Automated office blood pressure is associated with urine albumin excretion in hypertensive subjects

The Prognostic Role of Automated Office Blood Pressure Measurement in Hypertensive Patients with Chronic Kidney Disease

BACKGROUND

The aim of this study was to evaluate the prognostic value of automated office blood pressure (AOBP) measurement in patients with hypertension and chronic kidney disease (CKD) stage 3-5 not on dialysis.

METHODS

At baseline, 140 patients were recruited, and blood pressure (BP) measurements with 3 different methods, namely, office blood pressure (OBP), AOBP, and ambulatory blood pressure measurement (ABPM), were recorded. All patients were prospectively followed for a median period of 3.4 years. The primary outcome of this study was a composite outcome of cardiovascular (CV) events (both fatal and nonfatal) or a doubling of serum creatine or progression to end-stage kidney disease (ESKD), whichever occurred first.

RESULTS

At baseline, the median age of patients was 65.2 years; 36.4% had diabetes; 21.4% had a history of CV disease; the mean of estimated glomerular filtration rate (eGFR) was 33 mL/min/1.73 m²; and the means of OBP, AOBP, and daytime ABPM were 151/84 mm Hg, 134/77 mm Hg, and 132/77 mm Hg, respectively. During the follow-up, 18 patients had a CV event, and 37 patients had a renal event. In the univariate cox regression analysis, systolic AOBP was found to be predictive of the primary outcome (HR per 1 mm Hg increase in BP, 1.019, 95% CI 1.003-1.035), and after adjustment for eGFR, smoking status, diabetes, and a history of CV disease and systolic and diastolic AOBP were also found to be predictive of the primary outcome (HR per 1 mm Hg increase in BP, 1.017, 95% CI 1.002-1.032 and 1.033, 95% CI 1.009-1.058, respectively).

CONCLUSIONS

In patients with CKD, AOBP appears to be prognostic of CV risk or risk for kidney disease progression and could, therefore, be considered a reliable means for recording BP in the office setting.

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.

Comparison Between Automated Office Blood Pressure Measurements and Manual Office Blood Pressure Measurements-Implications in Individual Patients: a Systematic Review and Meta-analysis

PURPOSE OF REVIEW

Automated office blood pressure (AOBP) measurements may provide more accurate estimation of blood pressure (BP) than manual office blood pressure (MOBP) measurements. This systematic review investigated the diagnostic performance of AOBP and MOBP using ambulatory blood pressure measurement (ABPM) as reference. Several databases including MEDLINE, Embase, Scopus, and China Academic Journals were searched. Data were extracted, double-checked by two investigators, and were analysed using a random effects model.

RECENT FINDINGS

A total of 26 observational studies were included. The mean systolic/diastolic BP obtained by AOBP was not significantly different from that obtained by ABPM. The sensitivity and specificity of AOBP to detect elevated BP were approximately 70%. Fewer participants had white-coat hypertension on AOBP measurement than on MOBP measurement (7% versus 14%); however, about 13% had masked hypertension on AOBP measurement. The width of the limit of agreement comparing (i) AOBP and ABPM and (ii) MOBP and ABPM was comparable. AOBP may reduce the rate of the observed white-coat effect but undermine masked hypertension. The current recommendation, however, is limited by the absence of high-quality studies and the high heterogeneity of our results. More high-quality studies using different AOBP machines and in different population are therefore needed.

Reference values of retinal microcirculation parameters derived from a population random sample

