Validation of the Raycome model M2 ambulatory blood pressure monitor in the general population according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization Universal Standard (ISO 81060-2:2018)

OBJECTIVE

The aim of this study was to evaluate the accuracy of the Raycome model M2 oscillometric upper-arm blood pressure (BP) monitor developed for ambulatory BP measurement in the general population according to the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Universal Standard (ISO 81060-2:2018) at rest and during dynamic exercise.

METHOD

Subjects were recruited to fulfill the age, gender, BP and cuff distribution criteria of the AAMI/ESH/ISO Universal Standard in the general population using the same arm sequential BP measurement method. Three cuffs of the test device were used for arm circumference 18-22 cm (small), 22-32 cm (medium) and 32-42 cm (large).

RESULTS

For the general validation study, 106 subjects were recruited and 85 were analyzed. For validation criterion 1, the mean ± SD of the differences between the test device and reference BP readings was 0.5 ± 6.2/-0.2 ± 5.1 mmHg (systolic/diastolic). For criterion 2, the SD of the mean BP differences between the test device and reference BP per subject was 5.23/4.50 mmHg (systolic/diastolic). In the ambulatory validation study ( N  = 35), the mean difference was 0.4 ± 5.9/-1.1 ± 5.8 mmHg. The Raycome model M2 performed well against the standard in both the general and ambulatory validations and the Bland-Altman plots did not show any systematic variation in the error.

CONCLUSION

These data show that the Raycome model M2 monitor meets the requirements of the AAMI/ESH/ISO Universal Standard (ISO 81060-2:2018) and in the ambulatory setting, indicating its suitability for measuring BP in the general population.

Empowering Low-Income Patients with Home Blood Pressure Monitors to Improve Hypertension Control

INTRODUCTION

Effective management of hypertension (HTN) is a priority in primary care. With telehealth now considered a staple care delivery method, uninsured and low-income patients without home blood pressure (BP) monitors may need additional attention and resources to achieve successful HTN control.

METHODS

This prospective study at an underserved community clinic assessed the impact of distributing free BP monitors on patients' HTN control and therapy adherence. Enrollees were randomized into 2 groups, both completing 4 primary care physician (PCP) visits over a 6-month study period. Intervention participants collected home BP readings to report to their PCP and comparison participants completed an equivalent number of visits without having home BP data available for their PCP to review. Both groups completed an initial and final Therapy Adherence Scale (TAS) questionnaire.

RESULTS

263 patients were invited and 200 participants (mean age 50, 60% female, 19% Black, 67% Hispanic) completed the study. Intervention and comparison subjects featured comparable initial BP levels and TAS scores. After adjusting for age, race, ethnicity, sex, presence of diabetes and therapy adherence, intervention participants experienced higher odds of controlled HTN (OR 4.0; 95% Confidence Interval 2.1 to 7.7). A greater proportion of participants achieved BP control in the intervention arm compared with the comparison arm (82% vs 54% of participants, P < .001). TAS scores were higher in the intervention group (Mean = 44.1 vs 41.1; P < .001).

DISCUSSION

The provision of free home BP monitors to low-income patients may feasibly and effectively improve BP control and therapy adherence.

Availability, Cost, and Consumer Ratings of Popular Nonvalidated vs Validated Blood Pressure-Measuring Devices Sold Online in 10 Countries

This study examines the availability, cost, and consumer ratings of blood pressure–measuring devices relative to validation status across 10 countries.

Choice of home blood pressure monitoring device: the role of device characteristics among Alaska Native and American Indian peoples

BACKGROUND

Home blood pressure monitoring (HBPM) is an effective tool in treatment and long-term management of hypertension. HBPM incorporates more data points to help patients and providers with diagnosis and management. The characteristics of HBPM devices matter to patients, but the relative importance of the characteristics in choosing a device remains unclear.

METHODS

We used data from a randomized cross-over pilot study with 100 Alaska Native and American Indian (ANAI) people with hypertension to assess the choice of a wrist or arm HBPM device. We use a random utility framework to evaluate the relationship between stated likely use, perceived accuracy, ease of use, comfort, and participant characteristics with choice of device. Additional analyses examined willingness to change to a more accurate device.

RESULTS

Participants ranked the wrist device higher compared to the arm on a 5-point Likert scale for likely use, ease of use, and comfort (0.3, 0.5, 0.8 percentage points, respectively). Most participants (66%) choose the wrist device. Likely use (wrist and arm devices) was related to the probability of choosing the wrist (0.7 and - 1.4 percentage points, respectively). Independent of characteristics, 75% of participants would be willing to use the more accurate device. Ease of use (wrist device) and comfort (arm device) were associated with the probability of changing to a more accurate device (- 1.1 and 0.5 percentage points, respectively).

CONCLUSION

Usability, including comfort, ease, and likely use, appeared to discount the relative importance of perceived accuracy in the device choice. Our results contribute evidence that ANAI populations value accurate HBPM, but that the devices should also be easy to use and comfortable to facilitate long-term management.

Lack of Acceptance of Digital Healthcare in the Medical Market: Addressing Old Problems Raised by Various Clinical Professionals and Developing Possible Solutions

Various digital healthcare devices and apps, such as blood glucose meters, blood pressure monitors, and step-trackers are commonly used by patients; however, digital healthcare devices have not been widely accepted in the medical market as of yet. Despite the various legal and privacy issues involved in their use, the main reason for its poor acceptance is that users do not use such devices voluntarily and continuously. Digital healthcare devices generally do not provide valuable information to users except for tracking self-checked glucose or walking. To increase the use of these devices, users must first understand the health data produced in the context of their personal health, and the devices must be easy to use and integrated into everyday life. Thus, users need to know how to manage their own data. Medical staff must teach and encourage users to analyze and manage their patient-generated healthcare data, and users should be able to find medical values from these digital devices. Eventually, a single customized service that can comprehensively analyze various medical data to provide valuable customized services to users, and which can be linked to various heterogeneous digital healthcare devices based on the integration of various health data should be developed. Digital healthcare professionals should have detailed knowledge about a variety of digital healthcare devices and fully understand the advantages and disadvantages of digital healthcare to help patients understand and embrace the use of such devices.

Home Blood Pressure Monitoring Devices: Device Performance in an Alaska Native and American Indian Population

Objectives: Home blood pressure monitoring (HBPM) is an important component of blood pressure (BP) management. We assessed performance of two HBPM devices among Alaska Native and American Indian people (ANAIs). Methods: We measured BP using Omron BP786 arm cuff, Omron BP654 wrist cuff, and Baum aneroid sphygmomanometer in 100 ANAIs. Performance was assessed with intraclass correlation, paired t-tests, and calibration models. Results: Compared to sphygmomanometer, average BP was higher for wrist cuff (systolic = 4.8 mmHg and diastolic = 3.6 mmHg) and varied for arm cuff (systolic = -1.5 mmHg and diastolic = 2.5 mmHg). Calibration increased performance from grade B to A for arm cuff and from D to B for wrist cuff. Calibration increased false negatives and decreased false positives. Discussion: The arm HBPM device is more accurate than the wrist cuff among ANAIs with hypertension. Most patients are willing to use the arm cuff when accuracy is discussed.

Detection of Atrial Fibrillation Using a Home Blood Pressure Monitor

PURPOSE

Atrial fibrillation (AF) is the most common arrhythmia and is associated with an increased risk of complications. A screening test has the potential to prevent AF-related complications. This study investigated the diagnostic accuracy of an automated device for home blood pressure (BP) monitoring, which implements an algorithm for AF detection.

PATIENTS AND METHODS

A modified, automated oscillometric device for home BP monitoring (Omron BP785N (HEM-7321-Z), Omron Healthcare) with an AF detector was used to measure the BP in patients. During each BP measurements, the electrocardiogram (ECG) was recorded simultaneously. Simultaneous BP measurements and ECG recordings were obtained from 99 subjects.

