The Value of the GRACE Risk Score for Triaging Non-ST-Elevation Acute Coronary Syndrome Patients
By Michael H. Crawford, MD, Editor
SYNOPSIS: A prospective, pragmatic, cluster, randomized clinical study of using the Global Registry of Acute Coronary Events (GRACE) risk score and standard care for the management of non-ST-elevation acute coronary syndromes failed to demonstrate more use of guideline-recommended care or better outcomes.
SOURCE: Gale CP, Stocken DD, Aktaa S, et al. Effectiveness of GRACE risk score in patients admitted to hospital with non-ST elevation acute coronary syndrome (UKGRIS): Parallel group cluster randomized controlled trial. BMJ 2023;381:e073843.
Managing non-ST-elevation acute coronary syndromes (NSTEACS) involves selecting the highest-risk patients to treat with the most advanced, evidence-based therapies. The Global Registry of Acute Coronary Events (GRACE) global risk score (GRS) has been shown to be of value in this determination and superior to other ACS risk scores. However, there are a lack of data that confirm using GRACE improves outcomes when compared to other risk scores.
Gale et al studied England’s hospital admission and mortality database, from which researchers routinely and systematically collect information, to conduct a prospective, pragmatic, cluster, randomized clinical trial (UKGRIS) to test the hypothesis that using the GRS would lead to more guideline-recommended therapy for hospitalized ACS patients and reduce the number of major adverse cardiovascular (CV) events. Clusters of patients were from one hospital or a group of hospitals participating in other registry studies to prevent contamination among patients at the same hospital undergoing different care. Randomization to GRS use or standard care was at the cluster level, and outcomes were measured at the patient level. The primary outcome was the use of class I guideline-recommended care processes and the composite of CV death, myocardial infarction, new heart failure hospital admissions, or readmissions for a CV event within 12 months.
From 42 hospitals in 38 clusters, researchers enrolled 3,050 patients between 2017 and 2019 (1,440 GRS; 1,610 standard care; mean age = 66 years; 69% were men). The mean baseline GRACE risk score for the standard care group was 126 and 120 for the GRS group. The use of guideline-based care was not significantly different between groups (75% and 77%, standard and GRS, respectively). The time to the first major CV event was not significantly improved by use of the GRS (HR, 0.89; 95% CI, 0.68-1.16; P = 0.37). Also, none of the individual components of the primary outcome were significantly different between the two groups. The authors concluded using the GRS did not significantly expand the use of guideline-recommended care, nor did it improve CV outcomes at one year among patients hospitalized for NSTEACS.
The main use of risk scores in suspected NSTEACS patients is to decide in whom to employ more aggressive pharmacologic therapy, such as intravenous P2Y12 inhibitors and heparin, and whom to triage to early invasive coronary angiography. In my hospital, the Thrombolysis in Myocardial Infarction (TIMI) score has been popular among the house staff for this purpose, largely because it is simple (containing only seven elements, with one point for each). However, cardiologists might avoid TIMI because it was never designed for this purpose, as it was derived from patients with known NSTEACS, and the scoring system is nonsensical. For example, a patient older than age 65 years with three risk factors for coronary artery disease (CAD) who has used aspirin within the last seven days records a TIMI score of 3. So does a patient with known significant CAD, ECG ST changes, and a positive troponin test. There is no way these two patients are at the same risk of experiencing an adverse event, but both recorded the same TIMI score.
The GRS includes eight scoring elements, but is more complicated, because it requires numerical input, such as heart rate speed, blood pressure readings, and creatinine levels. The only data points it shares with TIMI are age, elevated troponin, and ST changes on ECG. GRS usually is determined using an online calculator, and the outputted score usually is three digits, with a score higher than 140 constituting a high-risk patient. GRS has been validated in observational studies and shown to predict bad outcomes if high-risk patients are not treated aggressively.
The prospective, cluster, randomized UKGRIS study failed to show any improvement in the use of guideline-recommended therapies by employing the GRS, nor did it improve 12-month outcomes. The authors proposed several reasons why the outcomes were negative. First, the use of guideline-recommended drugs was high in both groups (more than 82% for all). Also, the use of invasive coronary angiograms was low in both groups (12% at 24 hours and 54% at 72 hours). In addition, the GRS group recorded a lower risk score than the standard care group (120 vs. 126, respectively), and both groups recorded mean scores in the intermediate-risk range. This might partly explain the low use of coronary angiography. Finally, although follow-up extended for up to 45 months, only the 12-month outcome data were presented. The strengths of the UKGRIS study included the relatively high numbers of patients and a 100% follow-up rate. However, outcome events were taken from the medical record, and no one performed independent adjudication.
Where does this leave the practitioner? One conclusion is that experienced physicians have internalized the determination of risk in NSTEACS patients and do not need an external scoring system. However, trainees still might benefit from the exercise of a risk calculator. For that purpose, I would recommend the GRS over TIMI.
A prospective, pragmatic, cluster, randomized clinical study of using the Global Registry of Acute Coronary Events (GRACE) risk score and standard care for the management of non-ST-elevation acute coronary syndromes failed to demonstrate more use of guideline-recommended care or better outcomes.
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