BpTRU Device Research Articles

Comparative accuracies of automated and manual office blood pressure measurements in a Chinese population.

We aimed to assess the difference in the accuracy of readings from automated office blood pressure machines with each other or with manual office blood pressure measurements in Chinese individuals. We collected awake 48-h ambulatory blood pressure monitoring, two automated office blood pressure device (BpTRU and WatchBP) readings, and manual office blood pressure measurements in Chinese patients (n = 135) with hypertension in a randomized sequence. Differences were compared using paired t-tests and Bland-Altman plots. The sensitivity and specificity of the techniques for detecting elevated blood pressure were calculated using awake ambulatory blood pressure monitoring as the reference standard. The WatchBP device's and awake ambulatory blood pressure readings were similar. The BpTRU device provided significantly lower mean systolic (P < 0.001) and diastolic (P < 0.001) blood pressure readings, while manual office BP provided significantly higher mean systolic (P = 0.008) and diastolic (P < 0.001) blood pressure readings than the awake automated office blood pressure readings. Automated and manual office blood pressure measurements showed similar sensitivity, specificity, and 95% limits of agreement as based on Bland-Altman plots. The mean systolic (P < 0.001) and diastolic (P < 0.02) blood pressure readings of WatchBP and BpTRU differed, and their diagnostic performances were not superior than those of manual office blood pressure measurements in Chinese patients. Therefore, automated office blood pressure measurements cannot be routinely recommended for Chinese individuals in clinical practice. More studies are needed to confirm these results.

Unattended automated office blood pressure measurement in children

Purpose We studied the performance of unattended automated office blood pressure (uAOBP) measurement in children, in relation to oscillometric office BP (OBP) and ambulatory blood pressure monitoring (ABPM). Materials and Methods One hundred and eleven stable treated and untreated outpatients investigated for hypertension underwent uAOBP measurements (seated unattended in a quiet room separate from the renal clinic room, six times after a 5 min rest with the BpTRU device), and immediately before using the oscillometric device. Ambulatory 24 h blood pressure monitoring (ABPM) was performed on the same day in a subgroup of 42 children. Results UAOBP measurements were successful in 106 children (95%), 5 pre-school children did not tolerate to be alone in the room. The mean ± SD systolic/diastolic uAOBP, OBP and daytime ABP were 109.1 ± 14.0/70.8 ± 10.7 mmHg, 121.6 ± 16.5/77.6 ± 10.5 mmHg and 123.5 ± 11.3/73.7 ± 6.8 mmHg, respectively. Systolic/diastolic uAOBP was significantly lower than OBP by 13.6/7.6 mmHg (p < 0.0001) and lower than daytime ABP by 14.4 ± 0.5/2.9 ± 0.3 mmHg (p < 0.0001). The heart rate was not significantly different during uAOBP than during OBP measurements. On Bland Altman analysis the uAOBP underestimated OBP by a mean of 15.6 mmHg for systolic BP and by 8.6 mmHg for diastolic BP. In all 9 children with white-coat systolic hypertension uAOBP was within the normal range (<95th pc for OBP), in six of nine children with white-coat diastolic hypertension uAOBP was within the normal range however, in three of them it was elevated despite normal ABP. Conclusion uAOBP measurement is feasible in school-aged children, its values are considerably lower than OBP as well as daytime ABP and it could help with detection of white-coat systolic hypertension. The clinical applicability of uAOBP in children should be confirmed in further studies.

ADHERENCE DECREASES WITH HIGHER NUMBER OF MEDICATIONS IN CONTROLLED HYPERTENSIVE PATIENTS, CONTROLLED RESISTANT PATIENTS HAVE LOWER ADHERENCE THAN CONTROLLED NON-RESISTANT PATIENTS

