Masked Hypertension Assessed by Ambulatory Blood Pressure Versus Home Blood Pressure Monitoring: Is It the Same Phenomenon?

BACKGROUND: Masked hypertension is defined as normal clinic blood pressure (CBP) and elevated out-of-clinic blood pressure assessed using either self-monitoring of blood pressure (BP) by the patients at home (HBP) or ambulatory BP (ABP) monitoring. This study investigated the level of agreement between ABP and HBP in the diagnosis of masked hypertension. METHODS: Participants referred to an outpatient hypertension clinic had measurements of CBP (two visits), HBP (4 days), and ABP (24 h). The diagnosis of masked hypertension based on HBP (CBP <140/90 mm Hg and HBP > or =135/85) versus ABP (CBP <140/90 and awake ABP > or =135/85) was compared. RESULTS: A total of 438 subjects were included (mean age +/- SD, 51.5 +/- 11.6 years; 59% men and 41% women, 34% treated and 66% untreated). Similar proportions of subjects with masked hypertension were diagnosed by ABP (14.2%) and HBP (11.9%). In both treated and untreated subjects, the masked hypertension phenomenon was as common as the white coat phenomenon. Among 132 subjects with normal CBP, there was disagreement in the diagnosis of masked hypertension between the HBP and the ABP method in 23% of subjects for systolic and 30% for diastolic BP (kappa 0.56). When a 5-mm Hg gray zone for uncertain diagnosis was applied to the diagnostic threshold, the disagreement was reduced to 9% and 6% respectively. CONCLUSIONS: Similar proportions of subjects with masked hypertension are detected by ABP and HBP monitoring. Although disagreement in the diagnosis between the two methods is not uncommon, in the majority of these cases the deviation of the diagnostic BP above the threshold in not clinically important. Both ABP and HBP monitoring appear to be appropriate methods for the detection of masked hypertension.     

Changes in home versus clinic blood pressure with antihypertensive treatments: a meta-analysis

Home blood pressure (HBP) monitoring is recommended for assessing the effects of antihypertensive treatment, but it is not clear how the treatment-induced changes in HBP compare with the changes in clinic blood pressure (CBP). We searched PubMed using the terms "home or self-measured blood pressure," and selected articles in which the changes in CBP and HBP (using the upper arm oscillometric method) induced by antihypertensive drugs were presented. We performed a systematic review of 30 articles published before March 2008 that included a total of 6794 subjects. As there was significant heterogeneity in most of the outcomes, a random effects model was used for the meta-analyses. The mean changes (+/-SE) in CBP and HBP (systolic/diastolic) were -15.2+/-0.03/-10.3+/-0.03 mm Hg and -12.2+/-0.04/-8.0+/-0.04 mm Hg respectively, although there were wide varieties of differences in the reduction between HBP and CBP. The reductions in CBP were correlated with those of HBP (systolic BP; r=0.66, B=0.48, diastolic BP; r=0.71, B=0.52, P<0.001). In 7 studies that also included 24-hour BP monitoring, the reduction of HBP was greater than that of 24-hour BP in systolic (HBP; -12.6+/-0.06 mm Hg, 24-hour BP; -11.9+/-0.04 mm Hg, P<0.001). In 5 studies that included daytime and nighttime systolic BP separately, HBP decreased 15% more than daytime ambulatory BP and 30% more than nighttime ambulatory BP. In conclusion, HBP falls approximately 20% less than CBP with antihypertensive treatments. Daytime systolic BP falls 15% less and nighttime systolic BP falls 30% less than home systolic BP.     

