The great myth of office blood pressure measurement

Clinical practice guidelines have traditionally recommended manual blood pressure (BP) measurement in the office setting as the standard method for diagnosing hypertension. In reality, manual BP in routine clinical practice is relatively inaccurate, over-diagnoses hypertension by provoking office-induced increases in BP and correlates poorly with both the awake ambulatory BP and target organ damage. The most recent guidelines recommend 24-h ambulatory BP and home BP for diagnosing hypertension. The advent of automated office BP (AOBP) represents a third alternative to conventional manual BP measurement, one that maintains the role of office BP readings in the diagnosis and management of hypertension. AOBP has three basic principles: multiple readings taken using a fully automated sphygmomanometer with the patient resting quietly alone. AOBP eliminates office-induced hypertension such that the cut-point for a normal AOBP is the same as for the awake ambulatory BP and home BP. As compared to routine manual office BP, AOBP provides more accurate BP readings, is more consistent during repeated office visits and in different settings and correlates better with both the awake ambulatory BP and target organ damage. The advantages of AOBP over manual BP measurement support its use in routine clinical practice.     

Automated office blood pressure

Manual blood pressure (BP) is gradually disappearing from clinical practice with the mercury sphygmomanometer now considered to be an environmental hazard. Manual BP is also subject to measurement error on the part of the physician/nurse and patient-related anxiety which can result in poor quality BP measurements and office-induced (white coat) hypertension. Automated office (AO) BP with devices such as the BpTRU (BpTRU Medical Devices, Coquitlam, BC) has already replaced conventional manual BP in many primary care practices in Canada and has also attracted interest in other countries where research studies using AOBP have been undertaken. The basic principles of AOBP include multiple readings taken with a fully automated recorder with the patient resting alone in a quiet room. When these principles are followed, office-induced hypertension is eliminated and AOBP exhibits a much stronger correlation with the awake ambulatory BP as compared with routine manual BP measurements. Unlike routine manual BP, AOBP correlates as well with left ventricular mass as does the awake ambulatory BP. AOBP also simplifies the definition of hypertension in that the cut point for a normal AOBP (< 135/85 mm Hg) is the same as for the awake ambulatory BP and home BP. This article summarizes the currently available evidence supporting the use of AOBP in routine clinical practice and proposes an algorithm in which AOBP replaces manual BP for the diagnosis and management of hypertension.     

Office blood pressure threshold of 130/80 mmHg better predicts uncontrolled out‐of‐office blood pressure in apparent treatment‐resistant hypertension

The objective of this study was to compare the diagnostic accuracy of office blood pressure (BP) threshold of 140/90 and 130/80 mmHg for correctly identifying uncontrolled out‐of‐office BP in apparent treatment‐resistant hypertension (aTRH). We analyzed 468 subjects from a prospectively enrolled cohort of patients with resistant hypertension in South Korea (clinicaltrials.gov: {"type":"clinical-trial","attrs":{"text":"NCT03540992","term_id":"NCT03540992"}}NCT03540992). Resistant hypertension was defined as office BP ≥ 130/80 mmHg with three different classes of antihypertensive medications including thiazide‐type/like diuretics, or treated hypertension with four or more different classes of antihypertensive medications. We conducted different types of BP measurements including office BP, automated office BP (AOBP), home BP, and ambulatory BP. We defined uncontrolled out‐of‐office BP as daytime BP ≥ 135/85 mmHg and/or home BP ≥ 135/85 mmHg. Among subjects with office BP < 140/90 mmHg and subjects with office BP < 130/80 mmHg, 66% and 55% had uncontrolled out‐of‐office BP, respectively. The prevalence of controlled and masked uncontrolled hypertension was lower, and the prevalence of white‐coat and sustained uncontrolled hypertension was higher, with a threshold of 130/80 mmHg than of 140/90 mmHg, for both office BP and AOBP. The office BP threshold of 130/80 mmHg was better able to diagnose uncontrolled out‐of‐office BP than 140/90 mmHg, and the net reclassification improvement (NRI) was 0.255. The AOBP threshold of 130/80 mmHg also revealed better diagnostic accuracy than 140/90 mmHg, with NRI of 0.543. The office BP threshold of 130/80 mmHg showed better than 140/90 mmHg in terms of the correspondence to out‐of‐office BP in subjects with aTRH.     

