Stress hyperglycemia ratio is associated with microcirculatory resistance in patients with ST-segment elevation myocardial infarction

Stress hyperglycemia is a common phenomenon in patients with critical illness, and its association with coronary microcirculation in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) remains poorly understood. The coronary angiography-derived index of microcirculatory resistance (AMR) is a tool used to assess coronary microcirculation. This study aimed to investigate the relationship between stress hyperglycemia ratio (SHR) and AMR in STEMI patients undergoing pPCI. Three hundred sixty-two consecutive patients who underwent pPCI at Taizhou People’s Hospital between 2022 and 2023 were initially screened in this observational study. The study populations were classified as three groups according to fasting SHR tertiles: SHR1: SHR ≤ 0.76 (n = 114); SHR2: 0.76 < SHR < 0.96 (n = 110); and SHR3: SHR ≥ 0.96 (n = 113). Restricted cubic spline analysis was performed to explore the relationship between SHR and AMR. Logistic regression analysis was performed to identify independent predictors of high AMR (AMR ≥ 2.5). A total of 337 STEMI patients were included in this observational study. The AMR was significantly lower in SHR1 and SHR2 than that in SHR3 (all P < 0.05). The AMR were positively correlated with SHR (p for overall < 0.001, p for non-linear = 0.236). Multivariable logistic regression analysis identified SHR3 as an independent risk factor for high AMR after adjusting for other covariates (odds ratio: 1.78, 95% confidence interval: 1.040–3.058, p = 0.035). The SHR is an independent predictor of high AMR in STEMI patients undergoing pPCI. These results may offer new insights into the pathophysiology of STEMI and highlight the potential value of SHR as a clinical marker for coronary microcirculation status.