Optimal number of days for home blood pressure measurement

Sleep blood pressure measured using a home blood pressure monitor was independently associated with cardiovascular disease incidence: the Nagahama study

BACKGROUND

Nocturnal blood pressure (BP) is associated with cardiovascular disease independently of awake BP. However, nocturnal BP measured using an ambulatory monitoring device has limited reproducibility because it is a single-day measurement. We investigated the association between sleep BP measured on multiple days using a timer-equipped home BP monitor and cardiovascular diseases in a general population.

METHODS

The study population comprised 5814 community residents. Participants were required to sleep with wrapping cuffs on their upper arm and BP was measured automatically at 0 : 00, 2 : 00, and 4 : 00. Actigraph was used to determine BP measured during sleep. Participants were also measured home morning and evening BP manually using the same device.

RESULTS

During the 7.3-year mean follow-up period, we observed 117 cases of cardiovascular diseases. The association between sleep BP (per 10 mmHg hazard ratio = 1.31, P  < 0.001) and cardiovascular events remained significant (hazard ratio = 1.22, P  = 0.036) even after adjusting for office BP and confounding factors, such as sleep-disordered breathing. Individuals with sleep-only hypertension ( n  = 1047; hazard ratio = 2.23, P  = 0.005) had a significant cardiovascular risk. Daytime-only hypertension ( n  = 264; hazard ratio = 3.57, P  = 0.001) and combined sleep and daytime hypertension ( n  = 1216; hazard ratio = 3.69, P  < 0.001) was associated with cardiovascular events to the same extent. Sleep BP dipping was not identified as a significant determinant of cardiovascular events.

CONCLUSION

Sleep BP measured using a home BP monitor was independently associated with the incidence of cardiovascular disease in a general population.

Use of Different Blood Pressure Thresholds to Reduce the Number of Home Blood Pressure Monitoring Days Needed for Detecting Hypertension

BACKGROUND

Home blood pressure (BP) monitoring over a 7-day period is recommended to confirm the diagnosis of hypertension.

METHODS

We determined upper and lower home BP thresholds with >90% positive predictive value and >90% negative predictive value using 1 to 6 days of monitoring to identify high home BP (systolic BP ≥130 mm Hg or diastolic BP ≥80 mm Hg) based on 7 days of home BP monitoring. The sample included 361 adults from the Improving the Detection of Hypertension Study who were not taking antihypertensive medication. We used two 7-day periods, at least 3 days apart, the first being a sampling period and the second a reference period. For each number of days in the sampling period, we determined the percentage of participants who had a high likelihood of having (>90% positive predictive value) or not having (>90% negative predictive value) high BP and would not need to continue home BP monitoring. Only the participants in an uncertain category (ie, positive predictive value ≤90% and negative predictive value ≤90%) after each day were carried forward to the next day of home BP monitoring.

RESULTS

Of the 361 participants (mean [SD] age of 41.3 [13.2] years; 60.4% women), 38.0% had high home BP during the reference period. There were 63.7%, 17.1%, 10.5%, 3.3%, 3.6%, and 1.4% participants who would not need to continue after 1, 2, 3, 4, 5, and 6 days of monitoring.

CONCLUSIONS

In most people, high home BP can be identified or excluded with a high degree of confidence with 3 days or less of monitoring.

Blood pressure dynamics during home blood pressure monitoring with a digital blood pressure coach—a prospective analysis of individual user data

Introduction

Self-monitoring of blood pressure at home is a better predictor of prognosis and recommended in hypertension guidelines. However, the influence of baseline blood pressure category and measurement schedule on BP values during a period of home blood pressure monitoring (HBPM) are still poorly defined, particularly when used in conjunction with a digital application.

Methods

We analysed temporal BP changes and performed BP classification tracking in users with self-reported hypertension performing HBPM with a digital and interactive blood pressure coach.

Results

Of 3175 users who enrolled in HBPM, 74.1% completed the first measurement period. Overall, mean systolic BP dropped significantly after the first day, but stratification by BP category demonstrated that initial category influenced BP course. BP classification tracking revealed that time to reach final BP category was dependent on baseline category, with users in categories high normal and grade 1 hypertension requiring more days to decrease BP class volatility and to reach their definitive BP class. This was driven by an intense switching between directly neighbouring categories until the middle phase of the HBPM period, while more distant class switching occurred less often and only early on. Overall, &gt;90% of users maintained their category by day 5. Omitting the first day from analysis lead to therapeutically relevant reclassification in 3.8% of users. Users who completed at least two HBPM periods (n = 864) showed a mean SBP/DBP decrease of 2.6/1.6 mmHg, which improved hypertension control from 55.6% to 68.1%.