The optimal use of automated office blood pressure measurement in clinical practice

This evidence‐based article endorses the use of automated office blood pressure (AOBP). AOBP is the most favorable office blood pressure (BP) measuring technique as it provides accurate readings with 3‐15 mm Hg lower values than the casual conventional office measurements with auscultatory or semi‐automated oscillometric devices and relates closely to awake ABP readings. The AOBP technique seems to be superior to conventional office BP in predicting hypertension‐mediated organ damage and appears to be equally reliable to awake ABP in the prediction of cardiovascular (CV) disease. AOBP readings should be obtained either unattended, with the patient alone in the examination room, or attended with the presence of personnel in the room but with no talking to the patient, although this recommendation is not frequently followed in routine clinical practice. To optimize office BP readings, the type of device, the rest period before AOBP measurements (preceding rest), and the time intervals between measurements were evaluated. As AOBP readings have the advantage of removing many confounding factors, the authors propose to perform measurements with a preceding rest in all patients at the initial visit; if AOBP readings remain <130 mm Hg in subsequent visits, measurements could be accepted, otherwise, if are higher, patients should be evaluated by out‐of‐office BP measurements.     

Eliminating the Human Factor in Office Blood Pressure Measurement

Factors related to the physician/nurse and patient and their interaction are potential sources of error in manual office blood pressure (MOBP). The use of automated sphygmomanometers to record blood pressure (BP) with the patient alone reduces measurement error and minimizes anxiety‐related increases in BP, thus eliminating the “white‐coat” response. Comparative studies have shown the cut‐point for a normal automated office BP (AOBP), awake ambulatory BP, and home BP (<135/85 mmHg) to be similar, providing the patient does not rest for a prolonged period before the first AOBP reading, as recommended for MOBP measurement. AOBP should now replace MOBP in routine clinical practice.     

Automated office blood pressure measurements obtained with and without preceding rest are associated with awake ambulatory blood pressure

Automated office blood pressure (AOBP) measurement, attended or unattended, eliminates the white coat effect (WCE) showing a strong association with awake ambulatory blood pressure (ABP). This study examined the difference in AOBP readings, with and without 5 minutes of rest prior to three readings recorded at 1‐min intervals. Cross‐sectional data from 100 randomized selected hypertensives, 61 men and 39 women, with a mean age of 52.2 ± 10.8 years, 82% treated, were analyzed. The mean systolic AOBP values without preceding rest were 127.0 ± 18.2 mm Hg, and the mean systolic AOBP values with 5 minutes of preceding rest were 125.7 ± 17.9 mm Hg (P = .05). A significant order effect was observed for the mean systolic BP values when AOBP without 5 minutes of preceding rest was performed as the first measurement (130.0 ± 17.7 vs 126.5 ± 16.2, P = .008). When we used a target systolic AOBP ≥ 130 mm Hg, awake ABP yielded lower readings, while at a target systolic AOBP value of < 130 mm Hg higher awake ABP values were obtained. Our findings indicate that systolic AOBP can be initially checked without any preceding rest and if readings are normal can be accepted. Otherwise, when AOBP is ≥ 130 mm Hg, measurements should be rechecked with 5 minutes of rest.     

