Office-based Blood Pressure Measurements Research Articles

Abstract P014: A Pilot Study To Develop A Telehealth Program For Self-Measured Blood Pressure Education And Assessment Within A Veterans Affairs Clinic

Background: Lack of education and assessment of self-measured blood pressure (BP) monitoring quality is a barrier to its widespread implementation. Objective: To develop a pilot Veterans Affairs (VA) Telehealth Program utilizing a tool to educate and assess competencies in self-measured BP technique. Methods: This pilot study was implemented in a single VA primary care clinic. Veterans aged 18 to 85 years old with an office-based BP measurement of ≥140/90 or ≥130/80 mmHg and high cardiovascular disease risk were eligible. Enrolled Veterans completed a four-week program whereby trained registered nurses (RNs) educated Veterans on self-measured BP techniques via video conferencing. At each visit, RNs conducted an 11-part assessment tool (Figure Top) adapted from the American Medical Association measurement skills assessment for patient self-measured BP technique. Results: Forty Veterans (mean age 66 years [SD 12.6], 100% male) were referred for enrollment and twenty completed the program. Veterans demonstrated overall high scores on self-BP measurement skills assessment at each time point (Figure Top), but most frequent skills with non-adherence included: avoiding stimulant use prior to BP measurement; emptying bladder; resting quietly for 3-5 minutes; and talking or using a personal device during measurement. Mean SBP and DBP generally declined over time from a baseline mean SBP and DBP of 147.9 and 81.7 mmHg at enrollment to a mean of 140.4 and 79.9 mmHg, respectively, at program completion (Figure Bottom). Conclusions: Education and assessment of self-measured BP technique may serve as a meaningful target for future education and quality improvement efforts.

Deriving Normative Data on 24-Hour Ambulatory Blood Pressure Monitoring for South Asian Children (ASHA): A Clinical Research Protocol.

Background:The global prevalence of hypertension in children and adolescents has increased over the past 2 decades and is the strongest predictor of adult hypertension. South Asians have an increased prevalence of metabolic syndrome associated risk factors including abdominal obesity, diabetes, and hypertension. All these factors contribute to their increased cardiovascular disease burden. Accurate and early identification of hypertension in South Asian children is a necessary aspect of cardiovascular disease prevention. Ambulatory blood pressure monitoring (ABPM) is considered the gold-standard for pediatric blood pressure (BP) measurement. However, its utilization is limited due to the lack of validated normative reference data in diverse, multiethnic pediatric populations.Objective:The primary objective is to establish normative height-sex and age-sex-specific reference values for 24-h ABPM measurements among South Asian children and adolescents (aged 5-17 years) in Ontario and British Columbia, Canada. Secondary objectives are to evaluate differences in ABPM measurements by body mass index classification, to compare our normative data against pre-existing data from German and Hong Kong cohorts, and to evaluate relationships between habitual movement behaviors, diet quality, and ABPM measurements.Design:Cross-sectional study, quasi-representative sample.Setting:Participants will be recruited from schools, community centers, and places of worship in Southern Ontario (Greater Toronto and Hamilton area, including the Peel Region) and Greater Vancouver, British Columbia.Participants:We aim to recruit 2113 nonoverweight children (aged 5-17 years) for the primary objective. We aim to recruit an additional 633 overweight or obese children to address the secondary objectives.Measurements:Ambulatory BP monitoring measurements will be obtained using Spacelabs 90217 ABPM devices, which are validated for pediatric use. The ActiGraph GT3X-BT accelerometer, which has also been validated for pediatric use, will be used to obtain movement behavior data.Methods:Following recruitment, eligible children will be fitted with 24-h ABPM and physical activity monitors. Body anthropometrics and questionnaire data regarding medical and family history, medications, diet, physical activity, and substance use will be collected. Ambulatory BP monitoring data will be used to develop height-sex- and age-sex-specific normative reference values for South Asian children. Secondary objectives include evaluating differences in ABPM measures between normal weight, overweight and obese children; and comparing our South Asian ABPM data to existing German and Hong Kong data. We will also use compositional data analysis to evaluate associations between a child’s habitual movement behaviors and ABPM measures.Limitations:Bloodwork will not be performed to facilitate recruitment. A non-South Asian comparator cohort will not be included due to feasibility concerns. Using a convenience sampling approach introduces the potential for selection bias.Conclusions:Ambulatory BP monitoring is a valuable tool for the identification and follow-up of pediatric hypertension and overcomes many of the limitations of office-based BP measurement. The development of normative ABPM data specific to South Asian children will increase the accuracy of BP measurement and hypertension identification in this at-risk population, providing an additional strategy for primary prevention of cardiovascular disease.