Objective: Controlled hypertension in treated hypertensive patients is defined as controlled blood pressure (BP) in clinic (automated office BP [AOBP] &lt; 130/80 mmHg) and out-of-clinic by 24-hr ambulatory blood pressure monitoring (ABPM &lt; 125/75 mmHg). Uncontrolled resistant hypertension (RHTN) is defined as uncontrolled blood pressure (BP) on 3 or more medications, including a diuretic; BP controlled on 4 or more medications is defined as controlled RHTN. Controlled non-RHTN is BP controlled on 3 or less medications. Antihypertensive medication adherence is known to decrease with increase in number of antihypertensive medications, as well as medication adherence is lower in patients with uncontrolled RHTN. Unknown is the relative medication adherence in patients with controlled hypertension with number of antihypertensive medications and medication adherence in controlled RHTN versus controlled non-RHTN. Design and method: In this prospective evaluation patients were recruited from the Hypertension Clinic after having controlled BP readings at 3 or more clinic visits. All the patients were evaluated by in-clinic AOBP with use of the BpTRU device, out-of-clinic 24-hr ABPM monitoring and 24-hr urine collection to determine antihypertensive medication adherence by high-performance liquid chromatography-tandem mass spectrometry. After excluding patients with masked uncontrolled hypertension, 82 patients were controlled by AOBP and 24-hr ABPM. Of these, 40 patients had controlled RHTN and 42 patients had controlled non-RHTN. Results: Higher number of prescribed antihypertensive medications was associated with lower levels of medication adherence in patients with controlled hypertension. In addition, patients with controlled RHTN (72.7%) had significantly lower medication adherence than controlled non-RHTN (90.9%). Conclusions: Similar to uncontrolled hypertension, patients with controlled hypertension have less medication adherence with use of higher numbers of antihypertensive medications. In addition, similar to uncontrolled RHTN, patients with controlled RHTN have lower medication adherence than patients with controlled non-RHTN.

Social connections and hypertension in women and men: a population-based cross-sectional study of the Canadian Longitudinal Study on Aging.

Associations between social ties and hypertension are poorly understood in women and men. We investigated the association between marital status, living arrangement, social network size and social participation and hypertension by sex/gender. Cross-sectional analysis of 28 238 middle-age and old-age adults (45-85 years) was conducted using the baseline Canadian Longitudinal Study on Aging Comprehensive cohort data. Blood pressure (BP) was measured using the automated BpTRU device and hypertension was defined as BP more than 140/90 mmHg, or more than 130/80 mmHg in participants with diabetes, self-reported history or receiving antihypertensive therapy. Being nonpartnered, having limited social participation (≤2 social activities per month) or a small social network size was associated with higher odds of having hypertension in women. Odds of hypertension were higher among widowed women [odds ratio 1.33 (95% confidence interval (CI): 1.16, 1.51)] compared with married women. The largest difference in adjusted mean SBP in women was between widowed [3.06 mmHg (95% CI: 2.01, 4.11)], vs. married women. For men, lone-living (vs. coliving) was linked to a lower odds of hypertension [odds ratio 0.85 (95% CI: 0.75, 0.96)] When considering two social ties simultaneously, the adverse associations between nonpartnership (mainly for singles and divorced) and BP were mitigated with increased social participation, especially among women. Social ties appear to be more strongly associated with hypertension in middle and older aged women than men. Women who are nonpartnered or who engage in few social activities and men who are coliving represent at risk groups for having hypertension. Healthcare professionals may need to consider these social factors in addressing risk for hypertension and cardiovascular disease prevention.

LONG-TERM RELATIONSHIP BETWEEN UNATTENDED AUTOMATED BLOOD PRESSURE AND AUSCULTATORY BP MEASUREMENTS IN HYPERTENSIVE PATIENTS

Aims: Unattended automated office blood pressure (uAutoOBP) has attracted more attention since SPRINT trial had been published. However, its long-term relationship to attended office blood pressure (AuscOBP) is not known. Material and methods: Stable treated hypertensive subjects were examined in four Czech academic hypertension centers. All subjects attended four clinical visits three months apart. uAutoOBP was measured with the BP Tru device; AuscOBP was measured three times with auscultatory method by the physician. 24-hour ambulatory blood pressure monitoring (ABPM) was performed within one week from the second clinical visit. Results: Data on 112 subjects aged 65.6 +/- 10.8 years with mean AuscOBP 128.2 +/- 12.2/78.5 +/- 10.3 mm Hg are reported. Across the four clinical visits, the uAutoOBP was by 10.1/3.7 mm Hg lower than AuscOBP and the mean difference was similar during all four visits (P >=.061). Both uAutoOBP and AuscOBP had similar intra-individual variability during study follow-up as demonstrated by similar intraclass correlation coefficients (ICC, for systolic ICC = 0.50, for diastolic ICC = 0.72). However, the intra-individual variability of the systolic AuscOBP and uAutoOBP difference was high as demonstrated by low ICCs for absolute (ICC = 0.17 [95%CI, 0.09 - 0.25]) and low kappa coefficients for categorized differences (kappa <= 0.16). The main determinant of AuscOBP-uAutoOBP difference was AuscOBP level. The AuscOBP-uAutoOBP difference was poor tool to identify hypertension control categories defined on the basis of AuscOBP and ABPM. Conclusions: Although mean AuscOBP-uAutoOBP differences were relatively similar across the four clinical visits, intra-individual variability of this difference was high. The AuscOBP-uAutoOBP difference was poor tool to identify hypertension control categories defined on the basis of AuscOBP and ABPM. Therefore, uAutoOBP cannot be used as a replacement for ABPM.

