Marwah Abdalla

Role of Ambulatory and Home Blood Pressure Monitoring in Clinical Practice: A Narrative Review

Key Summary Points Ambulatory blood pressure monitoring (ABPM) assesses blood pressure during routine daily activities (typically during one 24-hour period), whereas home blood pressure monitoring (HBPM) assesses blood pressure at specific times during the day and night over a longer period while the patient is seated and resting. Blood pressure measures on ABPM and HBPM have a stronger association with cardiovascular disease outcomes than clinic blood pressure. ABPM and HBPM can quantify mean out-of-clinic blood pressure and can be used to identify white coat hypertension, masked hypertension, blood pressure variability, and hypotension. ABPM can also assess nighttime blood pressure and diurnal blood pressure patterns. Most guidelines, scientific statements, and position papers recommend that blood pressure monitoring outside of the clinic primarily be done using ABPM to rule out white coat hypertension in persons with elevated clinic blood pressure. HBPM is recommended if ABPM is not available or is poorly tolerated by the patient. Barriers have limited the implementation of ABPM and HBPM in clinical practice. Core competency requirements may be essential for successful ABPM and HBPM. There is a need for randomized, controlled trials to test whether treating blood pressure determined by ABPM or HBPM is more advantageous than treating clinic blood pressure on cardiovascular disease outcomes. Guidelines and scientific statements recommend measuring blood pressure in the clinic setting (1, 2). However, blood pressure measured in the clinic may not accurately reflect levels in the out-of-clinic naturalistic setting (3). Ambulatory blood pressure monitoring (ABPM) and home blood pressure monitoring (HBPM) are 2 well-accepted approaches for measuring blood pressure outside of the clinic (4, 5). The utility of these methods in guiding patient care has been widely debated (6, 7), and there is controversy about which is better for determining blood pressure outside of the clinic. This review describes ABPM and HBPM procedures, the blood pressure measures that can be obtained by using these methods, and the current evidence base supporting the use of ABPM and HBPM in clinical practice; barriers and clinical competencies that are required for the successful implementation of ABPM and HBPM in practice; and areas of future research. Methods We searched MEDLINE through July 2015 using the following key words: ambulatory blood pressure, home blood pressure, out of office blood pressure, self-measured blood pressure, and self-measurement of blood pressure. We focused on studies that had prospective follow-up for cardiovascular disease (CVD) events or mortality; systematic reviews, meta-analyses, and narrative reviews; and hypertension guidelines, scientific statements, and position papers. A search of PubMed for related articles and a cited reference search through ISI Web of Science were done using identified articles. We also manually searched the reference lists from identified reviews. This study was funded by the National Heart, Lung, and Blood Institute. The funding source had no role in the study design, collection, analysis, interpretation, or drafting of the manuscript or in the decision to submit the manuscript for publication. Fundamentals of ABPM and HBPM Overview of ABPM In the 1960s, a manually inflated device was introduced that could take blood pressure readings on an ambulatory basis throughout the day (8). Ambulatory monitors are now fully automated, use the oscillometric technique to estimate blood pressure, and are typically used to obtain blood pressure readings for 24 hours (3). Ambulatory monitors are compact, are typically worn on a belt or in a pouch, and are connected to a sphygmomanometer cuff on the upper arm by a tube. The monitors are usually programmed to obtain readings every 15 to 30 minutes throughout the day and night and set so the readings are not displayed to the patient. Although persons go about their normal daily activities during ABPM, they are asked to keep their arm still while the cuff is inflating and to avoid excessive motion, which is associated with unobtainable or artifactual readings. At the end of the recording period, the readings are downloaded into a computer for processing. Persons can fill out a diary during the monitoring period to document any symptoms, awakening and sleeping times, naps, periods of stress, timing of meals, and medication ingestion (4). Various criteria can be used to determine whether a 24-hour ABPM session is valid, such as requiring that a minimum of 70% or 80% of the planned readings are obtained (4, 9), at least 14 readings are obtained during the daytime period (10), or at least 10 readings are obtained during the daytime period and at least 5 during the nighttime period (11). None of these criteria is considered to be a gold standard. The daytime and nighttime periods on ABPM can be