Target-organ damage and cardiovascular risk profile in resistant hypertension. Influence of the white-coat effect.

BACKGROUND: It is difficult to draw definite conclusions about the prevalence and clinical characteristics of patients with resistant hypertension because of the heterogeneity of study designs described in published studies. OBJECTIVES: To estimate the prevalence of resistant hypertension, the associated cardiovascular risk factors and the degree of target-organ damage, and to analyze the differences between true resistant hypertension (TRH) and white-coat resistant hypertension (WCRH). DESIGN: Cross-sectional study. METHODS: Patients who visited the Hypertension Clinic with resistant hypertension were sequentially included. Resistant hypertension was defined as an average of three measurements of systolic blood pressure, >/= 160 mmHg or a diastolic blood pressure >/= 95 mmHg, or both, in patients treated with a triple-drug regimen, over at least 2 months. Twenty-four-hour ambulatory blood pressure monitoring and M-mode bi-dimensional echocardiography were performed. WCRH was defined as a mean daytime ambulatory blood pressure