Mobile health application usage and quality of care at a hypertension clinic: an observational cohort study.

The aim of this study was to test whether a physician-supervised web-based app, integrated with an electronic medical record, helps in improving blood pressure (BP) management in clinical practice. An observational study of 1633 patients seen at a hypertension clinic managed by an endocrinologist with two cohorts (726 adopted the app and 907 had not). The app allowed patients and doctors to monitor BP, blood sugar and other vital signs. Patients decided whether to opt in to using the app and how often to upload their readings. The provider could offer feedback and communicate with patients through the app. We evaluated the change in office-based BP measurement before and after app adoption (at least 12 months apart). We performed a difference-in-difference analysis along with matching based on patient-individual characteristics. The difference-in-difference estimates were 6.23 mmHg systolic [95% confidence interval (95% CI) 0.87-11.59] for patients with SBP 150 mmHg or above, 4.01 mmHg systolic (95% CI 1.11-6.91) for patients with SBP 140 mmHg or above, 4.37 mmHg diastolic (95% CI 1.06-7.68) for patients with DBP 90 mmHg or above, 1.89 mmHg systolic (95% CI 0.58-3.2) and 0.87 mmHg diastolic (95% CI 0.17-1.57) overall for an average patient. Higher frequency of app usage was also associated with a greater reduction in BP. Use of an mHealth app in a clinical practice, was associated with a significant reduction in BP for average patients as well as high-severity patients. Physician-supervised mHealth apps in a clinical practice could be instrumental in managing patient BP.

Persistence of "non-dipping" pattern in blood pressure after curative parathyroidectomy in apparently normotensive patients with symptomatic primary hyperparathyroidism.

The prevalence of hypertension in primary hyperparathyroidism (PHPT) varies from 20-80% with data being based on office-based blood pressure measurements. Little is known about ambulatory monitoring of blood pressure (AMBP) in PHPT and changes in blood pressure (BP) variables post-curative parathyroidectomy. Hence, we conducted a prospective study wherein we performed AMBP in apparently normotensive patients with PHPT and reevaluated them 3 months post-curative parathyroidectomy. Consecutive patients with symptomatic PHPT aged 20 years and above underwent 24 hours AMBP at enrollment and at 3 months after successful parathyroidectomy. Pre- and postoperative BP variables were compared and correlated with serum calcium, creatinine and intact parathyroid hormone (iPTH) levels. After exclusion, 17 symptomatic PHPT patients were enrolled in the study. AMBP detected hypertension in 4 (23.5%) patients. There was a significant reduction in the average nighttime systolic (P=0.007) and diastolic BP (P=0.034) after parathyroidectomy. However, the average 24 hours systolic/diastolic BP, daytime systolic/diastolic BP and average 24 hours mean arterial pressure did not differ before and after surgery. Non-dipping blood pressure pattern was seen in 53% of patients at presentation and persisted in 50% of cases after successful surgery. None of the biochemical parameters significantly correlated with any BP variable. AMBP can help detect hypertension in patients with PHPT that remains unrecognized with routine office-based blood pressure measurement. In addition, AMBP detects loss of normal dipping pattern in BP that persists in almost half of the patients even after successful parathyroidectomy, perhaps because of permanent vascular damage induced by PHPT.

Cuffless Blood Pressure Monitoring from an Array of Wrist Bio-Impedance Sensors Using Subject-Specific Regression Models: Proof of Concept.