RESULTS

Twenty out of 20 patients with atrial fibrillation were correctly recognized by the device and the device correctly identified 67 patients with sinus rhythm as "Not-AF". On the other hand, 12 patients with basic rhythm: sinus rhythm were incorrectly referred to as "atrial fibrillation". In summary, the device has a diagnostic accuracy of 87.88% with a sensitivity of 100% and a specificity of 84.8%. On the other hand, in 23 patients, the raw data of the device showed that a body movement occurred during the measurement of the blood pressure. If these subjects were excluded of the analysis, then the diagnostic accuracy of the device would be even better, namely 90.79%. The sensitivity would be 100% and the specificity 89.5%.

CONCLUSION

These data suggest that an automated device for home blood pressure has an excellent diagnostic accuracy for detecting an AF and could be used as a reliable screening test for early diagnosis of atrial fibrillation. Body movements have an impact of the accuracy and specificity of a blood pressure monitor.

Sociodemographic Characteristics Predicting Digital Health Intervention Use After Acute Myocardial Infarction

Increasing evidence suggests that digital health interventions (DHIs) are an effective tool to reduce hospital readmissions by improving adherence to guideline-directed therapy. We investigated whether sociodemographic characteristics influence use of a DHI targeting 30-day readmission reduction after acute myocardial infarction (AMI). Covariates included age, sex, race, native versus loaner iPhone, access to a Bluetooth-enabled blood pressure monitor, and disease severity as marked by treatment with CABG. Age, sex, and race were not significantly associated with DHI use before or after covariate adjustment (fully adjusted OR 0.98 (95%CI: 0.95-1.01), 0.6 (95%CI: 0.29-1.25), and 1.22 (95% CI: 0.60-2.48), respectively). Being married was associated with high DHI use (OR 2.12; 95% CI 1.02-4.39). Our findings suggest that DHIs may have a role in achieving equity in cardiovascular health given similar use by age, sex, and race. The presence of a spouse, perhaps a proxy for enhanced caregiver support, may encourage DHI use.

Automated office BP measurement: The new standard in HTN screening

Obtain greater accuracy in blood pressure measurement with an automated office device.

Home blood pressure monitoring in the diagnosis and treatment of hypertension in pregnancy: a systematic review and meta-analysis

BACKGROUND

Home blood pressure monitoring is increasingly used for pregnant individuals; however, there are no guidelines on such monitoring in this population. We assessed current practices in the prescription and use of home blood pressure monitoring in pregnancy.

METHODS

We conducted a systematic review and meta-analysis of observational studies and randomized controlled trials (RCTs). We conducted a structured search through the MEDLINE (from 1946), Embase (from 1974) and CENTRAL (from 2018) databases up to Oct. 19, 2020. We included trials comparing office and home blood pressure monitoring in pregnant people. Outcomes included patient education, home blood pressure device, monitoring schedule, adherence, diagnostic thresholds for home blood pressure, and comparison between home and office measurements of blood pressure.

RESULTS

We included in our review 21 articles on 19 individual studies (1 RCT, 18 observational) that assessed home and office blood pressure in pregnant individuals (n = 2843). We observed variation in practice patterns in terms of how home monitoring was prescribed. Eight (42%) of the studies used validated home blood pressure devices. Across all studies, measurements were taken 3 to 36 times per week. Third-trimester home blood pressure corresponding to office blood pressure of 140/90 mm Hg after application of a conversion factor ranged from 118 to 143 mm Hg (systolic) and from 76 to 92 mm Hg (diastolic), depending on the patient population and methodology. Systolic and diastolic blood pressure values measured at home were lower than office values by 4 (95% confidence interval [CI] -6 to -3) mm Hg and 3 (95% CI -4 to -2) mm Hg, respectively.

INTERPRETATION

Many issues related to home blood pressure monitoring in pregnancy are currently unresolved, including technique, monitoring schedule and target values. Future studies should prioritize the use of validated home measuring devices and standardized measurement schedules and should establish treatment targets.

PROSPERO REGISTRATION

CRD42020147352.

Towards Continuous and Ambulatory Blood Pressure Monitoring: Methods for Efficient Data Acquisition for Pulse Transit Time Estimation

We developed a prototype for measuring physiological data for pulse transit time (PTT) estimation that will be used for ambulatory blood pressure (BP) monitoring. The device is comprised of an embedded system with multimodal sensors that streams high-throughput data to a custom Android application. The primary focus of this paper is on the hardware–software codesign that we developed to address the challenges associated with reliably recording data over Bluetooth on a resource-constrained platform. In particular, we developed a lossless compression algorithm that is based on optimally selective Huffman coding and Huffman prefixed coding, which yields virtually identical compression ratios to the standard algorithm, but with a 67–99% reduction in the size of the compression tables. In addition, we developed a hybrid software–hardware flow control method to eliminate microcontroller (MCU) interrupt-latency related data loss when multi-byte packets are sent from the phone to the embedded system via a Bluetooth module at baud rates exceeding 115,200 bit/s. The empirical error rate obtained with the proposed method with the baud rate set to 460,800 bit/s was identically equal to 0%. Our robust and computationally efficient physiological data acquisition system will enable field experiments that will drive the development of novel algorithms for PTT-based continuous BP monitoring.

Wearable Wireless-Enabled Oscillometric Sphygmomanometer: A Flexible Ambulatory Tool for Blood Pressure Estimation

This article presents the design of an unobtrusive and wireless-enabled blood pressure (BP) monitoring system that is suitable for ambulatory use. By adopting low-profile electromechanical actuators and a compact printed circuit board design, this lightweight device can be worn directly on the occlusive cuff, therefore eliminating the need of a long and obtrusive tubing interconnect between the device and the cuff, as seen in traditional ambulatory BP monitors (ABPM). Instead of executing the BP estimation algorithm directly on the device, the proposed design rather sends the raw oscillometric signal through a Bluetooth Low Energy link, thus granting any Bluetooth-enabled device to gather and process the signal using a dedicated application. This in turn allows to assess several BP estimation algorithms found in the literature without being limited by the device resources. Three of them were tested with the designed prototype and validated with a reference equipment on 11 subjects. Overall, two of the algorithms revealed a mean absolute difference with the reference equipment of less than 5 mmHg and almost zero bias along with a standard deviation of less than 6 mmHg. Reproducibility results shown a mean difference between successive measurements of less than 3.1 mmHg and a standard deviation of less than 2.4 mmHg. The assembled prototype dimensions are 63.8 × 134.8 × 24.8 mm and features an autonomy of 63.1 hours. Comparison with commercial ABPM devices shown that the proposed design is 18% to 33% smaller volume-wise, 5% to 27% weight-wise and height is reduced by 17% to 25%.

Self-Measured Blood Pressure Monitoring at Home: A Joint Policy Statement From the American Heart Association and American Medical Association

The diagnosis and management of hypertension, a common cardiovascular risk factor among the general population, have been based primarily on the measurement of blood pressure (BP) in the office. BP may differ considerably when measured in the office and when measured outside of the office setting, and higher out-of-office BP is associated with increased cardiovascular risk independent of office BP. Self-measured BP monitoring, the measurement of BP by an individual outside of the office at home, is a validated approach for out-of-office BP measurement. Several national and international hypertension guidelines endorse self-measured BP monitoring. Indications include the diagnosis of white-coat hypertension and masked hypertension and the identification of white-coat effect and masked uncontrolled hypertension. Other indications include confirming the diagnosis of resistant hypertension and detecting morning hypertension. Validated self-measured BP monitoring devices that use the oscillometric method are preferred, and a standardized BP measurement and monitoring protocol should be followed. Evidence from meta-analyses of randomized trials indicates that self-measured BP monitoring is associated with a reduction in BP and improved BP control, and the benefits of self-measured BP monitoring are greatest when done along with cointerventions. The addition of self-measured BP monitoring to office BP monitoring is cost-effective compared with office BP monitoring alone or usual care among individuals with high office BP. The use of self-measured BP monitoring is commonly reported by both individuals and providers. Therefore, self-measured BP monitoring has high potential for improving the diagnosis and management of hypertension in the United States. Randomized controlled trials examining the impact of self-measured BP monitoring on cardiovascular outcomes are needed. To adequately address barriers to the implementation of self-measured BP monitoring, financial investment is needed in the following areas: improving education and training of individuals and providers, building health information technology capacity, incorporating self-measured BP readings into clinical performance measures, supporting cointerventions, and enhancing reimbursement.

