Routine HbA1c screening identifies de novo (pre)diabetes mellitus in 37% of ACS patients which comes with an even higher ischemic risk compared to known diabetes mellitus
Authors: Janssen S , Woelders E C I , Peeters D A M , Luijck J J P , Winkler P J C , Damman P , Remkes W S , Van Geuns R M , Van T Hof A W J 
Published: October 2024

Background

Diabetes is a prominent risk factor for coronary artery disease (CAD). By exacerbating the progression of CAD, it puts these patients at increased risk of acute coronary syndrome (ACS) and recurrent ischemic events. It is therefore important to identify hyperglycaemic individuals and to treat them accordingly. However, in daily practice it is seen that a subsequent proportion of people with diabetes is undiagnosed.

Purpose

The aim of this research is to gain insight in the prevalence of patients with de novo (pre)diabetes, the treatment, and the risk of major adverse cardiac and cerebrovascular events (MACCE) compared to patients with known diabetes in an ACS cohort treated by percutaneous coronary intervention (PCI).

Methods

The Southeast Netherlands Heart Registry (ZON-HR) is an ongoing, multicentre registry collecting data of patients who underwent a PCI procedure. Of this cohort, patients presenting with ACS and measured HbA1c concentrations (on admission) were selected (N=1507). Patients with diagnosed diabetes are considered well-regulated when HbA1c &lt;53 mmol/mol. Patients undiagnosed with diabetes were divided into three groups: HbA1c concentration &lt;42 mmol/mol (normal), HbA1c 42-47 mmol/mol (pre-diabetes) and HbA1c ≥48 mmol/mol (diabetes). The rates of 30-day repeated myocardial infarction (MI), unplanned revascularisation, ischemic CVA, stent thrombosis, and cardiovascular mortality were determined, separately and combined as MACCE in patients with known diabetes compared to prediabetes and diabetes de novo.

Results

In the selected population, 28.5% of the patients were previously diagnosed with diabetes, which was well-regulated in only 30.2% of these patients. Of the patients not previously diagnosed, 23.1% and 14.4% had pre-diabetic and diabetic HbA1c concentrations, respectively. In 56.1% of patients with de novo diabetes, no glucose-lowering medication was prescribed at discharge (Table 1). At 30-day follow-up, de novo diabetes patients had increased rates of MACCE compared to patients with known diabetes (HR: 3.51, 95%CI 1.48-8.52) after multivariate analysis which corrected for differences at baseline (Figure 1). In addition, a significant increase in unplanned revascularisation (p=.014) and MI (p=.037) was found between de novo diabetes and known diabetes patients.

Conclusions

Almost half of the ACS patients in this cohort had either poorly regulated diabetes (305 patients) or was undiagnosed with (pre)diabetes while having an increased HbA1c concentration on admission (401 patients). Despite routine HbA1c screening, a subsequent part of these patients is not adequately treated for (pre)diabetes, especially the de novo diabetes patients. By this group, an even larger rate of MACCE was found, compared to the already established risk of diabetes in ACS. Therefore, active screening and treatment (as recommended in the guidelines) should get more attention to improve outcomes in these high-risk patients.Table 1:ACS population based on HbA1cFigure 1:Survival curves of 30D MACCE