Predictors of controlled ambulatory blood pressure in treated hypertensive patients with uncontrolled office blood pressure.

Although some treated hypertensive patients have controlled 24-h ambulatory blood pressure (ABP) despite their uncontrolled office blood pressure (BP), the factors relating to the control of 24-h ABP remain unknown. We conducted a study to assess 24-h ABP and its association with other cardiovascular risk factors, including echocardiographic left ventricular hypertrophy (LVH), in elderly hypertensive patients (n =41) with uncontrolled office BP (>140/90 mmHg) during long-term medication. Although a majority of the patients had isolated elevation of office systolic BP (SBP), there was no significant relationship between office SBP and 24-h SBP, and about half of the patients had controlled 24-h ABP (125+/-8/69+/-6 mmHg). Patients with controlled 24-h ABP (125+/-8/69+/-6 mmHg) had similar office BP (150+/-6/77+/-5 vs. 150+/-7/79+/-7 mmHg), but lower left ventricular mass index (LVMI) (123+/-34 vs. 156+/-34 g/m(2)) and body mass index (BMI) (24.4+/-2.1 vs. 26.4+/-3.6 kg/m(2)) compared with those with uncontrolled 24-h ABP (149+/-13/78+/-7 mmHg). Multivariate analysis showed that LVMI and BMI were independently associated with controlled 24-h ABP, and the control status of 24-h ABP was highly dependent on the presence of LVH and obesity. Therefore, absence of LVH and obesity may be useful for predicting the level of control of 24-h ABP in treated patients whose office BP is uncontrolled without ABP measurements.     

Normal ambulatory blood pressure: a clinical-practice-based analysis of recent American Heart Association recommendations

Purpose

The American Heart Association Council on High Blood Pressure Research recently issued recommendations for blood pressure measurement in humans. According to these recommendations, normal 24-hour ambulatory blood pressure is defined as less than 130/80 mm Hg. Concurrently, normal daytime and nighttime blood pressure levels are defined as less than 135/85 mm Hg and less than 120/70 mm Hg, respectively. Our aim was to investigate the intrinsic compatibility of these blood pressure cutoffs in clinical practice.

Subjects and methods

We analyzed 4121 consecutive ambulatory blood pressure measurement sessions. Age was 57 ± 7 years, 53% were female, and 64% and 9% were treated for hypertension and diabetes, respectively. Body mass index was 27 ± 4 kg/m², and manual blood pressure was 148 ± 22/85 ± 12 mm Hg. Subjects were classified as having normal 24-hour blood pressure if the corresponding value was less than 130/80 mm Hg. Normal awake-sleep blood pressure was diagnosed if awake blood pressure was less than 135/85 mm Hg and sleep blood pressure was less than 120/70 mm Hg.

Results

Concordance between the cutoffs was found in 92% of the subjects (kappa = 0.77). Among the 8% of discordant subjects, only 1% were hypertensive applying the 24-hour (but not awake-sleep) blood pressure values, whereas 7% were hypertensive according to awake-sleep but not 24-hour blood pressure values (P <.0001).

Conclusions

In real-life ambulatory blood pressure measurement, a generally good agreement was found between the recently issued ambulatory blood pressure normality suggestions. However, some subjects are classified as hypertensive only according to one of these methods, more often by the awake-sleep cutoff of 135/85 and 120/70 mm Hg. This discordance may be significant in large-scale clinical blood pressure monitoring.     

How reliable is isolated clinical hypertension defined by a single 24-h ambulatory blood pressure monitoring?