HIGH PREVALENCE OF INFLAMMATORY DISORDERS IN PATIENTS WITH REFRACTORY HYPERTENSION

Objective: Refractory hypertension (RfHTN) is a phenotype of antihypertensive treatment failure defined as uncontrolled BP (> = 135/85 mmHg) despite the use of five or more different antihypertensive agents, including a long-acting thiazide-like diuretic (chlorthalidone) and a mineralocorticoid receptor antagonist (spironolactone or eplerenone). Experimental and clinical studies link the development of hypertension to inflammation and various inflammatory disorders play an important role in development of hypertension. The prevalence of inflammatory disorders such as systemic lupus erythematosus (SLE) and sarcoidosis in patients with RfHTN has not been previously determined. Design and method: In this prospective evaluation, 40 patients with confirmed RfHTN were recruited from the Hypertension Clinic after having uncontrolled BP at three or more clinic visits. All patients were evaluated by automated office BP (AOBP) with the BpTRU device, ambulatory BP monitoring (ABPM), and by 24-hr urine collection to detect antihypertensive medication adherence by high-performance liquid chromatography-tandem mass spectrometry. Out of 36 patients who underwent ABPM monitoring, 32 patients had RfHTN as confirmed by AOBP and by ABPM. Of these, 9 patients were fully adherent on medications. Twenty-five patients with controlled resistant hypertension (RHTN) by AOBP, ABPM with total medication adherence served as the comparative group. Results: 56% of patients with RfHTN had sarcoidosis and/or SLE. In comparison, the prevalence of the two disorders in patients with controlled RHTN was only 16% (p = 0.034). In addition, C-reactive protein was significantly higher in rfhtn compared to controlled RHTN (19.8 ± 3.2 vs 3.2 ± 1.2 mg/L; p = 0.042). Conclusions: Patients with confirmed RfHTN have a higher prevalence sarcoidosis and/or SLE compared to non-refractory controls, suggesting a possible role autoimmune or inflammatory disorders in the development of RfHTN.

MASKED UNCONTROLLED HYPERTENSION IN TREATED HYPERTENSIVE PATIENTS IS NOT RELATED TO ANXIETY COMPARED TO TRUE CONTROLLED HYPERTENSION

Objective: Masked uncontrolled hypertension in treated hypertensive patients (MUCH) is defined as controlled blood pressure (BP) in clinic (Automated office BP [AOBP] < 135/85 mmHg) but uncontrolled BP out-of-clinic as measured by 24-hr ambulatory blood pressure monitoring (ABPM, daytime readings >= 135/85 mmHg). In- and out-of-clinic anxiety levels in patients with MUCH compared to patients with true controlled hypertension have not been previously compared. Design and method: In this prospective evaluation, 181 patients with controlled hypertension were recruited from the Hypertension Clinic. The patients were recruited after having controlled BP readings at 3 or more clinic visits. All the patients were evaluated by in-clinic AOBP with use of the BpTRU device, out-of-clinic ABPM, 24-hr urine collection to detect antihypertensive medication adherence by high-performance liquid chromatography-tandem mass spectrometry and state-trait anxiety inventory (STAI) to index self-reported anxiety both in- and out-of-clinic. Eighty patients had controlled hypertension in clinic and by daytime ABPM, indicating true controlled hypertension. The remaining 85 patients were controlled in clinic but uncontrolled by daytime ABPM, consistent with MUCH. Of these, 48 true controlled and 55 MUCH patients were fully adherent with prescribed antihypertensive medications. Results: Anxiety state levels were similar in patients with true controlled hypertension and MUCH both in-clinic (33.2 ± 11.6 vs 30.9 ± 11.8, p = 0.454) and out-of-clinic (32.4 ± 10.8 vs 32.2 ± 11.2, p = 0.943). In addition, anxiety trait levels were also similar in patients with true controlled hypertension and MUCH in-clinic (34.4 ± 12.2 vs 31.6 ± 10.7, p = 0.376) and out-of-clinic (33.6 ± 10.7 vs 33.7 ± 11.2, p = 0.972). Conclusions: Assessment of state and trait demonstrates a similar anxiety levels in both MUCH and true controlled hypertensive patients’ in- and out-of-clinic. This lack of difference in self-reported anxiety levels suggest that MUCH is not attributable to greater levels of anxiety.

