Impact of the 2023 ESC acute coronary syndromes guidelines on clinical practice and in-hospital outcomes - a registry-based study

Introduction The 2023 European Society of Cardiology (ESC) guidelines for the management of acute coronary syndromes (ACS) introduced major updates, including refined invasive strategy in high-risk patients, a more selective use of pretreatment with P2Y12 inhibitors, and a stronger recommendation for complete revascularization in STEMI. These changes aimed to improve outcomes through safer and more individualized care. Purpose To assess the impact of the implementation of the 2023 ESC ACS guidelines on clinical practice and patient outcomes in a real-world setting. Methods Single-centre retrospective study including patients hospitalized with ACS and enrolled in the Portuguese Registry of Acute Coronary Syndromes between October 2010 and July 2025. Patients were divided into two groups: before (Group A) and after August 2023 (Group B). Baseline characteristics, management strategies, and outcomes were compared. Results A total of 1455 patients were included (73.3% male, mean age of 67.0±12.8 years); 1154 (79.3%) in Group A and 301 (20.7%) in Group B. Patients in group A were older (67.3±12.7 vs 65.6±12.9 years, p=0.043), less often smokers (23.2% vs 30.2%, p=0.012) and had fewer previous percutaneous coronary interventions (PCI) (10.8% vs 15.6%, p=0.022). After guideline implementation, STEMI admissions increased (56.8% vs 45.4%, p<0.001). There was a higher rate of coronary angiography (99.7% vs 96.6%, p=0.004), PCI (85.0% vs 76.8%, p=0.002) and staged PCI (28.9% vs 19%, p=0.002), with greater use of radial access (94% vs 70.9%, p<0.001). In NSTEMI patients, the time to coronary angiography was reduced (18.7 vs 36.8 hours, p<0.001). In STEMI patients, fibrinolysis decreased (2% vs 11.6%, p<0.001) and pre-catheterization P2Y12 loading was less frequent (59.6% vs 85.1%, p<0.001). Regarding medical therapy, use of potent P2Y12 inhibitors (prasugrel/ticagrelor) and additional lipid-lowering agents increased, while clopidogrel, nitrates, and beta-blockers were less prescribed. In-hospital complications decreased, including heart failure (14.0% vs 21.0%, p=0.006), cardiogenic shock (1.3% vs 4.9%, p=0.006), and mechanical complications (0% vs 1%, p=0.035), with shorter hospital stay (5±3 vs 6±4 days, p=0.003). In-hospital mortality remained similar (1.0% vs 1.8%, p=0.318). Referral for cardiac rehabilitation increased significantly (52.7% vs 16.9%, p<0.001). Conclusion Implementation of the 2023 ESC ACS guidelines was associated with significant changes in clinical management, particularly in invasive strategy and antiplatelet therapy, leading to fewer in-hospital complications and shorter admissions. These results support their positive impact on real-world clinical practice.