Cardiovascular risk prediction based on home blood pressure measurement: the Didima study

OBJECTIVE: Although home blood pressure (HBP) is being used increasingly in clinical practice, the evidence on its prognostic value is still limited. This study in the general population investigated the value of HBP compared to office measurements (OBP) in predicting cardiovascular risk. SUBJECTS AND METHODS: In 1997 all adults of the Didima area in Greece were invited to participate in a cross-sectional study involving OBP (two visits) and HBP measurements (3 days). Incident cardiovascular morbidity and cause-specific mortality were assessed after 8.2 +/- 0.2 years (mean +/- SD). Average OBP and HBP were used in Cox regression analysis of fatal and non-fatal cardiovascular events with age, gender, history of cardiovascular disease, use of antihypertensive medication, smoking and diabetes as covariates. RESULTS: A total of 662 subjects were analysed (mean age at baseline 54.1 +/- 17.6 years). During follow-up 78 deaths (42 cardiovascular) and 67 cardiovascular events (fatal and non-fatal) were documented. Unadjusted hazard ratios for cardiovascular events per 1 mmHg blood pressure increase were for HBP systolic 1.034 (P < 0.001) and diastolic 1.037 (P < 0.01) and for OBP systolic 1.035 (P < 0.001) and diastolic 1.021 (P = 0.07). After adjustment for all available cardiovascular risk predictors, only diastolic OBP remained significant. The addition of HBP in the models already including OBP did not significantly improve the predictive ability. White coat but not masked hypertensives were at high risk. CONCLUSIONS: This study showed that both HBP and OBP are significant predictors of cardiovascular risk in the general population. However, no prognostic superiority of HBP compared to OBP has been demonstrated.     

Relative utility of home, ambulatory, and office blood pressures in the prediction of end-organ damage

BACKGROUND: Home blood pressure (HBP) monitoring plays an increasingly important role in the diagnosis and treatment of hypertension. We evaluated the independent value of HBP compared with ambulatory blood pressure (ABP) and office blood pressure (OBP) in the prediction of cardiovascular end-organ damage in normotensive subjects and untreated patients with mild hypertension. METHODS: One hundred sixty-three subjects underwent measurements of OBP, HBP, ABP, and echocardiography. A physician using a mercury-column sphygmomanometer performed three OBP measurements. The ABP was recorded using a noninvasive ambulatory monitor (mean, 35.4 awake readings per subject). Participants took HBP readings with an automatic, oscillometric device over a 10-week period (mean, 277.9 readings per subject). The left-ventricular mass index (LVMI) was calculated from measurements obtained from two-dimensionally guided M-mode or linear tracings on echocardiography. RESULTS: For systolic and diastolic blood pressures (SBP/DBP), the correlation coefficients of the LVMI with OBP, awake ABP, and HBP were 0.29/0.27, 0.41/0.26, and 0.47/0.35, respectively (all P < .01). In a multivariate regression analysis in which age, sex, body mass index, OBP, awake ABP, and HBP were included, only age, sex, and HBP were significant predictors of LVMI. When only the first 12 home readings were used, the superiority of HBP was no longer evident. CONCLUSIONS: In contrast to OBP and ABP, HBP measurements, when averaged over a 10-week period, are independently related to LVMI. The HBP adds prognostic information over and above OBP and ABP in the prediction of cardiovascular end-organ damage, but this relationship appears to depend on the number of readings taken.     

Unattended versus attended automated office blood pressure: Systematic review and meta‐analysis of studies using the same methodology for both methods

