Captopril suppression: limitations for confirmation of primary aldosteronism

• Published in: Journal of the renin-angiotensin-aldosterone system Vol. 12; no. 3; pp. 326 - 332
• Main Authors: Westerdahl, Christina, Bergenfelz, Anders, Isaksson, Anders, Valdemarsson, Stig
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.09.2011
• Subjects: Adult; Aldosterone - blood; Annan klinisk medicin; Antihypertensive Agents - therapeutic use; Basic Medicine; Captopril - therapeutic use; Clinical Medicine; Farmakologi och toxikologi; Female; Folkhälsovetenskap, global hälsa, socialmedicin och epidemiologi; Health; Health Sciences; Humans; Hyperaldosteronism - blood; Hyperaldosteronism - diagnosis; Hyperaldosteronism - drug therapy; Hälsovetenskap; Kirurgi; Klinisk medicin; Läkemedelskemi; Male; Medical and Health Sciences; Medicin och hälsovetenskap; Medicinal Chemistry; Medicinska och farmaceutiska grundvetenskaper; Other Clinical Medicine; Pharmacology and Toxicology; Public Health, Global Health, Social Medicine and Epidemiology; Renin - blood; Reproducibility of Results; ROC Curve; Sensitivity and Specificity; Surgery; Young Adult; Aldosterone; hypertension; renin; captopril; primary aldosteronism
• ISSN: 1470-3203; 1752-8976; 1752-8976
• DOI: 10.1177/1470320310390405

Introduction: The aldosterone/renin ratio (ARR) is the first line screening test for primary aldosteronism (PA). However, in hypertensive patients with an increased ARR, PA needs to be confirmed by other means. Methods: A 25 mg oral captopril test was performed in 16 healthy subjects to obtain reference values for aldosterone and ARR at 120 minutes after the test. Subsequently these data were applied to 46 hypertensive patients screened for PA with an increased ARR. Results: At 120 minutes after the captopril test ARR decreased in healthy subjects within a narrow range, but remained high in patients with PA and in patients with primary hypertension, especially for those with low renin characteristics. At 120 minutes after captopril, the range of ARR in primary hypertensive patients overlapped in 88% of the cases with the range of the ARR in the PA patients. Sensitivity and specificity of basal ARR and ARR after the captopril test to diagnose PA, calculated as receiver operator characteristics, showed an area under the curve of 0.595 for basal ARR and 0.664 for ARR at 120 minutes after the test. Conclusion: The ARR at 120 minutes after the captopril test is only marginally better than basal ARR in diagnosing PA in hypertensive patients screened with an increased ARR. Owing to an overall limited capacity to clearly discriminate PA from primary hypertension, the test could not therefore be recommended for the confirmatory diagnosis of PA.