Endocrine Abstracts

Case history: A 59 year old Afro-Carribbean male with a 25 year history of cardiac enlargement and hypertension, on multiple anti-hypertensives, presented with increasing breathlessness and several years of markedly reduced exercise tolerance. He was intolerant of spironolactone and eplerenone. His past medical history included hypertersion, obstructive sleep apnoea, Steven-Johnson syndrome secondary to allopurinol, thyrotoxicosis treated with radio-active iodine, monoclonal gammopathy, pernicious anaemia, glaucoma, carpal tunnel syndrome and previous tuberculosis exposure. He was initially referred to a cardiologist for assessment for poorly controlled hypertension and heart failure.

Investigations: His echocardiogram revealed severe concentric LVH with a normal LV ejection fraction and a large pericardial effusion. His coronary arteries were unobstructed. A presumptive diagnosis was made of cardiac amyloidosis although subsequent investigations, including a rectal biopsy, were not supportive of this. Endomyocardial biopsy revealed only myocardial hypertrophy and focal fibrosis with no evidence of lymphocytic, granulomatous or amyloid infiltration. His cardiac MRI demonstrated a very unusual pattern of LVH. The patient continued to suffer from ongoing worsening of breathlessness and was treated with pericardial drainage, followed by formation of pericardial window. He was then referred to endocrinology from his local hospital for a right sided adrenal nodule and hyperaldosteronism. Four years previously, hypokalaemic hypertension with aldosterone 8,200 pmol/l (100–800) and renin 0.2 pmol/ml per h (0.5–3.1) had been noted. Primary aldosteronism was re-confirmed (serum aldosterone >4,271 pmol/l, renin <0.17 nmol/h per l); an adrenal CT demonstrated bilateral adrenal nodules, 3 cm on the right and 2 cm on the left. Adrenal venous sampling was not possible as his interfering medications could not be weaned without cardiac decompensation. Subsequent 11-C Metomidate scan demonstrated bilateral uptake but with an obvious dominant very hot nodule to the right.

Results and treatment: The patient underwent a right laparoscopic adrenalectomy without complication. Three months post-operatively, the patient’s symptoms significantly improved with exercise capacity transforming from 5 to 10 metres to unlimited. His blood pressure and potassium normalised with a marked reduction in anti-hypertensive agents. His post-operative aldosterone normalised to 280 pmol/l with renin 0.80 nmol/h per l. More surprisingly there appeared to be significant LVH regression on his echocardiogram.

Conclusions and points for discussion: This case demonstrates the profound effect severe primary hyperaldosteronism has on myocardial function and the challenges faced with the diagnosis of lateralising disease justifying unilateral adrenalectomy. It also highlights the potential reversibility of myocardial inflammation and fibrosis when the aldosterone burden is reduced.