There is increasing interest in unattended automated office blood pressure (OBP) measurement, which gives lower blood pressure values than the conventional auscultatory OBP. Whether unattended automated OBP differs from standardized attended automated OBP performed using the same device and measurement protocol remains uncertain. A systematic review and meta‐analysis of studies (aggregate data) comparing unattended vs attended automated OBP using the same device and measurement protocol (conditions, number of measurements, visits) was performed. Ten eligible studies (n = 1004, weighted age 60.8 ± 4.2 [SD] years, 55% males) were analyzed. Unattended OBP (pooled systolic/diastolic 133.9 [95% CI: 129.7, 138]/80.6 [95% CI: 77, 84.2] mm Hg) did not differ from attended OBP (135.3 [95% CI: 130.9, 139.6]/81 [95% CI: 77.6, 84.3] mm Hg); pooled systolic OBP difference −1.3, 95% CI: −4.3, 1.7 mm Hg and diastolic −0.4, 95% CI: −1.2, 0.3 mm Hg. Nine of ten studies achieved high quality score and no publication bias was identified. Meta‐regression analysis did not reveal any effect of age, gender, or attended systolic OBP on the unattended‐attended systolic OBP difference (P = NS for all). However, there was a trend toward higher attended than unattended OBP at higher OBP levels. These data suggest that, when the same device and measurement protocol are used, attended automated OBP provides similar blood pressure values as unattended automated OBP. Although unattended automated OBP is theoretically advantageous as it ensures that standardized conditions and measurement protocol are used, attended automated OBP, if carefully performed, appears to be a reasonable and practical alternative.     

Automated office blood pressure measurements in primary care are misleading in more than one third of treated hypertensives: The VALENTINE-Greece Home Blood Pressure Monitoring study

BackgroundThis study assessed the diagnostic reliability of automated office blood pressure (OBP) measurements in treated hypertensive patients in primary care by evaluating the prevalence of white coat hypertension (WCH) and masked uncontrolled hypertension (MUCH) phenomena.MethodsPrimary care physicians, nationwide in Greece, assessed consecutive hypertensive patients on stable treatment using OBP (1 visit, triplicate measurements) and home blood pressure (HBP) measurements (7 days, duplicate morning and evening measurements). All measurements were performed using validated automated devices with bluetooth capacity (Omron M7 Intelli-IT). Uncontrolled OBP was defined as ≥140/90 mmHg, and uncontrolled HBP was defined as ≥135/85 mmHg.ResultsA total of 790 patients recruited by 135 doctors were analyzed (age: 64.5 ± 14.4 years, diabetics: 21.4%, smokers: 20.6%, and average number of antihypertensive drugs: 1.6 ± 0.8). OBP (137.5 ± 9.4/84.3 ± 7.7 mmHg, systolic/diastolic) was higher than HBP (130.6 ± 11.2/79.9 ± 8 mmHg; difference 6.9 ± 11.6/4.4 ± 7.6 mmHg, p < 0.001). WCH phenomenon (high OBP with low HBP) was observed in 22.7% of the patients, MUCH (low OBP with high HBP) in 15.8%, uncontrolled hypertension (high OBP with high HBP) in 29.9%, and controlled hypertension (low OBP with low HBP) in 31.6%. In multivariate logistic regression analysis, WCH was determined by stage-1 systolic hypertension (odds ratio [OR] 8.6, 95% confidence intervals [CI] 5.7, 13.1) and female gender (OR 1.6, 95% CI 1.1, 2.4), whereas MUCH was determined by high-normal systolic OBP (OR 6.2, 95% CI 3.8, 10.1) and male gender (OR 2.0, 95% CI 1.2, 3.1).ConclusionsIn primary care, automated OBP measurements are misleading in approximately 40% of treated hypertensive patients. HBP monitoring is mandatory to avoid overtreatment of subjects with WCH phenomenon and prevent undertreatment and subsequent excess cardiovascular disease in MUCH.     

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.     

Home blood pressure monitoring in children: how many measurements are needed?

OBJECTIVE: To investigate the minimum schedule of blood pressure (BP) measurements necessary to provide a reliable assessment of home BP (HBP) in children and adolescents. METHODS: Subjects aged 6-18 years referred for elevated BP were assessed with HBP monitoring (6 workdays, duplicate morning and evening measurements) and 24-h ambulatory BP monitoring (ABP). Criteria for HBP reliability were its reproducibility (test-retest correlations and SD of differences (SDDs) between repeated measurements), its stability (average home BP of an increasing number of readings and its SD), and its relationship with ABP. RESULTS: Data from 100 subjects were analyzed (mean age 13 +/- 2.8 (SD) years, 61 boys). The reproducibility of 3-day HBP (r 0.88/0.79, SDDs 5.1/4.9, systolic/diastolic) was superior to that of a single (r 0.79/0.65, SDDs 7.6/7.1) or 2-day HBP (r 0.85/0.72, SDDs 6.1/5.4). By averaging up to 12 readings (3 days), there was a progressive decline in average HBP, with no further decline thereafter. The SD of average HBP was also progressively reduced, with little change after day 3. The association of HBP with ABP was improved by averaging more readings up to 12, with no further improvement when more readings were averaged. The exclusion of first-day measurements slightly increased the SD of average HBP and weakened the correlation with ABP, probably due to reduced number of readings. CONCLUSIONS: In children and adolescents, 3-day monitoring with duplicate morning and evening measurements appears to be the minimum schedule for the reliable assessment of HBP.     

