Prognostic Value of Mean Platelet Volume-To-Monocyte Ratio and Ferritin in NSTEMI: Independent Impact of Angiotensin-Converting Enzyme Inhibitor Therapy.

BACKGROUND Inflammation-driven mechanisms play a central role in adverse outcomes after non-ST-elevation myocardial infarction (NSTEMI), yet simple, widely available biomarkers for early risk stratification remain insufficiently defined. Hemogram-derived indices and iron-related inflammatory markers may provide complementary prognostic information. OBJECTIVE To evaluate the prognostic significance of the mean platelet volume-to-monocyte ratio (MMR) and serum ferritin in predicting major adverse cardiovascular events (MACE) in patients with NSTEMI, and to assess the association of angiotensin-converting enzyme (ACE) inhibitor therapy with clinical outcomes. METHODS This prospective cohort study included 170 consecutive NSTEMI patients admitted to the University Clinical Center Tuzla between February 2022 and January 2023. All patients received dual antiplatelet therapy and high-intensity statins. The baseline evaluation included a complete blood count, serum ferritin, and C-reactive protein. MMR was calculated as the ratio of mean platelet volume to absolute monocyte count. Patients were followed for 12 months for the occurrence of MACE, defined as cardiovascular death, non-fatal myocardial infarction, urgent revascularization, stroke, or hospitalization for heart failure. RESULTS During follow-up, 103 patients (60.6%) experienced MACE. Admission MMR (18.1 ± 11.7 vs 13.2 ± 5.5; P = 0.003) and ferritin levels (284 ± 396 vs 152 ± 109 µg/L; P = 0.001) were significantly higher in patients with events. In multivariable analysis, both MMR (odds ratio [OR] 1.06, 95% confidence interval [CI] 1.02-1.11; P = 0.008) and ferritin (OR 1.28 per 100 µg/L, 95% CI 1.10-1.55; P = 0.003) independently predicted MACE, while ACE inhibitor therapy was associated with a lower risk (OR 0.24, 95% CI 0.08-0.70; P = 0.01). The combined model demonstrated good discriminative performance (AUC 0.72; 95% CI 0.64-0.80). CONCLUSION AND RELEVANCE Elevated admission MMR and ferritin were independently associated with a higher 1-year risk of MACE in patients with NSTEMI. ACE inhibitor therapy was associated with improved outcomes, although causality cannot be inferred. These findings suggest that readily available inflammatory biomarkers may complement established clinical parameters for early risk stratification and support continued guideline-directed pharmacotherapy in NSTEMI.