Ambulatory blood pressure monitoring in patients with chronic kidney disease and resistant hypertension

J Clin Hypertens (Greenwich). 2012; 14:611–617. © 2012 Wiley Periodicals, Inc. The role of ambulatory blood pressure (BP) monitoring (ABPM) has not been well‐studied in patients with chronic kidney disease and resistant hypertension. In a retrospective study of the outpatient chronic kidney disease population, 156 patients with chronic kidney disease and resistant hypertension who had 24‐hour ABPM and clinic BP measurements were identified. Resistant hypertension was defined as uncontrolled clinic BP while taking ≥3 medications including a diuretic or controlled BP while taking ≥4 medications. Within the study group, ambulatory BP <130/80 mm Hg was found in 35.9% of all patients. Only 6.4% had both ambulatory and clinic BP <130/80 mm Hg. Prevalence of white‐coat hypertension, masked hypertension, and sustained hypertension were 29.5%, 5.8%, and 58.3%, respectively. Compared with patients with sustained hypertension, more patients in the white‐coat hypertension group had low nocturnal average systolic BP (defined as nocturnal average systolic BP <100 mm Hg) (17.4% vs 0%) and low 24‐hour average diastolic BP (defined as 24‐hour average diastolic BP <60 mm Hg) (52.2% vs 22%, P<.01). ABPM provides more reliable assessment of BP in patients with chronic kidney disease and resistant hypertension.     

Home blood pressure normalcy: The Didima study

To evaluate reference values of home blood pressure (HBP) a cross-sectional community study was conducted on 694 adult subjects (aged ≥ 18 years) of the village Didima in southern Greece (participation rate 76.4%). Clinic blood pressure (CBP) was measured on two visits (triplicate measurements, mercury sphygmomanometer) and HBP on 3 workdays (duplicate morning and evening measurements, oscillometric devices; Omron HEM 705CP). After exclusion of 132 subjects (103 treated hypertensives and 29 with incomplete data), 562 subjects were analyzed (mean ± SD aged 51.2 ± 17.2 years, 42.7% men). Average HBP (120.0 ± 17.8/72.6 ± 8.8 mm Hg, systolic/diastolic) was strongly correlated (P < .0001) with CBP (118.7 ± 17.7/73.8 ± 10.5 mm Hg). Systolic CBP was 1.3 mm Hg lower than HBP (P < .01, 95% confidence interval 0.4, 2.2), whereas diastolic CBP was 1.2 mm Hg higher than HBP (P < .0001, 95% confidence interval 0.6, 1.7). The threshold of HBP normality determined using three different approaches was 1) 139.7/83.0 mm Hg (systolic/diastolic) using the distribution criterion (95th percentile of the HBP distribution among 476 normotensive subjects); 2) 139.7/85.8 mm Hg using the correspondence criterion (the percentiles of the CBP distribution that correspond to CBP ≥ 140/90 mm Hg were estimated, and the levels of BP that correspond to these same percentiles on the HBP distribution were calculated); and 3) 137.4/82.7 mm Hg using the regression criterion (calculation of the levels of HBP that correspond to CBP of 140/90 mm Hg using the regression equation between HBP and CBP). Overall, the findings of the three criteria suggest that average HBP < 137/82 mm Hg might be considered as probably normal, > 140/86 mm Hg as probably abnormal, and within these limits as borderline. Until mortality-based prospective data are available, this approach might be useful in the interpretation of HBP in clinical practice.     

The Bedtime Administration of Doxazosin Controls Morning Hypertension and Albuminuria in Patients with Type-2 Diabetes: Evaluation Using Home-Based Blood Pressure Measurements

The control of high blood pressure (BP) after awakening in the morning (morning hypertension) as determined by home BP (HBP), as well as BP control throughout the day, may prevent diabetic vascular complications. We examined the effect of an α-adrenergic blocker (doxazosin) on BP measurements taken by HBP after awakening and during clinic visits (CBP) in 50 patients with type-2 diabetes and morning hypertension. We evaluated the urinary albumin excretion rate as an indicator of nephropathy. Doxazosin was taken orally once at bedtime for 1 to 3 months. The mean (± SD) dose was 2.9 ± 2.1 mg/day (1 to 8 mg/day). The BP was measured monthly at the clinic during the day and at home after awakening in the morning. In this short-term trial (2.8 ± 0.4 months), the systolic HBP decreased significantly from 164 ± 17 mmHg before treatment to 146 ± 19 mmHg after treatment, and the diastolic HBP decreased significantly from 85 ± 14 mmHg before treatment to 80 ± 9 mmHg after treatment. The systolic, but not the diastolic CBP, decreased significantly after treatment. There was no significant difference in the systolic or diastolic values between the HBP and the CBP after treatment. The percentage change in the systolic HBP after treatment was three times greater than for the systolic CBP. The median (interquartile) urinary albumin excretion rate decreased significantly (P < 0.001) from 62 (25–203) mg/g creatinine before treatment to 19 (9–76) mg/g creatinine after treatment. On multiple regression analysis, the decrease in the systolic HBP with treatment positively correlated with the reduction in urinary excretion of albumin. The control of morning hypertension reduced the albuminuria found in both untreated and treated hypertensive patients with type-2 diabetes. Bedtime administration of doxazosin appears to be safe and effective in reducing morning hypertension as measured by HBP. This finding also demonstrates that HBP taken in the morning has a stronger predictive power for the albuminuria level than does CBP.     