Office blood pressure underestimates ambulatory blood pressure in peripheral arterial disease in comparison to healthy controls

Patients with peripheral arterial disease (PAD) constitute a subgroup of high-risk hypertensives, but controlled studies on 24-h blood pressure (BP) and diurnal variation of BP are lacking. This study was performed in order to test the hypothesis that office BP (OBP) may underestimate 24-h BP in PAD patients in comparison to a matched control group. In all, 98 male patients (mean age 68 years) with a history of intermittent claudication and an ankle/brachial index less than 0.9, and 94 controls matched for age but without PAD or ischaemic heart disease performed 24-h recordings of ambulatory BP. A total of 59 patients had a history of hypertension and 69 were on treatment with BP-lowering drugs as compared to 17 and 23 of the control subjects, respectively. Office as well as 24-h systolic BP (SBP) were higher in patients as compared to controls (151 +/- 22 vs 140 +/- 20 mmHg, P < 0.001 and 142 +/- 14 vs 133 +/- 15 mmHg, P < 0.001, respectively), but did not differ with regard to diastolic BP. In an analysis of covariance with the continuous factors age, office SBP and the categorical factor antihypertensive treatment, 24-h SBP was higher in PAD patients compared to controls (P < 0.05). The difference between office and night SBP was lower in PAD patients with antihypertensive treatment compared to controls (P = 0.01). In conclusion, Male patients with PAD had higher systolic but not diastolic BP than age-matched control subjects. In PAD patients, 24-h SBP was higher than expected from OBP compared to controls. Night SBP was higher only in patients with antihypertensive treatment. In PAD patients, especially when on antihypertensive treatment, the severity of hypertension may be underestimated when based on OBP only.     

Can validated wrist devices with position sensors replace arm devices for self-home blood pressure monitoring? A randomized crossover trial using ambulatory monitoring as reference

BACKGROUND: Electronic devices that measure blood pressure (BP) at the arm level are regarded as more accurate than wrist devices and are preferred for home BP (HBP) monitoring. Recently, wrist devices with position sensors have been successfully validated using established protocols. This study assessed whether HBP values measured with validated wrist devices are sufficiently reliable to be used for making patient-related decisions in clinical practice. METHODS: This randomized crossover study compared HBP measurements taken using validated wrist devices (wrist-HBP, Omron R7 with position sensor) with those taken using arm devices (arm-HBP, Omron 705IT), and also with measurements of awake ambulatory BP (ABP, SpaceLabs), in 79 subjects (36 men and 43 women) with hypertension. The mean age of the study population was 56.7 +/- 11.8 years, and 33 of the subjects were not under treatment for hypertension. RESULTS: The average arm-HBP was higher than the average wrist-HBP (mean difference, systolic 5.2 +/- 9.1 mm Hg, P < 0.001, and diastolic 2.2 +/- 6.7, P < 0.01). Twenty-seven subjects (34%) had a > or =10 mm Hg difference between systolic wrist-HBP and arm-HBP and twelve subjects (15%) showed similar levels of disparity in diastolic HBP readings. Strong correlations were found between arm-HBP and wrist-HBP (r 0.74/0.74, systolic/diastolic, P < 0.0001). However, ABP was more strongly correlated with arm-HBP (r 0.73/0.76) than with wrist-HBP (0.55/0.69). The wrist-arm HBP difference was associated with systolic ABP (r 0.34) and pulse pressure (r 0.29), but not with diastolic ABP, sex, age, arm circumference, and wrist circumference. CONCLUSIONS: There might be important differences in HBP measured using validated wrist devices with position sensor vs. arm devices, and these could impact decisions relating to the patient in clinical practice.Measurements taken using arm devices are more closely related to ABP values than those recorded by wrist devices. More research is needed before recommending the widespread use of wrist monitors in clinical practice.American Journal of Hypertension doi:10.1038/ajh.2008.176American Journal of Hypertension (2008); 21, 7, 753-758. doi:10.1038/ajh.2008.176.     

