SAT-497 Pheochromocytoma and the Heart: Insights from two cases of Cardiomyopathy

Abstract Disclosure: M.F. Hassan: None. S. Siddiqui: None. C.A. Onuegbu: None. M. Haque: None. A. Manavalan: None. Introduction: Pheochromocytomas are rare catecholamine-secreting tumors from the adrenalmedulla. Catecholamine-induced cardiomyopathy in pheochromocytoma (CICMP)is a severe complication with high morbidity and mortality, affecting 11% ofpatients. Here, we present two cases of CICMP managed successfully in theperioperative period. Case 1:A 44-year-old male with hypertension presented with one month of right-sidedabdominal fullness and SOB. Imaging showed bilateral heterogenous adrenalmasses (R>L, up to 15 cm) compressing the IVC. Laboratory tests revealed calcium12.5 mg/dL, iPTH 99.7 pg/mL, free normetanephrine 441 pg/mL, and 24-hoururine-free metanephrines 21,000. Thyroid biopsy confirmed medullary thyroidcarcinoma, and genetic testing revealed a RET mutation, consistent with MEN2A.Echocardiogram done for SOB and elevated troponin (0.03) showed LVEF 40%.The patient was admitted to the CCU for invasive hemodynamic monitoring,volume resuscitation, and phenoxybenzamine initiation. He underwent successfulbilateral adrenalectomy without postoperative complications. Case 2:A 56-year-old male with hypertension presented with headache, palpitations, andlabile blood pressure. Laboratory tests showed free metanephrines 950 pg/mL,free normetanephrines 875 pg/mL, and total metanephrines 1825 pg/mL. CTrevealed a 9.3 cm left suprarenal mass that was heterogeneous and solid/cystic.Echocardiogram done for elevated troponin (0.14) confirmed CICMP with LVEF40%. He was admitted to the CCU for invasive hemodynamic monitoring, fluidresuscitation, and alpha blockade. After left adrenalectomy, he developed acute hypoxic respiratory failure from decompensated heart failure but was dischargedon carvedilol and sacubitril/valsartan. Discussion: CICMP occurs due to chronic catecholamine elevation damaging myocardial tissuevia raised intracellular calcium, oxidative stress, inflammation, and mitochondrialdysfunction. Concurrent hypotension and volume depletion complicatemanagement, necessitating invasive hemodynamic monitoring. In both cases,tumor resection improved symptoms. Conclusion: CICMP is a life-threatening condition associated with shock, arrhythmias, andrenal failure. A multidisciplinary approach is crucial for successful outcomes. Presentation: Saturday, July 12, 2025