General HbA1c Goals Potentially Increase Myocardial Infarction Severity in Diabetes Patients with Comorbidities: Insights from a Nationwide Multicenter Study.

AIMS: 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 diabetic patients could benefit from glycosylated hemoglobin (HbA1c) below the recommended level. METHODS: Consecutive STEMI patients admitted in 2015-2017 across 244 hospitals in China STEMI Care Project-2. We conducted a cross-sectional study comprising 8370 participants with a record of HbA1c testing after admission. CAD extent and severity was assessed by admission heart rate (AHR), Killip classification, and the number of stenosed vessels based on the coronary angiogram (CAG). RESULTS: Diabetic patients showed a higher risk for higher Killip class, admission tachycardia (AHR≥100 beats per minute) and multi-vessel CAD (MVD, presence of left main and/or triple vessel disease). Likewise, HbA1c level was significantly associated with CAD extent and severity. While dividing diabetic patients according to general HbA1c targets (HbA1c ≤6.5, 6.5-7.0, and ≥7.0%), diabetic patients with HbA1c ≤6.5% showed a 1.30-fold higher risk for MVD (adjusted odds ratio [aOR] 1.30, 95% CI: 1.05-1.62). In stratified analysis, the association was even stronger in patients with hypertension (aOR 1.41, 95% CI: 1.08-1.86) or hyperlipidemia (aOR 1.57, 95% CI: 1.17-2.12). CONCLUSIONS: HbA1c level is independently correlated with CAD extent and severity in STEMI patients. HbA1c below generally recommended levels may still increase the risk of CAD progression, especially for diabetic patients with hypertension or hyperlipidemia.