The conventional versus automated measurement of blood pressure in the office (CAMBO) trial: masked hypertension sub-study

OBJECTIVES:: To determine the prevalence of masked hypertension [normal office blood pressure (BP) with high awake ambulatory BP] using automated office BP (AOBP) or conventional manual office BP (MOBP) measurement in routine clinical practice. METHODS:: The prevalence of masked hypertension was evaluated on three consecutive visits during a median 6 months period in patients with systolic hypertension randomized to management with AOBP (n?=?140) or continued conventional MOBP (n?=?112) in routine primary care practice. AOBP was recorded using the automated BpTRU device with the patient resting alone in a quiet examining room. All patients underwent 24-h ambulatory BP monitoring. RESULTS:: The prevalence of masked hypertension on any one of three visits calculated using only SBP varied between 12 and 17% in the AOBP group compared with 19 and 22 % in the MOBP group. Masked hypertension was present on both of the first two visits in 7 and 12% and on all three visits in 6 and 7% of AOBP and MOBP patients, respectively. The prevalence for masked hypertension based upon both SBP and DBP was similar being 11-15% for AOBP and 19-20% for MOBP patients on single visits, but decreased to 6 and 10% when readings from the first two visits were used and to 4 and 6% when all three visits were used for the AOBP and MOBP groups, respectively. CONCLUSION:: The prevalence of masked hypertension is lower with AOBP compared with MOBP. The number of patients with masked hypertension decreases if the criteria for having this condition need to be met on multiple visits.     

Diagnostic thresholds for ambulatory blood pressure monitoring based on 10-year cardiovascular risk

Current diagnostic thresholds for ambulatory blood pressure (ABP) mainly rely on statistical parameters derived from reference populations. We determined an outcome-driven reference frame for ABP measurement. We performed 24-h ABP monitoring in 5682 participants (mean age 59.0 years; 43.3% women) enrolled in prospective population studies in Copenhagen, Denmark; Noorderkempen, Belgium; Ohasama, Japan; and Uppsala, Sweden. In multivariate analyses, we determined ABP thresholds, which yielded 10-year cardiovascular risks similar to those associated with optimal (120/80 mmHg), normal (130/85 mmHg), and high (140/90 mmHg) blood pressure on office measurement. Over 9.7 years (median), 814 cardiovascular end points occurred, including 377 strokes and 435 cardiac events. Systolic/diastolic thresholds for optimal ABP were 118.3/74.2 mmHg for 24 h, 121.6/78.9 mmHg for daytime, and 104.7/65.3 mmHg for nighttime. Corresponding thresholds for normal ABP were 124.3/76.8, 129.9/82.6, and 111.6/68.1 mmHg, respectively, and those for ambulatory hypertension were 130.3/79.4, 138.2/86.4, and 118.5/70.8 mmHg. After rounding, approximate thresholds for optimal ABP amounted to 115/75 mmHg for 24 h, 120/80 mmHg for daytime, and 105/65 mmHg for nighttime. Rounded thresholds for normal ABP were 125/75, 130/85, and 110/70 mmHg, respectively, and those for ambulatory hypertension were 130/80, 140/85, and 120/70 mmHg. In conclusion, population-based outcome-driven thresholds for optimal and normal ABP are lower than those currently proposed by hypertension guidelines.     

Office and ambulatory blood pressure control in hypertensive patients treated with different two-drug and three-drug combinations

There is scarce information regarding ambulatory blood pressure (BP) achieved in daily practice with a wide range of antihypertensive drug combinations. We looked for differences in office and ambulatory BP among major drug combinations of two and three antihypertensive agents from a different drugs class. A total of 17187 patients treated with six types of two-drug combinations and 9724 treated with six types of three-drug combinations from the Spanish ABPM Registry were analyzed. We compared achieved office and ambulatory BP, as well as office (< 140/90 mmHg) and ambulatory (24-hour BP < 130/80; day BP < 135/85, and night BP < 120/70 mmHg) BP control among groups. The combination of renin-angiotensin system (RAS) blockers with diuretics and the triple combination of RAS blockers with diuretics and calcium channel blockers (CCB) were associated with lower values of 24-hour, daytime and nighttime BP, as well as more pronounced nocturnal BP dip. Compared with such combinations (reference), other double combinations had lower rates of ambulatory BP control. Moreover, triple combinations containing alpha blockers also had lower rates of ambulatory BP control. We conclude that even with similar office BP control, differences exist among antihypertensive two-drug and three-drug combinations with respect to ambulatory BP control achieved during treatment, with RAS blockers/diuretics and RAS blockers/CCBs/diuretics obtaining better control rates. This can help physicians choose among drug combinations in order to obtain further ambulatory BP reductions.     

