7th Brazilian Guideline of Arterial Hypertension: Chapter 13 - Resistant Arterial Hypertension

Resistant AH (RAH) is defined as uncontrolled office BP despite the use of at least three antihypertensive drugs at appropriate doses, including preferably one DIU, or as controlled BP using at least four drugs. Because it does not include the systematic assessment of therapy and adherence, that situation is better defined as apparent RAH (pseudoresistance). Identification of true RAH is fundamental to establish specific approaches. 2 Population-based studies have estimated a 12% prevalence in the hypertensive population. 2 In Brazil, the ReHOT study assesses prevalence and therapeutic choice. 4 Refractory hypertension is defined as uncontrolled BP using at least five antihypertensive drugs, 5 and corresponds to 3.6% of resistant hypertensive individuals. To diagnose RAH, ABPM is required, as well as systematic assessment of adherence. Causative factors are as follows: higher salt sensitivity, increased blood volume (higher sodium intake, CKD or inappropriate diuretic therapy), exogenous substances that raise BP, and secondary causes (OSAHS, primary aldosteronism, CKD, and renal artery stenosis). The pathophysiological aspects related to resistance are as follows: (i) sympathetic and RAAS hyperactivity; (ii) vascular smooth muscle proliferation; (iii) sodium retention; and (iv) activation of proinflammatory factors. 1,7 Greater endothelial dysfunction and arterial stiffness are present. 8 In ABPM, there is high prevalence (30%) of WCE and attenuation of nocturnal BP dipping. 9 The prevalence of black ethnicity, DM and albuminuria is higher among refractory hypertensive individuals. Pseudoresistance Pseudoresistance is due to poor BP measurement technique, low adherence to treatment and inappropriate therapeutic regimen. Studies have shown that 50-80% of the patients fail to adhere to treatment completely or partially. The diagnosis of RAH should only be established after inclusion of an appropriate DIU 13 and adjustment of the antihypertensive regimen. 12 Complementary tests Blood biochemistry, urinalysis and ECG should be requested at the time of diagnosis, and repeated at least once a year. Echocardiogram and retinal exam, when available, should be repeated every 2 to 3 years. Secondary causes Secondary causes are common in RAH, 6 OSAHS being the most prevalent (80%, and 50% with moderate-severe apnea), 14 followed by hyperaldosteronism (20%, mainly adrenal hyperplasia) 15 and renal artery stenosis (2.5%). 6 Other secondary causes should only be investigated in the presence of suggestive clinical findings. 6 ABPM and HBPM Although the diagnosis of RAH is based on office BP measurement, 1 BP assessment by using ABPM or HBPM is mandatory for the initial diagnosis and clinical follow-up. It …