Study of the relationship between hemoglobin A1C level and baseline and post PCI TIMI flow grade and thrombosis grade, in non-diabetic patients with acute ST-segment elevation myocardial infarction undergoing primary coronary angioplasty

Abstract

Coronary blood flow in the acute phase of ST-segment elevation myocardial infarction (STEMI) measured by TIMI grade, determines the clinical outcome of the patient and is influenced by multiple factors. Despite extensive studies the modifiable risk factors of impaired coronary blood flow (TIMI<3) and its effective treatment are not fully understood. Hyperglycemia may induce a prothrombotic state and thus affect TIMI flow before or after PCI. Objective: The aim of this study is to determine the relationship between admission HbA1c level and initial and final TIMI flow grade and thrombus burden grade in the infarct-related artery (IRA) and its predictive value, in non-diabetic patients with STEMI undergoing primary PCI (pPCI). Methods: A total of 383 consecutive patients diagnosed with STEMI and without history of diabetes mellitus (DM) underwent pPCI within 12 hours from symptoms onset. Of these 118 (31%) patients were excluded from the study due to having HbA1c equal to or greater than 6.5% which is in accordance with American Diabetes Association (ADA) for diagnosing DM. The remaining 265 patients were divided into three groups based on the HbA1c levels. Group 1(HbA1c ≤5%), group 2(5.1%-5.9%), and group 3(6%-6.4%). Comparison between three groups in term of risk factors, peak troponin, blood glucose, lipid profile, kidney function, number of diseased vessels, location of infarction, left ventricular ejection fraction, baseline and final TIMI flow and thrombus burden grade, complications and hospital mortality were performed. Results: With increase of HbA1c levels, the prevalence of TIMI 3 flow after pPCI decreased: group1 87%, group2 78%, group3 63%, p= 0.008. The prevalence of TIMI 2-3 flow before pPCI also decreased with increasing HbA1c levels but it was not statistically significant: group1 32%, group2 26%, group3 13%, p= 0.124. Increased HbA1c level had a significant relationship with large thrombus burden, p= 0.021. In multivariable regression analysis, HbA1c remained an independent predictor of post primary PCI TIMI flow grade and thrombus burden grade.