Prevalence and clinical profile of refractory hypertension in a large cohort of patients with resistant hypertension.

Refractory hypertension (RfHT) is an extreme phenotype of resistant hypertension (RHT) and is considered uncontrolled blood pressure (BP) despite the use of five or more antihypertensives. The objective of this study was to characterize the prevalence and clinical profile of RfHT patients in a historical cohort of patients with RHT at two different times: before and after the introduction of spironolactone. First, this cross-sectional study evaluated 1048 RHT patients (72.3% females, mean [SD] age: 61.2 [11.3] years) referred to a hypertension clinic (prespironolactone period). All patients were submitted to a standard protocol including clinical and complementary exams. Second, the analysis evaluated patients after the introduction of spironolactone (postspironolactone period). Statistical analysis included bivariate comparisons between patients with RHT and patients with RfHT and logistic regressions to assess the independent correlations of RfHT. A total of 146 patients (13.9%) remained refractory despite the use of at least five antihypertensives (prespironolactone period). After the introduction of spironolactone, the prevalence increased to 17.6%. For any criterion, RfHT patients were younger and more obese. In the initial period, current smoking and left ventricular hypertrophy were independently correlated with RfHT. Furthermore, after spironolactone use, RfHT patients had lower aortic stiffness and peripheral artery disease (PAD), pointing to a lower cardiovascular risk despite the lack of BP control. Younger age and lower prevalence of PAD correlated independently with RfHT. In conclusion, there was a high prevalence of RfHT, especially in younger and obese patients, and spironolactone use seemed to reduce cardiovascular risk despite the lack of BP control.

Prognostic impact of baseline urinary albumin excretion rate in patients with resistant hypertension: a prospective cohort study.

Moderately increased albuminuria, defined as urinary albumin excretion rate (UAER) between 30 and 300-mg/24-h is a well-known cardiovascular risk factor, especially in diabetic and hypertensive patients. This study aim to analyze the prognostic value of baseline UAER in a still understudied group, patients with resistant hypertension (RHT). This is a prospective observational study, which had enrolled 1048 outpatients with RHT, who were submitted to a clinical-laboratory assessment and ambulatory blood pressure monitoring (ABPM) during the follow-up. Primary endpoints were a composite of fatal and non-fatal cardiovascular events, all-cause mortality and cardiovascular mortality. Survival analysis by multiple Cox regression assessed the associations among endpoints, baseline UAER, glomerular filtration rate (GFR), and ABPM control. After a mean 7.5 years follow-up, 233 patients died, 120 from cardiac death; 215 cardiovascular events occurred, 90 strokes and 116 coronary diseases. UAER above 30-mg/24-h increased above 40% the risk of fatal and non-fatal cardiovascular events, and of all-cause mortality. At these UAER levels, secondary outcomes were associated to increased risk of stroke and risk of end-stage renal disease, but did not affect coronary events. Both the GFR below 60-mL/min and uncontrolled ABPM were related to nearly two-fold raised risk of fatal and non-fatal cardiovascular events, when coupled with UAER above 30-mg/24-h. In conclusion, moderately increased albuminuria predicts cardiovascular events and all-cause mortality in RHT, and its prognostic impact is enhanced in association with a GFR under 60-mL/min and uncontrolled baseline ABPM.