FRI197 Patient Suffering From Resistant HTN For 15 Years With Negative CT Diagnosed With Hyperaldosteronism Due To Adrenal Cortical Adenoma

Disclosure: J. Seidenberg: None. M.J. Ansari: None. Background: Resistant HTN, blood pressure remaining above goal despite concurrent use of three antihypertensives of different classes at maximum doses is a common presentation in both endocrinology and primary care settings. Patients can often be prescribed multiple max-dosed antihypertensives with varying results and adverse effects and still spend years with uncontrolled HTN leading to long term health concerns. Hyperaldosteronism is diagnosed for resistant HTN in 4% of primary care patients and 10% endocrinology-referred patients. Adrenal adenomas account for 40% of all cases characterized by high aldosterone/renin activity ratio, hypokalemia, mild hypernatremia and hypomagnesemia commonly diagnosed with a mass found in the adrenals on CT. Clinical Case: Patient is a 39 year old Female who presented to the endocrinology office due to elevated urine metanephrine levels, BP 159/100. Patient had resistant HTN since her early 20s treated currently with labetalol and nifedipine, and hypokalemia treated with potassium supplements. Lab results revealed potassium 3.4 mmol/L (3.6 -5.2 mmol/L), normetanephrines 787 mcg/g (0-145 mcg/g) , aldosterone 11 ng/dL (2-9 ng/dL) , renin 0.2 ng/mL/h (0.7- 3.3 ng/mg/hr), aldosterone/renin activity ratio 55 (<25) . Renal US showed no renal artery stenosis. The patient was suspected of having hyperaldosteronism using cutoff ratios aldosterone renin ratio >30, and 15 years of potassium levels between 3.0 and 3.5. CT of the adrenals revealed no masses. Patient underwent IR guided venous sampling which indicated R adrenal gland producing 45x more aldosterone than the L adrenal gland. Patient underwent R sided adrenalectomy for definitive management of primary hyperaldosteronism. Pathology showed cortical adenoma. Patient was continued on chlorthalidone, losartan and nifedipine, and within 3 months her BP averaged 120/70 mmHg, with potassium within normal limits, Aldosterone 13 ng/dL, renin 1.25 ng/mL. Conclusion: Concurrent hyperaldosteronism with essential HTN is an uncommon but potential cause of resistant HTN. Patients with resistant HTN, prescribed multiple max-dosage antihypertensive medications while also having negative renal artery US result should undergo aldosterone and renin lab work. CT scans can have low sensitivity for adrenal adenoma. Concerning lab work should be followed up by IR-guided venous sampling for evaluation of an adrenal cortical adenoma, which can be treated surgically. Underlying essential HTN will still require treatment, but at significantly decreased medication dosages. Patients with resistant HTN should be evaluated for hyperaldosteronism early in their disease course regardless of a negative CT to prevent sequelae of untreated hyperaldosteronism including cardiac hypertrophy, arrhythmias, nephrogenic diabetes insipidus and neuromuscular symptoms. Presentation: Friday, June 16, 2023