Appropriate time interval to repeat ambulatory blood pressure monitoring in patients with white-coat resistant hypertension

Resistant hypertension is defined as uncontrolled office blood pressure, despite the use of ≥3 antihypertensive drugs. Ambulatory blood pressure monitoring (ABPM) is mandatory to diagnose 2 different groups, those with true and white-coat resistant hypertension. Patients are found to change categories between controlled/uncontrolled ambulatory pressures without changing their office blood pressures. In this way, ABPM should be periodically repeated. The aim of this study was to evaluate the most appropriate time interval to repeat ABPM to assure sustained blood pressure control in patients with white-coat resistant hypertension. This prospective study enrolled 198 patients (69% women; mean age: 68.9±9.9 years) diagnosed as white-coat resistant hypertension on ABPM. Patients were submitted to a second confirmatory examination 3 months later and repeated twice at 6-month intervals. Statistical analyses included Bland-Altman repeatability coefficients and multivariate logistic regression. Mean office blood pressure was 163±20/84±17 mm Hg, and mean 24-hour blood pressure was 118±8/66±7 mm Hg. White-coat resistant hypertension diagnosis presented a moderate reproducibility and was confirmed in 144 patients after 3 months. In the third and fourth ABPMs, 74% and 79% of patients sustained the diagnosis. In multivariate regression, a daytime systolic blood pressure ≤115 mm Hg in the confirmatory ABPM triplicated the chance of white-coat resistant hypertension status persistence after 1 year. In conclusion, a confirmatory ABPM is necessary after 3 months of the first white-coat-resistant hypertension diagnosis, and the procedure should be repeated at 6-month intervals, except in patients with daytime systolic blood pressure ≤115 mm Hg, in whom it may be repeated annually.     

Home blood pressure self-monitoring: diagnostic performance in white-coat hypertension

OBJECTIVE: To determine the diagnostic performance of home blood pressure self-monitoring in white-coat hypertension using a 3-day reading program. MATERIAL AND METHODS: One hundred and ninety nontreated patients recently diagnosed with mild-moderate hypertension, selected consecutively at four primary healthcare centers in the city of Barcelona, were included. Each patient underwent morning and night home blood pressure self-monitoring with readings in triplicate for three consecutive days, followed by 24-h ambulatory blood pressure monitoring. The normality cut-off point value for home blood pressure self-monitoring and daytime ambulatory blood pressure monitoring was 135/85 mmHg. RESULTS: Sixty-three patients were diagnosed with white-coat hypertension with home blood pressure self-monitoring (34.8%; 95% confidence interval: 27.9-42.2) and 74 with ambulatory blood pressure monitoring (41.6%; 95% confidence interval: 33.7-48.4). No statistically significant differences were observed between home blood pressure self-monitoring values and those of diurnal ambulatory blood pressure monitoring [137.4 (14.3)/82.1 (8.3) mmHg vs. 134.8 (11.3)/81.3 (9.5) mmHg]. Home blood pressure self-monitoring diagnostic performance parameters were sensitivity 50.0% (95% confidence interval: 38.3-61.7), specificity 75.7% (95% confidence interval: 66.3-83.2), positive and negative predictive values 58.7% (95% confidence interval: 45.6-70.8) and 68.6% (95% confidence interval: 59.4-76.7), respectively, and positive and negative probability coefficients 2.05 and 0.66, respectively. Analysis of different normality cut-off points using a receiver operating characteristic curve failed to produce significant improvement in the diagnostic performance of home blood pressure self-monitoring. CONCLUSIONS: The diagnostic accuracy of a 3-day home blood pressure self-monitoring reading program in white-coat hypertension was poor. Ambulatory blood pressure monitoring continues to be the test of choice for this indication.     