Ambulatory blood pressure is still elevated in treated hypertensive diabetic subjects compared with untreated diabetic subjects with the same office blood pressure.

Ambulatory blood pressure, ABP, was determined every 15 min for 24 h (Spacelabs 5200 system) in 16 hypertensive diabetic subjects treated for high blood pressure. Office blood pressure (OBP) in these subjects (systolic BP greater than 160 mmHg and diastolic BP greater than 95 mmHg before treatment) had been reduced by treatment to the borderline range (systolic less than or equal to 160 mmHg and/or diastolic less than or equal to 95 mmHg). Sixty-five diabetic subjects with normal or borderline OBP were included as controls. The two groups had the same age (58 +/- 10 yrs in both groups), duration of diabetes (15 +/- 9 yrs), 24 hr microalbumin, and included the same percentage of subjects with moderate neuropathy (36% and 29%, NS). The two groups had the same OBP (138 +/- 16 mmHg and 140 +/- 16 mmHg systolic, NS, 84 +/- 9 mmHg and 84 +/- 13 mmHg diastolic, NS). In contrast, ambulatory BP was significantly higher in the treated group, when compared with the controls (123 +/- 13 mmHg and 133 +/- 23 mmHg systolic, P less than 0.025, 77 +/- 7 mmHg and 84 +/- 16 mmHg diastolic, P less than 0.015). The difference was significant both in daytime and in nighttime, and was more significant in nighttime (11 mmHg systolic, P less than 0.02, 9 mmHg diastolic, P less than 0.004) than in daytime (9 mmHg systolic, P less than 0.05 and 5 mmHg diastolic, P less than 0.05). Ambulatory heart rate was also significantly higher in the treated group, but only in daytime (7 b/min difference, P less than 0.02). The study demonstrated the need to survey and investigate ABP in treated hypertensive diabetic subjects.     

Sodium and potassium in children with hypertension

On a baseline survey of 4936 school children, age ranged from 6 to 16 years, 199 children with the systolic blood pressure (SBP) value equal or greater than 95-th percentiles for age and sex were chosen as the hypertensive group (HBP), and the same number of children with the SBP lower than 50-th percentiles were matched as the normotensive group (NBP). For both groups the intra-RBC and plasma Na and K content, three sequential nights 8-hour urinary Na, K and creatinine excretion, and an oral saline-load test were performed. The results show that: (1) The intra-RBC K in the HBP was lower than in NBP, 259 +/- 57 vs 291 +/- 78 mumol/g-protein, P less than 0.01. That in those with positive hypertensive family history (FH+) was lower than in those of negatives (FH-). The intra-RBC K content was correlated inversely with diastolic BP, r = -0.43, P less than 0.001. No correlation between intra-RBC Na and BP was found; (2) Plasma Na concentration in HBP was much lower than in NBP, 137.5 +/- 7.9 vs 142.6 +/- 6.9 mmol/L, P less than 0.001. No difference was found between FH+ and FH-; (3) Mean 8-hour urinary K excretion at night was lower in HBP than in NBP, 23.9 +/- 11.5 vs. 28.2 +/- 14.7 mmol/g-creatinine, P less than 0.01; (4) After a load of oral saline the 4-hour urinary Na excretion was significantly higher in HBP than in NBP, 39.5 +/- 29.1 vs 30.8 +/- 23.2 mmol, P less than 0.01. Of those children with FH-, the 4-hour Na excretion in HBP was higher than in NBP, 39.8 +/- 29.4 vs 29.3 +/- 21.5 mmol, P less than 0.001, but no significant difference was found between HBP and NBP in children with FH+. We believed that the above changes in electrolytes in the children with their BP at higher-level percentiles represent an abnormal relation between potassium and arterial BP in the early stage of hypertension, as well as the early compensatory natriuresis of the kidneys.     

Home or self blood pressure measurement? What is the correct term?

