Optimal timing of intervention in non-ST-elevation acute coronary syndromes without pre-treatment

Introduction: In patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS), an invasive strategy is recommended. However, the optimal timing to perform coronary angiog-raphy (CA) remains undetermined, and this issue has become particularly relevant since the 2020 European guidelines restricted pre-treatment (PT) with P2Y12 antagonists.Objective: To assess the prognostic value of an early (ES; <24 h) versus a delayed strategy (DS; >24 h) when no loading dose of a P2Y12 antagonist is given as PT in NSTE-ACS. Methods: A retrospective analysis was carried out of patients admitted with NSTE-ACS included in the Portuguese Registry of Acute Coronary Syndromes between 2015 and 2019. Patients under-going PT were excluded. Patients were divided into two groups regarding the timing of CA (<24 h vs. >24 h). Independent predictors of a composite of all-cause mortality and rehospital-ization for cardiovascular causes at one year were assessed by multivariate logistic regression.Results: A total of 619 patients were assessed, mean age 63 +/- 12 years, 77.5% male. On CA, 6.1% had normal coronary arteries, 49.6% single-vessel disease and 44.8% multivessel disease. Revas-cularization was performed in 88.6%. Pending CA, 66.0% were medicated with ticagrelor and 42.3% with clopidogrel. Adverse in-hospital outcomes were not significantly different between groups, except for more major bleeding in the DS group. The one-year composite endpoint of total mortality and cardiovascular rehospitalization occurred in 8.9%, with no difference between groups.