Long-term relationship between unattended automated blood pressure and auscultatory BP measurements in hypertensive patients

Aims: Unattended automated office blood pressure (uAutoOBP) has attracted more attention since SPRINT trial had been published. However, its long-term relationship to attended office blood pressure (AuscOBP) is not known.Material and methods: Stable treated hypertensive subjects were examined in four Czech academic hypertension centers. All subjects attended four clinical visits three months apart. uAutoOBP was measured with the BP Tru device; AuscOBP was measured three times with auscultatory method by the physician. 24-hour ambulatory blood pressure monitoring (ABPM) was performed within one week from the second clinical visit.Results: Data on 112 subjects aged 65.6 ± 10.8 years with mean AuscOBP 128.2 ± 12.2/78.5 ± 10.3 mm Hg are reported. Across the four clinical visits, the uAutoOBP was by 10.1/3.7 mm Hg lower than AuscOBP and the mean difference was similar during all four visits (P≥.061). Both uAutoOBP and AuscOBP had similar intra-individual variability during study follow-up as demonstrated by similar intraclass correlation coefficients (ICC, for systolic ICC = 0.50, for diastolic ICC = 0.72). However, the intra-individual variability of the systolic AuscOBP and uAutoOBP difference was high as demonstrated by low ICCs for absolute (ICC = 0.17 [95%CI, 0.09 – 0.25]) and low κ coefficients for categorized differences (κ ≤ 0.16). The main determinant of AuscOBP-uAutoOBP difference was AuscOBP level. The AuscOBP-uAutoOBP difference was poor tool to identify hypertension control categories defined on the basis of AuscOBP and ABPM.Conclusions: Although mean AuscOBP-uAutoOBP differences were relatively similar across the four clinical visits, intra-individual variability of this difference was high. The AuscOBP-uAutoOBP difference was poor tool to identify hypertension control categories defined on the basis of AuscOBP and ABPM. Therefore, uAutoOBP cannot be used as a replacement for ABPM.

A16939 Reliability of Triage Blood Pressure in the Emergency Department for Determination of Uncontrolled Hypertension

Objectives: In November 2017, the American Heart Association (AHA) revised their hypertension (HTN) guidelines, decreasing the criteria for diagnosis and target for blood pressure (BP) control to 130/80 mmHg. This change has markedly increased the number of Americans who are affected by HTN and the proportion whose BP will be considered uncontrolled. There is increasing emphasis in emergency departments (EDs) on improving management of chronic diseases such as HTN making the reliability of BP measurement important. The objective of this study was to evaluate the reliability of ED BP measurement for determining uncontrolled HTN based on the new guideline (NG), using repeat measurement in the ED via BpTRU as the gold standard. Methods: Data were collected as part of an on-going, prospective HTN registry for 338 participants who visited one of our three urban EDs and were identified as having a previous diagnosis of HTN. In addition to demographic data, triage BP was recorded along with a repeat BP using the BpTRU device. Descriptive analysis was performed using SAS version 9.4 and Tableau version 10.4. Results: Of the 338 participants (mean age 45 years [13.4], 37 % male, 95 % African American; mean BP at triage = 163/98 mm Hg; mean BP by BpTru = 151/96 mm Hg), 295 (87.3%) were considered uncontrolled using triage BP by OG compared to 313 (92.6%) under NG. Measurements collected using BpTRU showed that 219 (64.8%) were uncontrolled by OG, while 263 (77.8%) were uncontrolled using NG criteria. Conclusion: Based on NG criteria, more ED patients were found to have uncontrolled BP. However, use of BpTRU reduced the proportion with a BP above established criteria, suggesting that this approach to evaluation of patients with HTN may be beneficial in the effort to address the burden of chronic disease management.