Conclusion

The optimal length of HBPM period depends on BP category. HBPM with a digital coach is associated with a reduction in average BP and improvement in BP control.

Standardized home blood pressure monitoring: Rationale behind the 722 protocol

Home blood pressure (HBP) has been recognized as a prognostic predictor for cardiovascular events, and integrated into the diagnosis and management of hypertension. With increasing accessibility of oscillometric blood pressure devices, HBP monitoring is easy to perform, more likely to obtain reliable estimation of blood pressures, and feasible to document long-term blood pressure variations, compared to office and ambulatory blood pressures. To obtain reliable HBP estimates, a standardized HBP monitoring protocol is essential. A consensus regarding the optimal duration and frequency of HBP monitoring is yet to be established. Based on the current evidence, the "722" protocol, which stands for two measurements on one occasion, two occasions a day (morning and evening), and over a consecutive of 7 days, is most commonly used in clinical studies and recommended in relevant guidelines and consensus documents. HBP monitoring based on the "722" protocol fulfills the minimal requirement of blood pressure measurements to achieve agreement of blood pressure classifications defined by office blood pressures and to predict cardiovascular risks. In the Taiwan HBP consensus, the frequency of repeating the "722" protocol of HBP monitoring according to different scenarios of hypertension management, from every 2 weeks to 3 months, is recommended. It is reasonable to conclude that the "722" protocol for HBP monitoring is clinically justified and can serve as a basis for standardized HBP monitoring.

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.

Home blood pressure monitoring schedule: optimal and minimum based on 2122 individual participants' data

OBJECTIVES

Home blood pressure (HBP) monitoring has become a primary method for hypertension diagnosis and management. This analysis aimed to investigate the optimal and minimum schedule for HBP monitoring.

METHODS

A retrospective analysis of cross-sectional data was performed, which involved HBP and 24-h ambulatory blood pressure (ABP) monitoring in adults performed within the context of clinical studies in Finland, Greece and UK. Participants with six to seven HBP monitoring days and at least 12 HBP readings were included. The stability of HBP was assessed by evaluating the average value of an increasing number of readings and its variability (SD). Its association with awake ABP was also assessed.

RESULTS

Data from 2122 participants were analysed (mean age 53.9 ± 11.3 years, males 53%, treated 34%). A progressive HBP decline was observed in succeeding days, reaching a plateau after day 3. Day 1 HBP was higher than in the next days by about 2.8/1.4 mmHg (systolic/diastolic, P < 0.001). In a 3-day HBP monitoring schedule, the exclusion of day 1 reduced average HBP and SD, with a clinically important HBP decline in 115 participants (5%) and different hypertension diagnosis in 120 participants (6%). For schedules including more than three HBP monitoring days, the exclusion of day 1 had negligible impact. The 3-day average HBP was strongly correlated with awake ABP, with a little improvement thereafter.

CONCLUSION

These data support the recommendation for 7 days of HBP monitoring with a minimum of 3 days. Readings of the first day should be discarded, particularly when the minimum 3-day monitoring schedule is obtained (average readings of second and third day).

Home blood pressure monitoring: methodology, clinical relevance and practical application: a 2021 position paper by the Working Group on Blood Pressure Monitoring and Cardiovascular Variability of the European Society of Hypertension

The present paper provides an update of previous recommendations on Home Blood Pressure Monitoring from the European Society of Hypertension (ESH) Working Group on Blood Pressure Monitoring and Cardiovascular Variability sequentially published in years 2000, 2008 and 2010. This update has taken into account new evidence in this field, including a recent statement by the American Heart association, as well as technological developments, which have occurred over the past 20 years. The present document has been developed by the same ESH Working Group with inputs from an international team of experts, and has been endorsed by the ESH.

Home Blood Pressure Control and Drug Prescription Patterns among Thai Hypertensives: A 1-Year Analysis of Telehealth Assisted Instrument in Home Blood Pressure Monitoring Nationwide Pilot Project

Background

Several interventions have been proposed to improve hypertension control with various outcomes. The home blood pressure (HBP) measurement is widely accepted for assessing the response to medications. However, the enhancement of blood pressure (BP) control with HBP telemonitoring technology has yet to be studied in Thailand.