Identification of subjects with white-coat hypertension and persistently normal ambulatory blood pressure

OBJECTIVE: To assess the spontaneous changes in clinic blood pressure, ambulatory blood pressure (ABP) and left ventricular structure in untreated subjects with white-coat hypertension (WCH). DESIGN: A prospective observational study. PATIENTS AND METHODS: In 83 untreated subjects with WCH, 24 h non-invasive ABP monitoring and echocardiographic studies of the left ventricle were repeated after 0.5-6.5 years (mean 2.5) in the absence of antihypertensive drug treatment. WCH was defined by an average daytime ABP < 131/86 mmHg in women and < 136/87 mmHg in men. Ambulatory hypertension was defined by higher ABP values. RESULTS: In the whole population, the clinic blood pressure, ABP and left ventricular mass did not change from baseline to the follow-up visit, whereas the peak A: peak E ratio (where A is the velocity of transmitral blood flow after atrial contraction and E is the velocity during passive left ventricle filling) increased from 0.86 to 0.93. Sixty-three per cent of subjects remained in the WCH category at follow-up study; the remaining 37% shifted to the ambulatory hypertension category. The former group showed no changes in clinic blood pressure, ABP, left ventricular mass and peak A: peak E ratio. The clinic blood pressure of those who developed ambulatory hypertension did not change, whereas their ABP and peak A: peak E ratio increased and their left ventricular mass increased slightly but not significantly. The left ventricular mass increased from baseline to follow-up study by 6.2% in those who developed ambulatory hypertension and decreased by 1.6% in those who remained in the WCH category. The changes in left ventricular mass were associated with the changes in average 24 h systolic blood pressure, but not with the changes in clinic blood pressure. In a stepwise logistic regression analysis, average daytime diastolic blood pressure was the sole variable to enter the model and the probability of ambulatory hypertension at follow-up study was 20.0%percnt; in those with basal daytime ABP <130/80 mmHg, versus 81% in those with higher basal daytime blood pressure levels. CONCLUSION: After 0.5-6.5 years, WCH spontaneously evolved into ambulatory hypertension in 37% of subjects, with an accompanying rise in left ventricular mass. The probability of ambulatory hypertension increased with the baseline values of ABP, rather than with those of clinic blood pressure. WCH might be a prehypertensive state (particularly in subjects with higher baseline ABP levels) and should be defined by low levels of daytime ABP, possibly lower than 130/80 mmHg.     

Repeated office blood pressure controls reduce the prevalence of white-coat hypertension and detect a group of white-coat normotensive patients

BACKGROUND: The aim of this study was to evaluate whether repeated office blood pressure controls may change the prevalence of white-coat hypertension among hypertensive patients. METHODS: We studied 221 newly diagnosed, never-treated hypertensive patients, all men, aged 31-60 years. On the first visit, they underwent sitting blood pressure measurements (two readings were taken by mercury sphygmomanometer and averaged) and non-invasive 24 h ambulatory blood pressure monitoring (ABPM) every 15 min. Thereafter, each patient made four further visits over an 8-week period. On each visit, three sitting readings were taken and averaged. On the last visit, ABPM was performed again. Subjects who had hypertension in the clinic but whose daytime ambulatory blood pressure was less than 134/90 mmHg were considered to have white-coat hypertension. RESULTS: On the first visit, all patients were, by definition, clinically hypertensive and ABPM detected a prevalence of white-coat hypertension of 25.8%. On the following visits, the prevalence of clinical hypertensive patients progressively declined; on the last visit, the 82.3% of all patients resulted yet clinical hypertensive: on ambulatory blood pressure 71.9% were sustained hypertensives, whereas 10.4 had white-coat hypertension. Of the patients originally labelled as hypertensive, 17.7% proved to be clinically normotensive: 13.6% had also daytime ambulatory blood pressure in the normal range, whereas 4.1% showed elevated blood pressure during daytime ABPM (white-coat normotensives). CONCLUSION: These data suggest that repeated office blood pressure controls in newly diagnosed hypertensives reduce the number of office hypertensive patients, reduce the number of white-coat hypertensive patients and detect a small group of white-coat normotensive patients.     