Comparison between unattended automated office blood pressure and conventional office blood pressure under the environment of health checkup among Japanese general population

Unattended automated office blood pressure (AOBP) measurement has been endorsed as the preferred in‐office measurement modality in recent Canadian and American clinical practice guidelines. However, the difference between AOBP and conventional office blood pressure (CBP) under the environment of a health checkup remains unclear. We aimed to identify the clinical significance of AOBP as compared to CBP under the environment of a health checkup. There were 491 participants (333 females, mean age of 62.5 years) who were at least 20 years old, including 179 participants who were previously diagnosed with hypertension. Mean AOBPs were 131.8 ± 20.9/76.6 ± 11.7 mm Hg, and CBPs were 135.6 ± 21.6/77.3 ± 11.5 mm Hg. There was a difference of 3.9 mm Hg in systolic blood pressure (SBP) and 0.8 mm Hg in diastolic BP between AOBP and CBP. In all participants, SBP and pulse pressure, as well as the white coat effect (WCE), increased with age. The cutoff value used was 140/90 mm Hg for CBP and 135/85 mm Hg for AOBP, and the prevalence of WCE and masked hypertension effect (MHE) was 12.4% and 14.1%, respectively. Even in a health checkup environment of the general population, there was a difference between the AOBP and CBP, and the WCE was observed more strongly in the elderly with a history of hypertension, suggesting that a combination of AOBP with CBP may be useful in detecting WCE and MHE in all clinical scenarios including health checkups, and help solve the “hypertension paradox” not only in Japan but in all over the world.     

Home blood pressure is as reliable as ambulatory blood pressure in predicting target-organ damage in hypertension

BACKGROUND: Our objective was to assess the value of home blood pressure (BP) monitoring in comparison to office BP measurements and ambulatory monitoring in predicting hypertension-induced target-organ damage. METHODS: Sixty-eight untreated patients with hypertension with at least two routine prestudy office visits were included (mean age, 48.6 +/- 9.1 [SD] years; 50 men). Office BP was measured in two study visits, home BP was measured for 6 workdays, and ambulatory BP was monitored for 24 h. All BP measurements were obtained using validated electronic devices. Target-organ damage was assessed by measuring the echocardiographic left-ventricular mass index (LVMI), urinary albumin excretion rate (AER) in two overnight urine collections, and carotid-femoral pulse-wave velocity (PWV) (Complior device; Colson, Garges-les-Gonesse, Paris, France). RESULTS: The correlation coefficients of LVMI with office BP were 0.24/0.15 (systolic/diastolic), with home BP 0.35/0.21 (systolic, P < .01), and with 24-h ambulatory BP 0.23/0.19, awake 0.21/0.16, and asleep 0.28/0.26 (asleep, both P < .05). The correlation coefficients of AER with office BP were 0.24/0.31 (diastolic, P < .05), with home BP 0.28/0.26 (both P < .05), and with 24-h ambulatory BP 0.25/0.24, awake 0.24/0.25 (diastolic, P < .05), and asleep 0.26/0.18 (systolic, P < .05). There was a trend for negative correlations between PWV and diastolic BP measurements (not significant). In multiple-regression models assessing independent predictors of each of the three indices of target-organ damage, systolic home BP and age were the only independent predictors of increased LVMI that reached borderline statistical significance. CONCLUSIONS: These data suggest that home BP is as reliable as ambulatory monitoring in predicting hypertension-induced target-organ damage, and is superior to carefully taken office measurements.     

