The current work mainly assessed eGDR’s predictive value for negative outcome after PCI in NSTE-ACS patients. It demonstrated that low eGDR was highly associated with elevated incidence of the primary endpoint. Reduction in eGDR levels represented a significant and independent predictive factor of adverse outcome in the examined study population. Moreover, compared with eGDR calculated by BMI, eGDR calculated by WC was more potent in predicting poor prognosis after PCI in NSTE-ACS individuals. Furthermore, addition of eGDR improved the ability of a model incorporating currently recognized cardiovascular risk factors for predicting a negative prognosis.
IR is the most critical mechanism of T2DM progression. IR is tightly correlated with the onset, progression and long-term prognosis of CVD as demonstrated recently. Data have confirmed that IR is significantly correlated with the formation of atherosclerotic plaques and cardiac dysfunction , in agreement with previous studies revealing that IR has profound effects in the whole process of CVD [34, 35]. Additionally, IR is significantly linked to adverse patient outcome in individuals with pre-existing CVD [36, 37]. Therefore, accurate and efficient assessment of IR has important clinical value for predicting the progression and prognosis of CVD, especially coronary heart disease. Although direct assessment methods including hyperinsulinemic-euglycemic clamp, insulin suppression test and minimal model analysis of the insulin-modified frequently sampled intravenous glucose tolerance test can accurately assess IR, they have high operational complexity and invasive properties, precluding their wide application in clinical practice. Therefore, in recent years, clinicians have attempted to develop simple surrogate indicators of IR.
eGDR was developed and validated by the hyperinsulinemic-euglycemic clamp, which ensures its accuracy for the assessment of IR to a certain extent. IR assessed by eGDR is considered the only factor consistently associated with all chronic complications of T1DM . A cross-sectional study of T1DM patients found that individuals showing low eGDR have remarkably enhanced risk of CVD . In T1DM, eGDR was shown to be an effective predictor of survival with tight associations with all-cause mortality and cardiovascular mortality . In T2DM cases, eGDR was found to independently predict all-cause mortality upon adjustment for confounders such as diabetic kidney disease . Furthermore, eGDR is also considered a reliable, clinically applicable method for the assessment of double diabetes and could be used to monitor response to specific treatments, with an effect similar to that of HbA1c . As stated in the introduction, in a nationwide observational study of 3256 individuals with T2DM who underwent CABG with a median follow-up of 3.1 years, low eGDR was strongly associated with enhanced risk of all-cause mortality, independently of other cardiac vascular and metabolic risk factors . In addition, in another observational cohort trial of 104697 T2DM cases with a 5.6-year median follow-up, low eGDR was associated with escalated incidence rates of stroke and mortality, indicating eGDR might serve as a risk marker of stroke and death . These findings suggest that eGDR has great potential for predicting the prognosis of patients with cardio-cerebral diseases. Based on the above studies, this work also obtained consistent findings, further clarifying the predictive potential of eGDR reduction for adverse consequence in NSTE-ACS individuals treated by PCI. Multivariate and subgroup analysis suggested that eGDR was a strong and stable predictor of adverse events. This study also found that eGDRWC was more robust than eGDRBMI in multivariate analysis. Moreover, the incremental effect of eGDRWC on the predictive ability of CVD predictors for the primary endpoint was stronger than that of eGDRBMI. BMI is a currently recognized cardiovascular risk factor . WC, which reflects visceral fat, is strongly associated with IR and ASCVD progression . Whether the prognostic value of eGDRWC in NSTE-ACS cases undergoing PCI is higher than that of eGDRBMI needs to be determined in larger and better-designed studies.
The calculation formula of eGDR includes three factors: hypertension, HbA1c and WC. Hypertension is the most important component of the formula , with a well-known impact on ASCVD development and prognosis. HbA1c is a known predictor of CAD severity and early prognosis in stable angina pectoris . In diabetics with successful DES implantation, HbA1c is highly correlated with enhanced risk of major adverse cardiovascular events . In obesity, it is highly related not only to IR, but also to underlying diseases such as hypertension, dyslipidemia, CVD and stroke [44, 47]. WC is the preferred index recommended by the World Health Organization for the evaluation of central obesity, showing a strong association with visceral fat content measured by CT. WC shows associations with the incidence rates of cardiac death and non-fatal MI in cases administered PCI . For eGDR, IR assessed by eGDR is independently correlated with carotid plaque burden in T1DM . In addition, a study examining the correlations between eGDR and thrombotic biomarkers in T1DM patients showed that eGDR is a suitable indicator of prothrombotic status, with superiority to BMI and insulin requirements .
The limitations of the current study should be addressed. First, given its single-center, retrospective, observational features, larger prospective multicenter trials are warranted to validate the present findings and improve the power of this analysis. Secondly, UA patients accounted for the majority of all NSTE-ACS cases in this study, so these results may not reflect the prognostic potential of eGDR in NSTEMI patients. Finally, only Chinese individuals were included, and the generalizability and stability of the findings need to be verified in other ethnic groups.