HOspital care versus TELemonitoring in high-risk pregnancy (HOTEL): study protocol for a multicentre non-inferiority randomised controlled trial

INTRODUCTION

Pregnant women faced with complications of pregnancy often require long-term hospital admission for maternal and/or fetal monitoring. Antenatal admissions cause a burden to patients as well as hospital resources and costs. A telemonitoring platform connected to wireless cardiotocography (CTG) and automated blood pressure (BP) devices can be used for telemonitoring in pregnancy. Home telemonitoring might improve autonomy and reduce admissions and thus costs. The aim of this study is to compare the effects on patient safety, satisfaction and cost-effectiveness of hospital care versus telemonitoring (HOTEL) as an obstetric care strategy in high-risk pregnancies requiring daily monitoring.

METHODS AND ANALYSIS

The HOTEL trial is an ongoing multicentre randomised controlled clinical trial with a non-inferiority design. Eligible pregnant women are >26+0 weeks of singleton gestation requiring monitoring because of pre-eclampsia (hypertension with proteinuria), fetal growth restriction, preterm rupture of membranes without contractions, recurrent reduced fetal movements or an intrauterine fetal death in a previous pregnancy.Randomisation takes place between traditional hospitalisation (planned n=208) versus telemonitoring (planned n=208) until delivery. Telemonitoring at home is facilitated with Sense4Baby CTG devices, Microlife BP monitor and daily telephone calls with an obstetric healthcare professional as well as weekly hospital visits.Primary outcome is a composite of adverse perinatal outcome, defined as perinatal mortality, 5 min Apgar <7 or arterial cord blood pH <7.05, maternal morbidity (eclampsia, HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome, thromboembolic event), neonatal intensive care admission and caesarean section rate. Patient satisfaction and preference of care will be assessed using validated questionnaires. We will perform an economic analysis. Outcomes will be analysed according to the intention to treat principle.

ETHICS AND DISSEMINATION

The study protocol was approved by the Ethics Committee of the Utrecht University Medical Center and the boards of all six participating centres. Trial results will be submitted to peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NTR6076.

The Potential of mHealth Applications in Improving Resistant Hypertension Self-Assessment, Treatment and Control

PURPOSE OF REVIEW

To review the evidence supporting the use of mobile health (mHealth) apps to improve resistant hypertension self-assessment, treatment and control.

RECENT FINDINGS

mHealth apps have been used to directly measure blood pressure (BP) levels, either using the oscillometric method with automated inflatable cuffs or using pulse wave signals detected by smartphone technology without the need for cuffs. These app-based BP monitors tend to over or underestimate BP levels when compared to a gold standard aneroid sphygmomanometer. However, the differences in BP measurements are within the acceptable range of 5 mmHg pre-defined by the European Society of Hypertension International Protocol Revision 2010. mHealth apps are also used as tools to support physicians in improving hypertension treatment. App-based clinical decision support systems are innovative solutions, in which patient information is entered in the app and management algorithms provide recommendations for hypertension treatment. The use of these apps has been shown to be feasible and easily integrated into the workflow of healthcare professionals, and, therefore particularly useful in resource-limited settings. In addition, apps can be used to improve hypertension control by facilitating regular BP monitoring, communication between patients and health professionals, and patient education; as well as by reinforcing behaviours through reminders, including medication-taking and appointment reminders. Several studies provided evidence supporting the use of apps for hypertension control. Although some of the results are promising, there is still limited evidence on the benefits of using such mHealth tools, as these studies are relatively small and with a short-term duration. Recent research has shown that mHealth apps can be beneficial in terms of improving hypertension self-assessment, treatment and control, being especially useful to help differentiate and manage true and pseudo-resistant hypertension. However, future research, including large-scale randomised clinical trials with user-centred design, is crucial to further evaluate the potential scalability and effectiveness of such mHealth apps in the resistant hypertension context.

Non-Invasive Device for Blood Pressure Wave Acquisition by Means of Mechanical Transducer

Blood pressure wave monitoring provides interesting information about the patient’s cardiovascular function. For this reason, this article proposes a non-invasive device capable of capturing the vibrations (pressure waves) produced by the carotid artery by means of a pressure sensor encapsulated in a closed dome filled with air. When the device is placed onto the outer skin of the carotid area, the vibrations of the artery will exert a deformation in the dome, which, in turn, will lead to a pressure increase in its inner air. Then, the sensor inside the dome captures this pressure increase. By combining the blood pressure wave obtained with this device together with the ECG signal, it is possible to help the screening of the cardiovascular system, obtaining parameters such as heart rate variability (HRV) and pulse transit time (PTT). The results show how the pressure wave has been successfully obtained in the carotid artery area, discerning the characteristic points of this signal. The features of this device compare well with previous works by other authors. The main advantages of the proposed device are the reduced size, the cuffless condition, and the potential to be a continuous ambulatory device. These features could be exploited in ambulatory tests.

The accuracy of blood pressure measurement by a smartwatch and a portable health device

Objectives: Handheld medical devices and smartwatches that measure BP without a cuff have recently become available. Since these measurements are relatively more user-friendly than conventional cuff-based measurements they may aid in more frequent BP monitoring. We investigated the accuracy and precision of two popular cuff-less devices: the Everlast smartwatch and the BodiMetrics Performance Monitor.Methods: We enrolled 127 patients from the Thomas Jefferson University Hospital Preadmission Testing Center. Research staff were trained to measure BP according to manufacturer guidelines for the investigational devices. The Everlast smartwatch provides measurements of systolic (SBP) and diastolic (DBP) BP, whereas the Bodimetrics only provides SBP. Reference BP measurements were obtained using a hospital-grade automated sphygmomanometer. After 5 minutes of quiet sitting, four standard and three investigational BP measurements were taken with sixty seconds in between each measurement. The reference BP value was calculated by determining the average of the 2 standard BP measurements that bounded the investigational measurements. We thus determined 3 comparison pairs for each investigational device in each subject. We calculated the mean (SD) of the absolute difference between the respective investigational devices and the reference for SBP and DBP.Results: Data from 42 individuals was excluded because of variation in standard BP measurements per prespecified rules. Of 85 participants used for analysis, 36 (42%) were women, the mean (SD) age was 53 (21) years, 32 (38%) self-reported hypertension, and 97% of these (n = 31) reported taking antihypertensive medications. The average differences between the Everlast watch and reference were 16.9 (13.5) mm Hg for SBP and 8.3 (6.1) mm Hg for DBP. The average difference between the Bodimetrics performance monitor and the reference was 5.3 (4.7) mm Hg for SBP.Conclusions: The Everlast smartwatch and the BodiMetrics Performance Monitor we tested are not accurate enough to be used as BP measurement devices.

Transcapillary Refilling Rate and Its Determinants during Haemodialysis with Standard and High Ultrafiltration Rates

BACKGROUND

Achieving euvolaemia using ultrafiltration (UF) during haemodialysis (HD) without inducing haemodynamic instability presents a major clinical challenge. Transcapillary refill is a key factor in sustaining the circulating blood volume (BV) during UF, which is in turn predicted by the rate of refilling. However, absolute plasma refilling rate (PRR), its determinants and variability with UF rate (UFR), have not been reported in the literature.

