Impact of glucometabolic status on type 4a myocardial infarction in patients with non–ST-segment elevation myocardial infarction: the role of stress hyperglycemia ratio

Background: Type 4a myocardial infarction (MI) is a relevant complication in non-ST-segment elevation myocardial infarction (NSTEMI) patients undergoing percutaneous coronary intervention (PCI). While glucometabolic status has been linked to type 4a MI in chronic coronary syndromes, data in the acute setting are lacking. This study aimed to assess the association of glucometabolic parameters-admission blood glucose (ABG), glycated hemoglobin (HbA1c) and stress hyperglycemia ratio (SHR)-with type 4a MI in NSTEMI patients undergoing PCI and evaluate their independent predictive role. Methods: Consecutive NSTEMI patients undergoing PCI from the AMIPE multicenter prospective registry (NCT03883711) with stable or falling pre-procedural cardiac troponin levels were analyzed. The optimal glucometabolic predictor of type 4a MI among ABG, HbA1c and SHR was identified using receiver operating characteristic analysis. The best cut-off for each parameter was derived using Youden's index. Regression analysis and Kaplan-Meier curves were performed to identify independent predictors of type 4a MI and their prognostic implications. Results: The study population included 1005 patients (mean age 70.3 ± 12.5 years, 25.5% females), with 45.9% having diabetes mellitus. SHR showed a significantly higher accuracy (AUC 0.69, 95% CI 0.65-0.73) in predicting type 4a MI compared with ABG and HbA1c (p < 0.001), with an optimal cut-off of 1.14, consistent across diabetic and non-diabetic patients. SHR > 1.14 was independently associated with type 4a MI (aOR = 2.73; 95% CI 1.70-4.42; p < 0.001), unlike ABG and HbA1c, and was also linked to an increased risk of long-term major adverse cardiovascular events (p < 0.001). Conclusions: SHR emerged as a strong predictor of type 4a MI in NSTEMI patients undergoing PCI, outperforming other glucometabolic markers.