Detection of masked hypertension by home blood pressure measurement: is the number of measurements an important issue?

Masked phenomenon: renal and cardiovascular complications; review and updates

BACKGROUND

In the in-clinic blood pressure (BP) recording setting, a sizable number of individuals with normal BP and approximately 30% of patients with chronic renal disease (CKD) exhibit elevated outpatient BP records. These individuals are known as masked hypertension (MHTN), and when they are on antihypertensive medications, but their BP is not controlled, they are called masked uncontrolled hypertension (MUHTN). The masked phenomenon (MP) (MHTN and MUHTN) increases susceptibility to end-organ damage (a two-fold greater risk for cardiovascular events and kidney dysfunction). The potential extension of the observed benefits of MP therapy, including a reduction in end-organ damage, remains questionable.

AIM AND METHODS

This review aims to study the diagnostic methodology, epidemiology, pathophysiology, and significance of MP management in end-organs, especially the kidneys, cardiovascular system, and outcomes. To achieve the purposes of this non-systematic comprehensive review, PubMed, Google, and Google Scholar were searched using keywords, texts, and phrases such as masked phenomenon, CKD and HTN, HTN types, HTN definition, CKD progression, masked HTN, MHTN, masked uncontrolled HTN, CKD onset, and cardiovascular system and MHTN. We restricted the search process to the last ten years to search for the latest updates.

CONCLUSION

MHTN is a variant of HTN that can be missed if medical professionals are unaware of it. Early detection by ambulatory or home BP recording in susceptible individuals reduces end-organ damage and progresses to sustained HTN. Adherence to the available recommendations when dealing with masked phenomena is justifiable; however, further studies and recommendation updates are required.

Sources of automatic office blood pressure measurement error: a systematic review

OBJECTIVE

Accurate and reliable blood pressure (BP) measurement is important for the prevention and treatment of hypertension. The oscillometric-based automatic office blood pressure measurement (AOBPM) is widely used in hospitals and clinics, but measurement errors are common in BP measurements. There is a lack of systematic review of the sources of measurement errors.

APPROACH

A systematic review of all existing research on sources of AOBPM errors. A search strategy was designed in six online databases, and all the literature published before October 2021 was selected. Those studies that used the AOBPM device to measure BP from the upper arm of subjects were included.

MAIN RESULTS

A total of 1365 studies were screened, and 224 studies were included in this final review. They investigated 22 common error sources with clinical AOBPM. Regarding the causes of BP errors, this review divided them into the following categories: the activities before measurement, patient's factors, measurement environment, measurement procedure, and device settings. 13 sources caused increased systolic and diastolic BP (SBP and DBP), 2 sources caused the decrease in SBP and DBP, only 1 source had no significant effect on BPs, and the other errors had a non-uniform effect (either increase or decrease in BPs). The error ranges for SBP and DBP were -14 to 33 mmHg and -6 to 19 mmHg, respectively.

SIGNIFICANCE

The measurement accuracy of AOBPM is susceptible to the influence of measurement factors. Interpreting BP readings need to be treated with caution in clinical measurements. This review made comprehensive evidence for the need for standardized BP measurements and provided guidance for clinical practitioners when measuring BP with AOBPM devices.

Association of masked uncontrolled hypertension and cardiovascular diseases in treated hypertensive patients

INTRODUCTION

The aim of the study was to evaluate the association of masked uncontrolled hypertension (MUCH) and prevalence of cardiovascular disease in treated hypertensive patients.

MATERIAL AND METHODS

Patients' demographics and prior medical histories were collected. Fasting venous blood was drawn for evaluation of serum creatinine level, which was used to calculate glomerular filtration rate (GFR). Clinic blood pressure (BP) and 24 h ambulatory blood pressure monitoring (ABPM) measurements were performed. Based on the clinic BP and 24 h ABPM results, patients were divided into MUCH and non-masked hypertension groups.