Secondary hypertension in a blood pressure clinic

The prevalence, reversibility, and mortality of secondary hypertension among 3783 patients with moderately severe nonmalignant hypertension attending the Glasgow (Scotland) Blood Pressure Clinic were assessed. Underlying causes of hypertension were found in 297 patients (7.9%). Eighty-seven patients (2.3%) were considered to have a potentially reversible cause for their hypertension, including the oral contraceptive pill (38 patients), renovascular disease (27 patients), and primary hyperaldosteronism (ten patients), but of these only 33 patients (0.9% of total clinic population) were cured by specific intervention. Two hundred ten patients (5.6%) had irreversible renal parenchymal disease and significantly higher mortality than men and women with other causes of hypertension. Excess deaths in the renal group were attributed to renal failure (International Classification of Diseases [ICD] 580 to 589) and vascular causes (ICD 390 to 458) but not to cancer (ICD 140 to 208; 235 to 239) or other nonvascular disease. These results suggest that investigation of hypertension for an underlying cause will reveal a small number of patients with treatable disorders, of whom only a few will be cured by specific intervention, and a moderate number with irreversible disease who are at high risk of myocardial infarction and stroke.     

原发性高血压病患者血压昼夜节律的临床意义探讨

目的 探讨原发性高血压病患者昼夜血压均值波动的节律与临床意义。方法 ９２例原发性高血压病人分成三组,单纯收缩压增高组（ＩＳＨ）３６例,收缩压和舒张压均增高认定为混合组（ＭＤＨ）,共３１例,二组均除外心,脑,肾损害。高血压合并左心室肥大（ＬＶＨ）组２５例。２０例正常个体为对照组,仪器采用美国Ｓｐａｃｅｌａｂｓ ９０２０７无创性携带式血压监测仪,获取２４小时平均收缩压（２４ｈＳＢＰ０和舒张压（２４ｈＤ     

Sequential follow-up clinic and ambulatory blood pressure evaluation in a low risk population of white-coat hypertensive patients and in normotensives

BACKGROUND: In subjects with white-coat hypertension (WCH) it is unclear how ambulatory blood pressure (ABPM) progresses over time and whether they exhibit an increased cardiovascular risk. METHODS: We prospectively evaluated the transition of clinic and ABPM values in 39 clinic and ABPM normotensive subjects (NT) (clinic BP<140/90 mmHg and awake BP<130/85 mmHg, ages 43.4+/-2.6 y) and in 79 untreated subjects (47.2+/-2.4 y) with WCH (clinic BP>140/90, awake ABP<130/85 mmHg) with no other major cardiovascular risk factors. Ambulatory blood pressure was evaluated at baseline and on at least two further occasions during follow-up. RESULTS: At baseline all subjects were untreated and groups did not differ on values of metabolic parameters, BMI, left ventricular mass index, and ABPM values. Subjects were revaluated for ABPM half way through and at the end of follow-up, 35+/-3 and 86+/-4 months in NT and 49+/-4 and 90+/-4 months in WCH. Thirty-six WCH were on antihypertensive treatment (AH) after baseline until the end of follow-up (WCH-tr), whereas 43 WCH (WCH-untr) were free from AH throughout the study. In a similar way all groups showed a significant (p<0.01) progressive increase in 24-h ABPM systolic blood pressure (SBP)/diastolic blood pressure (DBP) from baseline throughout the follow-up in NT (+4.9/2.1+/-0.8/0.9 mmHg), average annual increase of 0.72/0.37 mmHg/y, in WCH-tr (+ 5.0/1.2+/-1.1/1.5 mmHg), average annual increase of 0.66/0.31 mmHg/y and in WCH-untr (+5.4/3.2+/-0.9/1.1 mmHg), average annual increase of 0.74/0.39 mmHg/y. During the follow-up office SBP/DBP (mmHg) significantly rose in NT (+5.7/3.9) but was reduced in WCH-tr (-7.8/5.2) and in WCH-untr (-4.7/1.1). Development of ambulatory hypertension (daytime BP >130 and/or >85 mmHg) occurred in 15.4% (6/39) of NT, in 22.7% (8/36) of WCH-tr and in 26.1% (11/43) of WCH-untr (NS). First cardiovascular events recorded were three in subjects with WCH and none in NT. CONCLUSIONS: After 7.4 years of follow-up, both the progressive increase in ABPM and the rate of transition to ambulatory hypertension in subjects with WCH (either treated or untreated), who were selected under strict criteria were similar to that of normotensive subjects. Also there was no evidence that WCH exhibited a clear higher risk of development cardiovascular events.     

