MON-395 Takotsubo Cardiomyopathy And Metanephrines

Abstract

Takotsubo (stress) cardiomyopathy, is defined by transient left ventricular systolic dysfunction without epicardial coronary disease. Case report A 50-year-old man presented with headache and visual disturbance with no past medical history of note. He had recently separated from his wife and children had moved out of the family home. He was very depressed and stressed due to this. His blood pressure was 180/110 mmHg and bloods showed creatinine of 442 umol/L; potassium 3.6 mmol/L; eGFR 13 mL/min/1.73m2. Renal Ultrasound and virology/immunology screen were normal. Echocardiogram showed severe left ventricular (LV) dysfunction with an ejection fraction (EF) of 35% with LV hypertrophy. Plasma normetanephrine and metanephrine levels were elevated at 4805 pmol/L (120-1180) and 819 (80 - 510) respectively. Urine 24 hour metanephrines showed elevated urine normetanephrine output of 7.62 umol/24 h (0-3.3) and mildly elevated urine metanephrine output of 1.31 umol/24 h (0-1.2). CT Adrenals showed a low density 1 cm left adenoma with benign washout characteristics. He was started on alphablocker and amlodipine with good effect. 2 months later, repeat Echo normalised with LVEF of 55-60%. Repeat urine metanephrines were normal. Plasma normetanephrine dropped to 1253 pmol/L and plasma metanephrine to 338 pmol/L. I123 MIBG (meta-iodo-benzyl guanidine) SPECT-CT normal uptake. Overnight dexamethasone suppression test and aldosterone renin ratio were normal. Discussion: This 50-year-old gentleman under considerable emotional stress, presented with severe hypertension and severely impaired LV function. On follow-up, the LV impairment returned to normal and the initially elevated plasma and urine metanephrines normalised. The adrenal tumour was an incidental benign non-secretory tumour. There are several reports of phaeochromocytomas presenting with stress cardiomyopathy, however stress cardiomyopathy mimicking phaeochromocytoma is not well reported. A study by Wittstein et al reported significant elevations of metanephrines in patients with stress cardiomyopathy. However this has not been universally accepted and subsequent studies have not fully replicated this. As per a 2017 metanalysis by Darr et al the sensitivity and specificity of plasma metanephrines for phaeochromocytoma/paraganglioma is 94% and 93% and for urinary metanephrines, 91% and 93%. Critical illness can elevate plasma and urinary metanephrines. In this case, the patient did have severe hypertension, but was not critically ill. The current case report provides a cautionary example that the specificity of plasma and urinary metanephrines in the diagnosis of phaeochromocytoma and paraganglioma may be impaired in people presenting with stress related cardiomyopathy. This is especially true in this case given that this patient also had an incidental adrenal tumour.