Effects of Olmesartan‐Based Treatment on Masked,White‐Coat,Poorly Controlled,and Well‐Controlled Hypertension: HONEST Study

The authors examined the effects of olmesartan‐based treatment on clinic systolic blood pressure (CSBP) and morning home systolic blood pressure (HSBP) in 21,340 patients with masked hypertension (MH), white‐coat hypertension (WCH), poorly controlled hypertension (PCH), and well‐controlled hypertension (CH) using data from the Home Blood Pressure Measurement With Olmesartan Naive Patients to Establish Standard Target Blood Pressure (HONEST) study. MH, WCH, PCH, and CH were defined using CSBP 140 mm Hg and MHSBP 135 mm Hg as cutoff values at baseline. At 16 weeks, the MH, WCH, PCH, and CH groups had changes in CSBP by ?1.0, ?15.2, ?23.1, and 1.8 mm Hg, and changes in morning HSBP by ?12.5, 1.0, ?20.3, and 2.0 mm Hg, respectively. In conclusion, in “real‐world” clinical practice, olmesartan‐based treatment decreased high morning HBP or CBP without excessive decreases in normal morning HBP or CBP according to patients' BP status.     

The association of nocturnal hypertension and nondipping blood pressure with treatment‐resistant hypertension: The Jackson Heart Study

Apparent treatment‐resistant hypertension (aTRH), nocturnal hypertension, and nondipping blood pressure (BP) have shared risk factors. The authors studied the association between aTRH and nocturnal hypertension and aTRH and nondipping BP among 524 black Jackson Heart Study participants treated for hypertension. Nocturnal hypertension was defined by mean nighttime systolic BP ≥120 mm Hg or diastolic BP ≥70 mm Hg. Nondipping BP was defined by mean nighttime to daytime systolic BP ratio >0.90. aTRH was defined by mean clinic systolic BP ≥140 mm Hg and/or diastolic BP ≥90 mm Hg with three medication classes or treatment with four or more classes. The risk for developing aTRH associated with nondipping BP and nocturnal hypertension was estimated. After multivariable adjustment, participants with aTRH were more likely to have nocturnal hypertension (prevalence ratio, 1.20; 95% confidence interval, 1.03–1.39) and nondipping (prevalence ratio, 1.25; 95% confidence interval, 1.09–1.43). Over a median 7.3 years of follow‐up, nocturnal hypertension and nondipping BP at baseline were not associated with developing aTRH after adjustment.     

脑梗死患者急性期血压监测与预后的初步研究

目的探讨脑梗死患者急性期动态血压的变化及血压与预后的相关性。方法本研究为前瞻性地对发病48h内入院的53例脑梗死患者进行24 h动态血压监测,持续10天,记录其他影响预后的危险因素,并在21天、3个月做近远期神经功能评分。结果脑梗死患者急性期高血压常见,有自发下降的趋势。在入院4天时,收缩压和舒张压分别下降(8.8±7.9)mm Hg(、4.5±5.0)mm Hg(1 mm Hg=0.133 kPa,P<0.05),4~10天时血压下降趋势趋于平缓。脑梗死患者急性期血压与远期预后单因素分析显示呈U型曲线关系,血压的最适水平为收缩压140~160mm Hg,舒张压75~80 mm Hg。但在多因素分析中仅收缩压≥160 mm Hg与140~159.9 mm Hg比较是近期(P=0.024)和远期(P=0.046)预后不良的独立危险因素,收缩压每升高10 mm Hg,近期和远期预后不良的危险性分别增加368.2%和137.2%。结论脑梗死患者急性期血压显著升高(收缩压≥160 mm Hg)提示预后不良。     

