Glucose intolerance, as reflected by hemoglobin a1c level, is associated with the incidence and severity of transplant coronary artery disease Original Research Article

Objectives The possible effect of plasma hemoglobin A1c (HbA1c) on the development of transplant coronary artery disease (TxCAD) was investigated. Background Glucose intolerance is implicated as a risk factor for TxCAD. However, a relationship between HbA1c and TxCAD has not been demonstrated. Methods Plasma HbA1c was measured in 151 adult patients undergoing routine annual coronary angiography at a mean period of 4.1 years after heart transplantation. Intracoronary ultrasound (ICUS) was also performed in 42 patients. Transplant CAD was graded by angiography as none, mild (stenosis in any vessel ≤30%), moderate (31% to 69%), or severe (≥70%) and was defined by ICUS as a mean intimal thickness (MIT) ≥0.3 mm in any coronary artery segment. The association between TxCAD and established risk factors was examined. Results Plasma HbA1c increased with the angiographic grade of TxCAD (5.6%, 5.8%, 6.4%, and 6.2% for none, mild, moderate, and severe disease, respectively; p < 0.05 for none vs. moderate or severe) and correlated with disease severity (r = 0.24, p < 0.05). The HbA1c level was higher in patients with MIT ≥0.3 mm than in those with MIT <0.3 mm (6.4% vs. 5.7%, p < 0.05). Multivariate logistic regression analysis identified HbA1c as an independent predictor of TxCAD, as detected by angiography or ICUS (odds ratios 1.9 and 2.4, 95% confidence intervals 1.5 to 6.3 [p = 0.010] and 1.3 to 4.2 [p < 0.005], respectively). Conclusions Persistent glucose intolerance, as reflected by plasma HbA1c, is associated with the occurrence of TxCAD and may play an important role in its pathogenesis.