Current guidelines recommend an early (<24 h) invasive coronary angiography (ICA) strategy in non-ST-segment elevation acute coronary syndrome (NSTE-ACS) patients with Global Registry of Acute Coronary Events (GRACE) score over 140. Evidence for this recommendation is based on older trials.

Between 1 February 2016 and 31 July 2021, 1767 patients with a primary diagnosis of NSTE-ACS without indication for urgent ICA underwent ICA during index hospitalization. Six hundred and fifty-five patients underwent early invasive ICA (within 24 h) and 1112 underwent late ICA (between 24 h and 1 week). One hundred and seven patients had a GRACE risk score of 140 or above and 1660 had a GRACE risk score under 140. The primary composite outcome was all-cause mortality, stroke, and recurrent myocardial infarction (MI). Median time from admission to ICA was 13.3 h (IQR 6.0–20.6) for the early group and 59.9 h for the late group (IQR 23.5–96.3). There was no difference between the early and late ICA groups in the primary composite outcome [late catheterization >24 h hazard ratio 1.196, 95% confidence interval (CI) 0.969–1.475, P-value 0.096]. A multivariable Cox regression model for the composite outcome revealed no difference between the early and late ICA groups (late catheterization >24 h hazard ratio 1.0735, 95% CI 0.862–1.327, P-value 0.512) with no effect for performing early ICA in patients with GRACE score over 140 (hazard ratio 1.291, 95% CI 0.910–1.831, P-value 0.151).

An early ICA strategy in patients with NSTE-ACS patients and GRACE risk score over 140, compared with late ICA, was not associated with improved composite outcome of death, myocardial infarction, and stroke at 1 year.