Abstract P234: Obstructive Sleep Apnea is More Common in Patients With Masked Uncontrolled Hypertension

Introduction: Masked uncontrolled hypertension (MUCH) is defined as controlled automated office blood pressure (AOBP) in clinic, but uncontrolled out-of-clinic BP by 24-hr ambulatory blood pressure monitoring (ABPM). Prior studies indicate that the prevalence of masked hypertension in patients with newly diagnosed obstructive sleep apnea (OSA) is nearly 30%. In addition, patients with OSA have a higher prevalence of masked hypertension than patients without OSA. Aim: Prospective determination of the prevalence and severity of OSA in patients with MUCH. Methods: In this prospective evaluation, 167 treated hypertensive patients were recruited from the University of Alabama at Birmingham Hypertension Clinic after having controlled BP at three or more clinic visits. All patients were evaluated by AOBP with the BpTRU device, ABPM, and diagnostic polysomnography (PSG) to determine the presence and severity of OSA based on the apnea-hypopnea index (AHI). Out of 153 who completed ABPM, 58 patients were controlled by AOBP and by ABPM, indicating true controlled hypertension and the remaining 95 patients were controlled by AOBP, but uncontrolled by ABPM, indicative of MUCH. 49 true controlled hypertensive and 69 MUCH patients completed PSG. Results: MUCH patients had a mean AHI of 10.3±13.3 compared to 4.5±10.2 events/hr in true controlled hypertension (p =0.045). Overall, the prevalence of OSA was 48.5% in patients with MUCH compared to 26.5% in true controlled hypertension (p = 0.01). Conclusion: MUCH has significant higher prevalence and severity of OSA compared to true controlled hypertension. These findings suggest that untreated OSA may contribute to the development of MUCH.

Abstract P209: Antihypertensive Medication Non-Adherence is Common in Patients With Suspected Refractory Hypertension

Introduction: Refractory hypertension is a phenotype of antihypertensive treatment failure defined as uncontrolled BP (&gt; 135/85 mmHg) despite the use of five or more different antihypertensive agents, including long-acting thiazide like diuretic (chlorthalidone) and mineralocorticoid receptor antagonist (Spironolactone or Eplerenone). Recently white coat effect has been shown to be uncommon in patients with refractory hypertension. However, the degree of medication non-adherence, an important cause of apparent refractory hypertension, is unknown. Methods: In this prospective evaluation, 37 refractory hypertensive patients were recruited from the University of Alabama at Birmingham Hypertension Clinic after having uncontrolled BP at three or more clinic visits. All patients were evaluated by automated office BP (AOBP) with the BpTRU device, ambulatory BP monitoring (ABPM), and 24-hr urine collection to detect antihypertensive medication adherence by high-performance liquid chromatography-tandem mass spectrometry. Out of 34 patients who underwent ABPM monitoring, 30 (88%) patients were refractory hypertensive by AOBP and by ABPM. Of these, 27 patients had 24-hr urine collection for detection of prescribed antihypertensive medications or their metabolites. Results: Out of 27 patients, 11 (40.7%) patients had complete adherence with five or more antihypertensive medications, indicating true refractory hypertension. Ten (37.0%) patients were partially adherent, and 6 (22.2%) patients had total non-adherence to their antihypertensive medications. Conclusion: Of patients identified as having apparent refractory hypertension, 40% were adherent with at least 5 of their prescribed antihypertensive agents, confirming true refractory hypertension. The remaining 60% were partially or fully non-adherent. These results indicate that non-adherence is common in patients suspected of having refractory hypertension.

In the aftermath of SPRINT: further comparison of unattended automated office blood pressure measurement and 24-hour blood pressure monitoring