BACKGROUND: Isolated clinical hypertension (ICH) is characterized by a persistently elevated clinic blood pressure in the presence of a normal day-time or 24-h ambulatory blood pressure (ABP). This definition is based on a single ABP monitoring (ABPM) and little attention has been focused on the reproducibility of this condition. OBJECTIVE: To investigate the reliability of the criteria currently recommended by major hypertension guidelines to detect ICH based on a single 24-h ABPM session. METHODS: A total of 611 never-treated grade 1 and 2 hypertensive patients (mean age 46 +/- 12 years) referred for the first time to our out-patient clinic, underwent repeated clinic blood pressure measurements, routine investigations, two 24-h periods of ABPM 1-4 weeks apart, cardiac and carotid ultrasound examinations. ABPM was always performed over a working day and the same daily activities were recommended during the two periods. ICH was diagnosed by the following criteria: (i) mean daytime values < 135/85 mmHg or (ii) mean 24-h blood pressure values < 125/80 mmHg during the first ABPM. RESULTS: The overall prevalence of ICH was 7.1% according to criterion (i) and 5.4% according to criterion (ii). Twenty (46.6%) of the 43 patients with mean daytime blood pressure values < 135/85 mmHg during the first ABPM, exceeded this cut-off value during the second ABPM period. Twenty-two (66.6%) of the 33 patients with mean 24-h blood pressure values < 120/80 mmHg during the first ABPM did not confirm a normal blood pressure profile during the second ABPM recording. Cardiovascular involvement was significantly lower in subjects with persistent normal ABP compared to those with non-reproducible ICH pattern or sustained hypertensives. CONCLUSIONS: These findings clearly indicate that: (i) the classification of ICH on the basis of a single ABPM, using the cut-offs suggested by major hypertension guidelines, has a limited short-term reproducibility and (ii) repeated ABPM recordings should be recommended to correctly diagnose patients with ICH and improve cardiovascular risk stratification.     

Left ventricular hypertrophy in treated hypertensive patients with good blood pressure control outside the clinic,but poor clinic blood pressure control

OBJECTIVE: The aim of the study was to evaluate the prevalence of left ventricular hypertrophy (LVH) in treated patients with good blood pressure (BP) control during multiple home BP (HBP) measurements and during 24-h ambulatory BP monitoring (ABPM), but with unsatisfactory BP control in the clinic. These patients were compared with treated hypertensives whose BP was well controlled under the three circumstances. METHODS: Seventy-two treated consecutive patients (group I, age 56 +/- 10 years) with clinic BP values > or = 140/90 mmHg, and a difference between clinic and self-measured HBP > 10 mmHg for diastolic blood pressure (DBP) and/or > 20 mmHg for systolic blood pressure (SBP), underwent the following procedures: (1) clinic BP measurement; (2) routine diagnostic work-up; (3) HBP monitoring; (4) 24-h ABPM; (5) echocardiography. Thirty-five hypertensive patients with satisfactory BP control according to clinic (< 140/90 mmHg), HBP (< or = 131/82 mmHg) and ABP criteria (< or = 125/79 mmHg) were included as the control group (group II, age 55 +/- 9 years). RESULTS: In group I, 33 subjects out of the 72 (46%) with clinic BP > 140/90 mmHg had BP values controlled outside the clinic (23 according to HBP criteria and 22 according to ABP criteria). The prevalence of LVH (LV mass index > 134 g/m2 in men and > 110 g/m2 in women) was significantly higher in these patients (15.1 versus 2.8%, P < 0.01) than in group II (BP also controlled in the clinic), despite the fact that HBP and ABP were reduced to similar levels in the two groups. CONCLUSIONS Our data provide evidence that treated hypertensive patients with good BP control at home or during ambulatory monitoring, but incomplete BP control in the clinic, have more pronounced cardiac alterations than patients with both clinic and out of the clinic BP control. This finding offers a new piece of information about the diagnostic value of BP measurement in the clinic to assess BP control during antihypertensive treatment.     

Relationship between aortic stiffness and cardiovascular risk factors in a population of normotensives, white-coat normotensives, white-coat hypertensives, sustained hypertensives and diabetic patients.

