Endocrine Abstracts

Primary aldosteronism (PA) is generally caused by an adenoma or adrenal hyperplasia. To discern between these two, selective adrenal vein sampling (AVS) is necessary. Adequate interpretation requires that RAAS-interfering medication be withdrawn. We report a patient with severe PA, where it was not possible to safely withdraw RAAS-interfering medication.

Case: A 37-year-old male was referred for AVS. He had documented PA and bilateral adrenal adenomas on CT-abdomen. Previous attempts to withdraw medication had led to hypokalaemia (despite supplementation) and hypertensive crisis. Medication included spironolactone (up to 400 mg), barnidipine, doxazosine, metoprolol, and potassium. The patient complained of aggressiveness and sexual dysfunction. Blood pressure was 150/110 mmHg. Since AVS was required, RAAS-interfering medication was carefully withdrawn. Subsequently, potassium requirement increased to 400 mmol/day. Blood pressure medication consisted of doxazosine 16 mg, verapamil 240 mg and hydralazine 200 mg. Ten days before AVS, the patient presented with hypertension (185/110), headache and blurry vision. Enalapril was added and renin concentration monitored. Baseline renin was 3.81 mU/l, after titration to enalapril 40 mg/day it was 4.10 mU/l. Blood pressure decreased to 160/90 mmHg. AVS demonstrated a right-sided source. After surgery, the patient recovered uneventfully and was normotensive and normokalemic without medication. Two months later blood pressure was 135/88 mmHg with Lisinopril 10 mg/day; aldosterone concentration was low. The patient’s symptoms had resolved.

Conclusion: Even in severe PA, it is worthwhile to withdraw RAAS-interfering medication and perform AVS, so that surgical curation remains possible. If RAAS-interfering medication cannot be withdrawn, then renin (activity) should be monitored; diagnostic procedures can be interpreted reliably if this remains suppressed.