RESULTS

Compared to patients without masked hypertension, MUCH patients were older (62.4 ±11.2 vs. 59.7 ±10.4 years, p < 0.05), more likely to be male (66.9% vs. 63.4%), had diabetes (33.9% vs. 29.6%), longer hypertension duration (12.4 ±5.3 vs. 9.5 ±4.5 years, p < 0.05), lower GFR (79.5 ±11.6 vs. 82.4 ±10.3 ml/min/1.73 m², p < 0.05), treated with β-blocker (39.0% vs. 32.7%, p < 0.05) and required more antihypertensive medications (2.7 ±0.5 vs. 2.2 ±0.3, p < 0.05). MUCH patients have higher cardiovascular disease prevalence than that without masked hypertension (30.1% vs. 23.4%, p < 0.05). After adjustment for covariates, MUCH was still independently associated with higher cardiovascular disease prevalence with odds ratio 1.38 (95% confidence interval 1.17-1.62, p < 0.05).

CONCLUSIONS

The MUCH is independently associated with prevalent cardiovascular disease in treated hypertensive patients. Future studies are needed to evaluate whether correction of MUCH can improve patients' outcomes.

Blood Pressure Assessment in Adults in Clinical Practice and Clinic-Based Research: JACC Scientific Expert Panel

The accurate measurement of blood pressure (BP) is essential for the diagnosis and management of hypertension. Restricted use of mercury devices, increased use of oscillometric devices, discrepancies between clinic and out-of-clinic BP, and concerns about measurement error with manual BP measurement techniques have resulted in uncertainty for clinicians and researchers. The National Heart, Lung, and Blood Institute of the U.S. National Institutes of Health convened a working group of clinicians and researchers in October 2017 to review data on BP assessment among adults in clinical practice and clinic-based research. In this report, the authors review the topics discussed during a 2-day meeting including the current state of knowledge on BP assessment in clinical practice and clinic-based research, knowledge gaps pertaining to current BP assessment methods, research and clinical needs to improve BP assessment, and the strengths and limitations of using BP obtained in clinical practice for research and quality improvement activities.

Home and office blood pressure monitoring in renal transplant recipients

Background. Arterial hypertension in renal transplant recipients (RTR) is associated with increased morbid mortality. In the general population, home blood pressure monitoring (HBPM) was found to be superior to office blood pressure (OBP) in identifying true hypertensive patients. The aim of this study was to investigate HBPM for the assessment of blood pressure profile in RTR. Methodology and Principal Findings. We included prospectively 87 stable RTR. Sitting OBP was measured during the outpatient clinic. HBPM was performed by measuring BP every morning and night for 4 days. The accepted limits for the OBP and HBPM, were respectively, 140/90 mmHg and 135/85 mmHg. Patients were classified as “normotensive,” “uncontrolled,” “white-coat hypertensive” and “masked hypertensive”, (OBP below the limit and HBPM above). During the study, 81 patients (55 males, age 48.5 ± 14 years) were available for analysis. The mean OBP and HBP were 138/83 ± 14/10 mmHg and 133/79 ± 14/8 mmHg; 29% of patients were uncontrolled, 28% normotensive, 21% white coat, and 21% masked hypertensive. Age, glycemia, and number of antihypertensive drugs were associated with hypertension. Conclusion and Significance. In RTR, HBPM is well accepted and better define BP profile since there is 42% discrepancy between OBPM and HBPM. Whether this discrepancy is associated with worst outcome in the long term remains to be demonstrated.

Masked hypertension in the elderly: cross-sectional analysis of a population-based sample

BACKGROUND

Masked hypertension (MHT), defined as normal blood pressure (BP) at office associated with high BP at home, has been shown to be associated with an increased risk of vascular events. However, MHT is poorly known in the elderly, although this age segment is at high risk of hypertension-related vascular events. Our objectives were to assess frequency and determinants of MHT in the elderly.

METHODS

We studied MHT in a community-based sample of 1,814 participants aged 75 years or older, whose office BP and home BP measurements (HBPM) were both taken with the same device (Omron M6; Omron Healthcare, Kyoto, Japan).Hypertension was defined as a systolic BP (SBP) ≥ 140 mm Hg and/or a diastolic BP (DBP) ≥ 90 mm Hg for office BP, and SBP ≥ 135 mm Hg and/or DBP ≥ 85 mm Hg for HBPM.

RESULTS

Frequency of MHT was 16% in the overall sample and 41% in participants with a normal office BP. Multivariable analyses revealed that male subjects, >80 years of age, with diabetes, on antihypertensive medication, and with office SBP >120 mm Hg were independently associated with a higher risk of MHT.