determined by using the patients self-report of awakening and sleeping (4), fixed periods (4), and actigraphy (12). Herein, the terms daytime and nighttime (or nocturnal) are used interchangeably with awake and sleep, respectively. The Figure (top) shows blood pressure readings obtained from a person in the clinic followed by 24-hour ABPM. Figure. Blood pressure data from an untreated healthy person who had clinic blood pressure assessment followed by 24-h ABPM (top ) and then HBPM (bottom). ABPM = ambulatory blood pressure monitoring; DBP = diastolic blood pressure; HBPM = home blood pressure monitoring; SBP = systolic blood pressure. Top. Clinic blood pressure assessment immediately followed by 24-h ABPM. The points for clinic blood pressure represent the average of 3 readings. On ABPM, blood pressure decreases to its lowest level during the night, followed by a surge in the morning hours coinciding with waking up. Average clinic blood pressure was 118/66 mm Hg, and average awake, sleep, and 24-h blood pressure was 129/86 mm Hg, 103/62 mm Hg, and 118/78 mm Hg, respectively. Bottom. After the 24-h ABPM assessment, HBPM was then done for 18 d. The points represent the average of 2 morning or 2 evening readings. Because blood pressure readings on HBPM are obtained at fixed times during the day and are measured at rest, the variability of blood pressure over time is less than what is seen on ABPM. Unlike ABPM, HBPM cannot measure blood pressure readings during sleep. Average home blood pressure was 116/79 mm Hg. Overview of HBPM Home blood pressure was initially measured with the auscultatory technique by an observer (13). Most current HBPM devices are automatic, use the oscillometric technique, and are initiated by the patient. Some devices have the ability to store readings for several weeks, which minimizes the need for patients to record the measurements. Devices for HBPM, which measure blood pressure in the brachial artery, are more reliable than other types of devices, such as wrist monitors (13). Home blood pressure monitoring should be done in a quiet room after 5 minutes of rest in the seated position, with the back and arm supported. A common recommendation for HBPM (2, 5, 14) is that blood pressure be measured by the patient 2 times in the morning and 2 times in the evening. A minimum of 3 consecutive days and a preferred period of 7 consecutive days of HBPM is a reasonable approach for clinical practice (2, 5, 14). For assessment of mean blood pressure, readings obtained on the first day of HBPM are excluded and all subsequent readings are averaged (2, 5, 14). The Figure shows blood pressure readings in the same person from ABPM (top) followed by HBPM (bottom). Validated Devices Only validated devices are recommended for ABPM and HBPM. Validation protocols from the following 3 organizations are widely accepted: the Association for the Advancement of Medical Instrumentation (15), British Hypertension Society (16), and European Society of Hypertension (17). The 2010 European Society of Hypertension International Protocol (17) is the most commonly used. An up-to-date list of validated ambulatory and home blood pressure monitors is available on the dabl Educational Trust Web site (www.dableducational.org) (18) and the British Hypertension Society Web site (www.bhsoc.org/bp-monitors/bp-monitors) (19). Similarities and Differences in ABPM and HBPM More measurements are typically obtained with ABPM and HBPM than in the clinic setting. Ambulatory blood pressure monitoring and HBPM can assess average blood pressure outside of the clinic setting, which allows for the identification of white coat hypertension (20, 21) and masked hypertension (2224); blood pressure variability on ABPM (25) and HBPM (26); and hypotension (2, 4). Because ABPM and HBPM devices use the oscillometric technique, which assesses the amplitude of pressure oscillations during cuff deflation to estimate blood pressure, accurate measurements can be affected by movement (27). The ability to obtain accurate readings is also limited by larger upper arm circumference, arterial stiffness, and variability in heart rate (such as atrial fibrillation) (27). Because ABPM and HBPM devices inflate the blood pressure cuff above estimated systolic blood pressure followed by deflation, persons with severe hypertension may have discomfort or pain with repeated measurements. The main difference between ABPM and HBPM is that ABPM assesses daytime and nighttime blood pressure during routine daily activities (typically during one 24-hour period), whereas HBPM assesses blood pressure at specific times during the day and night over a longer period while the patient is seated and resting. For almost all HBPM devices, blood pressure readings cannot be obtained during sleep. Clinical Significance Elevated Blood Pressure on ABPM and HBPM Many studies have reported associations of average out-of-clinic blood pressure measured by ABPM, including average 24-hour blood pressure; daytime and nighttime blood pressure; and,