METHOD

We studied paired HD sessions (n = 48) in 24 patients over 2 consecutive mid-week HD treatments. Plasma refilling was measured using real-time, minute-by-minute relative BV changes obtained from the integrated BV monitoring device during UF. A fixed bolus dilution approach at the start of HD was used to calculate absolute BV. The first control HD session was undertaken with a standard UFR required to achieve the prescribed target weight, while during the second study session, a fixed (high) UFR (1 L/h) was applied, either in the first (n = 12 patients) or in the final hour (n = 12 patients) of the HD session. Participants' had their hydration status measured pre- and post-HD using multifrequency bioimpedance (BIS). Blood pressure was measured at 15-min intervals and blood samples were collected at 7 intervals during HD sessions.

RESULTS

The mean PRR during a standard 4-hr HD session was 4.3 ± 2.0 mL/kg/h and varied between 2 and 6 mL/kg/h. There was a mean time delay of 22 min (range 13.3-35.0 min) for onset of plasma refilling after the application of UF irrespective of standard or high UFRs. The maximum refilling occurred during the second hour of HD (mean max PRR 6.8 mL/kg/h). UFR (beta = 0.60, p < 0.01) and BIS derived pre-HD overhydration index (beta = 0.44, p = 0.01) were consistent, independent predictors of the mean PRR (R2 = 0.49) in all HD sessions. At high UFRs, PRR exceeded 10 mL/kg/h. The total overall plasma refill contribution to UF volume was not significantly different between standard and high UF. During interventions no significant haemodynamic instability was observed in the study.

CONCLUSION

We describe absolute transcapillary refilling rate and its profile during HD with UF. The findings provide the basis for the development of UF strategies to match varying PRRs during HD. An approach to fluid removal, which is tailored to patients' refilling rates and capacity, provides an opportunity for more precision in the practice of UF.

Monitoring Pulmonary Arterial Hypertension Using an Implantable Hemodynamic Sensor

BACKGROUND

Pulmonary arterial hypertension (PAH) is a chronic disease that ultimately progresses to right-sided heart failure (HF) and death. Close monitoring of pulmonary artery pressure (PAP) and right ventricular (RV) function allows clinicians to appropriately guide therapy. However, the burden of commonly used methods to assess RV hemodynamics, such as right heart catheterization, precludes frequent monitoring. The CardioMEMS HF System (Abbott) is an ambulatory implantable hemodynamic monitor, previously only used in patients with New York Heart Association (NYHA) class III HF. In this study, we evaluate the feasibility and early safety of monitoring patients with PAH and right-sided HF using the CardioMEMS HF System.

METHODS

The CardioMEMS HF sensors were implanted in 26 patients with PAH with NYHA class III or IV right-sided HF (51.3 ± 18.3 years of age, 92% women, 81% NYHA class III). PAH therapy was tracked using a minimum of weekly reviews of CardioMEMS HF daily hemodynamic measurements. Safety, functional response, and hemodynamic response were tracked up to 4 years with in-clinic follow-ups.

RESULTS

The CardioMEMS HF System was safely used to monitor PAH therapy, with no device-related serious adverse events observed and a single preimplant serious adverse event. Significant PAP reduction and cardiac output elevation were observed as early as 1 month postimplant using trends of CardioMEMS HF data, coupled with significant NYHA class and quality of life improvements within 1 year.

CONCLUSIONS

The CardioMEMS HF System provided useful information to monitor PAH therapy, and demonstrated short- and long-term safety. Larger clinical trials are needed before its widespread use to guide therapy in patients with severe PAH with right-sided HF.

Validation of two watch-type wearable blood pressure monitors according to the ANSI/AAMI/ISO81060-2:2013 guidelines: Omron HEM-6410T-ZM and HEM-6410T-ZL

There is growing evidence of the clinical significance of daytime masked hypertension (MHT) and blood pressure (BP) variability (BPV). Recently, watch-type wearable devices for self-BP measurement have become available. Such devices might be promising tools to identify patients with daytime MHT or large BPV in their real-life conditions. The present study aimed to validate the accuracy of the Omron HEM-6410T-ZM and the Omron HEM-6410T-ZL, which are automatic watch-type wearable devices for self-BP measurement, according to the American National Standards Institute, Inc/Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 81060-2:2013 guideline. Watches were held with the wrist at heart level. The mean differences between reference BPs and HEM-6410T-ZM readings were -0.9 ± 7.6/-1.1 ± 6.1 mm Hg for systolic BP (SBP)/diastolic BP (DBP) for criterion 1, and -0.9 ± 6.8/-1.1 ± 5.5 mm Hg for SBP/DBP for criterion 2. The mean differences between reference BPs and HEM-6410T-ZL readings were 2.4 ± 7.3/0.7 ± 7.0 mm Hg for SBP/DBP for criterion 1, and 2.4 ± 6.5/0.7 ± 6.5 mm Hg for SBP/DBP for criterion 2. The Omron HEM-6410T-ZM and the Omron HEM-6410T-ZL both fulfilled both validation criteria 1 and 2 of the ANSI/AAMI/ISO 81060-2:2013 guidelines.

Ambulatory Fontan pressure monitoring: Results from the implantable hemodynamic monitor Fontan feasibility cohort (IHM-FFC)

BACKGROUND

Implantable invasive hemodynamic monitoring (IHM) using the CardioMEMS™ HF system has been shown to reduce heart failure (HF) hospitalizations. IHMs have not yet been used in congenital heart disease (CHD). We aimed to evaluate feasibility and mid-term outcomes of IHM use in the single ventricle/Fontan population.

METHODS

Six adult Fontan patients (>1 HF admission, NYHA FC >3) were enrolled (30 ± 7 years old, mean pulmonary artery pressure (mPA) 16 ± 4.7 mm Hg). Heart failure mediated events (HFME) were evaluated for 12 months: CV medication change, hospital admission, paracentesis, and change in orthotopic heart transplant (OHT) listing status.

RESULTS

The IHM device was successfully placed in all participants. In total there were 671 IHM transmissions and 25(3.7%) HFME. The mean PA pressure across all episodes was 18.2 ± 6.6 mm Hg (range 6-40 mm Hg). Higher mPA pressures were associated with greater odds of having a HFME (OR 1.17 [1.09, 1.25], p < 0.0001). Mean PA pressure had good ability to discriminate transmissions associated with HFME (AUC 0.76 [0.654, 0.866]), with mean PA pressures >24 mm Hg or individual mPA change >4 mm Hg, best discriminating transmissions associated with HFME.

CONCLUSIONS

In the first feasibility series of adult Fontan patients undergoing CardioMEMS™ implantation we demonstrate early technical success and no device-related adverse events. We propose that ambulatory mean PA pressures >24 mm Hg or individual mPA change >4 mm Hg may be associated with more HFME. Further large-scale studies in this population are recommended.

Is home blood-pressure monitoring in hypertensive disorders of pregnancy consistent with clinic recordings?

OBJECTIVE

To assess the agreement between home blood-pressure monitoring (HBPM) and blood-pressure measurements in a clinic setting, in a cohort of pregnant women with hypertensive disorders of pregnancy (HDP).

METHODS

This was a cohort study of 147 pregnant women with HDP conducted at St George's Hospital, University of London, London, UK, between 2016 and 2017. Inclusion criteria were chronic hypertension, gestational hypertension or high risk of developing pre-eclampsia, no significant proteinuria and no hematological or biochemical abnormalities. Each included patient was prescribed a personalized schedule of hospital visits and blood-pressure measurements, according to their individual risk as per UK National Institute for Health and Care Excellence guidelines. The blood-pressure measurement at the clinic and the HBPM reading obtained closest to that hospital visit were paired for analysis. Only one pair of measurements was used per patient. Differences between home and clinic blood-pressure measurements were tested using the Wilcoxon signed rank test or paired t-test, and were also assessed visually using Bland-Altman plots. Comparison of the binary outcomes was performed using McNemar's chi-square test. Subgroup analysis was performed in the following gestational-age windows: < 14 weeks, 15-22 weeks, 23-32 weeks and 33-42 weeks' gestation.