Ambulatory blood pressure monitoring and risk of cardiovascular disease: a population based study

BACKGROUND: Information on the relationship between ambulatory blood pressure (BP) and cardiovascular disease in the general population is sparse. METHODS: Prospective study of a random sample of 1700 Danish men and women, aged 41 to 72 years, without major cardiovascular diseases. At baseline, ambulatory BP, office BP, and other risk factors were recorded. The end point was a combined end point consisting of cardiovascular mortality, ischemic heart disease, and stroke. RESULTS: After a mean follow-up of 9.5 years, 156 end points were recorded. In multivariate models, the relative risk (95% confidence interval) associated with increments of 10/5 mmHg of systolic/diastolic ambulatory BP were 1.35 (1.21-1.50) and 1.27 (1.16-1.39). The corresponding figures for office BP were 1.18 (1.09-1.29) and 1.11 (1.03-1.19). Compared with normotension (office BP <140/90 mm Hg; daytime BP <135/85 mm Hg) the relative risks associated with isolated office hypertension (office BP >/=140/90 mm Hg; daytime BP <135/85 mm Hg), isolated ambulatory hypertension (office BP <140/90 mm Hg; daytime BP >/=135/85 mm Hg), and sustained hypertension (office BP >/=140/90 mm Hg; daytime BP >/=135/85 mm Hg) were 0.66 (0.30-1.44), 1.52 (0.91-2.54), and 2.10 (1.45-3.06), respectively. A blunted BP decrease at night was a risk factor (P = .02) in subjects with daytime ambulatory hypertension, but not in subjects with daytime ambulatory normotension (P = .13). CONCLUSIONS: Ambulatory BP provided prognostic information about cardiovascular disease better than office BP. Isolated office hypertension was not a risk factor and isolated ambulatory hypertension tended to be associated with increased risk. A blunted BP decrease at night was a risk factor in subjects with daytime ambulatory hypertension.     

Clinical significance of nocturnal home blood pressure monitoring and nocturnal hypertension in Asia

Nocturnal home blood pressure (BP) monitoring has been used in clinical practice for ~20 years. The authors recently showed that nocturnal systolic BP (SBP) measured by a home BP monitoring (HBPM) device in a Japanese general practice population was a significant predictor of incident cardiovascular disease (CVD) events, independent of office and morning home SBP levels, and that masked nocturnal hypertension obtained by HBPM (defined as nocturnal home BP ≥ 120/70 mmHg and average morning and evening BP < 135/85 mmHg) was associated with an increased risk of CVD events compared with controlled BP (nocturnal home BP < 120/70 mmHg and average morning and evening BP < 135/85 mmHg). This evidence revealed that (a) it is feasible to use a nocturnal HBPM device for monitoring nocturnal BP levels, and (b) such a device may offer an alternative to ambulatory BP monitoring, which has been the gold standard for the measurement of nocturnal BP. However, many unresolved clinical problems remain, such as the measurement schedule and conditions for the use of nocturnal HBPM. Further investigation of the measurement of nocturnal BP using an HBPM device and assessments of the prognostic value are thus warranted. Asians are at high risk of developing nocturnal hypertension due to high salt sensitivity and salt intake, and the precise management of their nocturnal BP levels is important. Information and communication technology‐based monitoring devices are expected to facilitate the management of nocturnal hypertension in Asian populations.     

Unattended automated office blood pressure measurement: Time efficiency and barriers to implementation/utilization

Unattended automated office blood pressure (BP) measurement (u‐AOBP) improves office BP measurement accuracy and reduces white‐coat BP elevation, but there are reservations about its time efficiency in primary care. We used time‐stamp methodology to measure u‐AOBP procedure times performed without a rest period in 130 patients during routine clinic visits to three primary care clinics with 2.5‐4.9 years u‐AOBP experience. We documented the clinical activities of 30 medical assistants during the u‐AOBP procedures. We also assessed MA and clinician satisfaction and knowledge about u‐AOBP performance and interpretation. Median u‐AOBP procedure time was <5 minutes, and MAs engaged in productive clinical activities during 83% of the procedures. Ninety‐three percent of MAs and 100% of clinicians in the clinics agreed that u‐AOBP is an efficient method to improve hypertension management. Barriers to effective u‐AOBP implementation and ongoing utilization included initial difficulty incorporating u‐AOBP into clinic workflow and medical staff knowledge deficiencies concerning correct u‐AOBP performance and interpretation despite prior training and experience with the procedure. Intensive u‐AOBP education and training programs are needed to facilitate effective u‐AOBP implementation into primary care. The time required to perform u‐AOBP can be utilized productively by staff.     