Aims: Several papers reported that unattended automated office blood pressure (uAutoOBP) is closely related to daytime ambulatory blood pressure monitoring (ABPM). In the present study, we aim to study uAutoOBP and its relation to 24-hour ABPM and ABPM variability.Material and methods: Stable treated hypertensive subjects were examined in two Czech academic hypertension centres. uAutoOBP was measured with the BP Tru device; attended BP three times with auscultatory method (AuscOBP) by the physician. ABPM was performed within one week from the clinical visit.Results: Data on 98 subjects aged 67.7 ± 9.3 years with 24-hour ABPM 120.3 ± 10.6/72.7 ± 7.9 mm Hg are reported. uAutoOBP was lower than 24-hour (by −5.2 ± 11.3/−0.5 ± 6.9 mm Hg) and daytime (by −6.7 ± 12.82.4 ± 8.0 mm Hg) ABPM and the individual variability of the difference was very large (up to 30 mm Hg). The correlation coefficients between ABPM and uAutoOBP were similar compared to AuscOBP (p ≥ .17). Variability of uAutoOBP, but not AuscOBP, readings during one clinical visit was related to short-term blood pressure variability of ABPM. The difference between AuscOBP and uAutoOBP was larger in patients with white-coat effect compared to other blood pressure control groups (25.1 ± 7.0 vs. 2.2 ± 10.3 mm Hg; p = .0036).Conclusions: Our study shows that uAutoOBP is not good predictor of ambulatory blood pressure monitoring, not even of the daytime values. It might, however, indicate short-term blood pressure variability and, when compared with AuscOBP, also detect patients with white-coat effect.

IMPACT OF DEVICES AND ENVIRONMENTS ON AUTOMATED OFFICE BLOOD PRESSURE MEASUREMENTS

Automated office blood pressure (AOBP) devices are increasingly recommended as preferred BP diagnostic tool. It is unclear how different AOBP devices compare and how the clinical environment impacts on their performance. This study is a prospective randomized factorial parallel four (4) group study comparing the BpTRU and the Omron HEM 907 devices in a closed or open area. Hypertensive patients were recruited during office visits. After standard open room AOBP measurement with a BpTRU device, patients were required to take a second BP measurement with either the BpTRU or Omron device and to either an open or closed area. Absolute BP levels and the difference between the first and second measurements were compared. Diagnostic performance was also assessed. In this study were included 258 patients. Mean age was 66.2±12.0 years and 62% were male. The mean first AOBP was 127.4/73.3 mmHg. The analyses of subsequent measurements showed that there was no influence of open or closed areas on BP means or diagnostic performance. On the other hand, HEM 907 exceeded systolic BpTRU measurements by 4.6 mmHg ( < 0.01) in a closed area and by 3.9 mmHg ( < 0.01) in an open area. There was no significant statistical difference in diastolic BP measures. Diagnostic agreement between the HEM 907 and BpTRU device was 73.4% in open area measurements. While different areas did not influence BP estimates, Omron HEM 907 measurements significantly exceeded BpTRU measurements on systolic average. These differences should be considered when interchanging devices.

PP.16.35] AUTOMATED OFFICE BLOOD PRESSURE IN STABLE HYPERTENSIVE PATIENTS

Objective: Automated office blood pressure (AOBP), measured in the absence of health care professionals, may eliminate white-coat effect. In the SPRINT study, blood pressure was measured with this method, and therefore, it is important to study its relationships to manually measured office blood pressure (OBP) which is crucial for clinical decision making as it was used in the vast majority of other prospective studies in hypertension. Design and method: Stable treated hypertensive subjects were included in this study which was performed in six Czech hypertension centres. AOBP was measured with the BPTru device (six measurements, average of 2nd to 6th measurement is considered); after AOBP, blood pressure (BP) was measured six times in the office (three times with auscultatory method by the physician followed by three oscilometric measurements). 24-hour ambulatory BP monitoring (ABPM) was performed within one week from the clinical visit. Results: Data on 191 subjects aged 64 ± 12 years with OBP 127.3 ± 12.2/77.5 ± 10.0 mm Hg are reported. AOBP was by 9.6 ± 19.2/3.2 ± 12.6 mm Hg lower than OBP and the difference was relatively homogeneous in all the centres. The AOBP-OBP difference was independent of age, number of antihypertensive drugs, presence of diabetes, lipid disorders or kidney disease; the interval from the morning drug intake had no influence either. We further compared the 4th to 6th BPTru measurement and 4th to 6th OBP measurement (i.e., only oscilometric measurements without and with presence of physician); it was 8.0/2.0 mm Hg. 24-hour mean BP was by 4.2/3.4 mm Hg lower than OBP and by 4.3/0.5 mm Hg higher than AOBP; the correlation coefficients of 24-hour mean BP with OBP and with AOBP did not differ (p for difference >0.10). Conclusions: AOBP gives comparable results in different clinical centres and thus, it can be introduced in clinical practice as a supplementary method to classic OBP. AOBP values are systematically lower than classic OBPand this phenomenon may partly explain the SPRINT results. Interindividual variability of the AOBP-OBP difference is large. The prediction of ABPM by AOBP is not better than by OBP.