Retinal microcirculation reflects retinal perfusion abnormalities and retinal arterial structural changes at relatively early stages of various cardiovascular diseases. Our objective has been to establish reference values for major functional and structural parameters of retinal microcirculation in a randomly selected urban population sample. A total of 398 randomly selected individuals from an urban population aged 25 to 65 years, resident in Pilsen, Czech Republic, were screened for major cardiovascular risk factors. Retinal microcirculation was assessed using scanning laser Doppler flowmetry (SLDF), with data evaluable in 343 patients. Of this number, complete data were available for 256 individuals free from manifest cardiovascular disease, diabetes and drug treatment for hypertension and/or dyslipidemia, constituting the reference value population. Juxtapapillary retinal capillary blood flow has increased significantly with age whereas vessel and luminal diameters have decreased. No sex differences in retinal microcirculation parameters have been found. Therefore, reference values for retinal microcirculation parameters have been established by age groups. Unattended automated office systolic BP, after adjusting for age, correlated significantly with wall-to-lumen ratio (WLR) and wall thickness (WT). Moreover, after adjusting for age and mean BP, a positive relationship has been found between carotid femoral pulse wave velocity and WT, WLR and wall cross-sectional area, indicating the interaction between micro- and macro-vasculature. In conclusion, our study is the first to provide reference values of retinal microcirculation parameters in a random Caucasian population sample. Our results have shown that, at the population level, the first structural changes in retinal microcirculation are those in lumen diameters. Of note, a close relationship between BP and vascular remodeling of retinal arterioles and between aortic stiffness and WLR of retinal arterioles suggests an interaction between micro- and macro-vasculature.

Morning Surge and Peak Morning Ambulatory Blood Pressure Versus Automated Office Blood Pressure in Predicting Cardiovascular Disease

INTRODUCTION

Automated office blood pressure (AOBP) has been recently shown to predict equally well to ambulatory blood pressure (ABP), conventional office blood pressure (OBP) and home blood pressure (HBP), cardiovascular (CV) events among hypertensives.

AIM

To compare AOBP recording and ABP monitoring in order to evaluate morning blood pressure (BP) peak in predicting CV events and deaths in hypertensives.

METHODS

We assessed 236 initially untreated hypertensives, examined between 2009 and 2013. The end points were CV and non-CV death and any CV event including myocardial infarction, evidence of coronary heart disease, heart failure hospitalization, severe arrhythmia, stroke, and symptomatic peripheral artery disease. We fitted proportional hazards models using the different modalities as predictors and evaluated their predictive performance using two metrics: the Akaike's Information Criterion, and Harrell's C-index.

RESULTS

After a mean follow-up of 7 years, 23 subjects (39% women) had at least one CV event. In Cox regression models, systolic conventional OBP, AOBP and peak morning BP were predictive of CV events (p < 0.05). The Akaike Information Criterion showed smaller values for AOBP than peak morning BP, indicating a better performance in predicting CV events (227.2736 and 238.7413, respectively). The C-index was 0.6563 for systolic AOBP and 0.6243 for peak morning BP indicating a better predicting ability for AOBP.

CONCLUSION

In initially untreated hypertensives, AOBP appears to be at least equally reliable to 24-h monitoring in the evaluation of morning BP peak in order to detect CV disease whereas the sleep-trough and preawakening morning BP surge did not indicate such an effect.

Automated Office-Based Blood Pressure Measurement: an Overview and Guidance for Implementation in Primary Care

PURPOSE OF REVIEW

The purposes of this study are to review evidence supporting the use of automated office blood pressure (AOBP) measurement and to provide practical guidance for implementing it in clinical settings.

RECENT FINDINGS

Mean AOBP readings correlate with awake ambulatory blood pressure monitor (ABPM) values and predict cardiovascular outcomes better than conventional techniques. However, heterogeneity among readings suggests that AOBP does not replace ABPM. Blood pressure (BP) measurement protocols differ among commonly described AOBP devices, but all produce valid BP estimates. Rest periods should not precede AOBP with BpTRU devices but should occur before use with Omron HEM-907 and Microlife WatchBP Office devices. Attended and unattended AOBP appear to produce similar results. This review also describes a framework to aid AOBP's implementation in clinical practice. Evidence supports AOBP as the preferred method for measuring BP in office settings, but this approach should be a complement to out-of-office measurements, such as self-measured BP monitoring or 24-h ABPM, not a substitute for it.

Out-of-office blood pressure measurement for the diagnosis of hypertension in pregnancy: Survey of Canadian Obstetric Medicine and Maternal Fetal Medicine specialists

Background

Multiple hypertension guidelines recommend out-of-office measurements for the diagnosis of hypertension in non-pregnant adults, whereas pregnancy guidelines recommend in-office blood pressure measurements. The objective of our study was to determine how Canadian Obstetric Medicine and Maternal Fetal Medicine specialists measure blood pressure in pregnancy.