Masked Hypertension and Incident Clinic Hypertension Among Blacks in the Jackson Heart Study

Masked hypertension, defined as nonelevated clinic blood pressure (BP) and elevated out-of-clinic BP may be an intermediary stage in the progression from normotension to hypertension. We examined the associations of out-of-clinic BP and masked hypertension using ambulatory BP monitoring with incident clinic hypertension in the Jackson Heart Study, a prospective cohort of blacks. Analyses included 317 participants with clinic BP <140/90 mm Hg, complete ambulatory BP monitoring, who were not taking antihypertensive medication at baseline in 2000 to 2004. Masked daytime hypertension was defined as mean daytime blood pressure ≥135/85 mm Hg, masked night-time hypertension as mean night-time BP ≥120/70 mm Hg, and masked 24-hour hypertension as mean 24-hour BP ≥130/80 mm Hg. Incident clinic hypertension, assessed at study visits in 2005 to 2008 and 2009 to 2012, was defined as the first visit with clinic systolic/diastolic BP ≥140/90 mm Hg or antihypertensive medication use. During a median follow-up of 8.1 years, there were 187 (59.0%) incident cases of clinic hypertension. Clinic hypertension developed in 79.2% and 42.2% of participants with and without any masked hypertension, 85.7% and 50.4% with and without masked daytime hypertension, 79.9% and 43.7% with and without masked night-time hypertension, and 85.7% and 48.2% with and without masked 24-hour hypertension, respectively. Multivariable-adjusted hazard ratios (95% confidence interval) of incident clinic hypertension for any masked hypertension and masked daytime, night-time, and 24-hour hypertension were 2.13 (1.51–3.02), 1.79 (1.24–2.60), 2.22 (1.58–3.12), and 1.91 (1.32–2.75), respectively. These findings suggest that ambulatory BP monitoring can identify blacks at increased risk for developing clinic hypertension.

Management of pregnancy in the post-cardiac transplant patient.

Over the past 10 years, heart transplantation survival has increased among transplant recipients. Because of improved outcomes in both congenital and adult transplant recipients, the number of male and female patients of childbearing age who desire pregnancy has also increased within this population. While there have been many successful pregnancies in post-cardiac transplant patients reported in the literature, long-term outcome data is limited. Decisions regarding the optimal timing and management of pregnancy in male and female post-cardiac transplant patients are challenging and should be coordinated by a multidisciplinary team of healthcare providers. Pregnant patients will need to be counseled and monitored carefully for complications including rejection, graft dysfunction, and infection. This review focuses on preconception counseling for both male and female cardiac transplant recipients. The maternal and fetal risks during pregnancy and the postpartum period, including risks to the fetus fathered by a male cardiac transplant recipient will be reviewed. It also provides a brief summary of our own transplant experience and recommendations for overall management of pregnancy in the post-cardiac transplant recipient.