Normal ambulatory blood pressure: a clinical practice-based comparison of two recently published definitions

The European Society of Hypertension (ESH) has issued guidelines for the detection and treatment of hypertension. According to these guidelines, normal 24-h ambulatory blood pressure (ABP) is defined as lower than 125/80 mmHg. Another publication of ESH recommendations for blood pressure (BP) measurement defines normal awake and asleep blood pressure as lower than 135/85 and 120/70 mmHg, respectively. Our aim was to investigate the compatibility of these two recently proposed ABP cutoffs in clinical practice. We analysed 1495 consecutive ABP measurements. In all, 56% of the subjects were female; age 58 +/- 16 years; body mass index 27 +/- 4 kg/m(2); clinic BP 151+/-22/84 +/- 13 mmHg. Two-thirds were treated for hypertension, and 11% for diabetes. Subjects were classified as having normal 24-h BP if the corresponding value was <125/80 mmHg. Normal awake-sleep BP was diagnosed if awake BP was <135/85 mmHg and sleep BP was <120/70 mmHg. Concordance between the cutoffs was found in 93% of the subjects. Among the 7% discordant subjects, 4.5% were hypertensive applying the 24 h, but not awake-sleep, BP values, whereas only 2.5% were hypertensive according to awake-sleep, but not 24 h, BP values (P < 0.005). In Conclusion, in real-life ABP measurement, a good agreement was found between two recently issued ABP normality definitions. However, some subjects are classified as hypertensive only according to one of these methods, more often by the 24-h cutoff of 125/80. This discordance may be significant in large-scale clinical BP monitoring.     

Automated office blood pressure is in agreement with awake and mean 24‐hour ambulatory blood pressure at the lower blood pressure range

Automated office blood pressure measurement eliminates the white coat effect and is associated with awake ambulatory blood pressure. This study examined whether automated office blood pressure values at lower limits were comparable to those of awake and mean 24‐hour ambulatory blood pressure. A total of 552 patients were included in the study, involving 293 (53.1%) men and 259 (46.9%) women, with a mean age 55.0 ± 12.5, of whom 36% were treated for hypertension. Both systolic and diastolic automated office blood pressures exhibited lower values compared to awake ambulatory blood pressure among 254 individuals with systolic automated office blood pressure <130 mm Hg (119 ± 8 mm Hg vs 125 ± 11 mm Hg, P < .0001 and 75 ± 9 mm Hg vs 79 ± 9 mm Hg, P < .0001 for systolic and diastolic BPs, respectively). Furthermore, the comparison of systolic automated office blood pressure to the mean 24‐hour ambulatory blood pressure levels also showed lower values (119 ± 8 vs 121 ± 10, P = .007), whereas the diastolic automated office blood pressure measurements were similar to 24‐hour ambulatory blood pressure values. Our findings show that when automated office blood pressure readings express values <130/80 mm Hg in repeated office visits, further investigation should be performed only when masked hypertension is suspected; otherwise, higher automated office blood pressure values could be used for the diagnosis of uncontrolled hypertension, especially in individuals with organ damage.     