RESULTS

A total of 294 blood-pressure measurements from 147 women were included in the analysis. Median systolic HBPM measurements were significantly lower than clinic measurements (132.0 (interquartile range (IQR), 123.0-140.0) mmHg vs 138.0 (IQR, 132.0-146.5) mmHg; P < 0.001). When stratified according to gestational age, systolic blood-pressure measurements obtained at home were significantly lower than those at clinic in all gestational-age periods except 23-32 weeks' gestation (P = 0.057). Median diastolic blood-pressure measurements at home were also significantly lower than those at clinic (85.0 (IQR, 77.0-90.0) mmHg vs 89.0 (IQR, 82.0-94.0) mmHg; P < 0.001). When stratified according to gestational age, diastolic HBPM measurements were significantly lower in the periods 5-14 weeks (P < 0.001), 15-22 weeks (P = 0.008) and 33-42 weeks (P < 0.001), compared with clinic measurements. The incidence of clinically significant systolic and diastolic hypertension based on clinic blood-pressure measurements was four to five times higher than that based on HBPM measurements (P < 0.001 and P = 0.005, respectively).

CONCLUSIONS

Our study shows that, in women with HDP, blood pressure measured at home is lower than that measured in a clinic setting. This is consistent with observations in non-pregnant adults, in whom home and ambulatory monitoring of hypertensive patients is recommended. As such, HBPM has the potential to reduce the number of false-positive diagnoses of severe hypertension and unnecessary medical interventions in women with HDP. This must be carefully weighed against the risk of missing true-positive diagnoses. Prospective studies investigating the use of HBPM in pregnant women are urgently needed to determine the relevant blood-pressure thresholds for HBPM, and interval and frequency of monitoring. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Long-term Outcomes of the Effects of Home Blood Pressure Telemonitoring and Pharmacist Management on Blood Pressure Among Adults With Uncontrolled Hypertension: Follow-up of a Cluster Randomized Clinical Trial

IMPORTANCE

Hypertension is a leading cause of cardiovascular disease. The results were previously reported of a trial of home blood pressure (BP) telemonitoring and pharmacist management intervention in which the interventions stopped after 12 months. There were significantly greater reductions in systolic BP (SBP) in the intervention group than in the usual care group at 6, 12, and 18 months (-10.7, -9.7, and -6.6 mm Hg, respectively).

OBJECTIVES

To examine the durability of the intervention effect on BP through 54 months of follow-up and to compare BP measurements performed in the research clinic and in routine clinical care.

DESIGN, SETTING, AND PARTICIPANTS

Follow-up of a cluster randomized clinical trial among 16 primary care clinics and 450 patients with uncontrolled hypertension in a large health system from March 2009 to November 2015.

INTERVENTIONS

A home BP telemonitoring intervention with pharmacist management or usual care.

MAIN OUTCOMES AND MEASURES

Change from baseline to 54 months in SBP and diastolic BP (DBP) measured as the mean of 3 measurements obtained at each research clinic visit.

RESULTS

Among 450 patients, 228 (mean [SD] age, 62.0 [11.7] years; 54.8% male) were randomized to the telemonitoring intervention and 222 (mean [SD] age, 60.2 [12.2] years; 55.9% male) to usual care. Research clinic BP measurements were obtained from 326 of 450 (72.4%) study patients at the 54-month follow-up visit, including 162 (mean [SD] age, 62.0 [11.1] years; 54.9% male) randomized to the telemonitoring intervention and 164 (mean [SD] age, 60.0 [11.2] years; 57.3% male) to usual care. Routine clinical care BP measurements were obtained from 439 of 450 (97.6%) study patients at 6248 visits during the follow-up period. Based on research clinic measurements, baseline mean SBP was 148 mm Hg in both groups. In the intervention group, mean SBP at 6-, 12-, 18-, and 54-month follow-up was 126.7, 125.7, 126.9, and 130.6 mm Hg, respectively. In the usual care group, mean SBP at 6-, 12-, 18-, and 54-month follow-up was 136.9, 134.8, 133.0, and 132.6 mm Hg, respectively. The differential reduction by study group in SBP from baseline to 54 months was -2.5 mm Hg (95% CI, -6.3 to 1.2 mm Hg; P = .18). The DBP followed a similar pattern, with a differential reduction by study group from baseline to 54 months of -1.0 mm Hg (95% CI, -3.2 to 1.2 mm Hg; P = .37). The SBP and DBP results from routine clinical measurements suggested significantly lower BP in the intervention group for up to 24 months.

CONCLUSIONS AND RELEVANCE

This intensive intervention had sustained effects for up to 24 months (12 months after the intervention ended). Long-term maintenance of BP control is likely to require continued monitoring and resumption of the intervention if BP increases.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00781365.

Clinical accuracy of the Omron M3 Comfort® and the Omron Evolv® for self-blood pressure measurements in pregnancy and pre-eclampsia - validation according to the Universal Standard Protocol

BACKGROUND

Electronic devices for blood pressure (BP) measurements need to go through independent clinical validation as recommended by different authorities, both in general and in special populations such as pregnancy.

OBJECTIVE

To evaluate the accuracy of the Omron Evolv® (HEM-7600T-E) and the Omron M3 Comfort® (HEM-7134-E) devices in pregnancy and pre-eclampsia according to the Universal Standard Validation Protocol.

METHODS

Both devices, the Evolv and the M3 Comfort, measure BP at the brachial level using the oscillometric method. The study was performed according to the recently published protocol, the so-called "modified Advancement of Medical Instrumentation (AAMI)/British Hypertension Society (BHS)/European Society of Hypertension (ESH) protocol" or the "Universal Standard Protocol." Validation of each device included 45 pregnant women in the second and third gestational trimester of whom 15 had pre-eclampsia, 15 had gestational hypertension and 15 were normotensives. BP differences between the observer and the device BP values were classified into three categories (≤5, ≤10, and ≤15 mmHg) and the mean BP differences (test vs reference) and its SD were calculated.

RESULTS

Both devices, the Evolv and the M3 Comfort, achieved a grade A/A in both pregnancy and pre-eclampsia. The mean difference (SD) between the mercury standard and the device BP values in pregnancy were: 1) for the Evolv of -0.7±2.3 mmHg for systolic blood pressure (SBP) and -0.1±1.8 mmHg for diastolic blood pressure (DBP); 2) for the M3 Comfort of -1.6±2.8 mmHg for SBP and -0.1±2.3 mmHg for DBP.

CONCLUSION

Both devices, the Evolv and the M3 Comfort, achieved a grade A/A for both SBP and DBP and fulfill the validation protocol criteria in pregnancy and pre-eclampsia. Consequently, these two devices can be recommended for home BP measurements in this specific population.

A Novel Minimally Occlusive Cuff Method Utilizing Ultrasound Vascular Imaging for Stress-Free Blood Pressure Measurement: A-Proof-of-Concept Study

OBJECTIVE

Occlusive cuff inflation in ambulatory blood pressure (BP) monitoring disturbs the daily life of the user and affects efficacy of monitoring. To overcome this limitation, we have developed a novel minimally occlusive cuff method for stress-free measurement of BP. This study aimed to experimentally evaluate the reliability of this method.

METHODS

In this method, a thin plate-type ultrasound probe placed between the cuff and the skin is used to measure the ultrasonic dimension of the artery. Analyzing the arterial dimension and the cuff pressure measured during mild cuff inflation (cuff pressure <50 mmHg) allows estimation of systolic BP (SBP_e) and diastolic BP (DBP_e). We evaluated this method in six anesthetized dogs by attaching the cuff with the probe to the right thigh to get SBP_e and DBP_e. We measured reference SBP and DBP using an intra-arterial catheter and determined the pulse arrival time (PAT), commonly employed in cuffless BP monitoring. BP was perturbed by infusing noradrenaline or nitroprusside.

RESULTS

DBP_e correlated tightly with DBP with a coefficient of determination (R²) of 0.85 ± 0.08, and predicted DBP with a mean ± standard deviation of error of 3.9 ± 7.9 mmHg after one-time calibration. Reciprocal of PAT correlated poorly with DBP (R² = 0.49 ± 0.17), and predicted DBP less accurately than this method. SBP_e correlated well with SBP (R² = 0.78 ± 0.08).

