Prognostic Value of Inflammatory Status in Patients with Acute Coronary Syndromes: A Single-Center Experience

Background/Objectives: Acute coronary syndromes (ACS) encompass a spectrum of clinical entities from unstable angina to non–ST-segment elevation myocardial infarction (NSTEMI) and ST-segment elevation myocardial infarction (STEMI), all associated with significant morbidity and mortality. Inflammation plays a central role in the pathophysiology of ACS, contributing to atherosclerotic plaque destabilization, myocardial injury, and adverse clinical outcomes. Inflammatory biomarkers, together with N-terminal pro–B-type natriuretic peptide (NT-proBNP), are increasingly used for risk stratification, yet their prognostic value across different ACS presentations remains unclear. This study aimed to assess the prognostic value of inflammatory status in patients with acute coronary syndromes in a single-center cohort. Methods: This prospective observational study included 100 consecutive patients with ACS and elevated inflammatory biomarkers, enrolled in 2024–2025 at a tertiary cardiovascular center. Inflammatory status was assessed by using C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR) and systemic immune-inflammation index (SII); NT-proBNP was also measured. The primary endpoint was in-hospital MACE, defined as cardiovascular death, recurrent myocardial infarction, stroke, urgent coronary revascularization, or acute heart failure requiring escalation of therapy. Multivariable logistic regression and ROC analyses were performed. Results: Among the 100 ACS patients, half experienced in-hospital MACE. Compared with those without events, patients with MACE were older (p = 0.003) and had higher inflammatory biomarkers—CRP (p < 0.001; strongest association), NLR (p = 0.030), and SII (p = 0.042)—as well as higher NT-proBNP (p = 0.002). Patients with MACE also showed reduced renal function (p < 0.001) and lower left ventricular systolic function, reflected by reduced LVEF (p = 0.001), indicating concomitant renal impairment and ventricular dysfunction. Hypertension was more prevalent in the MACE group (p = 0.028), and new-onset atrial fibrillation was significantly more common among these patients (p < 0.001). In multivariable analysis, LVEF emerged as an independent predictor of short-term outcomes (OR 0.934 per 1% increase; p = 0.047). Conclusions: Inflammatory activation appears closely linked to the occurrence of in-hospital adverse events in patients with acute coronary syndromes. While left ventricular ejection fraction remained an independent determinant of short-term outcomes, inflammatory biomarkers may provide complementary insight into the inflammatory burden accompanying ACS.