褪黑素与血压昼夜节律的相关性研究

目的研究褪黑素（MLT）与血压昼夜节律的关系。方法选门诊、住院患者及健康查体者88例分为非杓型高血压组、杓型高血压组及对照组；行24小时动态血压监测；同期测定患者白昼和黑夜尿6羟基硫酸褪黑素（6-SMT）含量，并计算黑夜／白昼尿6-SMT比值。结果（1）非杓型高血压组的夜间收缩压、舒张压及平均动脉压下降率均低于杓型高血压组和对照组（P〈0．01）；杓型高血压组和对照组间差异无统计学意义（P〉0．05）。（2）各组患者的黑夜尿6-SMT含量高于白昼（P〈0．01）；非杓型高血压组的黑夜尿6-SMT含量和黑夜／白昼尿6-SMT比值低于杓型高血压组和对照组（P〈0．01）。（3）在各组内，各黑夜／白昼尿6-SMT比值与其组夜间血压下降率均存在正相关（P〈0．05）。结论血压节律呈现杓型分布的杓型高血压组和对照组，其MLT在黑夜分泌较多；非杓型高血压组MLT黑夜分泌明显减少，与血压昼夜节律异常存在密切关系。     

Impaired arterial elasticity in young patients with white-coat hypertension

BACKGROUND: Conflict still exists over whether patients with white-coat hypertension are at increased risk of developing target organ damage compared with normotensive individuals. METHODS: We studied vascular distensibility in 117 young-to-middle age patients with white-coat hypertension, 174 patients with sustained hypertension, and 51 normotensive controls. To obtain a measure of compliance, a model was used that divides the total systemic compliance into large artery (C1) and small artery (C2) compliance. With this aim, radial arterial pulse waves were recorded with a tonometer sensor array by means of an HDI CR2000 device (Eagan, Minnesota, USA). Moreover, pulse wave velocity and the augmentation index were measured using the Specaway DAT system (St Pauls, Sydney, Australia). RESULTS: Patients with sustained hypertension had a greater body mass index than patients with white-coat hypertension (P=0.04) or the normotensive individuals (P=0.01). C1 and C2 were decreased in the two hypertensive groups as compared with those in the normotensive group (P=0.0002 and 0.03, respectively, versus sustained hypertension; P=0.00007 and 0.0004, respectively, versus white-coat hypertension). Pulse wave velocity and aortic augmentation index were increased in the white-coat hypertension patients compared with the normotensive individuals (P=0.02 and 0.004, respectively). Aortic augmentation index (P=0.008) but not pulse wave velocity was increased in the sustained hypertensive patients compared with that in the normotensive individuals. All indexes of arterial distensibility were similar in the two hypertensive groups. CONCLUSIONS: Indexes of arterial distensibility are impaired in the white-coat hypertensive group and similar to those in the sustained hypertensive group, indicating that early changes in the arterial wall can occur in white-coat hypertension. This may account for the higher risk of stroke that has been described in this condition.     

Ambulatory blood pressure monitoring and clinical characteristics of the true and white-coat resistant hypertension

The resistant hypertension has been differentiated in true resistant hypertension and white-coat resistant hypertension by using ambulatory blood pressure monitoring. White-coat resistant hypertension was defined as high clinic blood pressure, despite triple treatment for at least 3 months, but day-time blood pressure values < 135/85 mmHg. The aim of this study was to evaluate the presence of different clinical characteristics between two types of resistant hypertension. The study group consisted of 49 patients with essential hypertension, resistant to an adequate and appropriate triple-drug therapy, that included a diuretic, with all 3 drugs prescribed in near maximal doses and that had persistently elevated clinic blood pressure (> 140/90 mm Hg), for at least 3 months. They represented the 2% of 2500 hypertensive outpatients that referred at our Hypertension Unit. Patients with white-coat resistant hypertension (n=19) were older (p<0.05) than those with true resistant hypertension (n=30). The sodium intake (p<0.05) and alcohol intake (p<0.05) were significantly higher in patients with true resistant hypertension than in those with white-coat resistant hypertension. The renin plasma activity and plasma aldosterone were higher (p<0.05) in patients with true resistant hypertension than in those with white-coat resistant hypertension with normal plasma electrolyte balance. There were no significant differences in mean values of office systolic and diastolic blood pressures between white coat resistant hypertensives and true resistant hypertensives (165+17 vs 172+28 and 98+12 vs 102+14 mmHg). Day-time and night-time ambulatory 24-h-systolic and diastolic blood pressures were significantly higher in the true resistant hypertensive patients when compared with white-coat resistant hypertensives (153+15 vs 124+10 mmHg and 97+9 vs 76+6 mmHg all p<0.001). Day-time and night-time ambulatory 24-h-heart rate were significantly higher in the true resistant hypertensive patients when compared with white-coat resistant hypertensives (79+11 vs 71+9 beats/min; p<0.01; 68+9 vs 60+6 beats/min, p<0.001). The ABP readings were analysed by a Fourier series with 4 harmonics. According to the runs test both two groups of patients showed a circadian rhythm for both systolic and diastolic blood pressure. The nocturnal fall in SBP, DBP and HR was not different in both groups of patients. In conclusion, our findings showed that true resistant hypertensive patients were characterized both by higher heart rate and higher plasma renin activity values as an expression of a possible increased sympathetic activity. Thus, the combination of ABPM with the assessment of the clinical characteristics allow to differentiate better the true drug-resistant hypertension from the white coat resistant hypertension.     