CONCLUSION

This method reliably tracks BP changes without occlusive cuff inflation. Once calibrated, this method measures DBP accurately.

SIGNIFICANCE

This method has the potential for stress-free BP measurement in ambulatory BP monitoring.

Home blood pressure monitoring in the 21st century

Home blood pressure monitoring provides multiple measurements in the usual environment of each individual, allows the detection of intermediate hypertension phenotypes (white-coat and masked hypertension), and appears to have superior prognostic value compared to the conventional office blood pressure measurements. Accumulating evidence suggests that home blood pressure monitoring improves long-term hypertension control rates. Moreover, it is widely available, relatively inexpensive, and well accepted by patients. Thus, current guidelines recommend home blood pressure monitoring as an essential method for the evaluation of almost all untreated and treated patients with suspected or treated hypertension. Validated automated upper-arm cuff devices with automated storage and averaging of readings should be used. The home blood pressure monitoring schedule for 4 to 7 days with exclusion of the first day (12-24 readings) should be averaged to provide values for decision making.

Hypertension Canada's 2018 Guidelines for the Management of Hypertension in Pregnancy

We present Hypertension Canada's inaugural evidence-based Canadian recommendations for the management of hypertension in pregnancy. Hypertension in pregnancy is common, affecting approximately 7% of pregnancies in Canada, and requires effective management to reduce maternal, fetal, and newborn complications. Because of this importance, these guidelines were developed in partnership with the Society of Obstetricians and Gynaecologists of Canada with the main common objective of improving the management of women with hypertension in pregnancy. Guidelines for the diagnosis, assessment, prevention, and treatment of hypertension in adults and children are published separately. In this first Hypertension Canada guidelines for hypertension in pregnancy, 7 recommendations for the management of nonsevere and severe hypertension in pregnancy are presented. For nonsevere hypertension in pregnancy (systolic blood pressure 140-159 mm Hg and/or diastolic blood pressure 80-109 mm Hg), we provide guidance for the threshold for initiation of antihypertensive therapy, blood pressure targets, as well as first- and second-line antihypertensive medications. Severe hypertension (systolic blood pressure ≥ 160 mm Hg and/or diastolic blood pressure ≥ 110 mm Hg) requires urgent antihypertensive therapy to reduce maternal, fetal, and newborn adverse outcomes. The specific evidence and rationale underlying each of these guidelines are discussed.

Thinking with care infrastructures: people, devices and the home in home blood pressure monitoring

The growing consumer market in health monitoring devices means that technologies that were once the preserve of the clinic are moving into spaces such as homes and workplaces. We consider how one such device, blood pressure monitors, comes to be integrated into everyday life. We pursue the concept of 'care infrastructure', drawing on recent scholarship in STS and medical sociology, to illuminate the work and range of people, things and spaces involved in self-monitoring. Drawing on a UK study involving observations and interviews with 31 people who have used a consumer blood pressure monitor, we apply the concept beyond chronic illness, to practices involving consumer devices - and develop a critical account of its value. We conclude that the care infrastructure concept is useful to highlight the socio-material arrangements involved in self-monitoring, showing that even for ostensibly personal devices, monitoring may be a shared practice that expresses care for self and for others. The concept also helps draw attention to links between different objects and spaces that are integral to the practice, beyond the device alone. Care infrastructure draws attention to the material, but ensures that analytic attention engages with both material and social elements of practice and their connections.

Seasonal variation in home blood pressure: findings from nationwide web-based monitoring in Japan

OBJECTIVES

Our aim was to assess seasonal variation in home blood pressure (BP) among free-living nationwide participants using home BP values accumulated from a web-based healthcare platform established in Japan.

SETTINGS

An observational study. OMRON Healthcare Co., Ltd. has been developing web-based personal healthcare record systems in Japan since November 2010; over two million voluntary participants had joined this platform in September 2015. Nationwide home BP measurements made by oscillometric-type electronic sphygmomanometers from over 110 000 voluntary participants have been transmitted to the system from devices.

PARTICIPANTS

Seasonal variation in home BP was evaluated among 64 536 (51 335 men, 13 201 women; mean age 52.9 years) free-living nationwide users for whom data were automatically and simultaneously transmitted to the system from devices.

PRIMARY OUTCOME MEASURES

Mean monthly and weekly home BP.

RESULTS

In multiple regression analysis, the relationship between BP and temperature was a significant inverse association, independent of age, gender and geological locations. Highest and lowest BP was observed in December and July, respectively. Substantial seasonal differences in the mean values of morning and evening home systolic BP between summer and winter were 6.2 mmHg and 5.5 mmHg in men, and 7.3 mmHg and 6.5 mmHg in women. Seasonal variation was a little greater in older (7.3 mmHg in men, 8.7 mmHg in women) than in younger individuals (5.8 mmHg in men, 6.5 mmHg in women). BP from February to July was approximately 1.5 mmHg lower than the value from August to December.

CONCLUSIONS

A web-based healthcare platform has enabled easier monitoring of population-wide BP. Tighter BP control is necessary in winter than in summer, and especially in a colder climate toward winter than toward summer. New technologies using web-based self-monitoring systems for health-related indexes are expected to initiate a new phase of cardiovascular disease prevention and public health promotion.

Rationale and design for the Asia BP@Home study on home blood pressure control status in 12 Asian countries and regions

Home blood pressure (BP) monitoring is endorsed in multiple guidelines as a valuable adjunct to office BP measurements for the diagnosis and management of hypertension. In many countries throughout Asia, physicians are yet to appreciate the significant contribution of BP variability to cardiovascular events. Furthermore, data from Japanese cohort studies have shown that there is a strong association between morning BP surge and cardiovascular events, suggesting that Asians in general may benefit from more effective control of morning BP. We designed the Asia BP@Home study to investigate the distribution of hypertension subtypes, including white-coat hypertension, masked morning hypertension, and well-controlled and uncontrolled hypertension. The study will also investigate the determinants of home BP control status evaluated by the same validated home BP monitoring device and the same standardized method of home BP measurement among 1600 or more medicated patients with hypertension from 12 countries/regions across Asia.

An Assessment of the Accuracy of Home Blood Pressure Monitors When Used in Device Owners

OBJECTIVE

To examine the accuracy of home blood pressure (BP) devices, on their owners, compared to auscultatory reference standard BP measurements.

METHODS

Eighty-five consecutive consenting subjects ≥18 years of age, who owned an oscillometric home BP device (wrist or upper-arm device), with BP levels between 80-220/50-120 mm Hg, and with arm circumferences between 25-43 cm were studied. Pregnancy and atrial fibrillation were exclusion criteria. Device measurements from each subject's home BP device were compared to simultaneous 2-observer auscultation using a mercury sphygmomanometer. Between-group mean comparisons were conducted using paired t-tests. The proportion of patients with device-to-auscultatory differences of ≥5, 10, and 15 mm Hg were tabulated and predictors of systolic and diastolic BP differences were identified using linear regression.

RESULTS

Mean age was 66.4 ± 11.0 years, mean arm circumference was 32.7 ± 3.7 cm, 54% were female and 78% had hypertension. Mean BPs were 125.7 ± 14.0/73.9 ± 10.4 mm Hg for home BP devices vs. 129.0 ± 14.7/72.9 ± 9.3 for auscultation (difference of -3.3 ± 7.3/0.9 ± 6.1; P values <0.0001 for systolic and 0.17 for diastolic). The proportion of devices with systolic or diastolic BP differences from auscultation of ≥5, 10, and 15 mm Hg was 69%, 29%, and 7%, respectively. Increasing arm circumference was a statistically significant predictor of higher systolic (parameter estimate 0.61 per cm increase; P value 0.004) and diastolic (0.38; 0.03) BP.