Continuous and beat-to-beat monitoring of blood pressure (BP), compared to office-based BP measurement, provides significant advantages in predicting future cardiovascular disease. Traditional BP measurement methods are based on a cuff, which is bulky, obtrusive and not applicable to continuous monitoring. Measurement of pulse transit time (PTT) is one of the prominent cuffless methods for continuous BP monitoring. PTT is the time taken by the pressure pulse to travel between two points in an arterial vessel, which is correlated with the BP. In this paper, we present a new cuffless BP method using an array of wrist-worn bio-impedance sensors placed on the radial and the ulnar arteries of the wrist to monitor the arterial pressure pulse from the blood volume changes at each sensor site. BP is accurately estimated by using AdaBoost regression model based on selected arterial pressure pulse features such as transit time, amplitude and slope of the pressure pulse, which are dependent on the cardiac activity and the vascular properties of the wrist arteries. A separate model is developed for each subject based on calibration data to capture the individual variations of BP parameters. In this pilot study, data was collected from 10 healthy participants with age ranges from 18 to 30 years after exercising using our custom low-noise bio-impedance sensing hardware. Post-exercise BP was accurately estimated with an average correlation coefficient and root mean square error (RMSE) of 0.77 and 2.6 mmHg for the diastolic BP and 0.86 and 3.4 mmHg for the systolic BP.

The role of CPAP treatment in elderly patients with moderate obstructive sleep apnoea: a multicentre randomised controlled trial.

The efficacy of continuous positive airway pressure (CPAP) treatment in elderly patients with nonsevere obstructive sleep apnoea (OSA) is controversial. The objective of this study was to assess the effect of CPAP treatment in elderly patients with moderate OSA in terms of clinical, quality-of-life and neurocognitive measures.This was an open-label, randomised, multicentre clinical trial in 145 elderly patients (≥70 years old) with confirmed moderate OSA (apnoea-hypopnoea index 15-29.9 events·h-1) randomised to receive CPAP (n=73) or no CPAP (n=72) for 3 months. The primary end-point was the Epworth Sleepiness Scale (ESS) score, and the secondary end-points included quality of life (Quebec Sleep Questionnaire (QSQ) domain scores), sleep-related symptoms, presence of anxiety/depression, office-based blood pressure measurements and some neurocognitive tests. The analysis was performed according to the intention-to-treat principle.Mean±sd age was 74.9±4.6 years. The CPAP group achieved a greater improvement in the ESS score (adjusted difference of 2.6 (95% CI 3.6-1.6) points; effect size 1) in some sleep-related symptoms and in some dimensions of the QSQ questionnaire (nocturnal symptoms: -0.7 (95% CI -0.3--1.0) points; p<0.0001 and emotions: -0.4 (95% CI -0.1--0.7) points; p=0.023). However, CPAP did not demonstrate any effect on either neurocognitive tests (including anxiety and depression) or blood pressure levels. There was a positive correlation between the effect of CPAP and the improvement in ESS scores and quality of life domains.CPAP treatment resulted in a significant improvement in diurnal hypersomnia and some sleep-related symptoms and quality of life domains in elderly patients with moderate OSA.

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

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

Trends in end digit preference for blood pressure and associations with cardiovascular outcomes in Canadian and UK primary care: a retrospective observational study

ObjectivesTo study systematic errors in recording blood pressure (BP) as measured by end digit preference (EDP); to determine associations between EDP, uptake of Automated Office BP (AOBP) machines and cardiovascular...

The use of ambulatory blood pressure monitoring to confirm a diagnosis of high blood pressure by primary-care physicians in Oregon.

Hypertension is the most commonly diagnosed medical condition in the USA. Unfortunately, patients are misdiagnosed in primary care because of inaccurate office-based blood pressure measurements. Several US healthcare organizations currently recommend confirming an office-based hypertension diagnosis with ambulatory blood pressure monitoring to avoid overtreatment; however, its use for the purpose of confirming an office-based hypertension diagnosis is relatively unknown. This descriptive study surveyed 143 primary-care physicians in Oregon with regard to their current use of ambulatory blood pressure monitoring. Nineteen percent of the physicians reported that they would use ambulatory blood pressure monitoring to confirm an office-based hypertension diagnosis, although over half had never ordered it. The most frequent indication for ordering ambulatory blood pressure monitoring was to investigate suspected white-coat hypertension (37.3%). In addition, many of the practices did not own an ambulatory blood pressure monitoring device (79.7%) and, therefore, had to refer patients to other clinics or departments for testing. Many primary-care physicians will need to change their current clinical practice to align with the shift toward a confirmation process for office-based hypertension diagnoses to improve population health.

