Pretreatment antithrombotic strategies in non-ST elevation acute coronary syndromes in contemporaneous clinical practice.

Background: Pretreatment antithrombotic strategies in non-ST elevation acute coronary syndromes (NSTE-ACS) during hospitalization is still a matter of contention within the cardiology community. Our aim was to analyze in-hospital and one-year follow-up outcomes of patients with NSTE-ACS pretreated with dual antiplatelet therapy (DAPT) versus single antiplatelet therapy (SAPT).

Methods: A retrospective study was carried out with NSTE-ACS patients who planned to undergo an invasive strategy and were included in the Portuguese Registry of ACS between 2018 and 2021. A composite primary outcome (in-hospital re-infarction, stroke, heart failure, hemorrhage, death) was compared regarding antiplatelet strategy (DAPT versus SAPT). Secondary outcomes were defined as one-year all-cause mortality and one-year cardiovascular rehospitalization.

Results: A total of 1469 patients were included, with a mean age of 66 ± 12 years, and 73.9 % were male. The DAPT regime was used in 38.2 % of patients and SAPT in 61.8 % of patients. NSTE myocardial infarction was the most frequent presentation (88.5 %). Revascularization was performed within 24 h in 55.2% of patients. Time until revascularization >24 h occurred in 44.8% of patients, with 16.5% of these between [24 h-48 h], 10.6% in [48 h-72 h] and 17.6% > 72 h. The primary outcome was more frequently observed in the SAPT group (10.4 %, p = 0.033), mainly driven by more ischemic events. Time until revascularization >72 h and the SAPT regime were independent predictors of the primary outcome (OR 3.09, p = 0.005, and OR 2.03, p = 0.008, respectively).

Conclusion: NSTE-ACS patients pretreated with SAPT had worse in-hospital outcomes. This difference can probably be explained by time until revascularization delay.