PS 05-05 Automated compared to manual office blood pressure and to home blood pressure in hypertensive patients

Objective: Automated office blood pressure (BP) was measured in the recently published SPRINT trial; low target values were shown beneficial. We studied the relationships of automated blood pressure, measured in the health care centre, to manual office BP and to home BP. Design and Method: Stable outpatients treated for hypertension were measured automatically, being seated alone in a quiet room, six times after a five-minute rest with the BpTRU device, and immediately afterwards using auscultatory method. Home BP was measured in a subgroup during seven days preceding the visit. Results: The automated, office and home BP values were 131.2 ± 21.8/77.8 ± 12.1, 146.9 ± 20.8/85.8 ± 12.4, and 137.7 ± 17.7/79.4 ± 8.2 mmHg, respectively. Limits of agreement between office and automated BP (2 SDs in the Bland Altman plot) were +42.6 to -12.6/+22.6 to -6.6 mmHg for systolic/diastolic BP; for home and automated BP, they were +45.8 to -25.8/+20.8 to -12.6 mmHg. For patients with two visits, intraclass correlation coefficients of BP values measured during the first and second visit were 0.66/0.72 for systolic/diastolic automated BP and 0.68/0.74 for systolic/diastolic office BP. Conclusions: Automated BP was much lower than manual office BP and still lower than home BP. It showed similar inter-visit variability as office BP. Whether automated BP and “white coat effect”, calculated as office BP – automated BP difference, should be used in clinical practice, deserves further studies.

Automated compared to manual office blood pressure and to home blood pressure in hypertensive patients

We studied the relationships of automated blood pressure (BP), measured in the healthcare centre, with manual office BP and home BP. Stable outpatients treated for hypertension were measured automatically, seated alone in a quiet room, six times after a 5 min rest with the BpTRU device, and immediately afterwards using the auscultatory method. Home BP was measured in a subgroup during 7 days preceding the visit. The automated, office and home BP values were 131.2 ± 21.8/77.8 ± 12.1 mmHg, 146.9 ± 20.8/85.8 ± 12.4 mmHg and 137.7 ± 17.7/79.4 ± 8.2 mmHg, respectively. Limits of agreement between office and automated BP (2 SDs in Bland–Altman plots) were +42.6 to –12.6/+22.6 to –6.6 mmHg for systolic/diastolic BP; for home and automated BP they were +45.8 to –25.8/+20.8 to –12.6 mmHg. For patients with two visits, intraclass correlation coefficients of BP values measured during the first and second visits were 0.66/0.72 for systolic/diastolic automated BP and 0.68/0.74 for systolic/diastolic office BP. Automated BP was lower than home BP and no more closely related to home BP than to office BP. It did not show better repeatability than office BP. Whether automated BP and the “white-coat effect”, calculated cas the office BP–automated BP difference, have clinical and prognostic importance deserves further studies.

Optimising the accuracy of blood pressure monitoring in chronic kidney disease: the utility of BpTRU.

BackgroundAccurate blood pressure monitoring is critical for the management of chronic kidney disease, but changes in management in secondary care clinics may be based on a single blood pressure reading, with a subsequent lack of accuracy. The aim of this study was to evaluate a fully automated sphygmomanometer for optimising the accuracy of blood pressure measurements in the setting of secondary care renal clinics.MethodsPatients had routine blood pressure measurements with a calibrated DINAMAP PRO400 monitor in a clinical assessment room. Patients then underwent repeat assessment with a DINAMAP PRO400 monitor and BpTRU device and subsequent 24 hour ambulatory blood pressure monitoring (ABPM).ResultsThe BpTRU systolic (± SD) reading (117.3 ± 14.1 mmHg) was significantly lower than the routine clinic mean systolic blood pressure (143.8 ± 15.5 mmHg; P < 0.001) and the repeat blood pressure taken with a DINAMAP PRO400 monitor in a quiet room (129.9 ± 19.9 mmHg; P < 0.001). The routine clinic mean diastolic (82.4 ± 11.2 mmHg) was significantly higher than the BpTRU reading (78.4 ± 10.0 mmHg; P < 0.001). Clinic BpTRU measurements were not significantly different to the daytime mean or overall mean of 24 hour ABPM.ConclusionsIn patients with CKD, routine clinic blood pressure measurements were significantly higher than measurements using a BpTRU machine in a quiet room, but there was no significant difference in this setting between BpTRU readings and 24 hour ABPM. Adjusting clinic protocols to utilise the most accurate blood pressure technique available is a simple manoeuvre that could deliver major improvements in clinical practice.

