Endocrine Abstracts

A 48-year-old man presented with classical symptoms and physical signs of severe acromegaly. Investigations revealed: fT4 12.8 picomoles per litre, TSH 1.4 milliunits per litre, testosterone 3.9 nanomoles per litre, FSH 4.3 units per litre, LH 2.1 units per litre, cortisol (09.00 hrs) 710 nanomoles per litre, prolactin 1657 microinternational units per millilitre and IGF1 155 nanomoles per litre. Growth hormone levels were greater than 150 milliunits per litre throughout an oral glucose tolerance test. A pituitary CT scan (MRI precluded by presence of a permanent cardiac pacemaker) demonstrated the presence of a macroadenoma with suprasellar extension.

Five years earlier he had undergone orthotopic cardiac transplantation following a diagnosis of idiopathic dilated cardiomyopathy. Prior to transplantation, cardiac output was 7 litres per minute. Histology of the explanted heart, which weighed 985 grams (224%) was consistent with acromegalic cardiomyopathy. Cardiac output of the transplanted heart was initially 6.5 litres per minute rising to 9 litres per minute at the time of diagnosis of acromegaly. Fluid retention requiring diuretic treatment was experienced post transplantation.

The patient refused pituitary surgery but growth hormone levels fell with subcutaneous octerotide. Depot octerotide at one monthly intervals decreased adenoma size with normalisation of growth hormone and IGF1 levels. Cardiac output fell and previous fluid retention resolved.

A photographic history of the patient suggested a diagnosis of severe acromegaly at the time of cardiac transplantation and the presence of the disease for at least ten years previously.

Cardiac transplantation for acromegalic cardiomyopathy is a rare occurrence, the authors being aware of only two previous cases in both of which acromegaly was diagnosed pre transplantation.

This case provides a unique view of the effects of untreated acromegaly on the transplanted heart.