Bilan étiologique de l’HTA : dosages hormonaux toujours avant imagerie ?

Abstract

The purpose is to consider the practical management of etiological work up in hypertension, beyond national or international recommendations, leading to consider the prior practice of hormonal assays or renal, renovascular or adrenal imaging. The ease of access to imaging, difficulties to meet the requirements to obtain reliable hormonal assays explain the use of first-line imaging in clinical practice. The renal and adrenal CT angiography provides diagnostic orientation without allowing a formal conclusion. Incidentaloma prevalence in the general population, increasing with age, underlines the limitations of a decision based only on imaging. The discovery of adrenal morphological abnormalities justifies the realization of hormonal assays to determine their causal relationship with hypertension. The aldosterone/PRA ratio, in standardized conditions, has the best diagnostic performance to screen for primary aldosteronism and is the pivotal test of the etiological diagnosis of hypertension. The identification of a subclinical Cushing should be considered in patients with adrenal morphological abnormalities, particularly in case of metabolic syndrome. The abdominal CTscan is initially recommended in the diagnosis of pheochromocytoma, but the recommende boichemical testing is urine metanephrines whose result will lead to search a pheochromocytoma or an extra-abdominal paraganglioma. Many drug interactions must be considered in order to interpret hormonal measurements and avoid erroneous diagnosis. Finally, a genetic context and the possibility of endocrine causes with normal abdominal CT scan should be considered: extra-abdominal paraganglioma, parathyroid adenoma and Cushing's disease with pituitary adenoma, requiring a multidisciplinary decision. The efficiency of imaging as first-line in the screening of secondary hypertension is relative and confrontation with hormone assays will be critical to the diagnostic and therapeutic management. In young women, hormonal measurements precede imaging in the etiological investigation of hypertension.