Prevalence of Secondary Hypertension in Patients With Resistant Arterial Hypertension

Abstract

Objective: Resistant hypertension is defined as blood pressure that remains above therapeutic goal despite concurrent use of three antihypertensive agents (at full or maximum tolerated doses) of different classes, one of which is a diuretic. The prevalence of secondary hypertension among patients with resistant hypertension is not exactly known. Design and method: We retrospectively analysed the hospital records of patients with resistant arterial hypertension, who underwent complete laboratory and imaging examinations to exclude the secondary etiology of arterial hypertension. Standard descriptive statistics, Mann-Whitney U test and Fisher's exact test were used for statistical evaluation. Results: Among the 432 patients with resistant hypertension, secondary etiology of hypertension was found in 135 (31.1%). The most frequent cause was primary aldosteronism in 85 cases (63% relatively), followed by renovascular hypertension (21 cases, 15.6%), renal parenchymal hypertension (20 cases, 14.8%). Less common causes were hyperreninism (3.7%), hypercortisolism (1.5%), pheochromocytoma (0.7%) and adrenogenital syndrome (0.7%). Obstructive sleep apnoea has been found in 63 (14.7%) patients. Patients with secondary hypertension were more frequently male (70.4% vs. 52.2%, p < 0.001), had a higher left ventricular mass index (LVMI 119 vs. 106 g / m2, P = 0.037) and lower estimated glomerular filtration rate (69 vs. 75 ml/min/1.73m2, P = 0.009). Both groups did not differ in age, office blood pressure or albuminuria. Conclusions: Secondary etiology was much more frequent (31%) in our group of patients with resistant hypertension than in non-selected hypertensive population (5–15%). Patients with secondary hypertension had more advanced target organ damage. This work was supported by the grant UP - IGA_LF_2019_036 a IGA_LF_2019_035. This work was supported by the grant IGA_LF_2020_039