CONCLUSIONS

Although mean differences from 2-observer auscultation were acceptable, when tested on their owners, most home BP devices were not accurate to within 5 mm Hg. Ensuring acceptable accuracy of the device-owner pairing should be prioritized.

Diagnostic performance of an automatic blood pressure measurement device, Microlife WatchBP Home A, for atrial fibrillation screening in a real-world primary care setting

OBJECTIVE

To evaluate the diagnostic performance of a UK National Institute for Health and Care Excellence-recommended automatic oscillometric blood pressure (BP) measurement device incorporated with an atrial fibrillation (AF) detection algorithm (Microlife WatchBP Home A) for real-world AF screening in a primary healthcare setting.

SETTING

Primary healthcare setting in Hong Kong.

INTERVENTIONS

This was a prospective AF screening study carried out between 1 September 2014 and 14 January 2015. The Microlife device was evaluated for AF detection and compared with a reference standard of lead-I ECG.

PRIMARY OUTCOME MEASURES

Diagnostic performance of Microlife for AF detection.

RESULTS

5969 patients (mean age: 67.2±11.0 years; 53.9% female) were recruited. The mean CHA₂DS₂-VASc ( C : congestive heart failure [1 point]; H : hypertension [1 point]; A₂ : age 65-74 years [1 point] and age ≥75 years [2 points]; D : diabetes mellitus [1 point]; S : prior stroke or transient ischemic attack [2 points]; VA : vascular disease [1 point]; and Sc : sex category [female] [1 point])score was 2.8±1.3. AF was diagnosed in 72 patients (1.21%) and confirmed by a 12-lead ECG. The Microlife device correctly identified AF in 58 patients and produced 79 false-positives. The corresponding sensitivity and specificity for AF detection were 80.6% (95% CI 69.5 to 88.9) and 98.7% (95% CI 98.3 to 98.9), respectively. Among patients with a false-positive by the Microlife device, 30.4% had sinus rhythm, 35.4% had sinus arrhythmia and 29.1% exhibited premature atrial complexes. With the low prevalence of AF in this population, the positive and negative predictive values of Microlife device for AF detection were 42.4% (95% CI 34.0 to 51.2) and 99.8% (95% CI 99.6 to 99.9), respectively. The overall diagnostic performance of Microlife device to detect AF as determined by area under the curves was 0.90 (95% CI 0.89 to 0.90).

CONCLUSIONS

In the primary care setting, Microlife WatchBP Home was an effective means to screen for AF, with a reasonable sensitivity of 80.6% and a high negative predictive value of 99.8%, in addition to its routine function of BP measurement. In a younger patient population aged <65 years with a lower prevalence of AF, Microlife WatchBP Home A demonstrated a similar diagnostic accuracy.

[Implantable sensors for outpatient assessment of ventricular filling pressure in advanced heart failure : Which telemonitoring design is optimal?]

INTRODUCTION

Patients with advanced heart failure suffer from frequent hospitalizations. Non-invasive hemodynamic telemonitoring for assessment of ventricular filling pressure has been shown to reduce hospitalizations. We report on the right ventricular (RVP), the pulmonary artery (PAP) and the left atrial pressure (LAP) sensor for non-invasive assessment of the ventricular filling pressure.

METHODS

A literature search concerning the available implantable pressure sensors for noninvasive haemodynamic telemonitoring in patients with advanced heart failure was performed.

RESULTS

Until now, only implantation of the PAP-sensor was able to reduce hospitalizations for cardiac decompensation and to improve quality of life. The right ventricular pressure sensor missed the primary endpoint of a significant reduction of hospitalizations, clinical data using the left atrial pressure sensor are still pending.

CONCLUSION

The implantation of a pressure sensor for assessment of pulmonary artery filling pressure is suitable for reducing hospitalizations for heart failure and for improving quality of life in patients with advanced heart failure.

Which cuff should I use? Indirect blood pressure measurement for the diagnosis of hypertension in patients with obesity: a diagnostic accuracy review

OBJECTIVE

To determine the diagnostic accuracy of different methods of blood pressure (BP) measurement compared with reference standards for the diagnosis of hypertension in patients with obesity with a large arm circumference.

DESIGN

Systematic review with meta-analysis with hierarchical summary receiver operating characteristic models. Bland-Altman analyses where individual patient data were available. Methodological quality appraised using Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS2) criteria.

DATA SOURCES

MEDLINE, EMBASE, Cochrane, DARE, Medion and Trip databases were searched.

ELIGIBILITY CRITERIA

Cross-sectional, randomised and cohort studies of diagnostic test accuracy that compared any non-invasive BP tests (upper arm, forearm, wrist, finger) with an appropriate reference standard (invasive BP, correctly fitting upper arm cuff, ambulatory BP monitoring) in primary care were included.

RESULTS

4037 potentially relevant papers were identified. 20 studies involving 26 different comparisons met the inclusion criteria. Individual patient data were available from 4 studies. No studies satisfied all QUADAS2 criteria. Compared with the reference test of invasive BP, a correctly fitting upper arm BP cuff had a sensitivity of 0.87 (0.79 to 0.93) and a specificity of 0.85 (0.64 to 0.95); insufficient evidence was available for other comparisons to invasive BP. Compared with the reference test of a correctly fitting upper arm cuff, BP measurement at the wrist had a sensitivity of 0.92 (0.64 to 0.99) and a specificity of 0.92 (0.85 to 0.87). Measurement with an incorrectly fitting standard cuff had a sensitivity of 0.73 (0.67 to 0.78) and a specificity of 0.76 (0.69 to 0.82). Measurement at the forearm had a sensitivity of 0.84 (0.71 to 0.92) and a specificity 0.75 of (0.66 to 0.83). Bland-Altman analysis of individual patient data from 3 studies comparing wrist and upper arm BP showed a mean difference of 0.46 mm Hg for systolic BP measurement and 2.2 mm Hg for diastolic BP measurement.

CONCLUSIONS

BP measurement with a correctly fitting upper arm cuff is sufficiently sensitive and specific to diagnose hypertension in patients with obesity with a large upper arm circumference. If a correctly fitting upper arm cuff cannot be applied, an incorrectly fitting standard size cuff should not be used and BP measurement at the wrist should be considered.

PURLs: Monitoring home BP readings just got easier

This novel method of identifying patients with uncontrolled hypertension correlates well with ambulatory BP monitoring.

A new automatic blood pressure kit auscultates for accurate reading with a smartphone: A diagnostic accuracy study

The widely used oscillometric automated blood pressure (BP) monitor was continuously questioned on its accuracy. A novel BP kit named Accutension which adopted Korotkoff auscultation method was then devised. Accutension worked with a miniature microphone, a pressure sensor, and a smartphone. The BP values were automatically displayed on the smartphone screen through the installed App. Data recorded in the phone could be played back and reconfirmed after measurement. They could also be uploaded and saved to the iCloud. The accuracy and consistency of this novel electronic auscultatory sphygmomanometer was preliminarily verified here. Thirty-two subjects were included and 82 qualified readings were obtained. The mean differences ± SD for systolic and diastolic BP readings between Accutension and mercury sphygmomanometer were 0.87 ± 2.86 and -0.94 ± 2.93 mm Hg. Agreements between Accutension and mercury sphygmomanometer were highly significant for systolic (ICC = 0.993, 95% confidence interval (CI): 0.989-0.995) and diastolic (ICC = 0.987, 95% CI: 0.979-0.991). In conclusion, Accutension worked accurately based on our pilot study data. The difference was acceptable. ICC and Bland-Altman plot charts showed good agreements with manual measurements. Systolic readings of Accutension were slightly higher than those of manual measurement, while diastolic readings were slightly lower. One possible reason was that Accutension captured the first and the last korotkoff sound more sensitively than human ear during manual measurement and avoided sound missing, so that it might be more accurate than traditional mercury sphygmomanometer. By documenting and analyzing of variant tendency of BP values, Accutension helps management of hypertension and therefore contributes to the mobile heath service.

