Endocrine Abstracts

Cushing’s syndrome (CS) associated with dilated cardiomyopathy without LVH is rare but important to recognise as treatment of CS can lead to total recovery of heart function.

A 30-year-old previously fit and well Turkish man presented with chest pain and was diagnosed with NSTEMI and CCF. An MRI of the heart and CT coronary angiogram showed normal coronary arteries but a large right adrenal tumour of 11.5 cm with extension into IVC. The transthoracic echocardiogram showed a globally dilated left ventricle with an estimated ejection fraction 20%. There was moderate to severe functional mitral regurgitation. Clinically the patient had gross clinical CS and was hypertensive (BP-170/90).

Further investigations revealed Na-140, K-3.3, cortisol after a 1 mg ODST; 509 nmol/l, 24 h urinary cortisol; 4026 nmol/day (normal range 100–379 nmol/day), ACTH <5 ng/l. Aldosterone, renin, urinary metanephrines, DHEA and androstendione all normal. His heart failure was managed with optimal medical treatment and metyrapone was started. Right adrenalectomy with extraction of intracaval tumour thrombus was performed with evidence of complete excision both on histological assessment and a post operative CT scan. Histology confirmed adrenal cortical carcinoma. Weiss score 5.

1 year post surgery, clinical features of Cushing’s have almost resolved. Echocardiogram 7 months after adrenalectomy showed a reduction in LV size and an EF of 40-45%. A recent echocardiogram in Turkey showed EF 56%.

Studies examining the relationship between hypercortisolism and cardiac dysfunction suggest that excess cortisol is contributory to cardiac re-modelling and dilated cardiomyopathy, independent of hypertension. The pathophysiology of cardiac remodeling involves complex mechanisms including activation of neurohormonal factors, alpha adrenergic and renin–angiotensin–aldosterone systems. Experimental models have found that the effects of noradrenaline, angiotensin II, and aldosterone can be heightened by hypercortisolism. The saturation of 11β-HSD2 enzyme resulting in mineralocorticoid receptor activation by cortisol has also been suggested as a possible reason for cardiomyopathy in CS.