OBJECTIVE: Blood pressure measurements taken by patients at home (HBP) are usually referred to as 'self' or 'home' measurements. To demonstrate the most appropriate term we compared self-home measurements (S-HBP), with home measurements taken by relatives (R-HBP), clinic measurements taken by physicians (P-CBP) and self-measurements in the clinic (S-CBP). PATIENTS AND METHODS: Thirty treated hypertensives were randomized to an initial clinic BP (CBP) monitoring period (week 1, P-CBP followed by S-CBP measurements, or the opposite; 1 visit each), then to a HBP monitoring period (weeks 2-3, S-HBP followed by R-HBP or the opposite; 3 workdays each), and finally to a second CBP monitoring period (week 4, S-CBP followed by P-CBP, or the opposite). Triplicate morning trough measurements were taken per occasion using the same fully automated device. RESULTS: There was no difference between S-CBP and P-CBP (mean difference -1.9 +/- 6.1 mmHg, 95% confidence interval (CI) -4.2, 0.4/-1.6 +/- 4.7, 95% CI -3.3, 0.2, systolic/diastolic), or between S-HBP and R-HBP (-0.9 +/- 6.9, 95% CI -3.5, 1.8/-0.4 +/- 4.3, 95% CI -2.0, 1.2). S-CBP was higher than S-HBP (mean difference 9.3 +/- 9.0/4.9 +/- 5.4 mmHg, systolic/diastolic, P < 0.001) and R-HBP (8.4 +/- 9.1/4.5 +/- 5.0, P < 0.001). P-CBP was also higher than S-HBP (11.2 +/- 11.9/6.5 +/- 6.8, P < 0.001) and R-HBP (10.3 +/- 11.2/6.1 +/- 6.5, P < 0.001). CONCLUSIONS: Self-measurements provide similar BP levels to measurements taken by relatives or physicians, provided that measurements are taken in the same setting. 'Self-BP' is a misnomer because self-measurement has no impact on the difference between home and clinic BP. Given that this difference can be exclusively attributed to the effect of the different setting, the term 'home BP' represents a more appropriate term.     

A comparison between the oscillometric and the auscultatory method for ambulatory 24 h blood pressure monitoring

OBJECTIVES: To investigate the compatibility between oscillometric and auscultatory methods, and to determine whether one is preferable over the other for ambulatory 24 h blood pressure monitoring. METHODS: For the blood pressure monitoring system we used an A&D TM 2421 device (Takeda), which enabled us to measure the blood pressure simultaneously with the two methods on the same arm. Our investigation included 281 patients (122 women and 159 men, aged 18-85 years) with suspected hypertension or undergoing treatment for hypertension. RESULTS: We obtained 23 531 measurements by the oscillometric method, which was 98% of the maximal possible number, and 81% of the maximal possible number were obtained by the auscultatory methjod. We were able to compare 98% of the paired measurements. The auscultatory method showed a uniform distribution of errors throughout the 24 h. Compared to the auscultatory method, the oscillometry method had fewer errors in the evenings, but more when the subjects were at work. There was a difference in paired single readings between the two methods amounting to 1.4+/-19 mmHg (mean+/-SD) for systolic and -2.4+/-18 mmHg for diastolic readings (auscultatory - oscillometric). The differences in mean values for the 281 cases of 24 h monitoring amounted to 0.7+/- 4 mmHg for systolic and -2.2+/-6 mmHg for diastolic measurements. For the mean systolic blood pressure, we found a difference of 0.3+/-4 mmHg in the daytime and 0.3+/-8 mmHg during the night. The mean diastolic pressures differed by -2.0+/-6 mmHg in the daytime and -1.6+/-8 mmHg during the night. We found only a weak correlation between the differences in the readings by the two methods and systolic blood pressure levels, age, pulse pressure and body mass index, and no correlations between these differences and the diastolic blood pressure levels. CONCLUSION: Although we found a considerable SD on single readings by the two methods, there was a good agreement between the mean values of the 24 h monitoring for the two methods. We obtained a significantly higher success rate by the oscillometric method. The findings suggest that, for this equipment, the oscillometric method is preferable for 24 h ambulatory blood pressure monitoring because it provides a much higher rate of successful readings.     