OBJECTIVE: To evaluate the relationship between carotid-femoral pulse wave velocity (PWV) and office and ambulatory blood pressure (ABP) and other cardiovascular risk factors and to determine the discriminatory value of PWV in a large population including normotensive subjects (NT), white-coat normotensives (masked hypertension) (WCNT), and white-coat hypertensives (WCHT) compared to a group of treated and untreated hypertensive patients. METHODS: The study population included a total of 688 subjects aged from 18 to 80 years, with no previous cardiovascular events, who underwent 24 h ABP monitoring, biochemical evaluation and determination of PWV and left ventricular mass index (LVMI). Subjects were classified as true normotensives (NT, n=132; normal office and ABP values), WCNT (n=39; office BP < 140/90 and daytime BP > or =135 or > or =85 mmHg), WCHT (n=87; office BP > or =140 or > or =90 and daytime BP < 135/85 mmHg). Untreated (UT-HT, n=154) and treated (T-HT, n=171) hypertensive patients and type 2 diabetic patients (DM, n=102) were also studied. RESULTS: Values of PWV (m/s) in all groups were, in ascending order: NT (8.9 +/- 0.2) < WCHT (9.9 +/- 0.2) < T-HT (11.4 +/- 0.2) = WCNT (11.5 +/- 0.4) < UT-HT (11.9 +/- 0.3) < DM (12.6 +/- 0.4) (ANOVA, p = 0.043), and of LVMI (g/m2): NT (59 +/- 2) = WCHT (63 +/- 2) < WCNT (73 +/- 3) = T-HT (75 +/- 3) = UT-HT (77 +/- 3) < DM (84 +/- 4) (ANOVA, p < 0.05). The percentage of subjects with PWV values below the median (10.7 m/s) was higher (p < 0.02) in NT (81.8%) and WCHT (72.6%) than in UT-HT (49.2%), T-HT (43.6%), WCNT (47.6%) and DM (27.7%). In multiple regression analysis, taking PWV as the dependent variable, age (all groups), 24h systolic BP (UT-HT, T-HT, WCNT and DM) and 24h diastolic BP (NT and WCHT) were the variables that independently influenced the PWV value. CONCLUSIONS: Higher values of PWV occur in clinical situations associated with higher cardiovascular risk. This is in agreement with risk stratification based on ABP values but not on office BP values. Lower PWV and LVMI values occur in NT and WCHT subjects, supporting a low cardiovascular risk in these groups. By contrast, higher PWV values were associated with higher ABP values in DM, hypertensive patients and white-coat normotensives, i.e. clinical situations that are associated with higher cardiovascular risk, who in the present study also exhibited higher LVMI than subjects with normal ABP values.     

24-hour ambulatory blood-pressure effects of valsartan and hydrochlorothiazide combinations compared with amlodipine in hypertensive patients at increased cardiovascular risk: a VAST sub-study

BACKGROUND: There is a lack of data on the effects of angiotensin-receptor blocker and diuretic combinations on ambulatory blood pressure (ABP) in hypertensive patients with additional cardiovascular risk factors. METHODS: In a randomized, double-blind trial, the effects on 24-h ABP of the combination valsartan 160 mg od and hydrochlorothiazide 25 or 12.5 mg during 24 weeks of therapy were compared with the effects of amlodipine 10 mg monotherapy (group A10) in 474 stage-II hypertensive patients with additional cardiovascular risk factors. After a two-week single-blind placebo run-in period, patients were randomized to receive valsartan 160 mg od or amlodipine 5 mg od. At week 4, HCTZ 12.5 mg (group V160/HCTZ12.5) and 25 mg (group V160/HCTZ25) were added to the valsartan groups and in the A10 patients the amlodipine dose was force-titrated to 10 mg od. RESULTS: All three treatments reduced 24-h BP as well as night-time and daytime BP levels from baseline. Twenty-four hour systolic blood pressure (SBP) was reduced by 15.9+/-1.0 mmHg (least-squares mean change+/-SE), 19.3+/-1.0 mmHg and 16.1+/-1.1 mmHg in the V160/HCTZ12.5, V160/HCTZ25 and A10 groups, respectively and 24-h diastolic blood pressure (DBP) was reduced by 9.3+/-0.6 mmHg, 11.4+/-0.6 mmHg and 9.6+/-0.7 mmHg in the three groups. The differences between the V160/HCTZ25 group and the A10 group were significant (p<0.05) for the changes in 24-h systolic BP as well as for changes in daytime systolic BP and night-time diastolic BP. Control rates defined as ABPM < or =130/80 mmHg were: 48.4%, 60.8% and 50.9% in the V160/HCTZ12.5, V160/25 and A10 groups, respectively. The differences in control rates between the V160/HCTZ25 group and the other two treatment groups were significant at p<0.05. CONCLUSIONS: The fixed-dose combination of valsartan 160 mg+HCTZ 25 mg od is an attractive therapeutic option measured on the effects on 24-h ABPM, night-time and daytime BP reduction and control rates in hypertensive patients at additional cardiovascular risk.     

