12343 Cardiac Function Recovery Following Left Adrenalectomy For A Pheochromocytoma With Ectopic ACTH Syndrome

Abstract Disclosure: T.D. Williams: None. D. Lovre: None. R.C. Galagan: None. Background: Pheochromocytoma and Cushing’s Syndrome are implicated in Non-ischemic Cardiomyopathy/Heart Failure with reduced Ejection Fraction (NICM/HfrEF) due to catecholamine induced hypertension and cardiomyocyte toxicity. Subsequent hypoxia and calcium overload in cardiomyocytes results in oxidative stress and cell death. Excess cortisol secretion increases angiotensin II, causing hypertrophy. Subsequent increases in atrogin I lead to myo-fibrinolysis and fibrosis. We present a patient with NICM/HFrEF due to both catecholamine excess and ectopic ACTH syndrome from an adrenal pheochromocytoma. Following adrenalectomy, systolic cardiac function returned to normal. Clinical Case A 42-year-old female was referred to endocrinology after a hypertensive emergency concurrent with NSTEMI, NICM, and HFrEF (EF 45%). Initial work up revealed: Troponin I 0.49 ng/ml; (0 - 0.04 ng/ml), Na+ 140 mmol/L; (136 - 144 mmol/L), K+ 2.3 mmol/L; ​​(3.7 - 5.2 mmol/L), CO2 41 mmol/L; (23 - 29 mmol/L), Glucose 53 mg/dL; (64 - 100 mg/dL), Cortisol 57.2 ug/dL; (5 - 25 ug/dL), ACTH 363.7 pg/mL; (7.2 - 63.3 pg/mL). She failed both 1 mg and 8 mg overnight dexamethasone suppression tests: 0800 cortisol 48.5 ug/dL (< 1.8 ug/dL) & 56.8 ug/dL (> 50% decrease in baseline cortisol level of 57.2 ug/dL) consistent with ectopic ACTH syndrome. Elevated plasma normetanephrine 0.98 nmol/L; (0 - 0.89 nmol/L) and chromogranin A 250 ng/mL; (0 - 103 ng/mL) suggested a neuroendocrine tumor. Pituitary MRI revealed a normal pituitary gland. Abdominal MRI detected a 3.6 x 2.5 cm left adrenal nodule and PET/CT CU-64 showed increased activity (Krenning 4) consistent with a pheochromocytoma. Notwithstanding Ketoconazole (200 mg/day) for 7 months, her EF fell to a low of 15-20%. A left adrenalectomy was performed and post-op 0800 cortisol was 12.3 ug/dL (6.0 - 26.0 ug/dL). Oral hydrocortisone was initiated at 20 mg QAM/10 mg QPM for steroid withdrawal syndrome, tapered over 8 months and withdrawn when a cosyntropin stimulation test 60-min cortisol was 19.3 ug/dL; (>18.0 ug/dL). Eleven months post op, her 0800 cortisol was 8.8 ug/dL and ACTH 27.4 pg/mL. One month post-op, TTE showed EF: 15-20%, six months post-op EF: 25-30%, eight months post-op EF: 35-40% and 15 months post-op EF was normal at 50%. Her heart failure symptoms resolved, and her activity returned to normal. Conclusion This case illustrates a remarkable restoration of cardiac function following resection of a pheochromocytoma. Our patient's case is unique due to the restoration of cardiac function despite the dual impact of excessive catecholamines and cortisol. Our patient’s clinical course contributes to an evolving understanding of cardiomyopathy associated with pheochromocytoma and ectopic ACTH syndrome and highlights the potential for cardiomyopathy reversal with targeted endocrine surgical and medical interventions. Presentation: 6/1/2024