THU405 A Delicate Balance

Abstract Disclosure: N. Mohan: None. M.S. Shah: None. Introduction: Primary hyperparathyroidism is a disorder of excessive parathyroid hormone production causing increased calcium levels, usually due to a parathyroid adenoma. Commonly these cases are asymptomatic and detected incidentally on routine labs. They can be managed conservatively with sufficient fluid intake and avoiding dehydration. Congestive heart failure patients on diuretics with primary hyperparathyroidism require a delicate balance of their volume status to prevent exacerbation of either condition. We present a case of a woman with repeated hospitalizations due to poor volume status control. Clinical Case: An 82-year-old female with congestive heart failure (CHF), primary hyperparathyroidism (diagnosed 17 years ago), sick sinus syndrome with a pacemaker, and persistent atrial fibrillation presented to the emergency room with worsening b/l lower limb swelling for a few months. The remaining review of systems was largely negative. At home, she was on Losartan, Furosemide, and Carvedilol. Vitals were stable and physical exam revealed b/l lower extremity pitting edema. Chest x-ray showed cardiomegaly with mild pulmonary vascular congestion. Pertinent labs were NT pro-BNP 2190, Calcium 11.3 mg/dL, PTH 143 pg/mL, and Vit D, 25-hydroxy 48.6 ng/mL. The patient was started on IV diuretics and her home medications for CHF exacerbation. ECHO showed EF 39%, grade III diastolic dysfunction, severe pulmonary hypertension, mitral and tricuspid regurgitation. She was managed conservatively for her hypercalcemia and advised to maintain hydration at home. Spironolactone and Dapagliflozin were added to her regimen, and Furosemide was increased at discharge. The patient was re-admitted three weeks later with fatigue and decreased fluid intake. Vitals were stable and physical exam revealed dehydration. Pertinent labs were Calcium 13.4 mg/dL, Potassium 5.7 mmol/L, Creatinine 1.7 mg/dL (baseline 1.0), PTH 204 pg/mL, and Vit D 54.1 ng/mL. Repeat ECHO showed EF 15%. She was started on gentle 0.9% NS IV fluid to correct the hypercalcemia while preventing volume overload. Hypercalcemia and acute kidney injury improved with hydration. She was put on Cinacalcet 30 mg and home medications were modified for better volume control at discharge. Conclusion: This case highlights the complications of balancing the volume status with primary hyperparathyroidism and CHF. This patient’s primary hyperparathyroidism was well-controlled for more than fifteen years on adequate hydration. However, worsening CHF resulted in a higher requirement for diuretics, thereby worsening her hypercalcemia. Even though parathyroidectomy is an established treatment modality, she was not a suitable candidate due to age and comorbidities. Hence, to prevent such complications, parathyroidectomy must be considered early in patients with heart disease and even in asymptomatic hyperparathyroidism. Presentation: Thursday, June 15, 2023