Association of Admission Glycaemia With High Grade Atrioventricular Block in ST-Segment Elevation Myocardial Infarction Undergoing Reperfusion Therapy: An Observational Study

Several studies have demonstrated the association between elevated admission glycaemia (AG) and the occurrence of some arrhythmias such as atrial fibrillation, ventricular tachycardia, and ventricular fibrillation after myocardial infarction. However, the impact of elevated AG on the high grade atrioventricular block (AVB) occurrence after ST-segment elevation myocardial infarction (STEMI) remains unclear. Included were 3359 consecutive patients with STEMI who received reperfusion therapy. The primary endpoint was the development of high grade AVB during hospital course. Patients were divided into non-diabetes mellitus (DM), newly diagnosed DM, and previously known DM according to the hemoglobin A1c level. The optimal AG value was determined by receiver operating characteristic curves analysis with AG predicting the high grade AVB occurrence. The best cut-off value of AG for predicting the high grade AVB occurrence was 10.05 mmol/L by ROC curve analysis. The prevalence of AG ≥ 10.05 mmol/L in non-DM, newly diagnosed DM, and previously known DM was 15.7%, 34.1%, and 68.5%, respectively. The incidence of high grade AVB was significantly higher in patients with AG ≥ 10.05 mmol/L than <10.05 mmol/L in non-DM (5.7% vs. 2.1%, P < 0.001) and in newly diagnosed DM (10.2% vs.1.4%, P < 0.001), but was comparable in previously known DM (3.6% vs. 0.0%, P = 0.062). After multivariate adjustment, AG ≥ 10.05 mmol/L was independently associated with increased risk of high grade AVB occurrence in non-DM (HR = 1.826, 95% CI 1.073–3.107, P = 0.027) and in newly diagnosed DM (HR = 5.252, 95% CI 1.890–14.597, P = 0.001). Moreover, both AG ≥ 10.05 mmol/L and high grade AVB were independent risk factors of 30-day all cause-mortality (HR = 1.362, 95% CI 1.006–1.844, P = 0.046 and HR = 2.122, 95% CI 1.154–3.903, P = 0.015, respectively). Our study suggested that elevated AG level (≥10.05 mmol/L) might be an indicator of increased risk of high grade AVB occurrence in patients with STEMI.