Glycemic status at admission may provide important prognostic insight in patients with acute coronary syndrome (ACS), yet its role beyond diabetes diagnosis remains uncertain. A retrospective, single-center study published in Frontiers in Clinical Diabetes and Healthcare evaluated whether hemoglobin A1c (HbA1c) levels are associated with mortality outcomes in patients admitted to an intensive cardiovascular care unit (ICCU).

The analysis included 2,772 consecutive patients with ACS between July 2019 and December 2024, with HbA1c measured at admission. Patients were categorized into non-diabetes mellitus (DM), pre-diabetes mellitus (pre-DM), and DM groups based on standard HbA1c thresholds. Demographic characteristics, clinical features, in-hospital complications, and mortality outcomes up to 60 months were assessed.

Dysglycemia was common, with 41.4% classified as non-DM, 29.1% as pre-DM, and 29.5% as DM. In-hospital mortality did not differ significantly across groups (2.0%, 1.6%, and 2.9%, respectively; p=0.294). However, long-term mortality increased progressively with higher HbA1c categories, reaching 11.4%, 14.7%, and 18.1%, respectively (p<0.001).

Multivariate analysis showed that DM was independently associated with mortality (hazard ratio 1.635; 95% confidence interval 1.280–2.08; p<0.001). The retrospective design and single-center setting may limit generalizability. These findings indicate that both pre-DM and DM are associated with higher long-term mortality after ACS and highlight the importance of identifying dysglycemia in acute cardiovascular care settings.