CONCLUSION

MHT is frequent in the elderly and is associated with a high vascular profile. These results should encourage a more widespread use of home BP monitoring in this age segment.

Compliance with home blood pressure monitoring among middle-aged Korean Americans with hypertension

The primary objective of this study was to investigate the factors affecting the level of compliance of home blood pressure monitoring (HBPM) and its relation to blood pressure (BP) control among hypertensive adults in a community setting. A total of 377 middle-aged Korean Americans with high BP participated in this study. Along with structured behavioral education, the participants were instructed to measure their BP 3 times in a row upon waking and thrice again at bedtime, at least 2 or more times a week for 48 weeks. Using multivariate logistic regression, the authors examined the patterns and factors affecting HBPM and its relation to BP control status. The analyses revealed that older participants were more compliant with the HBPM instruction than were younger participants (adjusted odds ratio [OR], 5.29; 95% confidence interval [CI], 1.77-15.81) and those with more depressive symptoms were less compliant (OR, 0.19; 95% CI, 0.04-0.88). Participants who were more compliant to HBPM instruction were 4 times more likely than those who were noncompliant to have controlled their BP by the end of the intervention period (OR, 4.28; 95% CI, 1.79-10.23). These results suggest that the participants who checked their BP regularly at home had a stronger tendency to achieve BP control.

Location not quantity of blood pressure measurements predicts mortality in hemodialysis patients

BACKGROUND

Blood pressure (BP) measurements obtained outside the dialysis unit are prognostically superior. Whether it is the greater number of measurements made outside the dialysis unit that correlates with prognosis or whether BPs outside dialysis units are ecologically more valid is unknown.

METHODS AND RESULTS

A prospective cohort study was conducted in 133 patients on chronic hemodialysis. BP was measured by the patients at home for 1 week, over an interdialytic interval by ambulatory recording, and by 'routine' and standardized methods in the dialysis unit for 2 weeks. Up to 6 BPs were randomly selected from a 44-hour recording of ambulatory or 1-week recording of home BPs, such that the dialysis unit BPs were exactly matched to the number of ambulatory or home BPs. The relationship with left ventricular hypertrophy and all-cause mortality was analyzed using receiver-operating characteristic curves and Cox proportional hazards analysis, respectively. Over a median follow-up of 24 months, 46 patients (31%) died. A BP change of 10/5 mm Hg increased the risk of all-cause mortality by 1.22 (95% CI 1.07-1.38)/1.18 (95% CI 1.05-1.31) with the average of the 44-hour recording and 1.20 (95% CI 1.07-1.34)/1.15 (95% CI 1.03-1.27) when up to 6 random BPs from the same ambulatory recording were drawn and averaged. With home BPs the hazard ratios were 1.17/1.15 per 10/5 mm Hg increase in BP with the average of 1-week recording and 1.18/1.13 when up to 6 random BPs were drawn and averaged. Limited duration ambulatory BP monitoring of any 6-hour interval during the first 24 h or 4-day home BP recorded after the midweek dialysis was similarly predictive of all-cause mortality.

CONCLUSIONS

In patients on hemodialysis, the location, not the quantity, of the BP recordings obtained outside the dialysis unit is associated with target organ damage and mortality.

Masked hypertension in diabetes mellitus: a potential risk

The prevalence and clinical significance of masked hypertension (MHT) in diabetics have infrequently been described. The authors assessed the association of MHT (defined using a clinic blood pressure [BP] <140/90 mm Hg and daytime ambulatory BP > or = 135/85 mm Hg) with microvascular and macrovascular end organ damage in 81 clinically normotensive Japanese diabetic persons. The prevalence of silent cerebral infarcts (SCIs), increased left ventricular mass, and albuminuria were evaluated. Of 81 patients, 38 (46.9%) were classified as having MHT and showed significantly more SCIs (mean +/- SE: 2.5+/-0.5 vs 1.1+/-0.2; P=.017), and more albuminuria (39% vs 16%; P=.025), but no increase in left ventricular mass index, than the normotensive persons in office and on ambulatory BP monitoring group. The prevalence of MHT in this diabetic population was high (47%). Diabetic patients with MHT showed evidence of brain and kidney damage. Hence, out-of-office monitoring of BP may be indicated in diabetics whose BP is normal in the clinic.