Ambulatory blood pressure monitoring after successful repair of coarctation of the aorta at mid-term follow-up

Variations of systolic and diastolic blood pressure in patients with normotension at rest after successful surgical repair of coarctation of the aorta were examined using 24 hour ambulatory monitoring at mid-term follow-up. Ambulatory blood pressure monitoring, m-mode measurements of left ventricle and transmitral Doppler spectrals in 18 patients aged 7.6 +/- 4.5 years after 9 months to 6.1 years (2.5 +/- 1.9 years) following operation were compared with the findings in 18 matched controls. Patients had significantly higher mean systolic blood pressures (24 hours: 115 +/- 10 mmHg, awake: 119 +/- 11 mmHg and asleep: 106 +/- 8 mmHg) than controls (24 hours: 108 +/- 6 mmHg, awake: 112 +/- 7 mmHg and asleep: 101 +/- 7 mmHg) (p = 0.04, 0.03 and 0.03, respectively). Patients had also more systolic blood pressure readings above the 95th percentile for age (24 hours: 28 +/- 20%, awake: 39 +/- 27% and asleep: 12 +/- 14%) than controls (24 hours: 10 +/- 9%, awake: 14 +/- 13% and asleep: 1 +/- 4%) (p = 0.03, 0.002 and 0.007, respectively). No significant difference was found in diastolic blood pressure profiles. There were no significant differences in left ventricular m-mode measurements and diastolic function parameters. Left ventricular mass index was significantly increased in patients (81.7 +/- 28.7 g/m2) compared with controls (64.5 +/- 20.9 g/m2) (p = 0.03). Operation age and post-surgical period did not affect ambulatory blood pressure profiles at mid-term follow-up. Patients who are normotensive at rest after successful surgical repair of coarctation of the aorta show higher systolic blood pressure profiles than healthy children with ambulatory blood pressure monitoring at mid-term follow-up. Ambulatory blood pressure monitoring in patients operated on for coarctation of the aorta despite their good clinical status is useful to detect and monitor subtle abnormalities of blood pressure.     

Effect of estrogen receptor modulator tamoxifen on blood pressure,plasma renin activity,and renal sodium excretion

BACKGROUND: Adjuvant treatment with the estrogen receptor modulator tamoxifen is a well established long-term therapy in breast cancer. This study investigated the effect of tamoxifen on blood pressure (BP) and on factors by which it might be influenced. METHODS: Normotensive postmenopausal women on > 12 months adjuvant tamoxifen therapy were randomized to withdraw or continue tamoxifen for 6 weeks and then to crossover to the alternative regimen for a second 6-week period. Measurements of clinic and ambulatory BP, plasma renin activity (PRA), and fractional sodium excretion (FE(Na)) were performed at baseline and at the end of each study period. RESULTS: Twenty-three women completed the study (mean age 60.6 +/- 8.3 years). There was no effect of tamoxifen on clinic BP (mean difference between withdrawal and continuation for systolic BP, 0.4 +/- 8.4 mm Hg, 95% confidence interval [CI] -4.0 to 3.2, and diastolic 0.6 +/- 4.7, 95%CI -1.4 to 2.7) or 24-hour ambulatory BP (systolic 0.7 +/- 7.4 mmHg, 95%CI -2.6 to 3.9; diastolic BP, 1.9 +/- 5.5, 95% CI -0.5 to 4.2). Furthermore, no effect of tamoxifen on PRA (mean difference between withdrawal and continuation 0.03 +/- 0.5 ng/mL/h, 95% CI -0.3 to 0.2) or FENa (0.05 +/- 0.5, 95% CI -0.2 to 0.2) was detected. CONCLUSIONS: Tamoxifen seems to have no effect on BP, PRA, or FE(Na) in normotensive postmenopausal women.     