Methods

An email survey was sent to 69 Canadian Obstetric Medicine and Maternal Fetal Medicine specialists in academic centers across Canada to explore the practice patterns of blood pressure measurement in pregnant women.

Results

The response rate was 48%. The majority of respondents (63.6%) preferred office blood pressure measurement for diagnosing hypertension, but relied on home blood pressure readings for ongoing monitoring and management of hypertension during pregnancy (59.4%). The preferred method of out-of-office blood pressure measurement was home monitoring; 24-hour ambulatory blood pressure monitoring was not used due to limited availability and cost.

Conclusions

There is wide practice variation in methods of measuring blood pressure among Canadian specialists managing hypertension in pregnancy.

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

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

Attended and Unattended Automated Office Blood Pressure Measurements Have Better Agreement With Ambulatory Monitoring Than Conventional Office Readings

BACKGROUND

Automated office blood pressure (AOBP) measurement is superior to conventional office blood pressure (OBP) because it eliminates the "white coat effect" and shows a strong association with ambulatory blood pressure.

METHODS AND RESULTS

We conducted a cross-sectional study in 146 participants with office hypertension, and we compared AOBP readings, taken with or without the presence of study personnel, before and after the conventional office readings to determine whether their variation in blood pressure showed a difference in blood pressure values. We also compared AOBP measurements with daytime ambulatory blood pressure monitoring and conventional office readings. The mean age of the studied population was 56±12 years, and 53.4% of participants were male. Bland-Altman analysis revealed a bias (ie, mean of the differences) of 0.6±6 mm Hg systolic for attended AOBP compared with unattended and 1.4±6 and 0.1±6 mm Hg bias for attended compared with unattended systolic AOBP when measurements were performed before and after conventional readings, respectively. A small bias was observed when unattended and attended systolic AOBP measurements were compared with daytime ambulatory blood pressure monitoring (1.3±13 and 0.6±13 mm Hg, respectively). Biases were higher for conventional OBP readings compared with unattended AOBP (-5.6±15 mm Hg for unattended AOBP and oscillometric OBP measured by a physician, -6.8±14 mm Hg for unattended AOBP and oscillometric OBP measured by a nurse, and -2.1±12 mm Hg for unattended AOBP and auscultatory OBP measured by a second physician).

CONCLUSIONS

Our findings showed that independent of the presence or absence of medical staff, AOBP readings revealed similar values that were closer to daytime ambulatory blood pressure monitoring than conventional office readings, further supporting the use of AOBP in the clinical setting.

Choosing the optimal method of blood pressure measurement for limited-resource rural communities in the "Community Health Assessment Program-Philippines"

The Community Health Assessment Program-Philippines (CHAP-P) is an international collaboration of investigators whose aim is to adapt a previously proven Canadian community-based cardiovascular awareness and prevention intervention to the Philippines and other low-middle-income countries. Choosing a method of blood pressure measurement for the research program presents a challenge. There is increasing consensus globally that blood pressure measurement with automated devices is preferred. Recommendations from low-middle-income countries, including the Philippines, are less supportive of automated blood pressure devices. The value placed on factors including device accuracy, durability, cost, energy source, and complexity differ with local context. Our goal was to support the progress of local policy concerning blood pressure measurement while testing a comprehensive approach to community-based screening for cardiovascular risk. The authors describe the challenges in making a choice of blood pressure device and the approach to determine optimal method of measurement for our research program.

Home, automated office, and conventional office blood pressure as predictors of cardiovascular risk

