# Association between insulin resistance and coronary microcirculatory function and adverse cardiovascular events after PCI in non-diabetic STEMI patients

## TL;DR

This study finds that insulin resistance in non-diabetic heart attack patients is linked to poor coronary microcirculation and higher risk of future heart problems.

## Contribution

The study establishes a novel link between insulin resistance and microcirculatory dysfunction in non-diabetic STEMI patients.

## Key findings

- Higher HOMA-IR levels correlate with increased IMR and decreased CFR in non-diabetic STEMI patients.
- Elevated HOMA-IR is an independent predictor of microcirculatory dysfunction and MACE after PCI.
- Patients with higher insulin resistance have a significantly higher 1-year MACE incidence.

## Abstract

Hyperglycemia and insulin resistance (IR) are common in patients with acute ST-segment elevation myocardial infarction (STEMI). However, the impact of IR on coronary microcirculatory function in non-diabetic STEMI patients remains unclear. This study aimed to investigate the relationship between IR and coronary microcirculation function and the incidence of major adverse cardiovascular events (MACE) at one year after Percutaneous Coronary Intervention (PCI) in non-diabetic STEMI patients.

A total of 298 non-diabetic STEMI patients who underwent emergency PCI between 2022 and 2024 were retrospectively enrolled. Patients were divided into low, medium, and high groups based on Homeostasis Model Assessment of Insulin Resistance (HOMA-IR tertiles). Coronary microcirculation function was assessed using the index of microcirculatory resistance (IMR) and coronary flow reserve (CFR). IMR, CFR, and MACE were compared among the three groups. Pearson correlation was used to analyze the relationships between HOMA-IR and IMR/CFR. Logistic regression was used to identify predictors of microcirculatory dysfunction, and Cox regression was used to assess risk factors for MACE.

IMR increased and CFR decreased with rising HOMA-IR levels (P < 0.001). HOMA-IR was positively correlated with IMR and negatively correlated with CFR. Patients with higher HOMA-IR levels had significantly higher 1-year MACE incidence than those with lower HOMA-IR. Multivariate logistic regression analysis showed that high HOMA-IR was an independent predictor of elevated IMR (≥25) and reduced CFR (<2.0). Multivariate Cox regression analysis indicated that high HOMA-IR was an independent risk factor for MACE.

In non-diabetic STEMI patients, elevated HOMA-IR is closely associated with coronary microcirculatory dysfunction and increased risk of 1-year MACE. Routine assessment of HOMA-IR may help identify high-risk individuals and support the development of individualized treatment strategies.