Objective

To evaluate the attainment of HBP control and drug prescription patterns in Thai hypertensives at one year after initiating the TeleHealth Assisted Instrument in Home Blood Pressure Monitoring (THAI HBPM) nationwide pilot project.

Methods

A multicenter, prospective study enrolled treated hypertensive adults without prior regular HBPM to obtain monthly self-measured HBP using the same validated, oscillometric telemonitoring devices. The HBP reading was transferred to the clinic via a cloud-based system, so the physicians can adjust the medications at each follow-up visit on a real-life basis. Controlled HBP is defined as having HBP data at one year of follow-up within the defined target range (<135/85 mmHg).

Results

A total of 1,177 patients (mean age 58 ± 12.3 years, 59.4% women, 13.1% with diabetes) from 46 hospitals (81.5% primary care centers) were enrolled in the study. The mean clinic BP was 143.9 ± 18.1/84.3 ± 11.9 mmHg while the mean HBP was 134.4 ± 15.3/80.1 ± 9.4 mmHg with 609 (51.8%) patients having HBP reading <135/85 mmHg at enrollment. At one year of follow-up after implementing the HBP telemonitoring, 671 patients (57.0%) achieved HBP control. Patients with uncontrolled HBP had a higher prevalence of dyslipidemia and greater waist circumference than the controlled group. The majority of uncontrolled patients were still prescribed only one (36.0%) or two drugs (34.4%) at the end of the study. The antihypertensive drugs were not uptitrated in 136 (24%) patients with uncontrolled HBP at baseline. Calcium channel blocker was the most prescribed drug class (63.0%) followed by angiotensin-converting enzyme inhibitor (44.8%) while the thiazide-type diuretic was used in 18.9% of patients with controlled HBP and 16.4% in uncontrolled patients.

Conclusion

With the implementation of HBP telemonitoring, the BP control rate based on HBP analysis was still low. This is possibly attributed to the therapeutic inertia of healthcare physicians. Calcium channel blocker was the most frequently used agent while the diuretic was underutilized. The long-term clinical benefit of overcoming therapeutic inertia alongside HBP telemonitoring needs to be validated in a future study.

2020 Consensus Statement of the Taiwan Hypertension Society and the Taiwan Society of Cardiology on Home Blood Pressure Monitoring for the Management of Arterial Hypertension

To facilitate the applications of home blood pressure (HBP) monitoring in clinical settings, the Taiwan Hypertension Society and the Taiwan Society of Cardiology jointly put forward the Consensus Statement on HBP monitoring according to up-to-date scientific evidence by convening a series of expert meetings and compiling opinions from the members of these two societies. In this Consensus Statement as well as recent international guidelines for management of arterial hypertension, HBP monitoring has been implemented in diagnostic confirmation of hypertension, identification of hypertension phenotypes, guidance of anti-hypertensive treatment, and detection of hypotensive events. HBP should be obtained by repetitive measurements based on the " 722 " principle, which is referred to duplicate blood pressure readings taken per occasion, twice daily, over seven consecutive days. The " 722" principle of HBP monitoring should be applied in clinical settings, including confirmation of hypertension diagnosis, 2 weeks after adjustment of antihypertensive medications, and at least every 3 months in well-controlled hypertensive patients. A good reproducibility of HBP monitoring could be achieved by individuals carefully following the instructions before and during HBP measurement, by using validated BP devices with an upper arm cuff. Corresponding to office BP thresholds of 140/90 and 130/80 mmHg, the thresholds (or targets) of HBP are 135/85 and 130/80 mmHg, respectively. HBP-based hypertension management strategies including bedtime dosing (for uncontrolled morning hypertension), shifting to drugs with longer-acting antihypertensive effect (for uncontrolled evening hypertension), and adding another antihypertensive drug (for uncontrolled morning and evening hypertension) should be considered. Only with the support from medical caregivers, paramedical team, or tele- monitoring, HBP monitoring could reliably improve the control of hypertension.

Blood pressure control in patients with chronic kidney disease according to office and home blood pressures

OBJECTIVES

The aim of this study was to assess blood pressure (BP) control in patients with chronic kidney disease (CKD) according to office and home BP and to assess the prevalence of normal BP, white-coat uncontrolled hypertension (WUCH), masked uncontrolled hypertension (MUCH) and elevated BP.

METHODS

Patients with renal failure with or without proteinuria were included in this multicenter observational study. Office BP was first measured by the physician using a self-monitoring BP device (three automatic readings), then by the patient at home (morning and evening) over 3 consecutive days. WUCH was defined as a systolic BP (SBP)/diastolic BP (DBP) ≥140/90 mmHg in the clinic and SBP/DBP<135/85 mmHg at home. MUCH was defined as SBP/DBP <140/90 mmHg in the clinic and SBP/DBP ≥135/85 mmHg at home.

