IntroductionWe aimed to assess the effectiveness of ambulatory blood pressure monitoring (ABPM) and subclinical target organ damage parameters for diagnosis of resistant hypertension (RH). MethodsWe assessed demographic and anthropometric variables, the incidence of cardiovascular events and subclinical target organ damage (n=112). We also studied the relationship between these variables and the ABPM results. ResultsOf the 112 patients referred from primary care with a diagnosis of RH, 69 (61.6%) were confirmed by ABPM. We found statistically significant differences (p<0.001) between patients with RH and pseudo-resistant hypertension in the appearance of subclinical target organ damage. A percentage of 84 of the patients had microalbuminuria: 66.25±30.7mg/dl); 44.9% had stage 3 chronic kidney disease: the average glomerular filtration was 59ml/min/1.73m2; and 56.5% had left ventricular hypertrophy on echocardiography. Fundoscopy revealed that 64% of the patients had hypertensive retinopathy. Three variables were associated with an increased HR risk: microalbuminuria, hypertensive retinopathy and left ventricular hypertrophy (OR 5.7, 6.2 and 11.2, respectively). ConclusionsThis study shows that the systematic testing for target organ damage, particularly in terms of albuminuria, is a simple and inexpensive tool, with a high predictive value for RH (85%), which could be useful for prioritizing patients who need ABPM.