Usefulness of Immature Granulocytes as A Prognostic Factor in ST-Elevation Myocardial Infarction

ABSTRACT Objective: ST-segment elevation myocardial infarction (STEMI) is a serious, life-threatening disease. Inflammatory markers have recently become the focus of attention in the assessment of severity in the early stages of STEMI. This study aimed to evaluate the importance of immature granulocytes (IG) as a prognostic marker in STEMI. Methods: Patients admitted to the coronary care unit with a diagnosis of STEMI and who underwent primary percutaneous coronary intervention (pPCI) within the period from January 1, 2019 to January 1, 2020, were retrospectively scanned. A total of 146 patients were analised; of these, 112 (76.7%) were male and 34 (33.3) were female, with a mean age of 62.65±14.06 years. Patients’ age, gender, haemogram, biochemistry, and mortality results were recorded. The patients were divided into two groups as low (<0.6) and high (≥0.6) IG levels and compared. Results: The mean IG levels were significantly higher in the non-survivor group compared to the survivor group (1.12±0.22 vs. 0.50±0.28, P<0.001). Mortality rates were significantly higher in the high IG group compared to the low IG group (26.9% vs. 9.6%, P=0.006). IG was shown to predict mortality with a sensitivity of 72.2% and a specificity of 77.8% at a cut-off value of 0.65 (area under the curve: 0.740, 95% CI: 0.635-0.846, P<0.001). Conclusion: High IG values in the blood collected at the time of admission to the emergency department are a marker of mortality in patients with STEMI.

摘要
目的：ST段抬高型心肌梗死（ST-segment elevation myocardial infarction, STEMI）是一种严重危及生命的疾病。近年来，炎症标志物在STEMI早期病情严重程度评估中成为研究热点。本研究旨在评估未成熟粒细胞（immature granulocytes, IG）作为STEMI预后标志物的临床价值。
方法：回顾性筛选2019年1月1日至2020年1月1日期间，因确诊STEMI收入冠心病监护病房并接受直接经皮冠状动脉介入治疗（primary percutaneous coronary intervention, pPCI）的患者。最终共纳入146例患者进行分析，其中男性112例（76.7%），女性34例（33.3%），平均年龄为62.65±14.06岁。收集患者的年龄、性别、血常规、生化指标及死亡率结局数据。根据IG水平将患者分为低水平组（<0.6）与高水平组（≥0.6），并开展组间比较。
结果：非存活组患者的平均IG水平显著高于存活组（1.12±0.22 vs. 0.50±0.28，P<0.001）。高水平IG组患者的死亡率显著高于低水平IG组（26.9% vs. 9.6%，P=0.006）。当截断值为0.65时，IG预测死亡的灵敏度为72.2%，特异度为77.8%（曲线下面积：0.740，95%置信区间：0.635~0.846，P<0.001）。
结论：急诊入院时采集的外周血中高水平IG可作为STEMI患者死亡风险的预测标志物。