Twenty-four hour ambulatory blood pressure in a population of elderly men

OBJECTIVES: The principal aim was to study ambulatory and office blood pressure in a population of elderly men. We also wanted to describe the prevalence of hypertension and investigate the blood pressure control in treated elderly hypertensives. DESIGN: A cross-sectional study of a population of elderly men, conducted between 1991 and 1995. SUBJECTS: Seventy-year-old men (n = 1060), participants of a cohort study that began in 1970. MAIN OUTCOME MEASURES: Office and 24 h ambulatory blood pressure. RESULTS: Average 24 h blood pressure in the population was 133 +/- 16/75 +/- 8 mmHg, and daytime blood pressure 140 +/- 16/80 +/- 9 mmHg. Corresponding values in untreated subjects (n = 685) were 131 +/- 16/74 +/- 7 and 139 +/- 16/79 +/- 8, respectively. An office recording of 140/90 mmHg corresponded to an ambulatory pressure of 130/78 (24 h) and 137/83 mmHg (daytime) in untreated subjects. In subjects identified as normotensives according to office blood pressure (n = 270), the 95th percentiles of average 24 h and daytime blood pressures were 142/80 and 153/85 mmHg, respectively. The prevalence of hypertension, defined as office blood pressure greater than or = 140/90 mmHg, was 66%. Despite treatment, treated hypertensives (n = 285) showed higher office (157/89 vs. 127/76 mmHg) and 24 h ambulatory (138/78 vs. 122/71 mmHg) pressures than normotensives (P < 0.05). Fourteen per cent of the treated hypertensives had an office blood pressure < 140/90 mmHg. CONCLUSIONS: Our results provide a basis for 24 h ambulatory blood pressure reference values in elderly men. The study confirms previous findings of a high prevalence of hypertension at older age. It also indicates that blood pressure is inadequately controlled in elderly treated hypertensives.     

Ambulatory monitoring predicts development of drug-treated hypertension in subjects with high normal blood pressure

BACKGROUND: High normal blood pressure (HNBP), i.e. blood pressure (BP) > or = 130/85 mmHg and <140/90 mmHg, is an important predictor of progression to established hypertension. DESIGN: The purpose of this retrospective study was the evaluation of the predictive value of ambulatory blood pressure monitoring (ABPM) for the development of drug-treated hypertension in subjects with HNBP and other risk factors. METHODS: We studied 127 subjects (69 M, 58 F, age 50 +/- 14 years): 59 subjects had normal BP (NBP: < 130/85 mmHg), 68 subjects had systolic and/or diastolic HNBP. All the subjects underwent ABPM. There were 21/68 (30.9%) subjects in the HNBP group vs. 1/59 (1.7%) in the NBP group with an elevated (>135/85 mmHg) daytime ambulatory blood pressure (ABP) (p < 0.01). RESULTS: After an average follow-up of 103 +/- 28 months, 27 subjects (39.7%) in the HNBP group and 4 subjects (6.8%) in the NBP group developed drug-treated hypertension (p < 0.01). An elevated daytime ABP correctly predicted development of drug-treated hypertension in 17/21 subjects (81%) of the HNBP group and in the only subject of the NBP group. Development of drug-treated hypertension was associated with higher office and ambulatory BP (p < 0.01) and pulse pressures (p < 0.05), longer follow-up (p < 0.05) and higher prevalence of hypercholesterolaemia and smoking (p < 0.01). CONCLUSIONS: We conclude that ABPM correctly predicts development of drug-treated hypertension in most subjects who were identified early as having a daytime mean ABP >135/85 mmHg. ABPM appears to be a useful clinical tool in the early diagnosis of hypertension in subjects with metabolic risk factors and smoking.     

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.     

Ambulatory blood pressure monitoring in clinical practice

Ambulatory blood pressure (ABP) monitoring has become increasingly more available in routine clinical practice in Canada. The ABP is more reliable and more reproducible than office readings, and is a better predictor of target organ damage. Normal values for ABP have been established using both cross-sectional and longitudinal outcome data. Abnormal mean 24 h and awake ABP values should exceed 135/85 mmHg and 140/90 mmHg, respectively. ABP recordings are useful in making a diagnosis of hypertension by identifying people with high office but normal ABP values. ABP monitoring can also be performed in patients already receiving antihypertensive therapy to determine the extent of any white coat effect that may be increasing office readings. The interpretation of the ABP should take into account cardiac risk factors, any target organ damage that may be present or coexisting conditions such as diabetes mellitus.