Evaluation of prehypertension and masked hypertension rate among clinically normotensive patients

Background: The present cross-sectional study was aimed to identify pre-hypertension and masked hypertension rate in clinically normotensive adults in relation to socio-demographic, clinical and laboratory parameters. Methods: A total of 161 clinically normotensive adults with office blood pressure (OBP) <140/90?mmHg without medication were included in this single-center cross-sectional study. OBP, home BP (HBP) recordings and ambulatory BP monitoring (ABPM) were used to identify rates of true normotensives, true pre-hypertensives and masked hypertensives. Data on sociodemographic and clinical characteristics were collected in each subject and evaluated with respect to true normotensive vs. pre-hypertensive patients with masked hypertension or true pre-hypertensive. Target organ damage (TOD) was evaluated in masked hypertensives based on laboratory investigation. Results: Masked hypertension was identified in 8.7% of clinically normotensives. Alcohol consumption was significantly more common in masked hypertension than in true pre-hypertension (28.6 vs. 0.0%, p?=?0.020) with risk ratio of 2.7 (95% CI 1.7–4.4). Patients with true pre-hypertension and masked hypertension had significantly higher values for body mass index, waist circumference, systolic and diastolic OBP and HBP (p?<?0.05 for each) compared to true normotensive subjects. ABPM revealed significantly higher values for day-time and night-time systolic and diastolic BP (p?=?0.002 for night-time diastolic BP, p?<?0.001 for others) in masked hypertension than true pre-hypertension. Conclusions: Given that the associations of pre-hypertension with TOD might be attributable to the high prevalence of insidious presentation of masked hypertension among pre-hypertensive individuals, ABPM seems helpful in early identification and management of masked hypertension in the pre-hypertensive population.     

Lack of agreement between office and ambulatory blood pressure responses to hydrochlorothiazide

BACKGROUND: Differences between the antihypertensive responses to drug therapy measured by office blood pressure (OBP) and ambulatory blood pressure monitoring (ABPM) techniques have been noted but rarely analyzed. We studied whether the OBP and 24-h ABPM responses to hydrochlorothiazide differ and, if so, the relevance of these differences. METHODS: The OBP and ABPM responses to hydrochlorothiazide (25 mg/d, for 4 weeks) were measured in 228 subjects with essential hypertension, and mean responses were compared between methods using the Student paired t test. To assess variation in the agreement between OBP and ABPM responses among subjects, the limits of agreement were calculated as the mean difference between OBP and ABPM responses +/-2 standard deviations. RESULTS: The mean systolic OBP response was 4.8 mm Hg greater than the response measured by ABPM (-14.3 v -9.5 mm Hg, P < .001), and the mean diastolic OBP response was 2.1 mm Hg greater than the response measured by ABPM (-7.5 v -5.5, P < .001). The limits of agreement between the OBP and ABPM responses ranged from -18.7 to +28.2 mm Hg for systolic response and from -12.9 to +17.1 mm Hg for diastolic response. The systolic and diastolic OBP and ABPM responses were in opposite directions in 22.8% and 23.7% of the subjects, respectively. CONCLUSIONS: Compared to ABPM, OBP overestimates the mean systolic and mean diastolic blood pressure responses to hydrochlorothiazide. Variation among subjects in the magnitude and direction of responses renders OBP an unreliable predictor of ABPM responses.     

Comparison of Office, Ambulatory, and Home Blood Pressure Antihypertensive Response to Atenolol and Hydrochlorthiazide

J Clin Hypertens (Greenwich). 2010;12:14–21. ^© 2009 Wiley Periodicals, Inc.
Office, home, and ambulatory blood pressure (BP) demonstrate variable associations with outcomes. The authors sought to compare office BP (OBP), home BP (HBP), and ambulatory BP (ABP) for measuring responses to hydrochlorothiazide (HCTZ), atenolol, and their combination. After completing washout, eligible patients were randomized to atenolol 50 mg or HCTZ 12.5 mg daily. Doses were doubled after 3 weeks and the alternate drug was added after 6 weeks if BP was >120/70 mm Hg (chosen to allow maximum opportunity to assess genetic associations with dual BP therapy in the parent study). OBP (in triplicate), HBP (twice daily for 5 days), and 24-hour ABP were measured at baseline, after monotherapy, and after combination therapy. BP responses were compared between OBP, HBP, and ABP for each monotherapy and combination therapy. In 418 patients, OBP overestimated BP response compared with HBP, with an average 4.6 mm Hg greater reduction in systolic BP ( P <.0001) and 2.1 mm Hg greater reduction in diastolic BP ( P <.0001) across all therapies. Results were similar for atenolol and HCTZ monotherapy. ABP response was more highly correlated with HBP response ( r =0.58) than with OBP response ( r =0.47; P =.04). In the context of a randomized clinical trial, the authors have identified significant differences in HBP, OBP, and ABP methods of measuring BP response to atenolol and HCTZ monotherapy.     