Prevalence of Masked Hypertension and Its Association With Subclinical Cardiovascular Disease in African Americans: Results From the Jackson Heart Study

Background Studies consisting mostly of whites have shown that the prevalence of masked hypertension differs by prehypertension status. Using data from the Jackson Heart Study, an exclusively African American population‐based cohort, we evaluated the association of masked hypertension and prehypertension with left ventricular mass index and common carotid intima media thickness. Methods and Results At the baseline visit, clinic blood pressure (CBP) measurement and 24‐hour ambulatory blood pressure monitoring were performed. Masked hypertension was defined as mean systolic/diastolic CBP <140/90 mm Hg and mean daytime systolic/diastolic ambulatory blood pressure ≥135/85 mm Hg. Clinic hypertension was defined as mean systolic/diastolic CBP ≥140/90 mm Hg. Normal CBP was defined as mean systolic/diastolic CBP <120/80 mm Hg and prehypertension as mean systolic/diastolic CBP 120 to 139/80 to 89 mm Hg. The analytic sample included 909 participants. Among participants with systolic/diastolic CBP <140/90 mm Hg, the prevalence of masked hypertension and prehypertension was 27.5% and 62.4%, respectively. The prevalence of masked hypertension among those with normal CBP and prehypertension was 12.9% and 36.3%, respectively. In a fully adjusted model, which included prehypertension status and antihypertensive medication use as covariates, left ventricular mass index was 7.94 g/m2 lower among those without masked hypertension compared to participants with masked hypertension (P<0.001). Left ventricular mass index was also 4.77 g/m2 lower among those with clinic hypertension, but this difference was not statistically significant (P=0.068). There were no significant differences in left ventricular mass index between participants with and without masked hypertension, or clinic hypertension. Conclusions Masked hypertension was common among African Americans with prehypertension and also normal CBP, and was associated with subclinical cardiovascular disease.

Studies comparing ambulatory blood pressure and home blood pressure on cardiovascular disease and mortality outcomes: a systematic review

Ambulatory blood pressure monitoring (ABPM) is more commonly recommended for assessing out-of-clinic blood pressure (BP) than home blood pressure monitoring (HBPM). We conducted a systematic review to examine whether ABPM or HBPM is more strongly associated with cardiovascular disease events and/or mortality. Of 1007 abstracts published through July 20, 2015, nine articles, reporting results from seven cohorts, were identified. After adjustment for BP on HBPM, BP on ABPM was associated with an increased risk of outcomes in two of four cohorts for systolic blood pressure and two of three cohorts for diastolic blood pressure. After adjustment for BP on ABPM, systolic blood pressure on HBPM was associated with outcomes in zero of three cohorts; an association was present in one of two cohorts for diastolic blood pressure on HBPM. There is a lack of strong empiric evidence supporting ABPM or HBPM over the other approach for predicting cardiovascular events or mortality.

Thresholds for Ambulatory Blood Pressure Among African Americans in the Jackson Heart Study