TCT-493 Renal Sympathetic Denervation In Patients With Resistant Hypertension - Inducing An Immediate And Persisting 24h Ambulatory Blood Pressure (ABPM) Reduction - Results From The Halle-RDN-Registry

Catheter-based renal sympathetic denervation (RDN) has shown to significantly reduce blood pressure (BP) in patients with resistant hypertension. So far, current available data are almost entirely derived from office-based blood pressure measurements (OBPM) with only few data basing on more reliable

Screening For Hypertension Annually Compared With Current Practice

Hypertension is the most common diagnosis in ambulatory care, yet little evidence exists regarding recommended screening intervals or the sensitivity and specificity of a routine office-based blood pressure measurement, the most common screening test. Screening for hypertension is usually performed by measuring blood pressure at every outpatient visit, which often results in transiently elevated findings among adults who do not have a diagnosis of hypertension. We hypothesize that a more limited annual screening strategy may increase specificity while maintaining sensitivity. A retrospective case-control study of 372 adults without hypertension and 68 patients with newly diagnosed hypertension was conducted to compare the usual screening practice of checking blood pressure at every visit with a second strategy that considered only annual blood pressure measurements. Specificity improved from 70.4% (95% CI, 65.5%-75.0%) for the usual practice to 82.0% (95% CI, 77.7%-85.8%) for the annual screening strategy. No statistically significant difference in sensitivity existed between the 2 methods. A limited annual screening strategy for hypertension can improve specificity without sacrificing sensitivity when compared with routine screening at every visit in previously normotensive adults.

Role of Home Blood Pressure Monitoring in Overcoming Therapeutic Inertia and Improving Hypertension Control

Hypertension remains the most common modifiable cardiovascular risk factor, yet hypertension control rates remain dismal. Home blood pressure (BP) monitoring has the potential to improve hypertension control. The purpose of this review was to quantify both the magnitude and mechanisms of benefit of home BP monitoring on BP reduction. Using a structured review, studies were selected if they reported either changes in BP or percentage of participants achieving a pre-established BP goal between randomized groups using home-based and office-based BP measurements. A random-effects model was used to estimate the magnitude of benefit and relative risk. The search yielded 37 randomized controlled trials with 9446 participants that contributed data for this meta-analysis. Compared with clinic-based measurements (control group), systolic BP improved with home-based BP monitoring (-2.63 mm Hg; 95% CI, -4.24, -1.02); diastolic BP also showed improvement (-1.68 mm Hg; 95% CI, -2.58, -0.79). Reductions in home BP monitoring-based therapy were greater when telemonitoring was used. Home BP monitoring led to more frequent antihypertensive medication reductions (relative risk, 2.02 [95% CI, 1.32 to 3.11]) and was associated with less therapeutic inertia defined as unchanged medication despite elevated BP (relative risk for unchanged medication, 0.82 [95% CI, 0.68 to 0.99]). Compared with clinic BP monitoring alone, home BP monitoring has the potential to overcome therapeutic inertia and lead to a small but significant reduction in systolic and diastolic BP. Hypertension control with home BP monitoring can be enhanced further when accompanied by plans to monitor and treat elevated BP such as through telemonitoring.

Renal sympathetic denervation in patients with treatment-resistant hypertension (The Symplicity HTN-2 Trial): a randomised controlled trial