Effects of salt substitute on home blood pressure differs according to age and degree of blood pressure in hypertensive patients and their families

Background: It is known that home blood pressure (HBP) is a more reliable assessment of hypertension treatments than clinical blood pressure (BP). Despite this, HBP response to a salt substitute has only been evaluated by one study which, did not look at the salt substitute’s effect on family members and did not analyze by age, gender, or BP degree. The aim of this current study was to assess the effects of a low-sodium and high-potassium salt substitute on HBP among hypertensive patients and their family members. Methods: A total of 220 households (including 220 hypertensive patients and 380 their families) were randomly assigned to the regular salt or salt substitute groups. HBP was measured at the beginning, 3rd, 6th, and 12th months. Among the patients (n = 220), only home systolic blood pressure (HSBP) was significantly reduced, by an adjusted baseline BP of 4.2 mm Hg (95% CI: 1.3–7.0 mm Hg), in the salt substitute group compared with those in the regular salt group at each visit (all P < 0.05). There were no detectable differences between groups for home diastolic blood pressure (HDBP) at any visit. Among the family members, HSBP and HDBP were not significantly different between the groups. Furthermore, Individuals ≥60 years old, hypertensive patients with stage-2 hypertension, family members with hypertension, and women experienced greater HSBP reduction. Conclusions: Older subjects, those with higher blood pressure, and women experienced greater home blood pressure reduction from the salt substitute compared to regular salt.     

Usefulness of morning home blood pressure measurements in patients with type 2 diabetes mellitus: results of a 10-year,prospective, longitudinal study

Abstract

Previous cross-sectional studies and 6-year longitudinal study have demonstrated that home blood pressure (HBP) measurements upon awakening have a stronger predictive power for death, micro- and macrovascular complications than clinic blood pressure (CBP) measurements in patients with type 2 diabetes (T2DM). This study investigated which of these measurements offers stronger predictive power for outcomes over 10 years. At baseline, 400 Japanese patients with T2DM were classified as having hypertension (HT) or normotension (NT) based on HBP and CBP. The mean survey duration was 95 months. Primary and secondary end-points were death and new or worsened micro- and macrovascular complications, respectively. Differences in outcomes for each end-point between HT and NT patients were analyzed using Kaplan–Meier survival curves and log-rank testing. Associated risk factors were assessed using Cox proportional hazards analysis. Based on HBP, death and micro- and macrovascular complications were significantly higher in patients with HT than with NT at baseline and end-point. Based on CBP, there were no significant differences in incidence of death, micro- or macrovascular complications between patients with HT and NT at baseline and end-point, although a significant difference in incidence of death was observed between the HT and NT groups at end-point. However, the significance was significantly lower in CBP than in HBP. One risk factor associated with micro- and macrovascular complications in patients with HBP was therapy for HT. This 10-year longitudinal study of patients with T2DM demonstrated that elevated HBP upon awakening is predictive of death, and micro- and macrovascular complications.     

Masked Hypertension Defined by Ambulatory Blood Pressure Monitoring Is Associated With an Increased Serum Glucose Level and Urinary Albumin‐Creatinine Ratio

J Clin Hypertens(Greenwich). 2010;12:578–587. © 2010 Wiley Periodicals, Inc. The authors evaluated the relationship of hypertensive target organ damage to masked hypertension assessed by ambulatory blood pressure (BP) and home blood pressure (HBP) monitoring in 129 participants without taking antihypertensive medication. Masked hypertension was defined as office BP ≤140/90 mm Hg and 24-hour ambulatory BP ≥130/80 mm Hg. The masked hypertensive participants defined by 24-hour ambulatory BP (n=13) had a higher serum glucose level (126 vs 96 mg/dL, P=.001) and urinary albumin-creatinine ratio (38.0 vs 7.5 mg/gCr, P<.001) than the normotensive participants (n=74); however, these relationships were not observed when the authors defined groups using HBP (≥135/85 mm Hg). Masked hypertension by both 24-hour ambulatory BP and HBP had a higher urinary albumin-creatinine ratio than normotension by both 24-hour ambulatory BP and HBP (62.1 vs 7.4 mg/gCr, P=.001), and than masked hypertension by HBP alone (9.3 mg/gCr, P=.009). Masked hypertension defined by 24-hour ambulatory BP is associated with an increased serum glucose level and urinary albumin-creatinine ratio, but these relationships are not observed in masked hypertension defined by HBP.     