Automated office blood pressure (AOBP) has recently been shown to closely predict cardiovascular (CV) events in the elderly. Home blood pressure (HBP) has also been accepted as a valuable method in the prediction of CV disease. This study aimed to compare conventional office BP (OBP), HBP, and AOBP in order to evaluate their value in predicting CV events and deaths in hypertensives. We assessed 236 initially treatment naïve hypertensives, examined between 2009 and 2013. The end points were any CV and non-CV event including mortality, myocardial infarction, coronary heart disease, hospitalization for heart failure, severe arrhythmia, stroke, and intermittent claudication. We fitted proportional hazards models using the different modalities as predictors and evaluated their predictive performance using three metrics: time-dependent receiver operating characteristics curves, the Akaike's Information Criterion, and Harrell's C-index. After a mean follow-up of 7 years, 23 participants (39% women) had experienced ≥1 CV event. Conventional office systolic (hazard ratio [HR] per 1 mm Hg increase in BP, 1.028; 95% confidence interval [CI], 1.009-1.048), automated office systolic (HR per 1 mm Hg increase in BP, 1.031; 95% CI, 1.008-1.054), and home systolic (HR, 1.025; 95% CI, 1.003-1.047) were predictive of CV events. All systolic BP measurements were predictive after adjustment for other CV risk factors (P < .05). The predictive performance of the different modalities was similar. Conventional OBP was significantly higher than AOBP and average HBP. AOBP predicts equally well to OBP and HBP CV events. It appears to be comparable to HBP in the assessment of CV risk, and therefore, its introduction into guidelines and clinical practice as the reference method for assessing BP in the office seems reasonable after verification of these findings by randomized trials.

Hypertension Canada's 2016 Canadian Hypertension Education Program Guidelines for Blood Pressure Measurement, Diagnosis, Assessment of Risk, Prevention, and Treatment of Hypertension

Hypertension Canada's Canadian Hypertension Education Program Guidelines Task Force provides annually updated, evidence-based recommendations to guide the diagnosis, assessment, prevention, and treatment of hypertension. This year, we present 4 new recommendations, as well as revisions to 2 previous recommendations. In the diagnosis and assessment of hypertension, automated office blood pressure, taken without patient-health provider interaction, is now recommended as the preferred method of measuring in-office blood pressure. Also, although a serum lipid panel remains part of the routine laboratory testing for patients with hypertension, fasting and nonfasting collections are now considered acceptable. For individuals with secondary hypertension arising from primary hyperaldosteronism, adrenal vein sampling is recommended for those who are candidates for potential adrenalectomy. With respect to the treatment of hypertension, a new recommendation that has been added is for increasing dietary potassium to reduce blood pressure in those who are not at high risk for hyperkalemia. Furthermore, in selected high-risk patients, intensive blood pressure reduction to a target systolic blood pressure ≤ 120 mm Hg should be considered to decrease the risk of cardiovascular events. Finally, in hypertensive individuals with uncomplicated, stable angina pectoris, either a β-blocker or calcium channel blocker may be considered for initial therapy. The specific evidence and rationale underlying each of these recommendations are discussed. Hypertension Canada's Canadian Hypertension Education Program Guidelines Task Force will continue to provide annual updates.

Blood pressure control is similar in treated hypertensive patients with optimal or with high-normal albuminuria

BACKGROUND

Although elevated urinary albumin excretion (UAE) is associated with cardiovascular prognosis and high blood pressure (BP), it is unknown whether differences in BP control could also exist between patients with different grades of UAE, even in the normal range. We sought to explore the association between different levels of UAE and BP control in treated hypertensive patients.

METHODS

A cohort of 1,200 treated hypertensive patients was evaluated. Clinical data, including 2 office BP measurements and UAE averaged from 2 samples, were recorded. Albuminuria was categorized into 4 groups: G0 (UAE <10mg/g), G1 (UAE 10-29 mg/g), G2 (UAE 30-299 mg/g), and G3 (UAE ≥300 mg/g).

RESULTS

Forty-three percent of patients had systolic BP ≥140 mm Hg and/or diastolic BP ≥90 mm Hg. Median UAE was significantly higher (20.3 vs. 11.7 mg/g; P < 0.001) in these patients than in controlled hypertensive patients (BP<140/90 mm Hg). When UAE was categorized into the 4 groups, there were differences in BP control among groups (P < 0.001).The proportion of noncontrolled patients in G2 (52.3%) was significantly higher than in G0 (36.8%) and G1 (41.5%) (P < 0.01 and P < 0.05, respectively). Importantly, no significant differences were observed between G0 and G1 (P = 0.18) or between G2 and G3 (P = 0.48). With G0 as the reference group, the odds ratio of lack of BP control for the G2 group after adjustment for confounders was 1.40 (95% confidence interval =1.16-1.68; P < 0.001).

CONCLUSIONS

Lack of BP control is more prevalent among patients with microalbuminuria than in patients with normoalbuminuria. No significant difference was seen between patients with optimal or high-normal UAE.