How Accurate Are Home Blood Pressure Devices in Use? A Cross-Sectional Study

Background

Out of office blood pressure measurements, using either home monitors or 24 hour ambulatory monitoring, is widely recommended for management of hypertension. Though validation protocols, meant to be used by manufacturers, exist for blood pressure monitors, there is scant data in the literature about the accuracy of home blood pressure monitors in actual clinical practice. We performed a chart review in the blood pressure assessment clinic at a tertiary care centre.

Methods

We assessed the accuracy of home blood pressure monitors used by patients seen in the nephrology clinic in Ottawa between the years 2011 to 2014. We recorded patient demographics and clinical data, including the blood pressure measurements, arm circumference and the manufacturer of the home blood pressure monitor. The average of BP measurements performed with the home blood pressure monitor, were compared to those with the mercury sphygmomanometer. We defined accuracy based on a difference of 5 mm Hg in the blood pressure values between the home monitor and mercury sphygmomanometer readings. The two methods were compared using a Bland-Altman plot and a student’s t-test.

Results

The study included 210 patients. The mean age of the study population was 67 years and 61% was men. The average mid-arm circumference was 32.2 cms. 30% and 32% of the home BP monitors reported a mean systolic and diastolic BP values, respectively, different from the mercury measurements by 5 mm Hg or more. There was no significant difference between the monitors that were accurate versus those that were not when grouped according to the patient characteristics, cuff size or the brand of the home monitor.

Conclusions

An important proportion of home blood pressure monitors used by patients seen in our nephrology clinic were inaccurate. A re-validation of the accuracy and safety of the devices already in use is prudent before relying on these measurements for clinical decisions.

[Circulatory Function Tests for Home & Community Use.]

Currently, the main circulatory function-testing tools for home use are blood pressure monitors and elec- trocardiography devices. Just like blood pressure monitors that are already widespread for home use, some devices with an electrocardiographic function have recently become available for purchase for personal use by the general public. On the other hand, clinic equipment on loan from doctors to patients in need can perform circulatory function tests like 24-hour ambulatory blood pressure monitoring (ABPM), Holter monitoring, and real-time electrocardiography. We introduce the actual clinical usage of ABPM and real-time electro- cardiography, and discuss the usefulness of these procedures. ABPM uses a blood pressure measurement device worn on the body for 24 hours a day to measure blood pressure at regular intervals. This makes it possible to check blood pressure changes throughout the day in a way in which conventional home-use blood pressure monitors cannot, like during sleep. This method al- lows the identification of masked hypertension like early-morning and nocturnal hypertension, stress hyper- tension including workplace hypertension, and white coat hypertension that only occurs in the doctor's office. Under routine care, there are few opportunities to perform electrocardiography at the time a patient is experiencing symptoms. Now, real-time electrocardiography has begun to be used in routine care, and pa- tients can record an electrocardiogram by themselves anytime, anywhere, and send the data by telephone or the Internet for analysis and diagnosis. Transmission-capable electrocardiography devices can play an im- portant role in the event of dangerous symptoms like arrhythmia, angina, or acute myocardial infarction. The spread of ABPM and event heart monitors is likely to make the early treatment and prevention of stroke and heart disease possible. We are expecting rapid development in this field in the future.

Cost-Effectiveness of Implantable Pulmonary Artery Pressure Monitoring in Chronic Heart Failure

OBJECTIVES

This study aimed to evaluate the cost-effectiveness of the CardioMEMS (CardioMEMS Heart Failure System, St Jude Medical Inc, Atlanta, Georgia) device in patients with chronic heart failure.

BACKGROUND

The CardioMEMS device, an implantable pulmonary artery pressure monitor, was shown to reduce hospitalizations for heart failure and improve quality of life in the CHAMPION (CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Heart Failure Patients) trial.

METHODS

We developed a Markov model to determine the hospitalization, survival, quality of life, cost, and incremental cost-effectiveness ratio of CardioMEMS implantation compared with usual care among a CHAMPION trial cohort of patients with heart failure. We obtained event rates and utilities from published trial data; we used costs from literature estimates and Medicare reimbursement data. We performed subgroup analyses of preserved and reduced ejection fraction and an exploratory analysis in a lower-risk cohort on the basis of the CHARM (Candesartan in Heart failure: Reduction in Mortality and Morbidity) trials.

RESULTS

CardioMEMS reduced lifetime hospitalizations (2.18 vs. 3.12), increased quality-adjusted life-years (QALYs) (2.74 vs. 2.46), and increased costs ($176,648 vs. $156,569), thus yielding a cost of $71,462 per QALY gained and $48,054 per life-year gained. The cost per QALY gained was $82,301 in patients with reduced ejection fraction and $47,768 in those with preserved ejection fraction. In the lower-risk CHARM cohort, the device would need to reduce hospitalizations for heart failure by 41% to cost <$100,000 per QALY gained. The cost-effectiveness was most sensitive to the device's durability.

CONCLUSIONS

In populations similar to that of the CHAMPION trial, the CardioMEMS device is cost-effective if the trial effectiveness is sustained over long periods. Post-marketing surveillance data on durability will further clarify its value.

Opportunistic screening of atrial fibrillation by automatic blood pressure measurement in the community

OBJECTIVE

Timely detection of atrial fibrillation (AF) may effectively prevent cardiovascular consequences. However, traditional diagnostic tools are either poorly reliable (pulse palpation) or not readily accessible (ECG) in general practice. We tested whether an automatic oscillometric blood pressure (BP) monitor embedded with an algorithm for AF detection might be effective for opportunistic screening of asymptomatic AF in the community.

SETTING

A community-based screening campaign in an unselected population to verify the feasibility of AF screening with a Microlife WatchBP Office BP monitor with a patented AFIB algorithm. When possible AF was detected (≥2 of 3 BP measurements reporting AF), a doctor immediately performed a single-lead ECG in order to confirm or exclude the presence of the arrhythmia. The main demographic and clinical data were also collected.

PARTICIPANTS

220 consecutive participants from an unselected sample of individuals in a small Italian community.

PRIMARY AND SECONDARY OUTCOME MEASURES

Number of patients detected with AF and diagnosed risk factors for AF.

RESULTS

In 12 of 220 participants, the device detected possible AF during the BP measurement: in 4 of them (1.8%), the arrhythmia was confirmed by the ECG. Patients with AF were more likely to be older (77.0±1.2 vs 57.2±15.2 years, p=0.010), obese (50.0 vs 14.4%, p=0.048) and to suffer from a cardiovascular disease (50.0 vs 10.6%, p=0.014) than patients without AF. Participants with a positive BP AF reading and non-AF arrhythmias (n=8) did not differ in their general characteristics from participants with a negative BP AF reading and were younger than patients with AF (mean age 56.4±14.8, p=0.027; 5 of 8 participants aged <65 years).

CONCLUSIONS

Opportunistic screening of AF by BP measurement is feasible to diagnose this arrhythmia in unaware participants, particularly in those older than 65 years, who are the target patient group recommended by current AF screening guidelines.

Improved Blood Pressure Control Using an Interactive Mobile Phone Support System

This explorative, longitudinal study evaluated the effect of the daily use of a mobile phone-based self-management support system for hypertension in reducing blood pressure (BP) among 50 primary care patients with hypertension over 8 weeks. The self-management system comprises modules for (1) self-reports of BP, pulse, lifestyle, symptoms, and well-being; (2) delivery of reminders and encouragements; and (3) graphical feedback of self-reports. Daily use of the support system significantly reduced BP (systolic BP -7 mm Hg, diastolic BP -4.9 mm Hg) between baseline and week 8, with daily improvements leveling off as the study progressed. Three homogenous subsets of patients were identified who, despite different initial BP levels, showed similar decreases in BP during the study, indicating that patients benefited irrespective of baseline BP. In showing significant reductions in BP, our results suggest that the self-management support system may be a useful tool in clinical practice to help patients self-manage their hypertension.