Diagnostic accuracy of home vs. ambulatory blood pressure monitoring in untreated and treated hypertension

Several studies with relatively small size and different design and end points have investigated the diagnostic ability of home blood pressure (HBP). This study investigated the usefulness of HBP compared with ambulatory monitoring (ABP) in diagnosing sustained hypertension, white coat phenomenon (WCP) and masked hypertension (MH) in a large sample of untreated and treated subjects using a blood pressure (BP) measurement protocol according to the current guidelines. A total of 613 subjects attending a hypertension clinic (mean age 53±12.4 (s.d.) years, men 57%, untreated 59%) had measurements of clinic BP (three visits, triplicate measurements per visit), HBP (6 days, duplicate morning and evening measurements) and awake ABP (20-min intervals) within 6 weeks. Sustained hypertension was diagnosed in 50% of the participants by ABP and HBP (agreement 89%, κ=0.79), WCP in 14 and 15%, respectively (agreement 89%, κ=0.56) and MH in 16% and 15% (agreement 88%, κ=0.52). Only 4% of the subjects (27/613) showed clinically significant diagnostic disagreement with BP deviation >5?mm?Hg above the diagnostic threshold (for HBP or ABP). By taking ABP as reference, the sensitivity, specificity, positive and negative predictive value of HBP in detecting sustained hypertension were 90, 89, 89 and 90%, respectively, WCP 61, 94, 64 and 94% and MH 60, 93, 60 and 93%. Similar diagnostic agreement was found in untreated and treated subjects. HBP appears to be a reliable alternative to ABP in the diagnosis of hypertension and the detection of WCP and MH in both untreated and treated subjects.     

Evaluation of Criteria to Detect Masked Hypertension

The prevalence of masked hypertension (out‐of‐clinic daytime systolic/diastolic blood pressure (SBP/DBP) ≥135/85 mm Hg on ambulatory blood pressure monitoring [ABPM] among adults with clinic SBP/DBP <140/90 mm Hg) is high. It is unclear who should be screened for masked hypertension. The authors derived a clinic blood pressure (CBP) index to identify populations for masked hypertension screening. Index cut points corresponding to 75% to 99% sensitivity and prehypertension were evaluated as ABPM testing criterion. In a derivation cohort (n=695), the index was clinic SBP+1.3*clinic DBP. In an external validation cohort (n=675), the sensitivity for masked hypertension using an index ≥190 mm Hg and ≥217 mm Hg and prehypertension status was 98.5%, 71.5%, and 82.5%, respectively. Using National Health and Nutrition Examination Survey data (n=11,778), the authors estimated that these thresholds would refer 118.6, 44.4, and 59.3 million US adults, respectively, to ABPM screening for masked hypertension. In conclusion, the CBP index provides a useful approach to identify candidates for masked hypertension screening using ABPM.     

Diagnosis of hypertension using home or ambulatory blood pressure monitoring: comparison with the conventional strategy based on repeated clinic blood pressure measurements

