Noninvasive imaging of endothelial damage in patients with different HbA _1c levels: A proof-of-concept study

The aim of this study was to compare endothelial permeability, which is considered a hallmark of coronary artery disease, between patients with different HbA _1c levels using an albumin-binding magnetic resonance (MR) probe. This cross-sectional study included 26 patients with clinical indication for X-ray angiography who were classified into three groups according to HbA _1c level (<5.7% [<39 mmol/mol], 5.7–6.4% [39–47 mmol/mol], and ≥6.5% [48 mmol/mol]). Subjects underwent gadofosveset-enhanced coronary magnetic resonance and X-ray angiography including optical coherence within 24 h. Contrast-to-noise ratios (CNRs) were assessed to measure the probe uptake in the coronary wall by coronary segment, excluding those with culprit lesions in X-ray angiography. In the group of patients with HbA _1c levels between 5.7 and 6.4%, 0.30 increased normalized CNR values were measured, compared with patients with HbA _1c levels <5.7% (0.30 [95% CI 0.04, 0.57]). In patients with HbA _1c levels ≥6.5%, we found 0.57 higher normalized CNR values compared with patients with normal HbA _1c levels (0.57 [95% CI 0.28, 0.85]) and 0.26 higher CNR values for patients with HbA _1c level ≥6.5% compared with patients with HbA _1c levels between 5.7 and 6.4% (0.26 [95% CI 20.04, 0.57]). Additionally, late atherosclerotic lesions were more common in patients with high HbA _1c levels (HbA _1c ≥6.5%, n = 14 [74%]; HbA _1c 5.7–6.4%, n = 6 [60%]; and HbA _1c <5.7%, n = 10 [53%]). In conclusion, coronary MRI in combination with an albumin-binding MR probe suggests that both patients with intermediate and patients with high HbA _1c levels are associated with a higher extent of endothelial damage of the coronary arteries compared with patients with HbA _1c levels <5.7%.