Home and clinic blood pressure responses in elderly individuals with systolic hypertension

Home blood pressure (BP) monitoring may enhance assessment of BP control. In this 16-week study, men and women 70 years or older with systolic BP between 150 and 200 mm Hg were randomized to receive valsartan/hydrochlorothiazide (V/HCTZ) 160/12.5 mg (n = 128), HCTZ 12.5 mg (n = 128), or V 160 mg (n = 128) for 4 weeks. Participants whose BP was 140/90 mm Hg or higher at weeks 4, 8, or 12 were uptitrated to a maximum of V/HCTZ 320/25 mg. Participants were evaluated by home BP monitoring using an automated device weekly before taking daily study medication (n = 301). Baseline BP ± SD for clinic (165.5 ± 11.8/85.1 ± 9.5 mm Hg) was approximately 3/1 mm Hg greater than home readings (162.5 ± 15.8/84.3 ± 10.2 mm Hg). Reductions in BP ± SEM at week 4 were similar for clinic (12.6 ± 1.0/4.7 ± 0.5 mm Hg) and home (10.9 ± 1.1/3.8 ± 0.5 mm Hg) readings (P = .25/P = .23; clinic versus home); differences between V/HCTZ and HCTZ or V were also similar for both home and clinic readings and results by either technique correlated significantly (P < .0001). Home BP measurements confirm that treatment initiated with V/HCTZ versus monotherapy resulted in greater antihypertensive efficacy. Home BP monitoring, if done with proper technique, provides a reliable indicator of BP control in elderly patients and may help guide drug dosing and titration.     

Long-term blood pressure changes in renal homotransplantation.

Long-term blood pressure changes were studied in 50 patients who had undergone renal homotransplantation. Excluded were those subjects with arterial stenosis of the transplanted kidney, acute or rapidly progressive rejection, or recurrent glomerulonephritis, as well as those retaining their own diseased kidney(s). The blood pressure after the end of the first year was stable and, therefore, was utilized as the reference blood pressure for this study. One year after transplantation, hypertension was observed in 20% of the patients. Mean blood pressure was positively correlated with age (P less than .01), body weight (P less than .001), and serum creatinine level (P less than .001), and negatively correlated with maintenance dose of prednisone (P less than .01). A higher incidence of hypertension was observed in cadaver kidney transplantation than in living related-donor transplantation. The study minimizes the role of glucocorticoids and emphasizes the role of renal factors in the mechanism of the long-term blood pressure changes.     

VALUE trial: Long-term blood pressure trends in 13,449 patients with hypertension and high cardiovascular risk

