Major Adverse Cardiovascular Events (Mace) in Stemi Patients With Elevated Neutrophil-to-Lymphocyte Ratio Undergoing Primary Percutaneous Coronary Intervention-a Study in Pakistani Cohort

Background: Cardiovascular diseases (CVDs) remain the leading cause of death globally, with approximately 20.5 million fatalities recorded in 2021, representing nearly one-third of all deaths.¹ Low- and middle-income countries (LMICs) bear a disproportionate burden, accounting for 80% of these cases.¹ ST-segment elevation myocardial infarction (STEMI), a severe form of coronary heart disease (CHD), continues to contribute significantly to global morbidity and mortality.² In countries such as India and China, STEMI accounts for 60–80% of hospital admissions related to myocardial infarction (MI). This study aimed to evaluate the association between an elevated neutrophil-to-lymphocyte ratio (NLR) and the occurrence of major adverse cardiovascular events (MACE) in patients with STEMI undergoing primary percutaneous coronary intervention (PPCI). Methods: A retrospective observational study was conducted at a tertiary care cardiac center in Rawalpindi, Pakistan, from December 2018 to May 2019. A total of 155 STEMI patients treated with PPCI were included. Patients with active infections, autoimmune disorders, hematologic malignancies, severe renal or hepatic impairment, or those receiving immunosuppressive therapy were excluded. NLR values were calculated from blood samples collected upon hospital admission, and patients were divided into two groups: those with elevated NLR (≥4.8) and those with lower NLR (<4.8). The primary outcome was in-hospital MACE, defined as mortality and non-fatal MI. Statistical analysis involved univariate and multivariate logistic regression to identify independent predictors of MACE. Results: Of the 155 patients, 39 (25.2%) experienced MACE. The incidence of MACE was significantly higher in the elevated NLR group (84.6%) compared to the lower NLR group (15.4%) (p= 0.001). Univariate analysis demonstrated a strong association between high NLR and increased MACE risk (OR: 2.11; 95% CI: 1.61–2.76; p=0.001). Multivariate analysis, after adjusting for confounding variables, confirmed NLR as an independent predictor of MACE (AOR: 2.08; 95% CI: 1.57–2.74; p=0.001). Conclusion: Elevated NLR is a significant predictor of MACE in STEMI patients undergoing PPCI. Given its simplicity and cost-effectiveness, NLR may serve as a valuable biomarker for early risk stratification and targeted intervention in STEMI management.