Disorders of Glucose Metabolism and Their Effects on Cardiac Allograft Vasculopathy after Heart Transplantation in Childhood: Preliminary Results

Background: Posttransplantation diabetes mellitus (PTDM) is known to be a risk factor for several complications such as graft failure and major cardiac events following solid organ transplantation. However, there are limited data on its impact on outcomes in heart transplant (HTX) recipients in the pediatric and adolescent age groups with inconsistent incidence. Whether PTDM has an impact on cardiac allograft vasculopathy (CAV), a leading cause of long-term graft failure, is still a matter of debate. Our aim was to investigate the incidence of PTDM and its possible influence on CAV in our patient group.

Methods: In our cohort of HTX patients (n = 178; 74 patients agreed to be included in the study, 58 patients have been investigated to date: 28 male, 30 female; age 4–37 years; median age of 22.3 years), we identified all patients with abnormal blood glucose levels (2022–2024, n = 30). The diagnosis of diabetes and prediabetes was made according to the WHO classification. An oral glucose tolerance test (OGTT) was conducted in patients with prediabetic blood glucose levels to assess the incidence of PTDM in this patient group. In all patients, a coronary angiography including an optical coherence tomography after HTX was performed to identify CAV. We assessed the incidence of CAV in our patients and compared those with impaired glucose metabolism (diabetes and prediabetes) and those with normal glucose metabolism.

Results: Thirty out of 58 patients (excluding 8 with preexisting PTDM and 20 with normal glucose metabolism) were initially classified as prediabetes and underwent an OGTT, resulting in the following findings: 2 patients with PTDM, 11 patients with prediabetes, and 17 patients with normal glucose metabolism. CAV was identified in 21/21 patients (100%) with impaired glucose metabolism and in 29/37 patients (78%) with normal glucose metabolism. The mean duration since HTX (14.2 years) as well as the incidence of hypertension, hyperlipidemia, and overweight did not differ significantly between these two patient groups.

Conclusion: Our study showed that more than one-third of our investigated HTX patients had abnormal blood glucose levels after OGTT. Following our preliminary analysis, patients with impaired glucose metabolism tend to have almost always coronary artery changes. In our opinion, this suggests that patients with abnormal blood glucose levels after HTX should be regularly tested using OGTT, as patients with prediabetes or diabetes diagnosed by OGTT appear to be at higher risk of developing CAV. Further studies on larger patient groups are needed to confirm these results and implement treatment options in patients after HTX.

Publication History

Article published online:
11 February 2025