Aim: The triglyceride–glucose (TyG) index has been shown to be an independent predictor for the progression and prognosis of coronary artery disease (CAD). Whether the TyG index predicts the severity of CAD in patients presenting with acute coronary syndrome (ACS) remains unknown. Methods: A total of 1,007 individuals presenting with ACS undergoing coronary angiography were stratified according to the tertiles of the TyG index and The Synergy Between Percutaneous Coronary Intervention (SYNTAX) score (SYNTAX score ≤ 22 versus SYNTAX score > 22). CAD complexity was determined by the SYNTAX score. Results: After adjusting for multiple confounding factors, the TyG index was still an independent risk factor for mid/high SYNTAX scores (SYNTAX score > 22, OR 2.6452, 95% CI 1.9020–3.6786, P < 0.0001). Compared with the lowest tertile of the TyG (T1) group, the risk for a mid/high SYNTAX score in the T2 and T3 groups was 2.574-fold higher (OR, 2.574; 95% CI 1.610–4.112; P < 0.001) and 3.732-fold higher (OR, 3.732; 95% CI 2.330–5.975; P < 0.001), respectively. Furthermore, there was a dose‒response relationship between the TyG index and the risk of complicated CAD (SYNTAX score > 22; nonlinear P = 0.200). The risk for a mid/high SYNTAX score in the T2 and T3 groups was significantly higher in normoglycemia, prediabetes mellitus, and diabetes mellitus subgroups. Conclusions: A higher TyG index was associated with the presence of a higher coronary anatomical complexity (SYNTAX score > 22) in ACS patients, irrespective of diabetes mellitus status. The TyG index might serve as a noninvasive predictor of CAD complexity in ACS patients and could potentially influence the management and therapeutic approach.

Background: The Global Registry of Acute Coronary Events (GRACE) score derived from clinical parameters at the time of hospital discharge is a powerful predictor of long-term mortality and reinfarction after acute coronary syndrome (ACS). The triglyceride glucose (TyG) index, which is a simple and reliable surrogate marker of insulin resistance, has been demonstrated to be an independent predictor of long-term adverse major adverse cardiac events, irrespective of diabetes mellitus. We investigate whether the addition of the TyG index improves the predictive ability of the GRACE score after percutaneous coronary intervention (PCI) in ACS patients regardless of diabetes mellitus. Method: A retrospective cohort of 986 ACS patients undergoing PCI was enrolled in the present analyses. The GRACE score for discharge to 6 months and the TyG index were calculated. The primary endpoint was the composite of MACEs, including all-cause death and nonfatal myocardial infarction. Patients were stratified according to the primary endpoint and the tertiles of the TyG index. Cumulative curves were calculated using the Kaplan–Meier method. Multivariate Cox regression was adopted to identify predictors of MACEs. The predictive value of the GRACE score alone and combined with the TyG index or fasting blood glucose (FBG) was estimated by the area under the receiver‑operating characteristic curve, likelihood ratio test, Akaike’s information criteria, continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI). Internal validation was assessed using the means of bootstrap method with 1000 bootstrapped samples. Results: During a median follow-up of 30.72 months ((interquartile range, 26.13 to 35.07 months), 90 patients developed MACEs, more frequently in the patients with a higher TyG index. Multivariate Cox hazards regression analysis found that the TyG index, but not FBG was an independent predictor of MACEs (hazard ratio 1.6542; 95% CI 1.1555–2.3681; P = 0.006) in all types of ACS regardless of diabetes mellitus when included in the same model as GRACE score. Furthermore, Kaplan–Meier analysis revealed that the incidence of the primary endpoint rose with increasing TyG index tertiles (log-rank, P < 0.01). Adjustment the GRACE score by the TyG index improved the predictive ability for MACEs (increase in C-statistic value from 0.735 to 0.744; NRI, 0.282, 95% CI 0.028–0.426, P = 0.02; IDI, 0.019, 95% CI 0.004–0.046, P = 0.01). Likelihood ratio test showed that the TyG index significantly improved the prognostic ability of the GRACE score (χ² = 12.37, 1 df; P < 0.001). The results remained consistent when the models were confirmed by internal bootstrap validation method. Conclusion: The TyG index, but not FBG is an independent predictor of long-term MACEs after PCI in all types of ACS patients regardless of diabetes mellitus after adjusting for the GRACE score, and improves the ability of the GRACE score to stratify risk and predict prognosis of ACS patients undergoing PCI.