RESULTS

Among the 243 included subjects, data of 225 patients were analyzed. Mean estimated glomerular filtration rate was 37.7 ± 15.7 mL/min/1.73 m and mean office SBP/DBP was 154 ± 19/83 ± 13 mmHg. Mean office SBP/DBP was significantly higher than home SBP/DBP (+9.0 ± 15.1/+7.0 ± 10.0 mmHg, P < 0.01). Normal BP (office and home BP), WUCH, MUCH and elevated BP (office and home BP) rates were 12.0, 14.2, 6.7 and 67.1%, respectively. The patients were taking, on average, 2.8 ± 1.5 antihypertensive drugs/day.

CONCLUSION

BP control in patients with CKD was poor. Routine use of 'out-of-office' BP measurement, in addition to office BP by which we can identify patients with WUCH or MUCH, should be recommended based on the current findings.

Evaluation of blood pressure through home monitoring in brazilian primary care: a feasibility study

Blood pressure measurements taken in a clinical setting are subject to errors, therefore there are advantages to monitoring blood pressure at home, especially in in patients diagnosed with hypertension. The study describes the feasibility of home monitoring to assess blood pressure in primary care and compares blood pressure measured at home and during a medical consultation. This cross-sectional study was carried out with patients whose used home blood pressure in the morning and evening, thrice for seven consecutive day sat home. Participants included patients older than 18 years with suspected whitecoat hypertension, taking antihypertensives, or those intolerant of ambulatory blood pressure monitoring, and excluded patients who did not follow the protocol, suffered from an irregular heart rate, and pregnant women. Of the 134 patients who participated in the study, 63.3% had altered blood pressure when measured at health facilities and 48% had higher blood pressure at home. The mean difference between the methods was 10.1 mmHg for systolic and 4.3 mmHg for diastolic. The prevalence of whitecoat hypertension was 19.4%. Blood pressure monitoring at home is a practicable strategy in the Brazilian healthcare system.

Schedules for Self-monitoring Blood Pressure: A Systematic Review

BACKGROUND

Self-monitoring of blood pressure better predicts prognosis than clinic measurement, is popular with patients, and endorsed in hypertension guidelines. However, there is uncertainty over the optimal self-monitoring schedule. We therefore aimed to determine the optimum schedule to predict future cardiovascular events and determine "true" underlying blood pressure.

METHODS

Six electronic databases were searched from November 2009 (updating a National Institute for Health and Care Excellence [NICE] systematic review) to April 2017. Studies that compared aspects of self-monitoring schedules to either prognosis or reliability/reproducibility in hypertensive adults were included. Data on study and population characteristics, self-monitoring regime, and outcomes were extracted by 2 reviewers independently.

RESULTS

From 5,164 unique articles identified, 25 met the inclusion criteria. Twelve studies were included from the original NICE review, making a total of 37 studies. Increasing the number of days of measurement improved prognostic power: 72%-91% of the theoretical maximum predictive value (asymptotic maximum hazard ratio) was reached by 3 days and 86%-96% by 7 days. Increasing beyond 3 days of measurement did not result in better correlation with ambulatory monitoring. There was no convincing evidence that the timing or number of readings per day had an effect, or that ignoring the first day's measurement was necessary.

CONCLUSIONS

Home blood pressure should be measured for 3 days, increased to 7 only when mean blood pressure is close to a diagnostic or treatment threshold. Other aspects of a monitoring schedule can be flexible to facilitate patient uptake of and adherence with self-monitoring.

How to reliably diagnose arterial hypertension: lessons from 24 h blood pressure monitoring

BACKGROUND

Hypertension is a common condition in modern society. As blood pressure fluctuates with time, a single blood pressure measurement is useless to diagnose hypertension. Nevertheless, no well-defined number of measurements is often used for this purpose. Diagnosis and therapeutic control of hypertension are therefore suboptimal.

OBJECTIVE

To determine the number and timing of measurements needed to give a trustworthy approximation of an individual's average blood pressure.

METHODS

In this observational study 306 clinically indicated 24h ABPM datasets were analysed. Hypertension was defined as a daytime blood pressure mean exceeding 135/85 mm Hg. Kappa coefficients determined the best time of day for measuring blood pressure. The optimal number of measurements was estimated using canonical correlation.