Blood Pressure Measurement in Peritoneal Dialysis: Which Method is Best?

The optimal approach to monitoring blood pressure (BP) in the peritoneal dialysis (PD) population is unclear. Ambulatory BP monitoring reliably predicts prognosis, but can be inconvenient. The accuracy of home BP monitoring in this population is unproven. The automated BpTRU device (BpTRU Medical Devices, Coquitlam, BC, Canada), which provides an average of up to 6 successive in-office BP measurements, has not been studied in this patient group. We studied 17 patients (average age: 54 ± 12 years; 12 men, 5 women; 94% on automated PD) attending a single center. All patients underwent office, home, BpTRU, and ambulatory BP measurement. The reference standard for analysis was daytime ambulatory BP. Correlation between the referent method and each comparator method was determined (Pearson correlation coefficient), and Bland-Altman scatter plots depicting the differences in the BP measurements were constructed. Mean office BP (126.4 ± 16.9/78.8 ± 11.6 mmHg) and BpTRU BP (123.8 ± 13.7/80.7 ± 11.1 mmHg) closely approximated mean daytime ambulatory BP (129.3 ± 14.8/78.2 ± 7.9 mmHg). Mean home BP (143.8 ± 15.0/89.9 ± 28.1 mmHg) significantly overestimated mean daytime systolic BP by 14.2 mmHg (95% confidence interval: 4.3 mmHg to 24.1 mmHg; p = 0.008). Bland-Altman plots demonstrated poorest agreement between home BP and daytime ambulatory BP. No patient had "white-coat hypertension," and only 1 patient had false-resistant hypertension. Most patients showed abnormal nocturnal dipping patterns (non-dipping: n = 11; reverse-dipping: n = 5; normal dipping: n = 1). We report a novel finding that BP measurement using the BpTRU device is more accurate than home BP measurement in a PD population. Potential explanations for this observation include poor home BP measurement technique, use of poorly validated home BP measurement devices, or a reduced prevalence of white-coat effect among PD patients. Our study also confirms that, in the PD population, BP measurements vary considerably with patient location, time of day, and measurement technique.

The conventional versus automated measurement of blood pressure in the office (CAMBO) trial

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. 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. 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. 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.

Conventional versus automated measurement of blood pressure in the office (CAMBO) trial

Effective strategies to identify office-induced hypertension in routine clinical practice are required to improve diagnosis and management of hypertension. To compare the quality and accuracy of automated office blood pressure (AOBP) measurement using the BpTRU device with manual office blood pressure (MOBP) in routine clinical practice using awake ambulatory blood pressure (AABP) as the gold standard. Primary care practices in Eastern Canada were allocated by cluster randomization to use of AOBP (36 practices, 52 physicians) or to MOBP (31 practices, 36 physicians) in patients with systolic hypertension. The last routine MOBP reading pre-enrolment was compared to the blood pressure (BP) at the first visit after enrollment and after 2 years of follow-up. The primary outcome measure was the mean difference between the AABP and MOBP versus AOBP. The mean (95% confidence interval) decrease in systolic BP from pre- to post-enrollment was greater (P < 0.001) at the first visit in the 252 AOBP patients [-14.3 (-16.6, -12.0)] compared to the 209 MOBP patients [-8.0 (-2.2, -5.8)]. At Year 2, AOBP decreased by -16.3 (-18.6, -14.1) compared to a decrease in MOBP of -12.4 (-14.7, -10.1) (P = 0.02). The mean difference between systolic AABP and MOBP at the first post-enrollment office visit [-7.3 (-9.7, -4.9)] was greater (P < 0.001) than the difference for AOBP [-1.8 (-4.0, 0.4)]. At Year 2, these differences were -5.2 (-7.5, -3.0) for MOBP and -2.8 (-4.9, -0.7) for AOBP (P = 0.13). AOBP virtually eliminated office-induced hypertension. The decrease in MOBP was attributed to participation in a research study and not to any specific intervention.