Circadian rhythm of blood pressure in patients with obstructive sleep apnea.

AIMS: The aims of this study were to examine the circadian variation in blood pressure (BP) in obstructive sleep apnea (OSA) and to compare this between normotensive and hypertensive subjects. METHODS: We measured 24-hour ambulatory BP (ABP) in 72 men (mean age 51 +/- 8 years), with OSA diagnosed on overnight sleep study. Measurements of BP were made at 15 min intervals for 24 h using either an Oxford Medilog ABP or Spacelabs 90207 recorder. All recordings were performed after > or = 3 week washout of anti-hypertensive drugs. The day-time monitoring period was defined as 07:00 hrs to 22:00 and night-time 22:00 to 07:00. The ratio of night:day systolic and diastolic BP was calculated. RESULTS: The patients were obese (mean body mass index 33 +/- 5 kg/m2) with a central pattern of obesity (waist:hip ratio 0.99 +/- 0.14, normal < 0.94). The mean 24-h ABP (systolic/diastolic) was 138 +/- 18/88 +/- 12 mmHg. The mean daytime ABP was 143 +/- 18/93 +/- 12 and night-time ABP 128 +/- 20/80 +/- 12 Hg. The night:day BP ratio was 0.90 +/- 0.07 (systolic) and 0.87 +/- 0.09 (diastolic) indicating that average BP was lower during the night. This pattern was similar in normotensive and hypertensive subjects. In contrast there was a significant relationship between increasing BMI and night:day blood pressure ratio (r = 0.56, p < 0.001) independent of the effects of OSA. CONCLUSION: In contrast to previous studies, men with OSA have a normal diurnal pattern of blood pressure levels. These findings suggest that any influence of OSA on BP is manifested throughout the 24-h period.     

Ambulatory blood pressure normality: experience in the Ohasama Study

OBJECTIVE: To define the reference values of ambulatory blood pressure (APB) using results from the Ohasama study. RESULTS: The distribution criteria of 24 h ABP for the total population of Ohasama were 135/79 (mean + SD), 148/86 (mean + SD), and 146/85 mmHg (95th percentile), and those for normotensive subjects were 129/76 (mean + SD), 142/85 (mean + 2 SD) and 139/81 mmHg (95th percentile). The corresponding criteria [i.e. the 24 h ABP corresponding to 140/90 and 160/95 mmHg casual (clinical) blood pressure of the total population] were 125/76 and 132/76 mmHg. A long-term prospective study based on cardiovascular morbidity and mortality would provide the most meaningful values. For the prognostic criteria, based on nonparametric analysis, the hypertensive range of the 24 h ABP was postulated to be >/= 134/>/= 78 mmHg, whereas that based on parametric analysis was postulated to be >/= 134/ 79 mmHg. The lowest relative hazard was observed at 128/74 mmHg in parametric analysis. Thus, we tentatively propose reference values>/= 135/>/= 80 mmHg for hypertensive 24 ABP and < 125/< 75 mmHg for normotensive 24 h ABP.CONCLUSION:     