Arterial stiffness as underlying mechanism of disagreement between an oscillometric blood pressure monitor and a sphygmomanometer

Oscillometric blood pressure devices tend to overestimate systolic blood pressure and underestimate diastolic blood pressure compared with sphygmomanometers. Recent studies indicate that discrepancies in performance between these devices may differ between healthy and diabetic subjects. Arterial stiffness in diabetics could be the underlying factor explaining these differences. We studied differences between a Dinamap oscillometric blood pressure monitor and a random-zero sphygmomanometer in relation to arterial stiffness in 1808 healthy elderly subjects. The study was conducted within the Rotterdam Study, a population-based cohort study of subjects aged 55 years and older. Systolic and diastolic blood pressure differences between a Dinamap and a random-zero sphygmomanometer were related to arterial stiffness, as measured by carotid-femoral pulse wave velocity. Increased arterial stiffness was associated with higher systolic and diastolic blood pressure readings by the Dinamap compared with the random-zero sphygmomanometer, independent of age, gender, and average mean blood pressure level of both devices. The beta-coefficient (95% CI) was 0.25 (0.00 to 0.50) mm Hg/(m/s) for the systolic blood pressure difference and 0.35 (0.20 to 0.50) mm Hg/(m/s) for the diastolic blood pressure difference. The results indicate that a Dinamap oscillometric blood pressure device, in comparison to a random-zero sphygmomanometer, overestimates systolic and diastolic blood pressure readings in subjects with stiff arteries.     

Clinical evaluation of the QuietTrak blood pressure recorder according to the protocol of the British Hypertension Society

METHODS: The QuietTrak ambulatory blood pressure recorder (Tycos-Welch-Allyn, Arden, North Carolina, USA) was evaluated according to the protocol of the British Hypertension Society (BHS). QuietTrak, a lightweight (355 g), automatic, programmable device, uses an auscultatory measuring system. The protocol of the BHS was composed of subsequent phases with QuietTrak and two observers taking simultaneous measurements on the same arm. RESULTS: No interdevice differences were observed at analysis of variance test either before or after a 1-month period of routine clinical use. The average difference between mercury sphygmomanometer and QuietTrak for systolic and diastolic blood pressures was -0.6+/-3.6 and -0.4+/- 3.6 mmHg before and -0.7+/- 3.3 mmHg and 0.6+/- 3.8 mmHg after the 1-month use. At the main static device validation procedure, performed in 85 subjects, the average difference between observers and QuietTrak was -0.3+/- 3.4 and 0.1+/- 3.5 mmHg for systolic and diastolic blood pressures. Eighty-nine per cent and 99% of systolic and 88% and 98% of diastolic QuietTrak readings were within 5 and 10 mmHg of obsevers, determinations (Class A). In children (n = 33) 87% of systolic and 90% of diastolic QuietTrak readings differed by less than 5 mmHg from the observers' readings (average difference -1.1+/-3.9 and 0.1+/- 3.6 mmHg, respectively). In the elderly (n = 30), 95% and 92% of systolic and diastolic readings were within 5 mmHg of mercury column determinations (average difference -0.8+/-3.2 and -0.2+/-4.5 mmHg). In pregnancy (n = 30), 93% of systolic and 100% of diastolic readings were within 5 mmHg of mercury column determination (average difference -0.3+/-3.4 and 0.1+/- 2.9 mmHg). Device reliability was not affected by posture. Ninety-six per cent and 89% of systolic and diastolic readings differed by less than 5 mmHg from the mercury column determinations in the supine position, 90% and 90% in the standing position, and 88% and 90% in the sitting position. During the treadmill exercise (Bruce protocol), 69% and 88% of systolic and 56% and 83% of diastolic QuietTrak readings differed by less than 5 and 10 mmHg from the observers' measurements. CONCLUSION: The QuietTrak achieved A rating for systolic blood pressure and A rating for diastolic blood pressure according to the criteria of the BHS protocol. The device was acceptable to patients because of its small size, light weight and noiseless performance.