Background: Ambulatory blood pressure (BP) monitoring is the reference standard for out-of-clinic BP measurement. Thresholds for identifying ambulatory hypertension (daytime systolic BP [SBP]/diastolic BP [DBP] ≥135/85 mm Hg, 24-hour SBP/DBP ≥130/80 mm Hg, and nighttime SBP/DBP ≥120/70 mm Hg) have been derived from European, Asian, and South American populations. We determined BP thresholds for ambulatory hypertension in a US population-based sample of African American adults. Methods: We analyzed data from the Jackson Heart Study, a population-based cohort study comprised exclusively of African American adults (n=5306). Analyses were restricted to 1016 participants who completed ambulatory BP monitoring at baseline in 2000 to 2004. Mean SBP and DBP levels were calculated for daytime (10:00 am–8:00 pm), 24-hour (all available readings), and nighttime (midnight–6:00 am) periods, separately. Daytime, 24-hour, and nighttime BP thresholds for ambulatory hypertension were identified using regression- and outcome-derived approaches. The composite of a cardiovascular disease or an all-cause mortality event was used in the outcome-derived approach. For this latter approach, BP thresholds were identified only for SBP because clinic DBP was not associated with the outcome. Analyses were stratified by antihypertensive medication use. Results: Among participants not taking antihypertensive medication, the regression-derived thresholds for daytime, 24-hour, and nighttime SBP/DBP corresponding to clinic SBP/DBP of 140/90 mm Hg were 134/85 mm Hg, 130/81 mm Hg, and 123/73 mm Hg, respectively. The outcome-derived thresholds for daytime, 24-hour, and nighttime SBP corresponding to a clinic SBP ≥140 mm Hg were 138 mm Hg, 134 mm Hg, and 129 mm Hg, respectively. Among participants taking antihypertensive medication, the regression-derived thresholds for daytime, 24-hour, and nighttime SBP/DBP corresponding to clinic SBP/DBP of 140/90 mm Hg were 135/85 mm Hg, 133/82 mm Hg, and 128/76 mm Hg, respectively. The corresponding outcome-derived thresholds for daytime, 24-hour, and nighttime SBP were 140 mm Hg, 137 mm Hg, and 133 mm Hg, respectively, among those taking antihypertensive medication. Conclusions: On the basis of the outcome-derived approach for SBP and regression-derived approach for DBP, the following definitions for daytime, 24-hour, and nighttime hypertension corresponding to clinic SBP/DBP ≥140/90 mm Hg are proposed for African American adults: daytime SBP/DBP ≥140/85 mm Hg, 24-hour SBP/DBP ≥135/80 mm Hg, and nighttime SBP/DBP ≥130/75 mm Hg, respectively.

Differences in night-time and daytime ambulatory blood pressure when diurnal periods are defined by self-report, fixed-times, and actigraphy: Improving the Detection of Hypertension study.

Objectives: To determine whether defining diurnal periods by self-report, fixed-time, or actigraphy produce different estimates of night-time and daytime ambulatory blood pressure (ABP). Methods: Over a median of 28 days, 330 participants completed two 24-h ABP and actigraphy monitoring periods with sleep diaries. Fixed night-time and daytime periods were defined as 0000–0600 h and 1000–2000 h, respectively. Using the first ABP period, within-individual differences for mean night-time and daytime ABP and kappa statistics for night-time and daytime hypertension (systolic/diastolic ABP≥120/70 mmHg and ≥135/85 mmHg, respectively) were estimated comparing self-report, fixed-time, or actigraphy for defining diurnal periods. Reproducibility of ABP was also estimated. Results: Within-individual mean differences in night-time systolic ABP were small, suggesting little bias, when comparing the three approaches used to define diurnal periods. The distribution of differences, represented by 95% confidence intervals (CI), in night-time systolic and diastolic ABP and daytime systolic and diastolic ABP was narrowest for self-report versus actigraphy. For example, mean differences (95% CI) in night-time systolic ABP for self-report versus fixed-time was −0.53 (−6.61, +5.56) mmHg, self-report versus actigraphy was 0.91 (−3.61, +5.43) mmHg, and fixed-time versus actigraphy was 1.43 (−5.59, +8.46) mmHg. Agreement for night-time and daytime hypertension was highest for self-report versus actigraphy: kappa statistic (95% CI) = 0.91 (0.86,0.96) and 1.00 (0.98,1.00), respectively. The reproducibility of mean ABP and hypertension categories was similar using each approach. Conclusion: Given the high agreement with actigraphy, these data support using self-report to define diurnal periods on ABP monitoring. Further, the use of fixed-time periods may be a reasonable alternative approach.

