator: Professor Christopher Gale
Trial registration number: ISRCTN29731761
Publication details
Effectiveness of GRACE risk score in patients admitted to hospital with non-ST elevation acute coronary syndrome (UKGRIS): parallel group cluster randomised controlled trial. BMJ. 2023 Jun 14;381:e073843.