Echocardiographic Strain-derived Predictors of Coronary Disease Burden Assessed by SYNTAX Score in Non-ST-elevation Acute Coronary Syndrome.

OBJECTIVE: The objective of this study was to evaluate whether global longitudinal strain (GLS), early systolic lengthening (ESL), and postsystolic shortening (PSS), individually and combined, predict anatomical disease severity and significant coronary artery stenosis in non-ST-elevation acute coronary syndrome (NSTE-ACS) with preserved left ventricular ejection fraction (LVEF). MATERIALS AND METHODS: We prospectively enrolled 112 NSTE-ACS patients with preserved LVEF and no regional wall motion abnormalities. GLS, ESL, and PSS were measured using two-dimensional speckle-tracking echocardiography. Significant coronary artery disease (CAD) was defined as ≥90% stenosis in at least one major epicardial artery, and anatomical burden was quantified using the SYNTAX score. Linear and logistic regression, receiver-operating characteristic (ROC) analysis, DeLong comparison, and internal validation were performed. RESULTS: GLS and PSS were significant predictors of SYNTAX score in univariate linear regression. In the multivariable model, only GLS remained independently associated with SYNTAX (P < 0.001), explaining 26.2% of variance (adjusted R² =0.24; variance inflation factor <5). Significant stenosis was present in 70 patients (62%). ESL (P = 0.028) and PSS (P = 0.001) predicted ≥ 90% stenosis in univariate analysis, whereas GLS reached significance only in multivariable analysis (odds ratio 1.28, 95% confidence interval 1.09-1.51, P = 0.003). The multimarker model (GLS + ESL + PSS) had the highest ROC area under the curve (AUC) (0.726) but did not significantly outperform GLS alone (AUC 0.707; P = 0.390). Model-predicted probabilities correlated with SYNTAX (ρ =0.480, P < 0.001). CONCLUSIONS: GLS is the strongest strain-derived predictor of both significant stenosis and anatomical CAD burden in NSTE-ACS with preserved LVEF. Strain-based analysis may aid early, noninvasive risk stratification in this population.