Endocrine Abstracts

Case history: A previously asymptomatic 58-year-old gentleman presented following an out-of-hospital cardiac arrest, precipitated by multiple, bilateral pulmonary emboli.

Investigations: In the course of investigation, a 35 mm, MIBG-negative, right adrenal lesion was discovered. Functional adrenal tests revealed significantly elevated normetanephrine and 3-methoxytyramine levels. Severe hypertension and type 2 diabetes were concurrently diagnosed.

Results and treatment: Histology confirmed a phaeochromocytoma and a marked improvement in normetanephrine levels, glycaemic control and blood pressure followed surgical resection. Four months later, biochemical tests revealed disease recurrence. Echocardiography showed moderate LV systolic dysfunction and high pulmonary artery systolic pressures, but there were no signs of fluid overload. Liver, perineal and rib metastases subsequently developed, and cardiac function continued to deteriorate, precipitating admission with acute, decompensated heart failure. Cardiac MRI showed a dilated LV with severe systolic dysfunction, LVEF of 19% and RV systolic dysfunction. MRI appearances were typical of myocardial fibrosis. Alpha-blockade was commenced and titrated against decreasing diuretic requirement and anti-failure medications. This allowed commencement of Temozolomide and external beam radiotherapy. As shown in the table below, commencement of alpha-blockade and subsequent chemotherapy and radiotherapy translated into an improvement in cardiac status. There was a fall in LV size and LVEF improved to 33%. A significant fall in RV size and normalisation of RV systolic function from 28 to 56% was also observed. These changes accompanied a reduction in late gadolinium enhancement and resolution of pleural effusions (Table 1).

Conclusions and points for discussion: The potential reversibility of cardiac remodeling in catecholamine-induced cardiomyopathy (CIM) highlights the importance of a prompt diagnosis. CIM is characteristically associated with a poor prognosis, caused by excessive adrenergic stimulation resulting in vasoconstriction, vasospasm, myocardial ischemia and necrosis. This case highlights the physiological benefit of alpha-blockade, in addition to lowering the catecholamine burden. We have demonstrated that alpha-blockade is important in normalising cardiac physiology, irrespective of whether this is given alone or in conjunction with systemic oncological treatment. This case also demonstrates the prognostic benefit of chemotherapy and radiotherapy even when complete biochemical normalisation of cathecolamines is not attained.