RESULTS

162 (53%) patients were diagnosed with hypertension. Kappa statistics indicated that measuring during the afternoon gave the best agreement with the 24h blood pressure mean (κ = 0.78). According to canonical correlation, about 8-10 blood pressure readings give enough information for hypertension diagnosis.

CONCLUSIONS

Eight to ten blood pressure measurements between 01:00 and 05:00 p.m. are sufficient to give a clinically useful approximation of the daytime mean blood pressure and therefore for diagnosing hypertension accurately. Future research should determine the ideal dispersion of measurements and include patient characteristics which could influence the required number and timing of measurements. These results may increase the future importance of telemonitoring in diagnosing hypertension.

Number of Measurements Needed to Obtain a Reliable Estimate of Home Blood Pressure: Results From the Improving the Detection of Hypertension Study

Background Obtaining out-of-clinic blood pressure ( BP ) measurements to confirm a diagnosis of hypertension is recommended before initiating treatment. There are few empiric data available on the number of measurements required to reliably estimate BP on home BP monitoring ( HBPM ). Methods and Results We analyzed data from 316 community-dwelling adults not taking antihypertensive medication from the IDH (Improving the Detection of Hypertension) study who performed HBPM for 14 days. The reliability of home BP measurements was assessed using the intraclass correlation coefficient and as the percentage of participants with an absolute difference in home BP <10 mm Hg between weeks. The reliability of home hypertension status was assessed by the κ statistic. In the IDH study, 13.6% of participants had clinic hypertension and 18.0% had home hypertension. Mean home systolic and diastolic BP exhibited excellent reliability and sufficient agreement using the average of 2 morning and 2 evening BP readings for a minimum of 2 days of HBPM and a single morning and single evening or 2 morning BP readings for a minimum of 3 days. For diagnosing home hypertension, there was good agreement with a minimum of 3 days of HBPM using the average of 2 morning and 2 evening measurements or a single morning and single evening BP reading. A greater number of days was required for the other HBPM strategies. Conclusions Using the average of morning and evening readings, 3 days of HBPM are needed to reliably estimate mean home BP and diagnose out-of-clinic hypertension.

Recommended standards for assessing blood pressure in human research where blood pressure or hypertension is a major focus

BACKGROUND

Although inaccurate, non-reproducible blood pressure values can result from non-standardized assessments, recommended approaches to standardize blood pressure measurement are often not followed in research studies.

METHODS

An expert consensus of national and international health and scientific organizations developed recommended minimum standards for assessing blood pressure in research subjects where: 1) blood pressure or hypertension is a major endpoint, or 2) blood pressure is likely a major mediator of the research outcome.

RESULTS

Minimum research standards are presented for training of observers, technical aspects of assessing blood pressure, and equipment for both adults and children.

LIMITATIONS

The standards are based on prior recommendations some of which did not conform to the current evidence based methods.

CONCLUSIONS

All new research should require adherence to these minimum standards on the patient populations described above. Readers need to use caution in interpreting studies if the standards are not met in the defined populations.

Understanding short-term blood-pressure-variability phenotypes: from concept to clinical practice

Clinic blood pressure (BP) is recognized as the gold standard for the screening, diagnosis, and management of hypertension. However, optimal diagnosis and successful management of hypertension cannot be achieved exclusively by a handful of conventionally acquired BP readings. It is critical to estimate the magnitude of BP variability by estimating and quantifying each individual patient's specific BP variations. Short-term BP variability or exaggerated circadian BP variations that occur within a day are associated with increased cardiovascular events, mortality and target-organ damage. Popular concepts of BP variability, including "white-coat hypertension" and "masked hypertension", are well recognized in clinical practice. However, nocturnal hypertension, morning surge, and morning hypertension are also important phenotypes of short-term BP variability that warrant attention, especially in the primary-care setting. In this review, we try to theorize and explain these phenotypes to ensure they are better understood and recognized in day-to-day clinical practice.