Activation of renal sympathetic nerves is key to pathogenesis of essential hypertension. We aimed to assess effectiveness and safety of catheter-based renal denervation for reduction of blood pressure in patients with treatment-resistant hypertension. In this multicentre, prospective, randomised trial, patients who had a baseline systolic blood pressure of 160 mm Hg or more (≥150 mm Hg for patients with type 2 diabetes), despite taking three or more antihypertensive drugs, were randomly allocated in a one-to-one ratio to undergo renal denervation with previous treatment or to maintain previous treatment alone (control group) at 24 participating centres. Randomisation was done with sealed envelopes. Data analysers were not masked to treatment assignment. The primary effectiveness endpoint was change in seated office-based measurement of systolic blood pressure at 6 months. Primary analysis included all patients remaining in follow-up at 6 months. This trial is registered with ClinicalTrials.gov, number NCT00888433. 106 (56%) of 190 patients screened for eligibility were randomly allocated to renal denervation (n=52) or control (n=54) groups between June 9, 2009, and Jan 15, 2010. 49 (94%) of 52 patients who underwent renal denervation and 51 (94%) of 54 controls were assessed for the primary endpoint at 6 months. Office-based blood pressure measurements in the renal denervation group reduced by 32/12 mm Hg (SD 23/11, baseline of 178/96 mm Hg, p<0·0001), whereas they did not differ from baseline in the control group (change of 1/0 mm Hg [21/10], baseline of 178/97 mm Hg, p=0·77 systolic and p=0·83 diastolic). Between-group differences in blood pressure at 6 months were 33/11 mm Hg (p<0·0001). At 6 months, 41 (84%) of 49 patients who underwent renal denervation had a reduction in systolic blood pressure of 10 mm Hg or more, compared with 18 (35%) of 51 controls (p<0·0001). We noted no serious procedure-related or device-related complications and occurrence of adverse events did not differ between groups; one patient who had renal denervation had possible progression of an underlying atherosclerotic lesion, but required no treatment. Catheter-based renal denervation can safely be used to substantially reduce blood pressure in treatment-resistant hypertensive patients. Ardian.

Ambulatory Blood Pressure Monitoring in Primary Care

The accurate assessment and appropriate management of blood pressure (BP) is critical for primary care physicians. Traditional office-based BP measurement has limitations that can be addressed, in part, through the use of ambulatory BP monitoring (ABPM). Because BP readings are provided at specific time intervals throughout a 24-hour period, ABPM represents a better picture of the normal fluctuations in BP levels associated with daily activities, including sleep. Blood pressure values obtained by 24-hour ABPM are a better predictor of cardiovascular risk than office-based BP measurements, and the technique can be used to discern white-coat hypertension and to evaluate masked, resistant, and pseudoresistant hypertension. It can also be helpful in the assessment of autonomic dysfunction and monitoring of a patient's response to antihypertensive therapy. Ambulatory BP monitoring is also being increasingly used in clinical trials that assess the antihypertensive effects of medications.

Does Reducing Physician Uncertainty Improve Hypertension Control?

Hypertension affects nearly one third of the US population overall, and the prevalence rises sharply with age. In spite of public educational campaigns and professional education programs to encourage blood pressure measurement and control of both systolic and diastolic control to <140/90 mm Hg (or 130/80 mm Hg if diabetic), 43% of treated hypertensives do not achieve the recommended Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure target. Among blacks, 48% are uncontrolled on treatment. The majority of persons classified as poorly controlled hypertensives have mild systolic blood pressure elevation (in the range of 140 to 160 mm Hg). We hypothesized that physician uncertainty regarding the patient's usual blood pressure, as well as uncertainty regarding the extent of medication nonadherence, represent an important barrier to further reductions in the proportion of uncontrolled hypertensives in the United States. Using cluster randomization, 10 primary care clinics (6 from a public health care system and 4 from a private clinic system) were randomized to either the uncertainty reduction intervention condition or to usual care. An average of 68 patients per clinic were recruited to serve as units of observation. Physicians in the 5 intervention clinics were provided with a specially designed study form that included a graph of recent blood pressure measurements in their study patients, a check box to indicate their assessment of the adequacy of the patient's blood pressure control, and a menu of services they could order to aid in patient management. These menu options included 24-hour ambulatory blood pressure monitoring; electronic bottle cap assessment of medication adherence, followed by medication adherence counseling in patients found to be nonadherent; and lifestyle assessment and counseling followed by 24-hour ambulatory blood pressure monitoring. Physicians in the 5 usual practice clinics did not have access to these services but were informed of which patients had been enrolled in the study. Substudies carried out to further characterize the study population and interpret intervention results included ambulatory blood pressure monitoring and electronic bottle cap monitoring in a random subsample of patients at baseline, and audio recording of patient-physician encounters after intervention implementation. The primary study end point was defined as the proportion of patients with controlled blood pressure (<140/90 mm Hg or <130/80 mm Hg if diabetic). Secondary end points include actual measured clinic systolic and diastolic blood pressure, patient physician communication patterns, physician prescribing patient self-reported lifestyle and medication adherence, physician knowledge, attitude and beliefs regarding the utility of intervention tools to achieve blood pressure control, and the cost-effectiveness of the intervention. Six-hundred eighty patients have been randomized, and 675 remain in active follow-up after 1.5 years. Patient closeout will be complete in March 2009. Analyses of the baseline data are in progress. Office-based blood pressure measurement error and bias, as well as physician and patient beliefs about the need for treatment intensification, may be important factors that limit further progress in blood pressure control. This trial will provide data on the extent to which available technologies not widely used in primary care will change physician prescribing behavior and patient adherence to prescribed treatment.