OBJECTIVE: To investigate whether measurement of blood pressure at home (HBP) and by ambulatory monitoring (ABP) are reliable alternatives to the traditional strategy for the diagnosis of hypertension based on blood pressure measurement on repeated clinic visits (CBP). DESIGN: Comparison of the diagnosis of hypertension based on HBP (on six workdays) or ABP monitoring (two occasions) with that based on CBP (five visits within 3 months). SETTING: Outpatient hypertension clinic. PARTICIPANTS: We enrolled 133 individuals with a diastolic CBP of 90-115 mmHg on the initial visit. MAIN OUTCOME MEASURES: CBP, HBP and ABP values, and the diagnosis of hypertension. RESULTS: Hypertension was diagnosed in 70, 63 and 56% of individuals using the CBP, ABP and HBP methods respectively (P = 0.04). Agreement in the diagnosis of hypertension between all three methods was found in 59% of individuals. Disagreement between CBP and ABP was found in 27%, between CBP and HBP in 29% and between ABP and HBP in 26% of individuals. The sensitivity, specificity and positive and negative predictive values of ABP to diagnose hypertension correctly were 76, 67, 85 and 53% respectively; for HBP the respective values were 69, 77, 88 and 51%. The same parameters for HBP compared with ABP in the detection of white-coat hypertension were 61, 79, 48 and 86% respectively. CONCLUSIONS: Indiscriminate use of HBP or ABP monitoring in the evaluation of all individuals with high blood pressure will probably result in confusion and therefore should be discouraged. However, in the detection of white-coat hypertension, HBP appears to be useful as a screening test, which, if positive, requires confirmation with ABP monitoring.     

The bedtime administration of doxazosin controls morning hypertension and albuminuria in patients with type-2 diabetes: evaluation using home-based blood pressure measurements

The control of high blood pressure (BP) after awakening in the morning (morning hypertension) as determined by home BP (HBP), as well as BP control throughout the day, may prevent diabetic vascular complications. We examined the effect of an alpha-adrenergic blocker (doxazosin) on BP measurements taken by HBP after awakening and during clinic visits (CBP) in 50 patients with type-2 diabetes and morning hypertension. We evaluated the urinary albumin excretion rate as an indicator of nephropathy. Doxazosin was taken orally once at bedtime for 1 to 3 months. The mean (+/- SD) dose was 2.9 +/- 2.1 mg/day (1 to 8 mg/day). The BP was measured monthly at the clinic during the day and at home after awakening in the morning. In this short-term trial (2.8 +/- 0.4 months), the systolic HBP decreased significantly from 164 +/- 17 mmHg before treatment to 146 +/- 19 mmHg after treatment, and the diastolic HBP decreased significantly from 85 +/- 14 mmHg before treatment to 80 +/- 9 mmHg after treatment. The systolic, but not the diastolic CBP, decreased significantly after treatment. There was no significant difference in the systolic or diastolic values between the HBP and the CBP after treatment. The percentage change in the systolic HBP after treatment was three times greater than for the systolic CBP. The median (interquartile) urinary albumin excretion rate decreased significantly (P < 0.001) from 62 (25-203) mg/g creatinine before treatment to 19 (9-76) mg/g creatinine after treatment. On multiple regression analysis, the decrease in the systolic HBP with treatment positively correlated with the reduction in urinary excretion of albumin. The control of morning hypertension reduced the albuminuria found in both untreated and treated hypertensive patients with type-2 diabetes. Bedtime administration of doxazosin appears to be safe and effective in reducing morning hypertension as measured by HBP. This finding also demonstrates that HBP taken in the morning has a stronger predictive power for the albuminuria level than does CBP.     

Out-of-office blood pressure in children and adolescents: disparate findings by using home or ambulatory monitoring

BACKGROUND: The validity of home blood pressure (HBP) measurements in children has not been evaluated, although in clinical practice such measurements are being used. This study compares HBP, with clinic (CBP) and daytime ambulatory blood pressure (ABP) in children and adolescents. METHODS: Fifty-five children and adolescents aged 6 to 18 years were evaluated with CBP (three visits), HBP (6 days), and daytime ABP. Mean age was 12.3 +/- 2.9 (SD) years, 33 boys. According to the Task Force CBP criteria, 26 were hypertensives, 6 had high-normal BP (hypertensive group), and 23 were normotensives (normotensive group). RESULTS: In the hypertensive group, CBP was 130.8 +/- 7.6/72.5 +/- 8.1 mm Hg (systolic/diastolic), HBP 118.9 +/- 6.3/73.7 +/- 6.7, and ABP 130.8 +/- 8.1/75.5 +/- 8.3. In the normotensive group, CBP was 112.8 +/- 8/63.1 +/- 6.3, HBP 106.7 +/- 8.4/67.2 +/- 5.2, and ABP 123.9 +/- 7.2/72 +/- 4.3. Strong correlations (P < .001) were observed between CBP-HBP (r = 0.73/0.57, systolic/diastolic), CBP-ABP (r = 0.59/0.49), and HBP-ABP (r = 0.72/0.66). In normotensive subjects, ABP was higher than both CBP and HBP for systolic and diastolic BP (P < .001). Furthermore, systolic HBP was lower than CBP (P < .01), whereas the opposite was true for diastolic BP (P < .05). In hypertensive subjects systolic HBP was lower than both CBP and ABP (P < .001), whereas CBP did not differ from ABP. For diastolic BP no differences were found among measurement methods. CONCLUSIONS: These data suggest that, in contrast to adults in whom HBP is close to the levels of daytime ABP, in children and adolescents HBP appears to be significantly lower than daytime ABP. Until more data become available, caution is needed in the interpretation of HBP in children and adolescents.     