The impact of unrecorded readings on the precision and diagnostic performance of home blood pressure monitoring: a statistical study

Hypertension is a major cardiovascular risk factor. To address the disease adequately, most clinicians rely on home blood pressure monitoring (HBPM). However, the impact of unrecorded BP values on the precision and diagnostic performance of BP schedules is unknown. We obtained 103 HBP patients schedules from a previous study. Then, readings were randomly removed from each schedule in order to create new incomplete schedules using a resampling technique. We obtained 10,000 new incomplete schedules. For each number of randomly removed readings, the percentages of incomplete schedules outside a systolic/diastolic blood pressure (SBP/DBP) range of 5/3 mmHg were calculated from the same complete patient's schedule. The sensitivity and specificity of incomplete HBPM schedules regarding BP control were also assessed. One hundred three HBPM schedules were analyzed. Mean patients' age was 67.9 ± 9.9 years. In non-diabetic patients, the mean BP of complete schedules' means was 131.9 ± 12.4/75.5 ± 10.5. In diabetic patients, the mean BP of complete schedules' means was 135.5 ± 14.0/73.4 ± 8.2 mmHg. When schedules were composed of 14 and 21 random measures, differences over 5 mmHg were seen in 2.6% and 0.1% of non-diabetic patients' schedule and 3.7% and 0.1% of diabetic patients' schedule, respectively. At 21 measurements, sensitivity and specificity were approximately 95% and 98% in non-diabetic patients and 90% and 99% in non-diabetic patients, respectively. HBPM precision and diagnostic performance improve rapidly with accumulation of readings. Incomplete schedules composed of 21 readings can provide an almost perfect diagnostic tool compared with the complete schedule reference.

The QardioArm App in the Assessment of Blood Pressure and Heart Rate: Reliability and Validity Study

BACKGROUND

Self-measurement of blood pressure is a priority strategy for managing blood pressure.

OBJECTIVE

The aim of this study was to evaluate the reliability and validity of blood pressure and heart rate following the European Society of Hypertension's international validation protocol, as measured with the QardioArm, a fully automatic, noninvasive wireless blood pressure monitor and mobile app.

METHODS

A total of 100 healthy volunteers older than 25 years from the general population of Ciudad Real, Spain, participated in a test-retest validation study with two measurement sessions separated by 5 to 7 days. In each measurement session, seven systolic blood pressure, diastolic blood pressure, and heart rate assessments were taken, alternating between the two devices. The test device was the QardioArm and the previously validated criterion device was the Omron M3. Sessions took place at a single study site with an evaluation room that was maintained at an appropriate temperature and kept free from noises and distractions.

RESULTS

The QardioArm displayed very consistent readings both within and across sessions (intraclass correlation coefficients=0.80-0.95, standard errors of measurement=2.5-5.4). The QardioArm measurements corresponded closely to those from the criterion device (r>.96) and mean values for the two devices were nearly identical. The QardioArm easily passed all validation standards set by the European Society of Hypertension International Protocol.

CONCLUSIONS

The QardioArm mobile app has validity and it can be used free of major measurement error.

A series of N-of-1 trials to assess the therapeutic interchangeability of two enalapril formulations in the treatment of hypertension in Addis Ababa, Ethiopia: study protocol for a randomized controlled trial

BACKGROUND

Hypertension is one of the leading causes of morbidity and mortality in Ethiopia. Treatment usually involves lifelong medication use. Enalapril is a common drug for the treatment of hypertension in Ethiopia. However, the drug is expensive and, therefore, there is limited capacity for people to afford the treatment. Locally produced Enalapril is a cost-effective solution to treat the disease. However, as local medicines regulation does not include bioequivalence tests on locally produced drugs, physicians and patients need assurance about the effectiveness and safety of local generics. Evidence on therapeutic equivalence is needed on these untested local drugs.

METHODS

This is a hospital-based, randomized, partially blinded, three-cycle crossover trial in single patients, comparing a locally produced version of enalapril with enalapril imported from Europe. Patients involved in this trial are not blinded, as there is no local facility to produce relatively small numbers of placebos or encapsulated drugs. To ensure blinding of study investigators and data analysts, study medications are prepared by an independent pharmacy unit using opaque medication packaging. The importance of maintaining blinding is also part of patient pre-trial education. Each N-of-1 trial will consist of three successive 14-day treatment pairs, each pair comprising 7 days of 5-20 mg local and 7 days of 5-20 mg imported enalapril taken once daily in the morning. The primary outcome will be the average difference in systolic blood pressure as measured by home blood pressure measurements.

DISCUSSION

The number of locally produced products, such as enalapril, being approved without proof of bioequivalence is dramatically increasing. By bridging the information gap on bioequivalence, the trial will give rigorous evidence on therapeutic equivalence of locally produced enalapril in the treatment of hypertension. If there is no difference, the hypothesized result, then patients can take the local medicine with confidence. This trial will also will determine whether aggregated N-of-1 studies are feasible to evaluate untested generic drugs in resource-limited countries where bioequivalence testing centers are unavailable.