Ambulatory blood pressure characteristics in normotensive and treated hypertensive older people

The objective of this study was to determine the normal values and characteristics of 24-h ambulatory blood pressure (ABP) and to describe the ABP level of treated hypertensive subjects in an older Finnish population. ABP was measured in 502 randomly selected subjects aged 64 years or over living in a Finnish municipality (mean age 70 years, range 64-87 years). A total of 211 subjects did not have blood pressure (BP) affecting medication. ABP measurements were taken every 30 min for 24 h, and the day- and night-time periods were diary-based. The results were that in untreated subjects, the average office BP was 134/82 +/- 16/9 (s.d.) mm Hg for men and 140/81 +/- 18/8 mm Hg for women. The 24-h average BP was 120/75 +/- 14/8 mm Hg (95th percentile upper limit 145/93 mm Hg) for men and 125/75 +/- 15/7 (95th = 154/89 mm Hg) for women. The daytime averages were 127/78 +/- 12/7 mm Hg (95th = 154/99 mm Hg) and 131/78 +/- 15/7 mm Hg (95th = 158/91 mm Hg) for men and women, respectively. The ABP daytime value of 130/83 mm Hg corresponded best to the office BP value of 140/90 mm Hg. All BP values were significantly higher in the treated hypertensive group compared to the normotensive group. Night-time BP was markedly lower than daytime BP, and no difference in circadian variability was found between the normotensive and hypertensive subjects. Both office and ambulatory BPs were significantly higher in women than in men. This study provides sex-specific normal values for ABP in a 64 to 87-year-old age group. The normal values of ABP were markedly lower than the office BP values. Hypertensives, even when treated, tended to have elevated values.     

Factors Related to Elevated 24-h Blood Pressure in Young Adults

Variation in 24-h blood pressure (BP) is associated with multiple factors, but the association has not been thoroughly examined in young adults. To elucidate the potential factors associated with variation in 24-h BP, 331 healthy medical students were investigated. Awake mean BP negatively correlated with sleep duration in males. Sixty-seven subjects (20.2%) had a high 24-h BP according to the ESH/ESC 2007 guidelines (systolic blood pressure (SBP) 125 and/or diastolic blood pressure (DBP) 80 mmHg). After multivariate analysis for confounding factors, male gender, body mass index (BMI), smoking, the 24-h low/high frequency component (heart rate variability spectral analysis), and short sleep (5 h or less) were found to be associated with high BP. The present study is the first to demonstrate the multivariate risk factors for elevated 24-h BP in a large number of young adults. Further investigation is required to determine the causal relationship between modifiable BP-related factors and elevated 24-h BP in young adults.     

The ambulatory blood pressure in normotensive and hypertensive subjects: results from an international database

Objective: To delineate more precisely an operational threshold for making clinical decisions based on ambulatory blood pressure (ABP) measurement by studying the ABP in subjects who were diagnosed as either normotensive or hypertensive by conventional blood pressure (CBP) measurement.Subjects: Twenty-four research groups recruited 7069 subjects. Of these, 4577 were normotensive (systolic CBP ≤ 140 mmHg and diastolic CBP ≤ 90 mmHg) and 1773 were hypertensive (systolic CBP ≥ 160 mmHg and/or diastolic CBP ≥ 90 mmHg). Of the latter, 1324 had systolic and 1310 had diastolic hypertension.Results: Ninety-five percent of the normotensive subjects had a 24-h ABP below (systolic and diastolic, respectively) 133 and 82 mmHg. Of the patients with systolic hypertension, 24% had a 24-h systolic ABP of < 133 mmHg. Similarly, 30% of those with diastolic hypertension had a 24-h diastolic ABP of < 82 mmHg. The probability that hypertensive patients had a 24-h ABP below these thresholds was higher in women than in men, increased with age and was 2- to 4-fold greater if the CBP of the patient had been measured at only one visit and if fewer than 3 CBP measurements had been averaged to establish the diagnosis of hypertension. By contrast, for each 10-mmHg increment in systolic CBP, this probability decreased by 54% for the 24-h systolic ABP and by 25% for the 24-h diastolic ABP, and for each 5 mmHg increment in diastolic CBP it increased by 6 and 9%, respectively.Conclusion: The ABP distributions of the normotensive subjects included in the present international database were not materially different from those in previous reports in the literature. One-fifth to more than one-third of the hypertensive patients had an ABP which was below the 95th centile of the ABP in normotensive subjects, but this proportion decreased if the hypertensive patients had shown a higher CBP upon repeated measurement. The prognostic implications of elevated CBP in the presence of normal ABP remain to be determined.     

