The white coat effect is not associated with additional increase of target organ damage in true resistant hypertension.

BACKGROUND AND OBJECTIVE: White coat effect (WCE) (i.e., the difference between office blood pressure [OBP] and awake ambulatory blood pressure monitoring [ABPM]) may be present in hypertensive individuals. The relationship between occurrence of WCE and target organ damage (TOD) has not yet been assessed in true resistant hypertension (RHTN). PATIENTS AND METHODS: RHTN patients were divided into two groups: RHTN with WCE (WCE, n=66) and RHTN without WCE (non-WCE, n=61). All patients were submitted to OBP measurement, ABPM, echocardiography and renal function evaluation in three visits. RESULTS: No differences were observed between the WCE and non-WCE groups regarding age, body mass index or gender. OBP were 169.8±15.8/95.1±14.0 (WCE) and 161.9±9.0/90.1±10.4mmHg (non-WCE), ABPM=143.0±12.8/86.1±9.9 (WCE) and 146.1±13.6/85.1±14.9mmHg (non-WCE). No statistical differences were observed between WCE and non-WCE subgroups with respect to left ventricular mass index (LVMI) (WCE=131±4.7; non-WCE=125±2.9g/m(2)), creatinine clearance (WCE=78±4.7; non-WCE=80±3.6ml/min/m(2)) and microalbuminuria (MA) (WCE=44±8.4; non-WCE=49±6.8mg/g Cr). CONCLUSIONS: This finding may suggest that WCE is not associated with additional increase of TOD in true RHTN subjects.

Vascular stiffness and endothelial dysfunction: Correlations at different levels of blood pressure.

UNLABELLED: Resistant hypertensive (RHTN) patients have endothelial dysfunction and aldosterone excess, which contribute to the development of resistance to antihypertensive treatment and cardiovascular complications. Biophysical forces within the arterial wall provide functional regulation of arterial stiffness. Carotid-femoral pulse wave velocity (PWV) and flow-mediated brachial artery dilation (FMD) can be used to evaluate vascular stiffness and endothelial function. Although both techniques have been used in several studies in hypertensive patients, it is unknown whether endothelial dysfunction is also associated with vascular stiffness in RHTN patients. METHODS: One hundred and ninety-three consecutive subjects were divided in three groups: 44 RHTN, 35 well-controlled hypertensive patients (HTN) and 25 normal healthy volunteers (NT). FMD was measured by high-resolution ultrasound and PWV was calculated from measurements of the pulse transit time and the distance traveled by the pulse between carotid and femoral arteries. RESULTS: No significant differences were observed in respect to body mass index, age or other biochemical variables among the three groups. FMD (NO-dependent) values were statistically different when comparing RHTN and well controlled HTN patients (respectively, 8.3 ± 4.7% and 10.1 ± 5.9%) and 12.3 ± 6.3% in normal subjects (p < 0.05). One-way analysis of variance (ANOVA) showed a significant difference in BP-adjusted PWV between RHTN and HTN (13.9 ± 1.0 and 11.5 ± 1.1 m/s, respectively; p < 0.05). FMD (NO-dependent) and PWV-adjusted values were strongly correlated in well-controlled HTN and NT subjects (r = - 0.74 and - 0.83, respectively). Although statistically significant, this correlation was lower in RHTN patients (r = - 0.43). CONCLUSION: We found a close relationship among high BP levels, endothelial dysfunction and vascular rigidity in hypertensive patients, demonstrated by a significantly higher increase in carotid-femoral PWV and a decrease in brachial artery FMD in RHTN when compared with well-controlled hypertensive patients. Although this study was not designed to test the prognostic, the vascular damage differences observed between patients with controlled vs uncontrolled hypertension suggest that the latter group may have a worse cardiovascular prognosis, requiring prospective assessment tests.