Small tumor size as favorable prognostic factor after adrenalectomy in Conn's adenoma.

OBJECTIVE

Primary aldosteronism (PA) due to aldosterone-producing adenoma (APA) is the most common curable form of secondary hypertension.

DESIGN

In order to evaluate blood pressure outcome after adrenalectomy for APA and to identify new favorable prognostic factors, data from 42 consecutive APA patients who underwent adrenalectomy were collected from 2005 to 2007.

METHODS

Renin-angiotensin-aldosterone system (upright and postsaline infusion test), serum and urinary electrolytes, office and ambulatory blood pressure monitoring were evaluated at baseline and after a follow-up of 2.7+/-2.2 years. Drug history and adenoma size at morphological evaluation were also collected.

RESULTS

Multiple regression analysis showed that, before surgery, patients with a small adenoma (diameter <20 mm) displayed higher postsaline aldosterone values (P=0.0001), and lower serum potassium levels (P=0.020), than patients with adenoma >20 mm. Before surgery, mineralocorticoid receptor (MR) antagonists were used in patients with small APA in greater percentage than patients with bigger adenomas (64 vs 30% respectively, P=0.037). At follow-up, blood pressure normalized in 63% of the subjects. Recovered patients had a shorter duration of hypertension (P=0.038), and a smaller adenoma size (P=0.035). Receiver operating characteristic curves showed that a duration of hypertension <or=6 years and an APA size <20 mm were the best predictors of blood pressure normalization. Patients with APA <20 mm showed the complete restoration of blood pressure circadian rhythm.

CONCLUSIONS

The presence of APA <20 mm, duration of hypertension equal or less than 6 years, and preoperative MR antagonists use are favorable prognostic factors for hypertension recovery after adrenalectomy.