General glycosylated hemoglobin goals potentially increase myocardial infarction severity in diabetes patients with comorbidities: Insights from a nationwide multicenter study

AIMS/INTRODUCTION: We aimed to investigate the relationship between glycemic status and coronary artery disease (CAD) extent and severity in ST‐elevation myocardial infarction (STEMI) patients, and further examine whether diabetes patients could benefit from glycosylated hemoglobin (HbA1c) below the recommended level. MATERIALS AND METHODS: Consecutive STEMI patients admitted in 2015–2017 across 244 hospitals were included in the China STEMI Care Project‐2. We carried out a cross‐sectional study comprising 8,370 participants with a record of HbA1c testing after admission. CAD extent and severity were assessed by admission heart rate, Killip classification and the number of stenosed vessels based on the coronary angiogram. RESULTS: Diabetes patients showed a greater risk for higher Killip class, admission tachycardia (admission heart rate ≥100 b.p.m.) and multivessel CAD (presence of left main and/or triple vessel disease). Likewise, HbA1c level was significantly associated with CAD extent and severity. While dividing diabetes patients according to general HbA1c targets (HbA1c ≤6.5, 6.5–7.0 and ≥7.0%), diabetes patients with HbA1c ≤6.5% showed a 1.30‐fold higher risk for multivessel CAD (adjusted odds ratio 1.30, 95% confidence interval 1.05–1.62). In stratified analysis, the association was even stronger in patients with hypertension (adjusted odds ratio 1.41, 95% confidence interval 1.08–1.86) or hyperlipidemia (adjusted odds ratio 1.57, 95% confidence interval 1.17–2.12). CONCLUSIONS: HbA1c level is independently correlated with CAD extent and severity in STEMI patients. HbA1c below generally recommended levels might still increase the risk of CAD progression, especially for diabetes patients with hypertension or hyperlipidemia.