Optimal timing of intervention in NSTE-ACS without pre-treatment
Authors: Almeida I , Santos H , Santos M , Miranda H , Chin J , Sa C , Almeida S , Sousa C , Almeida L ,   Portuguese Registry of Acute coronary syndromes
Published: October 2021

Abstract

Introduction
In patients (P) with non-ST segment elevation acute coronary syndromes (NSTE-ACS), an invasive strategy is recommended to reduce adverse outcomes. The optimal timing to perform coronary angiography (CA) remains undetermined, particularly in our era attending to the new European guidelines restricting pre-treatment (PT).

Objective
To evaluate the prognostic value of an early strategy (ES; &lt;24h) versus a delayed strategy (DS; &gt;24h) when no loading dose of a P2Y12 antagonist was given as PT in NSTE-ACS.

Material and methods
Retrospective analysis of P data admitted with NSTE-ACS at multicentric national registry between 2015–19. Compared demographic and clinical characteristics of P with an ES versus DS. A multivariate logistic regression was performed to evaluate predictor factors of in-hospital and 1-year endpoints. Survival was evaluated through Kaplan-Meier curve and Cox multivariate regression.

Results
691P were included, mean age 64±11 years, 77.4% male. 59.2% performed CA as an ES. P proposed to a DS presented higher KK class, higher levels of creatinine and lower of hemoglobin. They also needed more frequently invasive (1.1 vs 0.7%, p=0.692) or non-invasive ventilation (1.8 vs 0.7%, p=282). A higher proportion of DS patients used the transfemoral access (5.5 vs 9.3%, p=0.058). On CA, 6.2% had normal coronary arteries, 49.2% 1-vessel disease and 45.1% multivessel disease. Revascularization was performed in 88.2%: PCI in 86.2%, CABG in 1.7% and both in 0.3%, with no significant differences. Pending CA, 98.4% were medicated with aspirin, 64.8% ticagrelor and 44% clopidogrel, with no differences. P proposed to an ES were more medicated with glycoprotein inhibitor (36.3 vs 26.4%, p=0.015) and non-fractioned heparin (6.4 vs 2.1%, p=0.01) and less with fondaparinux (56.2 vs 65.2%, p=0.017). A higher percentage of calcium-channel blockers (25.2 vs 11.7%, p&lt;0.001) and nitrates (74.1 vs 53.3%, p&lt;0.001) was observed in the DS. No difference was observed in beta-blockers (p=0.581). Discharge medication followed these tendencies. There was a trend to worse in-hospital outcomes in the DS regarding heart failure, shock, ventricular arrhythmias, cardiac arrest and death, although not significatively different, except for major bleeding (1.8 vs 0.2%, p=0.044). 1-year composite endpoint of mortality and cardiovascular rehospitalization occurred in 9.9%, with no difference between groups (p=0.181). Predictor factors, evaluated through Cox multivariate regression, were ejection fraction &lt;50% (p=0.001), KK class &gt;I (p=0.002) and nitrate prescription at discharge (p=0.001). A DS was not a predictor factor (p=0.812).

Conclusion
Our results are in accordance with available data. In P with higher-risk NSTE-ACS in the absence of P2Y12 antagonist PT, an ES was not associated with a reduction in the composite of global mortality and rehospitalization for cardiovascular causes.

Funding Acknowledgement
Type of funding sources: None.