Factors determining cardiovascular and renal outcomes after adrenalectomy in patients with aldosterone-producing adrenal adenoma

Abstract

Primary aldosteronism is an important cause of secondary hypertension, because it is potentially curable, especially in case of unilateral aldosterone-producing adrenal adenoma (APA). However, the information is limited concerning the cardiovascular and renal outcomes in this patient population. We studied 52 patients with APA in order to determine the pre-operative and post-operative factors predicting cardiovascular and renal outcomes. All 52 patients were hypertensive before the operation. Among 35 patients who underwent pre-operative electrocardiogram, 23 patients had left ventricular hypertrophy (LVH). Patients with LVH had lower estimated glomerular filtration rate (eGFR). Adrenalectomy successfully normalized or improved hypertension, hypokalemia, and aldosterone excess. One month after the adrenalectomy, 32 patients (62%) became normotensive, but 20 patients (38%) remained hypertensive. However, after an average follow-up period of 51 months, only 18 patients remained normotensive, while 34 patients were hypertensive. Thus, the rate of recurrent hypertension after adrenalectomy was high (14/32, 43%). Preoperative systolic blood pressure (BP), diastolic BP, and post-operative plasma aldosterone concentrations were the only variables significantly different between the hypertensive and normotensive patients. Using pre-operative BP 165/110 mmHg as a cutoff has good positive predictive values (73-92%) for post-operative long-term hypertension. Patients whose renal function worsened after adrenalectomy had significantly higher pre-operative plasma active renin levels. Thus, in patients with APA, the presence of LVH is correlated with impaired renal function (lower eGFR). In conclusion, pre-operative BP and post-operative plasma aldosterone are important in predicting post-adrenalectomy hypertension, and a lower pre-operative plasma renin predicts the improvement in renal function after adrenalectomy. © 2009 Tohoku University Medical Press.