Association of dysglycaemic indices with coronary anatomical complexity in non-diabetic patients presenting with acute coronary syndrome

Background Subclinical dysglycemia contributes to atherosclerotic progression even in individuals without established diabetes mellitus. However, the relationship between composite dysglycaemic indices and coronary anatomical complexity in acute coronary syndrome (ACS) remains insufficiently characterized. Purpose To evaluate the association between multiple dysglycaemic indices and coronary anatomical complexity assessed by the SYNTAX score in non-diabetic patients presenting with ACS and to compare their predictive performance. Methods This prospective observational study included 240 consecutive non-diabetic patients admitted with ACS who underwent coronary angiography. Patients with known diabetes, previous coronary revascularisation, chronic kidney disease, significant valvular disease or anaemia were excluded. Metabolic parameters measured within 24 hours of admission included fasting plasma glucose, glycated haemoglobin (HbA1c), triglycerides and high-density lipoprotein cholesterol. The triglyceride–glucose (TyG) index and atherogenic index of plasma (AIP) were calculated. Coronary anatomical complexity was quantified using the SYNTAX score by two blinded interventional cardiologists. High complexity was defined as SYNTAX score ≥22. Correlation analysis assessed associations between metabolic indices and SYNTAX score. Multivariable linear and logistic regression models were adjusted for age, sex, body mass index, hypertension, smoking status, low-density lipoprotein cholesterol and C-reactive protein. Discrimination was evaluated using receiver operating characteristic analysis. Results Mean age was 58±9 years and 70% were male. High SYNTAX score (≥22) was observed in 86 patients (35.8%). Patients with high SYNTAX score had significantly higher HbA1c (6.0±0.5% vs 5.6±0.4%, p<0.001), TyG index (9.0±0.5 vs 8.6±0.4, p<0.001) and AIP (0.29±0.09 vs 0.21±0.07, p<0.001). TyG index showed the strongest correlation with SYNTAX score (r=0.47, p<0.001). In multivariable logistic regression analysis, independent predictors of high SYNTAX score were TyG index (odds ratio 2.62, 95% confidence interval 1.61–4.27, p<0.001), HbA1c (odds ratio 1.98, 95% confidence interval 1.22–3.19, p=0.005), age (odds ratio 1.04 per year, p=0.003) and hypertension (odds ratio 1.76, p=0.04). Area under the curve values were 0.81 for TyG index, 0.74 for HbA1c and 0.76 for AIP. A combined metabolic model demonstrated an area under the curve of 0.87. Conclusion(s) In non-diabetic patients presenting with ACS, dysglycaemic indices are independently associated with increased coronary anatomical complexity. The TyG index demonstrated the strongest predictive performance. Assessment of subclinical metabolic dysfunction may enhance early identification of patients with complex coronary disease.Multivariate Linear RegressionROC Curve Analysis