Diurnal Blood Pressure Pattern and Risk of Congestive Heart Failure

Context. High blood pressure (BP) is the most important risk factor for congestive heart failure (CHF) at a population level, but the relationship of an altered diurnal BP pattern to the risk of subsequent CHF is unknown. Objectives. To explore 24-hour ambulatory BP characteristics as predictors of CHF incidence and to investigate whether altered diurnal BP patterns confer any additional risk information beyond that provided by conventional office BP measurements. Design, Setting, and Participants. Prospective, community-based, observational cohort in Uppsala, Sweden, including 951 elderly men free of CHF, valvular disease, and left ventricular hypertrophy at baseline between 1990 and 1995, followed until the end of 2002. Twenty-four-hour ambulatory BP monitoring was performed at baseline, and the BP variables were analyzed as predictors of subsequent CHF. The main outcome measure was first hospitalization for CHF. Results. Seventy men developed CHF during follow-up, with an incidence rate of 8.6 per 1000 person-years at risk. In multivariable Cox proportional hazards models adjusted for antihypertensive treatment and established risk factors for CHF (myocardial infarction, diabetes, smoking, body mass index, and serum cholesterol level), a 1-SD (9-mm Hg) increase in nighttime ambulatory diastolic BP (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.02–1.55) and the presence of “nondipping” BP (night-day ambulatory BP ratio ≥1; HR, 2.29; 95% CI, 1.16–4.52) were associated with an increased risk of CHF. After adjusting for office-measured systolic and diastolic Bps, nondipping BP remained a significant predictor of CHF (HR, 2.21; 95% CI, 1.12–4.36 vs normal night-day pattern). Nighttime ambulatory diastolic BP and nondipping BP were also significant predictors of CHF after exclusion of all participants who had an acute myocardial infarction before baseline or during follow-up. Conclusions. Nighttime BP appears to convey additional risk information about CHF beyond office-measured BP and other established risk factors for CHF. The clinical value of this association remains to be established in future studies.—Ingelsson E, Bjorklund-Bodegard K, Lind L, et al. Diurnal blood pressure pattern and risk of congestive heart failure. JAMA. 2006;295:2859–2866. Comment. Ambulatory BP monitoring provides information that is not obtained from conventional office-based BP measurement, such as mean BP over a 24-hour period and circadian BP patterns. Staessen et al1demonstrated that a nondipping pattern of BP (night-day ambulatory BP ratio ≥1) and nighttime BP more accurately predicted cardiovascular events than daytime BP. A reduced circadian BP variation is a common finding in CHF patients. The association of diastolic dysfunction with increased diastolic BP and nondipping in patients with hypertension and type 2 diabetes is also known. The primary aim of this study was to determine what characteristics of the 24-hour ambulatory BP measurements best predicted new-onset CHF, and how these characteristics of the 24-hour ambulatory BP measurements compared with office measurements. The prospective, community-based, observational cohort included 951 elderly men free of CHF, valvular disease, and left ventricular hypertrophy at baseline followed for a median of 9.1 years. Twenty-four-hour ambulatory BP monitoring along with office-based BP measurements were performed at baseline, and the BP variables, including nondipping pattern, were analyzed as predictors of subsequent CHF. Seventy men developed CHF during follow-up, with an incidence rate of 8.6 per 1000 person-years at risk. After adjusting for antihypertensive treatment and established risk factors for CHF (myocardial infarction, diabetes, smoking, body mass index, and serum cholesterol level), a 1-SD (9-mm Hg) increase in nighttime ambulatory diastolic BP and the presence of nondipping BP were associated with an increased absolute risk of CHF. A 5-mm Hg increment in nighttime ambulatory diastolic BP was associated with a 13%–25% increased risk of CHF. After adjusting for office-measured systolic and diastolic Bps, nondipping pattern remained a significant predictor of CHF. The incidence of CHF was 15 cases higher per 1000 person-years at risk for those with nondipping vs normal night—day BP pattern. Nighttime ambulatory diastolic BP and nondipping BP were also significant predictors of CHF even after exclusion of all participants who had an acute myocardial infarction before baseline or during follow-up. The few limitations of this study include limited generalizability to women and other age or ethnic groups, inadvertent exclusion of nonhospitalized patients with mild CHF, and unknown impact of BP pattern on systolic vs diastolic HF. The pathophysiologic mechanism behind this association is not yet clear, but the authors speculate that endothelial dysfunction and/or increased sympathetic activity may be dysfunctions playing significant roles. Reversed circadian BP pattern (nondipping) may be important per se or may be an indicator of an important trait like sleep apnea. Previous studies have shown an association of nondipping nocturnal Bps and ambulatory BP readings with both cardiovascular disease incidence and left ventricular hypertrophy, and these findings with regard to CHF are consistent. The authors are rightfully cautious about the clinical implications of these findings, but they may provide additional clues to understanding the progression from hypertension to CHF.