BACKGROUND: The Valsartan Antihypertensive Long-term Use Evaluation (VALUE) study compares cardiovascular outcomes in 15,314 eligible patients from 31 countries randomized to valsartan or amlodipine-based treatment. METHODS: The blood pressure (BP) trends are analyzed in 13,449 of VALUE study patients who had baseline BP and 24 months BP and treatment data. RESULTS: In a cohort of 12,570 patients, baseline 24 and 30 months BP, but not 30 months treatment data, were available. Of 13,449 patients, 92% (N = 12,398) received antihypertensive therapy at baseline. The baseline BP was 153.5/86.9 mm Hg in treated compared to 168.1.8/95.3 mm Hg in 1051 untreated patients. After 6 months both groups had indistinguishable BP values. At 12 months the BP decreased to 141.2/82.9 mm Hg (P <.0001 for systolic BP and diastolic BP versus baseline), at 24 months to 139.1/80 mm Hg (P <.0001 v 12 months), and to 138/79 mm Hg at 30 months (P <.0001 v 24 months). The systolic BP control (<140 mm Hg) at 30 months increased from 21.9% at baseline to 62.2%, the diastolic BP (< 90 mm Hg) from 54.2% to 90.2% and the combined control (<140 and <90 mm Hg) from 18.9% to 60.5%. At 24 months 85.8% of patients were on protocol drugs: monotherapy = 39.7%, added hydrochlorothiazide = 26.6%, add-on drugs = 15.1%, and protocol drugs in nonstandard doses = 4.3%. CONCLUSIONS: The achieved BP control exceeds values reported in most published large-scale trials. The VALUE study is executed in regular clinical settings and 92% of the patients received antihypertensive drugs at baseline. When an explicit BP goal is set, and a treatment algorithm is provided, the physicians can achieve better control rates than in their regular practice.     

Assessment of age-dependent changes in circadian blood pressure rhythm in patients with essential hypertension.

The effects of age on the circadian blood pressure rhythm of patients with untreated essential hypertension (n = 133, World Health Organization stage I or II) were compared with those of normotensive subjects (n = 91). Subjects were classified into three groups by age: young (less than 40 years old), adult (40-59 years old) and old (greater than or equal to 60 years old). Blood pressure was monitored every 5 min for 24 h, using a finger volume oscillometric device under fixed external conditions. The single cosinor method was used to evaluate circadian rhythm. There was no difference in the amplitude of circadian systolic or diastolic blood pressure rhythm among the different normotensive and essentially hypertensive age groups although a wide distribution of amplitude was noted within each group. The distribution of amplitude was wider in the hypertensive than in the normotensive groups. The amplitude of circadian blood pressure rhythm was independent of the mesor level. On the other hand, the amplitude of circadian heart rate rhythm decreased with increasing age both in normotensive subjects (P less than 0.05, young versus adult or old) and hypertensive patients (P less than 0.01, young and old versus adult). The acrophase of circadian systolic blood pressure rhythm in young hypertensives was greater than that in adult or old hypertensives (P less than 0.05, for both). Such age-dependent changes were not observed in the normotensive groups. Consequently, the acrophase of circadian systolic or diastolic blood pressure rhythm in young hypertensives was larger than that in young normotensives (P less than 0.05, for both systolic and diastolic blood pressure).(ABSTRACT TRUNCATED AT 250 WORDS)     

Factors influencing blood pressure in salt-sensitive patients with hypertension

Eighteen patients with hypertension in whom all known causes of elevated blood pressure levels had been ruled out were studied during a low-sodium diet for seven days, a high-sodium diet for seven days and after the oral administration of furosemide. They were classified as “salt-sensitive” (SS) or “nonsalt-sensitive” (NSS) from the increase in 24-hour averages of mean blood pressure with changes in sodium intake from 9 meq to 249 meq/day (15.1 ± 1.2 (SE) mm Hg (SS) versus 2.7 ± 0.9 mm Hg (NSS), (p < 0.001)). With a highsodium diet, SS patients gained more weight (p < 0.001), retained more sodium (p < 0.05), had a greater increase in cardiac output (p < 0.05), showed higher plasma norepinephrine levels on day 4 (p < 0.05), showed lesser decrements in PRA and plasma aldosterone concentration than the NSS patients, and showed no change in urinary prostaglandin E₂ (PGE₂) which decreased (p < 0.01) in the NSS patients. With furosemide, SS patients showed greater decrements in cardiac output (p < 0.05) and showed no change in urinary PGE₂, whereas NSS patients showed increases (p < 0.01). Results suggest that the greater increase in blood pressure in SS patients with sodium loading can be attributed to greater sodium retention, leading in turn to an increase in cardiac output. The persistence of autonomic “drive” in the SS patients may contribute to the relative sodium retention with sodium loads and the increase in blood pressure.