Background: The residual SYNTAX score (rSS), a quantitative measure of angiographic completeness of revascularization after percutaneous coronary intervention (PCI), and the triglyceride–glucose index (TyG index), a reliable surrogate marker of insulin resistance, have been regarded as independent predictors of major adverse cardiac events (MACEs) after PCI. Whether a combination of the rSS and the TyG index improves the predictive ability for MACEs in patients with type 2 diabetes mellitus (T2DM) undergoing PCI remains unknown. Methods: A total of 633 consecutive patients with T2DM who underwent PCI were included in the present analyses. Patients were stratified according to the optimal cutoff point value of the TyG index, or the rSS determined by receiver‑operating characteristic (ROC) curve analysis. The primary endpoint was the composite of MACEs, including all-cause death, nonfatal myocardial infarction, and unplanned repeat revascularization. Cumulative curves were calculated using the Kaplan–Meier method. Multivariate Cox regression was used to identify predictors of MACEs. The predictive value of the TyG index combined with the rSS was estimated by the area under the ROC curve, continuous net reclassification improvement (NRI) and integrated discrimination improvement (IDI). Results: During a median follow-up of 18.83 months, 99 patients developed MACEs, more frequently in the patients with a higher TyG index or rSS. Multivariate Cox hazards regression analysis revealed that both the TyG index and rSS were independent predictors of MACEs (hazard ratio 1.8004; 95% CI 1.2603–2.5718; P = 0.0012; 1.0423; 95% CI 1.0088–1.0769; P = 0.0129, respectively). Furthermore, Kaplan–Meier analysis demonstrated that both the TyG index and the rSS were significantly associated with an increased risk of MACEs (log-rank, all P < 0.01). The addition of the rSS and the TyG index to the baseline risk model had an incremental effect on the predictive value for MACE (increase in C-statistic value from 0.660 to 0.732; IDI 0.018; NRI 0.274; all P < 0.01). Conclusions: The TyG index predicts intermediate-term MACE after PCI in patients with T2DM independent of known cardiovascular risk factors. Adjustment of the rSS by the TyG index further improves the predictive ability for MACEs in patients with T2DM undergoing PCI.

Background: Insulin resistance (IR) is linked to both the complexity of coronary artery lesions and the prognosis of acute coronary syndrome (ACS). However, the precise extent of this correlation and its impact on adverse cardiovascular outcomes in ACS patients remain unclear. Therefore, this study aims to investigate the intricate relationship between IR, coronary artery lesion complexity, and the prognosis of ACS through a cohort design analysis. Method: A total of 986 patients with ACS who underwent percutaneous coronary intervention (PCI) were included in this analysis. IR was assessed using the triglyceride-glucose (TyG) index, while coronary artery lesion complexity was evaluated using the SYNTAX score. Pearson’s correlation coefficients were utilized to analyze the correlations between variables. The association of the TyG index and SYNTAX score with major adverse cardiovascular events (MACEs) in ACS was investigated using the Kaplan-Meier method, restricted cubic splines (RCS), and adjusted Cox regression. Additionally, a novel 2-stage regression method for survival data was employed in mediation analysis to explore the mediating impact of the SYNTAX score on the association between the TyG index and adverse cardiovascular outcomes, including MACEs and unplanned revascularization. Results: During a median follow-up of 30.72 months, 167 cases of MACEs were documented, including 66 all-cause deaths (6.69%), 26 nonfatal myocardial infarctions (MIs) (2.64%), and 99 unplanned revascularizations (10.04%). The incidence of MACEs, all-cause death, and unplanned revascularization increased with elevated TyG index and SYNTAX score. Both the TyG index (non-linear, P = 0.119) and SYNTAX score (non-linear, P = 0.004) displayed a positive dose-response relationship with MACEs, as illustrated by the RCS curve. Following adjustment for multiple factors, both the TyG index and SYNTAX score emerged as significant predictors of MACEs across the total population and various subgroups. Mediation analysis indicated that the SYNTAX score mediated 25.03%, 18.00%, 14.93%, and 11.53% of the correlation between the TyG index and MACEs in different adjusted models, respectively. Similar mediating effects were observed when endpoint was defined as unplanned revascularization. Conclusion: Elevated baseline TyG index and SYNTAX score were associated with a higher risk of MACEs in ACS. Furthermore, the SYNTAX score partially mediated the relationship between the TyG index and adverse cardiovascular outcomes.