Myocardial ischemia during everyday life in patients with arterial hypertension: prevalence, risk factors, triggering mechanism and circadian variability

The objective of the present study was to investigate the prevalence, the risk factors, the hemodynamic triggering mechanisms, the circadian variability of ST segment depression (ST depression) and the effect of day and night fall in blood pressure on the prevalence of ST depression in hypertensive patients. In a multicentric study in Germany, 1,244 CardioTens registrations (combined 24-h ambulatory blood pressure measurement/electrocardiography with ST segment triggering; Meditech, Budapest, Hungary) from patients with arterial hypertension were consecutively monitored and evaluated centrally at the University of Bonn. Inclusion criterion was treated or untreated arterial hypertension. The ST segment was measured in accordance with the "1 : 1 : 1 rule" (horizontal or descending ST depression by 1 mm, 1 min duration, 1 min interval from the previous episode). ST segment depression was observed in 250 (20.1%) patients; 90.3% of the transient ST-segment depression was silent (without angina pectoris). Ambulatory 24-h blood pressure measurement, but not office-based blood pressure measurement, was predictive for the occurrence of ST-segment depression. Risk factors for ST-segment depression were the Sokolow index > or =3.5 mV, smoking status, severity of coronary heart disease, use of diuretics, reduced left ventricular function, pulse pressure > or =60 mmHg and increase of double product (1,000 mmHg/min). A significant rise of the systolic/diastolic blood pressure (+8+ or -18/+7+ or -10 mmHg), of the heart rate (+12+ or -13/min) and of the double product (+2,471+ or -2,517 mmHg/min) was found during the transient ST depression as compared with the corresponding 24-h ambulatory blood pressure measurement mean values (P<0.0001 for all parameters specified). In most intermittent ST depressions, a rise of the double product was seen (n=789 episodes), and in the remaining 239 ST depressions, a fall of the double product was observed. ST depressions with fall of the double product showed a circadian distribution with a peak in the late evening. ST depression accompanied by a rise in double product showed two peaks (one in the early morning and one in the late evening). The prevalence of ST depression was significantly higher (28.6%) in extreme dippers than in dippers (18.2%), risers (21.8%) and non-dippers (19.6%). ST depressions have a high prevalence of 20.1% in hypertensive patients. Clinical predictors for the occurrence of ST-segment depression were classical risk factors and cardiac target organ damage. Office-based blood pressure measurement was not a useful measuring tool for forecasting the likelihood of ST-segment depression. ST depressions were triggered inter alia by variations of blood pressure and the heart rate. The circadian variability of the ST depressions is crucially affected by the pressure double product characteristics on which the ST depression is based.