Early Post-PCI MACE in haemodynamically stable ACS confers a twofold long-term mortality risk: a 16,312-patient contemporary analysis

Background Percutaneous coronary intervention (PCI) is the principal revascularisation strategy in acute coronary syndrome (ACS). Although haemodynamic instability is a recognised determinant of adverse outcome, early post-procedural major adverse cardiovascular events (MACE) continue to occur in patients who present clinically stable. The predictors and long-term prognostic implications of these early complications remain insufficiently characterised. Purpose To determine the incidence, independent predictors, and long-term survival impact of immediate post-PCI MACE in haemodynamically stable ACS patients. Methods We analysed 16,312 consecutive adults undergoing PCI between 2012 and 2024 from a prospective institutional registry. Patients with cardiogenic shock, cardiac arrest, mechanical ventilation, or vasopressor requirement were excluded. Immediate MACE comprised in-hospital cardiovascular and major bleeding events. Baseline demographic, clinical, laboratory, echocardiographic, and angiographic characteristics were compared between groups. Univariable and multivariable logistic regression analyses were performed. Long-term survival was assessed using Kaplan–Meier analysis with log-rank testing. Results Immediate post-PCI MACE occurred in approximately 6% of haemodynamically stable patients. Patients experiencing MACE were older, more frequently female, and had higher prevalence of renal dysfunction, anaemia, impaired left ventricular systolic function, multivessel coronary artery disease, and impaired baseline TIMI flow (all p<0.001). On multivariable analysis, the strongest independent predictors were severe left ventricular dysfunction (aOR 3.6, 95% CI 2.5–5.2), impaired coronary flow (TIMI <3; aOR 2.6, 1.8–3.7), elevated creatinine (aOR 2.6, 2.2–3.1), moderate anaemia (aOR 2.7, 1.8–4.1), and three-vessel disease (aOR 2.1, 1.7–2.6) (all p<0.001). Female sex (aOR 1.9, 1.6–2.4) and age 71–80 years (aOR 1.6, 1.3–2.0) also remained significant. Kaplan–Meier analysis demonstrated early and sustained separation of survival curves. Cumulative mortality exceeded 30% among patients with immediate MACE compared with approximately 15% among those without MACE (log-rank χ² 348.6, p<0.001). Conclusion Among haemodynamically stable ACS patients undergoing PCI, immediate post-procedural MACE occurs in a substantial minority and is independently driven by ventricular dysfunction, renal impairment, anaemia, impaired coronary flow, and multivessel disease. Importantly, early complications confer a persistent and clinically meaningful excess risk of long-term mortality. Immediate post-PCI MACE should therefore be regarded as a powerful marker of systemic vulnerability warranting intensified follow-up and optimisation of secondary prevention.