Assessment of endothelial function in relation to the presence of type 2 diabetes mellitus in patients with prior myocardial infarction: a pilot study using peripheral arterial tonometry

Background. Endothelial dysfunction represents an early stage of atherosclerosis, while hyperglycaemia remains an important cause of endothelial dysfunction. The aim of this study was to assess endothelial function in patients with prior ST-segment elevation myocardial infarction (STEMI) in relation to the presence of type 2 diabetes mellitus (DM).Materials and methods: Eighty three adults treated with primary percutaneous intervention for STEMI within the previous 12–18 months were enrolled in a case-control study. The control group consisted of 21 healthy volunteers. Endothelial function was assessed with peripheral arterial tonometry (PAT). The value of reactive hyperemia index (RHI) and the presence of endothelial dysfunction (defined as RHI ≤ 2.0) were respectively the primary and secondary study endpoints.Results. RHI was significantly lower in post-STEMI subjects with concomitant type 2 DM (n = 21) than in healthy volunteers [1.70 (1.44–1.96) vs 2.15 (1.82–2.50); p = 0.006]. On the other hand, there were no significant differences in RHI between post-STEMI patients with and without type 2 DM [n = 62; RHI: 1.87 (1.59–2.39)], nor between the latter group and the control group. In terms of the secondary study endpoint, we observed a decreasing prevalence of endothelial dysfunction across the compared groups [76.2% vs 54.8% vs 38.1% for post-STEMI diabetics, post-STEMI non-diabetics and controls, respectively; p for trend = 0.013].Conclusions. Our study indicates that endothelial function assessed with PAT is significantly worse inpost-STEMI subjects with concomitant type 2 DM compared to healthy controls, but it does not seem to be substantially different in diabetic vs. non-diabetic STEMI survivors. The clinical significance of ourfindings warrants further investigation in adequately powered, prospective studies