Diabetic ketoacidosis: a metabolic emergency post-heart transplantation

Diabetic ketoacidosis (DKA) is a rare but serious metabolic complication following orthotopic heart transplantation (HT). Immunosuppressive agents, particularly tacrolimus and corticosteroids, contribute to the development of post-transplant diabetes mellitus (PTDM), which can precipitate hyperglycemic emergencies, including DKA. Timely recognition and intervention are crucial to prevent serious adverse outcomes of ketoacidosis.

We report a 21-year-old male with restrictive cardiomyopathy who underwent HT in September 2024. Six months post-transplant, he presented to the emergency department with DKA. In addition to the conventional treatment involving intravenous insulin infusion, isotonic fluid rehydration, and correction of electrolyte imbalances, the immunosuppressive regimen needed major modification. Subsequently, adjusting immunosuppression and maintaining glycemic control remained cornerstones of the patient's therapy.

Tacrolimus is known to impair pancreatic β-cell function, leading to insulin deficiency and hyperglycemia. It may also unmask underlying type 1 diabetes, leading to insulin dependency, serious risks like DKA, microvascular/macrovascular complications, and consequently reduced allograft survival.

Regular blood glucose monitoring, early recognition of metabolic abnormalities, and modification of the immunosuppressive regimen are essential for preventing life-threatening complications.