The combination of vitamin C and grape-seed polyphenols increases blood pressure: a randomized, double-blind, placebo-controlled trial

BACKGROUND: There is growing evidence that oxidative stress contributes to the pathogenesis of hypertension and endothelial dysfunction. Thus, dietary antioxidants may beneficially influence blood pressure (BP) and endothelial function by reducing oxidative stress. OBJECTIVE: To determine if vitamin C and polyphenols, alone or in combination, can lower BP, improve endothelial function and reduce oxidative stress in hypertensive individuals. DESIGN: A total of 69 treated hypertensive individuals with a mean 24-h ambulatory systolic blood pressure > or = 125 mmHg participated in a randomized, double-blind, placebo-controlled, factorial trial. Following a 3-week washout, participants received 500 mg/day vitamin C, 1000 mg/day grape-seed polyphenols, both vitamin C and polyphenols, or neither for 6 weeks. At baseline and post-intervention, 24-h ambulatory BP, ultrasound-assessed endothelium-dependent and -independent vasodilation of the brachial artery, and markers of oxidative damage, (plasma and urinary F2-isoprostanes, oxidized low-density lipoproteins and plasma tocopherols), were measured. RESULTS: A significant interaction between grape-seed and vitamin C treatments for effects on BP was observed. Vitamin C alone reduced systolic BP versus placebo (-1.8 +/- 0.8 mmHg, P = 0.03), while polyphenols did not (-1.3 +/- 0.8 mmHg, P = 0.12). However, treatment with the combination of vitamin C and polyphenols increased systolic BP (4.8 +/- 0.9 mmHg versus placebo; 6.6 +/- 0.8 mmHg versus vitamin C; 6.1 +/- 0.9 mmHg versus polyphenols mmHg, each P < 0.0001) and diastolic BP (2.7 +/- 0.6 mmHg, P < 0.0001 versus placebo; 1.5 +/- 0.6 mmHg, P = 0.016 versus vitamin C; 3.2 +/- 0.7 mmHg, P < 0.0001 versus polyphenols). Endothelium-dependent and -independent vasodilation, and markers of oxidative damage were not significantly altered. CONCLUSION: Although the mechanism remains to be elucidated, these results suggest caution for hypertensive subjects taking supplements containing combinations of vitamin C and polyphenols.     

Office blood pressure measurements overestimate blood pressure control in renal transplant patients

OBJECTIVE: As hypertension is an important risk factor for renal allograft failure, we aimed to assess blood pressure control in renal transplant patients with deteriorating graft function using different methods of blood pressure measurements. METHODS: Forty-nine patients with a graft survival of >1 year, and with more than a two-fold increase in urinary albumin excretion, and/or an increase in serum creatinine level >20% during the previous 12 months, were included. Office blood pressure and home BP were measured, and ambulatory blood pressures were obtained in all patients. RESULTS: The mean office blood pressure (133.2+/-16.3/81.7+/-9.6 mmHg) and 24 h ambulatory blood pressure (133.1+/-12.0/79.8+/-8.3 mmHg) were similar. Home blood pressure in the morning (144.2+/-23.3/87.1+/-12.7 mmHg) and evening (143.2+/-20.6/86.4+/-10.3 mmHg) were significantly higher than ambulatory blood pressure (P<0.001 for both). Only 18% of the patients exhibited a reduction of >or=10% in systolic blood pressure during nighttime while 39% had an overt rise. Adequate blood pressure control was found in 53% of the patients using office blood pressure (<140/90 mmHg), contrasting 29% using home blood pressure (<135/85 mmHg), and 16% using mean 24-h ambulatory blood pressure (<125/80 mmHg). These findings were substantiated by the use of receiver-operating characteristic curve analysis. CONCLUSIONS: Using the 24-h blood pressure as a standard, home blood pressure was superior to office blood pressure in estimating blood pressure control in renal transplant patients. Nocturnal hypertension, however, was observed frequently, adding important clinical information about blood pressure control in this high-risk population.     

