Comparison of the prognostic value of complete blood count-derived inflammatory markers for long-term outcomes in ST-segment elevation myocardial infarction.

Inflammation plays a key role in the pathophysiology of ST-segment elevation myocardial infarction (STEMI). Several complete blood count (CBC)-derived inflammatory markers have been proposed as prognostic tools, but comparative data on their long-term predictive value remain limited. This study aimed to evaluate and compare the prognostic value of six CBC-derived markers-neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), and pan-immune-inflammation value (PIV)-for 1 year mortality and reinfarction after STEMI. We conducted a retrospective cohort study involving 689 STEMI patients treated with primary percutaneous coronary intervention between 2013 and 2022. Inflammatory markers were calculated from initial CBC values. Optimal cut-off points were identified using receiver operating characteristic analysis. Associations with 1 year mortality were assessed using Kaplan-Meier survival curves and multivariable Cox regression. After adjustment for clinical variables, elevated NLR (HR: 2.18, 95% CI 1.26-3.75), SII (HR: 3.83, 95% CI 1.63-9.01), SIRI (HR: 2.70, 95% CI 1.50-4.88), and PIV (HR: 3.17, 95% CI 1.66-6.07) were independently associated with 1 year mortality. A dose-response relationship was observed across tertiles of these markers. Subgroup analyses showed stronger prognostic value in older adults, males, and patients with diabetes. For 1 year reinfarction, multivariable logistic regression showed that only elevated PLR (OR: 1.59, 95% CI 1.05-2.41) was independently associated and showed a dose-response relationship. Selected CBC-derived inflammatory markers may serve as accessible, cost-effective biomarkers for long-term risk stratification in STEMI patients.