Screening for primary aldosteronism in 1181 Swedish primary care hypertensive patients

Nikita Makhnov ^1,2,3* Jakob Skov ^2,4 Tobias Åkerström ^1,5 Fredrik Axling ¹ Daniel Andernord ³ Mikael Bergenheim ^2,6 Mauritz Walden ² Per Hellman ^1,5

• ¹ Uppsala University, Uppsala, Sweden
• ² Karlstad Central Hospital, Karlstad, Värmland, Sweden
• ³ Center for Clinical Research, Region Värmland Kommunalförbund, Karlstad, Värmland, Sweden
• ⁴ Karolinska Institutet (KI), Solna, Stockholm, Sweden
• ⁵ Uppsala University Hospital, Uppsala, Uppsala, Sweden
• ⁶ Karlstad University, Karlstad, Värmland, Sweden

Primary aldosteronism (PA) is a common cause of hypertension. It entails elevated morbidity and mortality that do not sufficiently ameliorate with conventional antihypertensive therapy. Screening for PA by plasma aldosterone-renin ratio (ARR) enables discovery and specific treatment of affected patients. By screening primary care hypertensive patients and evaluating them further according to the Endocrine Society guidelines, we aimed to assess: the prevalence of PA; the factors affecting biochemical diagnostics; the outcome of lateralization studies and of specific treatment of the discovered PA cases.Prospective evaluation of screening for PA was conducted in 1181 patients. Screening by ARR was performed under current therapy, but without mineralocorticoid receptor antagonists (MRA), under normokalaemia, and confirmed by the intravenous saline suppression test, SST#1. Those with results in a defined grey-zone underwent therapy adjustment and then completed SST#2. Plasma aldosterone and ARR were compared under different stages of the diagnostic process. All PA patients were offered adrenal venous sampling, or, in certain cases, adrenocortical-specific positron emission tomography. Lateralizing cases were offered laparoscopic adrenalectomy. Patients with bilateral disease were treated with MRA. Treatment results were assessed after a minimum of 6 months.Fifty-three discovered cases of (mostly mild) PA corresponded to its prevalence of 4,5%. Initial seated ARR was higher than recumbent ARR before SST#1. At SST#2, initial ARR and final aldosterone were higher than at SST#1. Localizing studies (accepted by 45 patients) found 14 lateralized cases. Of 11 operated cases four had aldosterone producing adenoma, and the remainder had micro-and macronodular histopathology. Thirty-one patients had bilateral PA. Both surgical and conservative treatments were well tolerated, and led to improved blood pressure and higher renin indicating risk amelioration.Primary aldosteronism is prevalent among primary care hypertensive patients, and can be screened for under current antihypertensive therapy. Aldosterone producing adenoma was rare in this cohort. The study results support active screening of primary care hypertensive patients for PA in order to offer appropriate treatment options.