TRIAL REGISTRATION NUMBER

Australian and New Zealand Clinical Trial Registry, ID: ACTRN12616001088437p . Registered on 12 August 2016.

Recommended Standards for Assessing Blood Pressure in Human Research Where Blood Pressure or Hypertension Is a Major Focus

Introduction

Although inaccurate, nonreproducible blood pressure values can result from nonstandardized assessments, recommended approaches to standardize blood pressure measurement are often not followed in research studies.

Methods

An expert consensus of national and international health and scientific organizations developed recommended minimum standards for assessing blood pressure in research subjects where: (i) blood pressure or hypertension is a major endpoint, or (ii) blood pressure is likely a major mediator of the research outcome.

Results

Minimum research standards are presented for training of observers, technical aspects of assessing blood pressure, and equipment for both adults and children.

Discussion

The standards are based on prior recommendations, some of which did not conform to current evidence-based methods. All new research should require adherence to these minimum standards on the patient populations described above. Readers need to use caution in interpreting studies if the standards are not met in the defined populations.

Patients' and clinicians' views on the optimum schedules for self-monitoring of blood pressure: a qualitative focus group and interview study

BACKGROUND

Self-monitoring of blood pressure is common but guidance on how it should be carried out varies and it is currently unclear how such guidance is viewed.

AIM

To explore patients' and healthcare professionals' (HCPs) views and experiences of the use of different self-monitoring regimens to determine what is acceptable and feasible, and to inform future recommendations.

DESIGN AND SETTING

Thirteen focus groups and four HCP interviews were held, with a total of 66 participants (41 patients and 25 HCPs) from primary and secondary care with and without experience of self-monitoring.

METHOD

Standard and shortened self-monitoring protocols were both considered. Focus groups and interviews were recorded, transcribed verbatim, and analysed using the constant comparative method.

RESULTS

Patients generally supported structured schedules but with sufficient flexibility to allow adaptation to individual routine. They preferred a shorter (3-day) schedule to longer (7-day) regimens. Although HCPs could describe benefits for patients of using a schedule, they were reluctant to recommend a specific schedule. Concerns surrounded the use of different schedules for diagnosis and subsequent monitoring. Appropriate education was seen as vital by all participants to enable a self-monitoring schedule to be followed at home.

CONCLUSION

There is not a 'one size fits all approach' to developing the optimum protocol from the perspective of users and those implementing it. An approach whereby patients are asked to complete the minimum number of readings required for accurate blood pressure estimation in a flexible manner seems most likely to succeed. Informative advice and guidance should incorporate such flexibility for patients and professionals alike.

Evaluation of the Use of Home Blood Pressure Measurement Using Mobile Phone-Assisted Technology: The iVitality Proof-of-Principle Study

Background

Mobile phone-assisted technologies provide the opportunity to optimize the feasibility of long-term blood pressure (BP) monitoring at home, with the potential of large-scale data collection.

Objective

In this proof-of-principle study, we evaluated the feasibility of home BP monitoring using mobile phone-assisted technology, by investigating (1) the association between study center and home BP measurements; (2) adherence to reminders on the mobile phone to perform home BP measurements; and (3) referrals, treatment consequences and BP reduction after a raised home BP was diagnosed.

Methods

We used iVitality, a research platform that comprises a Website, a mobile phone-based app, and health sensors, to measure BP and several other health characteristics during a 6-month period. BP was measured twice at baseline at the study center. Home BP was measured on 4 days during the first week, and thereafter, at semimonthly or monthly intervals, for which participants received reminders on their mobile phone. In the monthly protocol, measurements were performed during 2 consecutive days. In the semimonthly protocol, BP was measured at 1 day.

Results

We included 151 participants (mean age [standard deviation] 57.3 [5.3] years). BP measured at the study center was systematically higher when compared with home BP measurements (mean difference systolic BP [standard error] 8.72 [1.08] and diastolic BP 5.81 [0.68] mm Hg, respectively). Correlation of study center and home measurements of BP was high (R=0.72 for systolic BP and 0.72 for diastolic BP, both P<.001). Adherence was better in participants measuring semimonthly (71.4%) compared with participants performing monthly measurements (64.3%, P=.008). During the study, 41 (27.2%) participants were referred to their general practitioner because of a high BP. Referred participants had a decrease in their BP during follow-up (mean difference final and initial [standard error] −5.29 [1.92] for systolic BP and −2.93 [1.08] for diastolic BP, both P<.05).

