ABC | Volume 115, Nº1, July 2020

Original Article Clinical Characteristics of Resistant vs. Refractory Hypertension in a Population of Hypertensive Afrodescendants Cristiano Macedo, 1 Roque Aras Junior, 1 Isabella Sales de Macedo 2 Hospital Universitário Professor Edgard Santos – Cardiologia, 1 Salvador- BA - Brazil Universidade de São Paulo - Faculdade de Medicina, 2 São Paulo, SP – Brazil Mailing Address: Cristiano Macedo • Hospital Universitário Professor Edgard Santos – Cardiologia - Rua Augusto Viana, s/n. Postal Code 40110-040, Salvador, BA – Brazil E-mail: crbm@terra.com.br Manuscript received April 04, 2019, revised manuscript June 17, 2019, accepted July 17, 2019 DOI: https://doi.org/10.36660/abc.20190218 Abstract Background: Afrodescendants have been associated with a greater severity of arterial hypertension and a higher incidence of cardiovascular complications. Characteristics in the presentation of resistant hypertension (RH) or refractory hypertension (RfH), specifically in this ethnic group, have not been properly studied. Objectives: The study compares clinical and epidemiological characteristics and prevalence of cardiovascular events in people of African descent diagnosed with RH or RfH. Methods: Cross-sectional study carried out in a referral clinic for patients with severe hypertension. The level of significance was 5%. Results: 146 consecutive patients were evaluated, of which 68.7% were female. The average age was 61.8 years, with 88.4% of Afrodescendants (mixed race or black). 51% had RfH. There was a high prevalence of cardiovascular risk factors: 34.2% of subjects had diabetes, 69.4% dyslipidemia, 36.1% obesity, and 38.3% history of smoking. Reduced renal function was seen in 34.2%. Previous cardiovascular events occurred in 21.8% for myocardial infarction and in 19.9% ​for stroke. The Framingham’s risk score was moderate/high at 61%. RfH patients were younger (mean age 59.38±11.69 years versus 64.10±12.23 years, p=0.02), had more dyslipidemia (83.8 versus 66.7%, p=0.021), and stroke (30.4 versus 12.3%, p=0.011) when compared to those with RH. The use of a combination of ACEi/ARB+CCB+Diuretic, chlortalidone and spironolactone was also more frequent in individuals with RfH. Conclusion: Africandescendant people with RH had a high cardiovascular risk, a high prevalence of RfH, a higher frequency of dyslipidemia and stroke, compatible with a high incidence of injury to target organs. (Arq Bras Cardiol.2020; 115(1):31-39) Keywords: Hypertension/complications; African Continental Ancestry Grup/genetic; Comparative Stuy; Epidemiology; Myocardial Infarction; Stroke. Introduction The high proportion of individuals with systemic arterial hypertension (SAH) who do not reach the appropriate therapeutic goals has a direct impact on morbidity, mortality, disability and health costs. 1-3 Even with the proper use of antihypertensive drugs, a significant number of patients remain with high blood pressure (BP), a condition characterized as Resistant Hypertension (HR) and defined as the persistence of high BP despite the use of three antihypertensive drugs of different classes, or when BP control occurs only with the use of four or more drugs, always including a thiazide diuretic. 2-5 A subgroup of patients with HR exhibits a phenotypic presentation of apparently greater severity, in which BP is not controlled even with the use of five or more drugs, a situation currently defined as Refractory Hypertension (RfH). 2,6-8 The use of an association of Angiotensin Converting Enzyme Inhibitor (ACEI) or Angiotensin Receptor Blocker (BRA), CalciumChannel Blocker (BCC) and thiazide diuretic has been recommended as the basis of HR pharmacological therapy. 2,3,5,9 The estimate of the real prevalence of RH is uncertain, hampered by the presence of factors that determine pseudoresistance, such as inadequate adherence to therapy and the white coat effect. 9-12 Some studies report a proportion of 11 to 33% of resistant hypertensive patients among those with SAH varying according to the characteristics of the population and the definition criteria. 9,13,14 The prevalence of RfH among patients with RH is even less known, estimated between 3 and 31% in some studies. 6 Pathophysiological differences in the mechanisms involved in resistance to the treatment of hypertension in RH and RfH have been described. 14 Some studies point to an apparent worse prognosis, higher prevalence of injury to target organs and increased risk of cardiovascular events in patients with RH when compared to patients with non-resistant 31