Masked hypertension, a review of the literature

Masked hypertension (blood pressure that is normal in the physicians' office but elevated elsewhere) is a common phenomenon as prevalence among studies varies from 8 to 45% and is seen at all ages. large discrepancies, however, exist between studies that have dealt with masked hypertension. It is of high clinical importance as it is associated with higher target organ damage as compared with sustained normotension. Therefore more research should be determined. This paper provides an overview of current literature to improve knowledge about masked hypertension and about the cause of this phenomenon. In addition it provides some questions, which need to be answered for performing appropriate research into this subject in future.

Practical advice for home blood pressure measurement

Early diagnosis of hypertension is one benefit of home blood pressure monitoring. Home measurement may also be used for the detection of masked hypertension. Home blood pressure readings have a strong correlation with risk, and the method has many advantages over office measurement in the management of hypertension, especially in patients with chronic kidney disease or diabetes. The present article provides practical advice on incorporating home blood pressure monitoring into practice. Patient education and training are discussed, as are tips to aid in the selection of devices for blood pressure measurement at home.

[Prevalence of white-coat hypertension and masked hypertension in the general population, through home blood pressure measurement]

OBJECTIVE

To determine the prevalence of white-coat hypertension (WCH) and masked hypertension (MH) in the general population, by means of home blood pressure measurement (HBPM).

DESIGN

Cross-sectional, descriptive study.

SETTING

Four primary care centres.

PARTICIPANTS

A sample of 1400 individuals over 18 years old, selected from the Municipal Register of Inhabitants (Huelva, Spain) and randomised and stratified by age and gender.

MAIN MEASUREMENTS

Two blood pressure (BP) measurements in clinic (CBP) and 12 measurements in a week of BP by HBPM were performed (OMRON 705-CP). Pressure was seen as normal when CBP means were <140/90 mm Hg and HBPM was <135/85 mm Hg. WCH was defined as when CBP was >140/90 mm Hg and HBPM <135/85 mm Hg, and hypertension when CBP was >140 mm Hg and HBPM >135/85 mm Hg or patients were in treatment for hypertension. MH was when CBP was <140/90 mm Hg and at home was >135 mm Hg and/or 85 mm Hg.

RESULTS

A total of 1153 individuals (82.35% of the sample) with mean age of 45.4 (SD, 16.1) were included: 560 men and 593 women. The prevalence of MH was 8.9% (CI+/-1.6) in the general population and 9.8% (CI+/-3.2) in individuals with hypertension. WCH prevalence was 3.6% (CI+/-1.05) overall and 12.8% (CI+/-3.6) in hypertense patients, with its prevalence increasing steadily as age groups rose (P = .001).

CONCLUSIONS

The prevalence of WCH in the general population is low, whereas the prevalence of MH is high.

Masked hypertension: a common but insidious presentation of hypertension

A patient has masked hypertension when his office blood pressure is less than 140/90 mmHg but his ambulatory or home blood pressure readings are in the hypertensive range. Several recent studies have demonstrated that cardiovascular risk is similar between those with masked hypertension and those with sustained hypertension. The prevalence of masked hypertension in Canada is not known, but data from other countries suggest rates greater than 8%. Physicians need to use careful clinical judgment to identify and treat subjects with masked hypertension. The present review discusses masked hypertension, its importance to clinical practice and some aspects of patient management.

Highlights and summary of the 2006 Canadian Hypertension Education Program recommendations

The present paper summarizes and highlights key messages of the 2006 Canadian Hypertension Education Program recommendations for the management and diagnosis of hypertension. An important message in the 2006 Canadian Hypertension Education Program recommendations is to improve patient adherence to antihypertensive therapy by incorporating a number of techniques. These new recommendations still need to be incorporated into what remain as the older but still important considerations for the diagnosis, management and treatment of the patient with hypertension, namely, to assess blood pressure in all adults at all appropriate visits, to expedite the diagnosis of hypertension, to assess and manage global cardiovascular risk, to emphasize that lifestyle modifications are the cornerstone of antihypertensive therapy, to treat to target, and to use combinations of antihypertensive medications and lifestyles to achieve recommended targets. Minor changes in pharmacological therapies are discussed, and potentially important aspects related to home and self-monitoring, particularly with respect to patients with masked hypertension (blood pressure controlled in the office but not at home), are introduced.