White coat effect in treated versus untreated hypertensive individuals: a case-control study using ambulatory and home blood pressure monitoring

BACKGROUND: Some studies have shown a significant white coat effect (WCE) (i.e., difference between clinic blood pressure [CBP] and awake ambulatory blood pressure [ABP]) to be present not only in untreated but also in treated hypertensive individuals. This study aims to assess 1) the prevalence and the magnitude of the WCE in treated versus untreated hypertensive persons, and 2) the usefulness of home blood pressure (HBP) versus ABP in the detection of this phenomenon. METHODS: A case-control study was conducted in 138 treated hypertensive patients and same number of sex- and age-matched untreated hypertensive subjects who had measurements of CBP (at least three visits), HBP, and ABP. Subjects with a WCE of >20/10 mm Hg (systolic/diastolic) were classified as clinic reactors. RESULTS: There was a trend for a larger WCE assessed by ABP monitoring in the untreated group (mean difference in systolic WCE, 1.8 +/- 22.2 mm Hg, 95% CI -2.0 to 5.5; diastolic 1.8 +/- 11.9 mm Hg, 95% CI -0.2 to 3.8) and for more untreated clinic reactors (27% untreated v 20% treated, odds ratio 1.5, 95% CI 0.9 to 2.7). The sensitivity, specificity, and positive and negative predictive values of HBP to detect clinic reactors correctly were 56%/62% (treated/untreated), 87%/84%, 52%/59%, and 89%/86%, respectively, with moderate agreement between HBP and ABP (kappa 0.42/0.46). CONCLUSIONS: In treated hypertensive patients, WCE seems to be reduced compared with that in untreated hypertensive persons but is not eliminated. In both untreated and treated hypertensive individuals HBP monitoring appears to be useful in the detection of the WCE, but it may not be appropriate as an alternative to the ABP method.     

Classification of blood pressure levels by ambulatory blood pressure in hypertension

Whereas clinic blood pressure (CBP) above normality is divided into stages, no corresponding classifications are available for 24-hour ambulatory blood pressure (ABP). We conducted a study (1) to define stages of hypertension by ABP corresponding to CBP stages and (2) to evaluate if these stages have prognostic impact similar to CBP stages. Seven hundred thirty-six hypertensive patients were included. Mean systolic blood pressure was 149+/-15.2/87+/-8.6 mm Hg for CBP and 135+/-13/79+/-9.7 mm Hg for ABP. The mean bias between both methods was -13.3 mm Hg (95% CI, -14.3 to -12.2; 1.96xSD limits of agreement, 15.7 to -42.3) and -7.3 mm Hg (95% CI, -7.9 to -6.6; 1.96xSD limits of agreement, 9.8 to -24.3) for systolic and diastolic blood pressure (P>0.0001 for both), respectively. Classification of hypertension by ABP revealed lower cutoff values for the different stages of hypertension compared with the corresponding cutoff values for CBP (CBP versus ABP: 140/90 versus 132/81 mm Hg; 160/100 versus 140/88 mm Hg; 180/110 versus 148/94 mm Hg, P<0.001). Overall, 82 (11.1%) patients had nonfatal clinical cardiovascular events and 9 (1.2%) patients died of a cardiovascular cause during follow-up. The distribution of cardiovascular events was significantly associated with increasing ABP value (P<0.006). Staging of hypertension by ABP may facilitate the use of this method in daily clinical practice, as ABP can now be used not only to confirm the diagnosis of hypertension but also to assess the severity and prognosis of hypertensive disease.     

