Prognostic Value of the Residual SYNTAX Score in Patients With Non–ST-Segment Elevation Myocardial Infarction, Type 2 Diabetes Mellitus, and Preserved or Mildly Reduced Ejection Fraction: A Six-Month Follow-Up Study From Central Asia

Background: To evaluate the prognostic significance of the residual SYNTAX score (rSS) for predicting adverse cardiovascular outcomes in patients with non-ST elevation myocardial infarction (NSTEMI) and preserved or mildly reduced left ventricular ejection fraction (LVEF; ≥ 40%), among whom type 2 diabetes mellitus was a prevalent comorbidity, with a focus on the interplay among incomplete revascularization, myocardial dysfunction, and neurohormonal activation.Methods: This prospective cohort study included 163 patients with NSTEMI.Patients underwent coronary angiography, comprehensive echocardiographic assessment including diastolic function parameters, and biomarker analysis with an emphasis on heart failure markers.The rSS was calculated after percutaneous coronary intervention.Outcomes included cardiovascular death, recurrent myocardial infarction, ischemic stroke, heart failure hospitalization, and repeat revascularization during the 6-month follow-up period. Results:The rSS and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were independent predictors of adverse events.Each 1-unit increase in rSS was associated with a 9.6% higher risk (odds ratio [OR], 1.096; P = 0.048).NT-proBNP > 990 pg/mL predicted the need for repeat revascularization (OR, 1.082; P = 0.002).Patients with adverse outcomes had significantly lower LVEF (41.4% vs. 48.4%,P = 0.001), higher E/e′ ratios indicating diastolic dysfunction (11.8 vs. 8.6, P = 0.025), and larger left atrial volumes, reflecting elevated filling pressures.Receiver operating characteristic analysis showed moderate discriminative ability (area under the receiver operating characteristic curve = 0.72).