Adiponectin/resistin levels and insulin resistance in children: a four country comparison study

BackgroundThere are few reports on the effects of ethnicity or gender in the association between adipocytokines and insulin resistance in children of different ages. This study assessed associations between serum concentrations of adiponectin/resistin and parameters of insulin resistance in children from 4 different countries.MethodsA total of 2,290 children were analyzed in this study; each was from one of 4 different countries (Japan, Thailand, Italy and USA), and grouped according to age (8–11 years old in Group 1 and 12–15 years old in Group 2).ResultsAdioponectin was higher in female than in male children, and in Group 1 than in Group 2. Generally, adiponectin was lower in Asian as compared to Italian and American children. These tendencies remained even after adjustment for body mass index (BMI) or waist circumstance (WC). Among older children (Group 2), resistin was higher in female than in male children. Significant correlations by non-parametric univariate correlation coefficients and Spearman’s rank correlation coefficients were found between adiponectin and homeostasis model assessment of insulin resistance (HOMA-IR), and fasting serum insulin levels in young Japanese, Italian, and American female children(p < 0.01, p < 0.05, p < 0.05, respectively). Correlations between serum adiponectin and HOMA-IR were also found among older male Italian, American, and Thai children (p < 0.05, p < 0.001, p < 0.001, respectively). In multiple regression analysis by forced entry method, adiponectin correlated with HOMA-IR in Italian and American male children, and in all older female children regardless of country of origin. There was no correlation between resistin and markers of insulin resistance in children from any of the countries.ConclusionsWe conclude that serum adiponectin concentrations are lower in Asian as compared to Italian and American children, and that adiponectin but not resistin contributes to differences in markers for insulin resistance in children from different populations.

National Institutes of Health Career Development Awards for Cardiovascular Physician-Scientists: Recent Trends and Strategies for Success.

Nurturing the development of cardiovascular physician-scientist investigators is critical for sustained progress in cardiovascular science and improving human health. The transition from an inexperienced trainee to an independent physician-scientist is a multifaceted process requiring a sustained commitment from the trainee, mentors, and institution. A cornerstone of this training process is a career development (K) award from the National Institutes of Health (NIH). These awards generally require 75% of the awardees professional effort devoted to research aims and diverse career development activities carried out in a mentored environment over a 5-year period. We report on recent success rates for obtaining NIH K awards, provide strategies for preparing a successful application and navigating the early career period for aspiring cardiovascular investigators, and offer cardiovascular division leadership perspectives regarding K awards in the current era. Our objective is to offer practical advice that will equip trainees considering an investigator path for success.

Physical Activity and Incident Hypertension in African Americans: The Jackson Heart Study

There is limited empirical evidence to support the protective effects of physical activity in the prevention of hypertension among African Americans. The purpose of this study was to examine the association of physical activity with incident hypertension among African Americans. We studied 1311 participants without hypertension at baseline enrolled in the Jackson Heart Study, a community-based study of African Americans residing in Jackson, Mississippi. Overall physical activity, moderate–vigorous physical activity, and domain-specific physical activity (work, active living, household, and sport/exercise) were assessed by self-report during the baseline examination (2000–2004). Incident hypertension, assessed at examination 2 (2005–2008) and examination 3 (2009–2013), was defined as the first visit with systolic/diastolic blood pressure ≥140/90 mm Hg or self-reported antihypertensive medication use. Over a median follow-up of 8.0 years, there were 650 (49.6%) incident hypertension cases. The multivariable-adjusted hazard ratios (95% confidence interval) for incident hypertension comparing participants with intermediate and ideal versus poor levels of moderate–vigorous physical activity were 0.84 (0.67–1.05) and 0.76 (0.58–0.99), respectively (P trend=0.038). A graded, dose–response association was also present for sport/exercise-related physical activity (Quartiles 2, 3, and 4 versus Quartile 1: 0.92 [0.68–1.25], 0.87 [0.67–1.13], 0.75 [0.58–0.97], respectively; P trend=0.032). There were no statistically significant associations observed for overall physical activity, or work, active living, and household-related physical activities. In conclusion, the results of the current study suggest that regular moderate–vigorous physical activity or sport/exercise-related physical activity may reduce the risk of developing hypertension in African Americans.