Long-term development of blood pressure profile in hypertensive hemodialysis patients

OBJECTIVE: The prognostic value of nocturnal blood pressure (BP) in hemodialysis patients has been well established. The aim of this study was to evaluate the long-term outcome of ambulatory BP in hypertensive hemodialysis patients. DESIGN AND METHODS: Medical records of all hemodialysis patients seen for uncontrolled hypertension between 1993 and 1999 and who underwent an ambulatory blood pressure measurements (ABPM) were retrospectively studied. Uncontrolled hypertension was defined as office BP = 140/90 mmHg and 24 h ABP = 125/80 mmHg. Patients who underwent a second ABPM after an interval of at least 1 year were included in the study. Demographic characteristics, medical history, cardiovascular risk factors and treatments were recorded for each patient. A t-test (bilateral) was used to compare BP. RESULTS: 26 patients were included (545 +/- 18.9 years; 14 men). 7 had previous history of cardiovascular disease and 2 were diabetic. At the end of the follow-up (29 +/- 12.8 months), 9 patients (36%) had 24 h BP < 125/80 mmHg. A significant decrease in diurnal and nocturnal BP was observed (p < 0.05). No significant change was observed for office systolic BP and predialytic BP. CONCLUSION: Our data show that a long-term decrease in nocturnal BP can be obtained in hypertensive patients on hemodialysis. With respect to the prognostic value of this criteria, randomised trials could be carried out to determine whether nocturnal BP is superior to office BP as a target for antihypertensive therapy in this population.     

Ambulatory blood pressure monitoring in hypertensive patients with high cardiovascular risk: a cross-sectional analysis of a 20,000-patient database in Spain

OBJECTIVE: To evaluate ambulatory blood pressure monitoring (ABPM) parameters in a broad sample of high-risk hypertensive patients. METHODS: The Spanish Society of Hypertension is developing a nationwide project in which more than 900 physicians send ABPM registries and corresponding clinical records to a central database via www.cardiorisc.com. Between June 2004 and July 2005 a 20 000-patient database was obtained; 17 219 were valid for analysis. RESULTS: We identified 6534 patients with high cardiovascular risk according to the 2003 European Society of Hypertension/European Society of Cardiology guidelines stratification score. Office blood pressure (BP) was 158.8/89.9 mmHg and 24-h BP was 135.8/77.0 mmHg. Patients with grade 3 BP in the office showed ambulatory systolic BP values less than 160 mmHg in more than 80%. A non-dipping pattern was observed in 3836 cases (58.7%), whereas this abnormality was present in 47.9% of patients with low-to-moderate risk [odds ratio (OR) 1.54; 95% confidence interval (CI) 1.45-1.64]. The prevalence of non-dippers was higher as ambulatory BP increased ( approximately 70% when 24-h systolic BP > 155 mmHg) and was similar in both groups. At the lowest levels of BP (24-h systolic BP < 135 mmHg) a non-dipping pattern was more prevalent in high-risk cases (56.6 versus 45.7%; OR 1.51; 95% CI 1.40-1.64). CONCLUSION: There was a remarkable discrepancy between office and ambulatory BP in high-risk hypertensive patients. The prevalence of a non-dipper BP pattern was almost 60%. In the lowest levels of ambulatory BP, high-risk patients showed a higher prevalence of non-dipping BP than lower-risk cases. These observations support the recommendation of a wider use of ABPM in high-risk hypertensive patients.     