Blood pressure control in a hypertension hospital clinic.

OBJECTIVES: First, to evaluate the prevalence of clinic blood pressure (BP) control (BP < or = 140/90 mm Hg) in a representative sample of treated hypertensive patients followed in our hypertension clinic. Second, to assess in a subgroup of these patients: (a) the proportion of BP control with both clinic blood pressure (CBP < or =140/90 mm Hg) and daytime ambulatory blood pressure (ABP) (< or =132/85 mm Hg) criteria, and (b) the prevalence of echocardiographic left ventricular hypertrophy (LVH) (left ventricular mass index, LVMI>125 g/m2 in men and >110 g/m2 in women). DESIGN AND METHODS: Seven hundred consecutive hypertensive patients who attended our hypertension centre clinic during a period of 6 months and who had regularly been followed up by the same medical team were included in the study. BP was taken in the clinic by a doctor using a mercury sphygmomanometer with the participants seated. Seventy-four patients with similar demographic and clinical characteristics to the entire population of participants underwent complete echocardiographic examination and 24 h ABP monitoring. RESULTS: During follow-up, 352 of the treated patients had clinic BP < or =140/90 mm Hg, 198< or =160/95 mm Hg and 150>160/95 mm Hg, indicating that BP control was satisfactory in 50.3%, borderline in 28.3% and unsatisfactory in 21.4% of the cases. In the subgroup of 74 patients, the proportion of individuals with satisfactory clinic BP control (CBP< or =140/90 mm Hg) was higher (50.0 versus 33.6%) than with satisfactory ABP control (daytime ABP values < or =132/85 mm Hg). LVH was found in 21 of the 74 patients (28.3%): 12 of them had unsatisfactory CBP control and 19 had unsatisfactory ABP control. LVMI did not correlate with CBP values but only with ABP values (mean 24 h systolic r = 0.47, diastolic r = 0.40, P<0.001; mean daytime systolic r = 0.45, mean daytime diastolic r = 0.39, P<0.001; mean night-time systolic r = 0.38, mean night-time diastolic r = 0.38, P<0.001). CONCLUSION: This study demonstrates that hypertensive patients managed in a hypertension centre clinic have satisfactory CBP control in 50% of cases, but this rate seems to over-estimate the effective BP control during daily life. A large fraction of patients show persistence of LVH and this evidence of organ damage almost entirely concerns individuals with poor ABP control.     

Divergent results using clinic and ambulatory blood pressures: report of a darusentan-resistant hypertension trial

Patients with resistant hypertension are at increased risk for cardiovascular events. The addition of new treatments to existing therapies will help achieve blood pressure (BP) goals in more resistant hypertension patients. In the current trial, 849 patients with resistant hypertension receiving ≥3 antihypertensive drugs, including a diuretic, at optimized doses were randomized to the selective endothelin A receptor antagonist darusentan, placebo, or the central α-2 agonist guanfacine. The coprimary end points of the study were changes from baseline to week 14 in trough, sitting systolic BP, and diastolic BP measured in the clinic. Decreases from baseline to week 14 in systolic BP for darusentan (-15±14 mm Hg) were greater than for guanfacine (-12±13 mm Hg; P<0.05) but not greater than placebo (-14±14 mm Hg). Darusentan, however, reduced mean 24-hour systolic BP (-9±12 mm Hg) more than placebo (-2±12 mm Hg) or guanfacine (-4±12 mm Hg) after 14 weeks of treatment (P<0.001 for each comparison). The most frequent adverse event associated with darusentan was fluid retention/edema at 28% versus 12% in each of the other groups. More patients withdrew because of adverse events on darusentan as compared with placebo or guanfacine. We conclude that darusentan provided greater reduction in systolic BP in resistant hypertension patients as assessed by ambulatory BP monitoring, in spite of not meeting its coprimary end points. The results of this trial highlight the importance of ambulatory BP monitoring in the design of hypertension clinical studies.