Aims/Introduction: The predictive value of admission hyperglycemia in the long‐term prognosis of acute myocardial infarction patients is still controversial. We aimed to investigate this value based on the diabetes status.Materials and Methods: We carried out a multicenter, retrospective study of 1,288 acute myocardial infarction patients enrolled in 11 hospitals between March 2014 and June 2019 in Chengdu, China. The patients were classified into those with diabetes and those without diabetes, each was further divided into: hyperglycemia and non‐hyperglycemia subgroups, according to the optimal cut‐off value of the blood glucose to predict all‐cause mortality during follow up. The end‐points were all‐cause death and major adverse cardiovascular and cerebrovascular events, including all‐cause death, non‐fatal myocardial infarction, vessel revascularization and non‐fatal stroke.Results: In the follow‐up period of 15 months, we observed 210 (16.3%), 6 (0.5%), 57 (4.4%) and 34 (2.6%) cases of death, non‐fatal myocardial infarction, revascularization and non‐fatal stroke, respectively. The optimal cut‐off values of admission blood glucose for patients with diabetes and patients without diabetes to predict all‐cause mortality during follow up were 14.80 and 6.77 mmol/L, respectively. We divided patients with diabetes (n = 331) into hyperglycemia (n = 92) and non‐hyperglycemia (n = 239), and patients without diabetes (n = 897) into hyperglycemia (n = 425) and non‐hyperglycemia (n = 472). The cumulative rates of all‐cause death and major adverse cardiovascular and cerebrovascular events among the patients in each hyperglycemia group was higher than that in the corresponding non‐hyperglycemia group (P < 0.001). In patients without diabetes, admission hyperglycemia was an independent predictor of all‐cause mortality and major adverse cardiovascular and cerebrovascular events.Conclusion: Admission hyperglycemia was an independent predictor for long‐term prognosis in acute myocardial infarction patients without diabetes.

The Global Registry of Acute Coronary Events (GRACE) score is a powerful tool used to predict in-hospital mortality after acute myocardial infarction (AMI) and does not include a glycometabolism-related index. We investigated whether the addition of the stress hyperglycemia ratio (SHR) provides incremental prognostic value in addition to the GRACE score. A retrospective cohort of 613 AMI patients was enrolled in the present analyses. The patients were stratified according to the primary endpoint (in-hospital mortality) and the tertiles of the SHR. During hospitalization, 40 patients reached the primary endpoint, which was more frequently observed in patients with a higher SHR. The SHR, but not admission blood glucose (ABG), adjusted for the GRACE score independently predicted in-hospital mortality [odds ratio 2.5861; 95% confidence interval (CI), 1.3910-4.8080; P = 0.0027]. The adjustment of the GRACE score by the SHR improved the predictive ability for in-hospital death (an increase in the C-statistic value from 0.787 to 0.814; net reclassification improvement, 0.6717, 95% CI 0.3665-0.977, P < 0.01; integrated discrimination improvement, 0.028, 95% CI 0.0066-0.0493, P = 0.01028). The likelihood ratio test showed that the SHR significantly improved the prognostic models, including the GRACE score. Adding the SHR to the GRACE score presented a larger net benefit across the range of in-hospital mortality risk than the GRACE score alone. The SHR, but not the ABG, is an independent predictor of in-hospital mortality after AMI even after adjusting for the GRACE score. The SHR improves the predictability and clinical usefulness of prognostic models containing the GRACE score.