Prevalence of masked uncontrolled and treated white-coat hypertension defined according to the average of morning and evening home blood pressure value: from the Japan Home versus Office Measurement Evaluation Study

OBJECTIVE

To evaluate the prevalence of masked uncontrolled and treated white-coat hypertension defined according to the average of morning and evening home blood pressure values.

METHODS

The study population consisted of 3303 essential hypertensive outpatients receiving antihypertensive treatment in Japan. Information on the characteristics of the patients was collected by a physician's self-administrated questionnaire. The office blood pressure value was calculated as the average of the four readings in two visits. All patients were asked to measure their blood pressure once every morning and once every evening. In the study, we included patients with at least three measurements in the morning and in the evening, respectively. The average of all home blood pressure values was taken as the home blood pressure value.

RESULTS

The mean value of home systolic/diastolic blood pressure was 136.8/79.3 mmHg, and the mean value of office systolic/diastolic blood pressure was 142.8/80.6 mmHg. Of the 3303 patients, 758 (23.0%) had controlled hypertension (home <135/85 mmHg and office <140/90 mmHg), 628 (19.0%) had masked uncontrolled hypertension (home > or =135/85 mmHg and office <140/90 mmHg), 640 (19.4%) had treated white-coat hypertension (home <135/85 mmHg and office > or =140/90 mmHg), and 1277 (38.7%) had uncontrolled hypertension (home > or =135/85 mmHg and office > or =140/90 mmHg).

CONCLUSIONS

Treated white-coat hypertension and masked uncontrolled hypertension were often observed in clinical settings. Physicians need to understand the prevalence of such patients to prevent inadequate diagnosis and treatment in them.

Management of hypertension in elderly diabetic patients

Hypertension is a major vascular risk factor in the elderly diabetic. The benefit of proper management is well recognized, even if treatment has no influence on overall mortality or might even tend to increase it in very elderly subjects. Globally, the efficacy of the major classes of antihypertensive drugs, diuretics, beta-blockers, calcium channel blockers, angiotensin converting enzyme inhibitors, or angiotensin II receptor antagonists appears to be equivalent so that the therapeutic choice depends on the type of hypertension, systolic or systolic-diastolic, and the rapidity of the desired effect, co-morbid conditions, particularly coronary or renal disease, or drug tolerance. Blood pressure goals are similar to those in middle-aged persons, except in very old, frail or sick subjects.

Use of home blood-pressure monitoring in the detection, treatment and surveillance of hypertension

PURPOSE OF REVIEW

Use of home blood-pressure monitoring is increasing but the technique and the equipment have limitations. We provide an overview of recent evidence in this rapidly evolving field.

RECENT FINDINGS

Home blood-pressure monitoring is an acceptable method for screening patients for hypertension. There is increasing evidence supporting the predictive power of home blood pressure for stroke risk even in the general population. The identification of white-coat and masked hypertension remains an important role for home blood-pressure monitoring. Unvalidated equipment and poor patient technique are major concerns. The purchase of devices needs to be linked to a simple patient-education programme, which is perhaps an opportunity for collaboration between healthcare providers and commercial companies. Devices that store the blood-pressure measurements in the memory are preferred to ensure accuracy of reporting. Data-transmission systems providing automatic storage, transmission and reporting of blood pressure, direct involvement of the patient and potentially a reduced number of hospital/general practitioner visits, offer significant advantages. To reduce patient anxiety, overuse of home blood-pressure monitoring should be avoided but there is the potential for self-modification of treatment, subject to certain safeguards.

SUMMARY

Self-monitoring of blood pressure is developing rapidly, linked to increasing awareness of the impact of reducing high blood pressure on public health and the marketing/advertising strategies used to sell automatic devices. Home blood-pressure monitoring has a role in the detection and management of blood pressure, but not at the expense of careful blood-pressure measurement in the office and adherence to national guidelines.