Masked hypertension in obstructive sleep apnea syndrome

BACKGROUND: Ambulatory blood pressure (BP) monitoring (ABPM) detects subjects with normal clinic but high ambulatory 24-h BP, that is, masked hypertension. METHODS: One hundred and thirty newly diagnosed obstructive sleep apnea syndrome (OSAS) patients, free of recognized cardiovascular disease were included (111 men, age = 48 +/- 1 years, BMI = 27.6 +/- 0.4 kg/m, respiratory disturbance index (RDI = 42 +/- 2/h). Clinic BP, 24-h ABPM, baroreflex sensitivity (BRS), echocardiography and carotid intima-media thickness (IMT) were assessed. RESULTS: Forty-one patients (31.5%) were normotensive, 39 (30.0%) exhibited masked hypertension, four (3.1%) white-coat hypertension and 46 (35.4%) hypertension. Significant differences were found between normotensive, masked hypertensive and hypertensive patients in terms of BRS (10.5 +/- 0.8, 8.0 +/- 0.6 and 7.4 +/- 0.4 ms/mmHg, respectively, P < 0.001), carotid IMT (624 +/- 17, 650 +/- 20 and 705 +/- 23 microm, respectively, P = 0.04) and left ventricular mass index (37 +/- 1, 40 +/- 2 and 43 +/- 1 g/height2.7, respectively, P = 0.003). A clinic systolic BP more than 125 and a diastolic BP more than 83 mmHg led to a relative risk (RR) of 2.7 and a 90% positive predictive value for having masked hypertension. CONCLUSION: Masked hypertension is frequently underestimated in OSAS and is nearly always present when clinic BP is above 125/83 mmHg.     

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.     

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.     

Nurse-recorded and ambulatory blood pressure predicts treatment-induced reduction of left ventricular hypertrophy equally well in hypertension: results from the Swedish irbesartan left ventricular hypertrophy investigation versus atenolol (SILVHIA) study

OBJECTIVE : To compare the relationships of treatment-induced reductions of left ventricular hypertrophy to the changes in clinic and ambulatory blood pressure (BP). DESIGN : Double-blind and randomized treatment with irbesartan or atenolol for 48 weeks. PATIENTS : Patients with hypertension and left ventricular hypertrophy (n = 66) with a seated diastolic BP 90-115 mmHg (average of three measurements one minute apart by nurses). MAIN OUTCOME MEASURES : Registrations of echocardiographic left ventricular (LV) mass. Clinic and ambulatory BP. RESULTS : In the total material, nurse-measured BP was reduced by 23 +/- 15/16 +/- 7.7 mmHg and 24-h ambulatory BP fell 20 +/- 15/14 +/- 8.5 mmHg by treatment. The correlation between the change in nurse-measured BP and LV mass index (LVMI) induced by treatment was r = 0.35, P = 0.004 for systolic BP and r = 0.26, P = 0.03 for diastolic BP. Corresponding values for 24-h ambulatory BP were r = 0.29, P = 0.02 and r = 0.35, P = 0.004, respectively, with similar correlations for day- and night-time ambulatory BP. The nurse-recorded BP was slightly higher than ambulatory BP (systolic clinic - systolic 24-h ambulatory BP = 5 mmHg). Using 130/80 mmHg as a cut-off value for normal 24-h ambulatory BP, eight subjects had normal diastolic or systolic ambulatory BP, or both. Interestingly, these patients also experienced LVMI regression following treatment (low/normal ABP, -13 +/- 21 g/m2; remaining patients, -18 +/- 22 g/m2, P > 0.5). CONCLUSIONS : In patients with hypertension and left ventricular hypertrophy, ambulatory BP is not superior to carefully standardized nurse-recorded seated BP in terms of associations with treatment-induced changes in LV mass.