Conclusion

Mobile phone-assisted technology is a reliable and promising method with good adherence to measure BP at home during a 6-month period. This provides a possibility for implementation in large-scale studies and can potentially contribute to BP reduction.

Does Antihypertensive Drug Class Affect Day-to-Day Variability of Self-Measured Home Blood Pressure? The HOMED-BP Study

Background

Recent literature suggests that blood pressure variability (BPV) predicts outcome beyond blood pressure level (BPL) and that antihypertensive drug classes differentially influence BPV. We compared calcium channel blockers, angiotensin‐converting enzyme inhibitors, and angiotensin receptor blockade for effects on changes in self‐measured home BPL and BPV and for their prognostic significance in newly treated hypertensive patients.

Methods and Results

We enrolled 2484 patients randomly allocated to first‐line treatment with a calcium channel blocker (n=833), an angiotensin‐converting enzyme inhibitor (n=821), or angiotensin receptor blockade (n=830). Home blood pressures in the morning and evening were measured for 5 days off treatment before randomization and for 5 days after 2 to 4 weeks of randomized drug treatment. We assessed BPL and BPV changes as estimated by variability independent of the mean and compared cardiovascular outcomes. Home BPL response in each group was significant (P≤0.0001) but small in the angiotensin‐converting enzyme inhibitor group (systolic/diastolic: 4.6/2.8 mm Hg) compared with the groups treated with a calcium channel blocker (systolic/diastolic: 8.3/3.9 mm Hg) and angiotensin receptor blockade (systolic/diastolic: 8.2/4.5 mm Hg). In multivariable adjusted analyses, changes in home variability independent of the mean did not differ among the 3 drug classes (P≥0.054). Evening variability independent of the mean before treatment significantly predicted hard cardiovascular events independent of the corresponding home BPL (P≤0.022), whereas BPV did not predict any cardiovascular outcome based on the morning measurement (P≥0.056). Home BPV captured after monotherapy had no predictive power for cardiovascular outcome (P≥0.22).

Conclusions

Self‐measured home evening BPV estimated by variability independent of the mean had prognostic significance, whereas antihypertensive drug classes had no significant impact on BPV changes. Home BPL should remain the primary focus for risk stratification and treatment.

Clinical Trial Registration

URL: http://www.umin.ac.jp/ctr/index.htm. Unique identifier: C000000137.

Target Organ Complications and Cardiovascular Events Associated With Masked Hypertension and White-Coat Hypertension: Analysis From the Dallas Heart Study

BACKGROUND

Multiple epidemiological studies from Europe and Asia have demonstrated increased cardiovascular risks associated with isolated elevation of home blood pressure (BP) or masked hypertension (MH). Previous studies have not addressed cardiovascular outcomes associated with MH and white-coat hypertension (WCH) in the general population in the United States.

OBJECTIVES

The goal of this study was to determine hypertensive target organ damage and adverse cardiovascular outcomes associated with WCH (high clinic BP, ≥140/90 mm Hg; normal home BP, <135/85 mm Hg), MH (high home BP, ≥135/85 mm Hg; normal clinic BP, <140/90 mm Hg), and sustained hypertension (high home and clinic BP) in the DHS (Dallas Heart Study), a large, multiethnic, probability-based population cohort.

METHODS

Associations among WCH, MH, sustained hypertension, and aortic pulsed wave velocity by magnetic resonance imaging; urinary albumin-to-creatinine ratio; and cystatin C were evaluated at study baseline. Then, associations between WCH and MH with incident cardiovascular outcomes (coronary heart disease, stroke, atrial fibrillation, heart failure, and cardiovascular death) over a median follow-up period of 9 years were assessed.

RESULTS

The study cohort comprised 3,027 subjects (50% African Americans). The sample-weighted prevalence rates of WCH and MH were 3.3% and 17.8%, respectively. Both WCH and MH were independently associated with increased aortic pulsed wave velocity, cystatin C, and urinary albumin-to-creatinine ratio. Both WCH (adjusted hazard ratio: 2.09; 95% confidence interval: 1.05 to 4.15) and MH (adjusted hazard ratio: 2.03; 95% confidence interval: 1.36 to 3.03) were independently associated with higher cardiovascular events compared with the normotensive group, even after adjustment for traditional cardiovascular risk factors.

CONCLUSIONS

In a multiethnic U.S. population, both WCH and MH were independently associated with increased aortic stiffness, renal injury, and incident cardiovascular events. Because MH is common and associated with an adverse cardiovascular profile, home BP monitoring should be routinely performed among U.S. adults.