2013 Ambulatory Blood Pressure Monitoring Recommendations for the Diagnosis of Adult Hypertension, Assessment of Cardiovascular and other Hypertension-associated Risk, and Attainment of Therapeutic Goals

Ambulatory blood pressure monitoring in clinical practice: a review

Ambulatory blood pressure monitoring offers the ability to collect blood pressure readings several times an hour across a 24-hour period. Ambulatory blood pressure monitoring facilitates the identification of white-coat hypertension, the phenomenon whereby certain individuals who are not taking antihypertensive medication show elevated blood pressure in a clinical setting but show nonelevated blood pressure averages when assessed by ambulatory blood pressure monitoring. In addition, readings can be segmented into time windows of particular interest, for example, mean daytime and nighttime values. During sleep, blood pressure typically decreases, or dips, such that mean sleep blood pressure is lower than mean awake blood pressure. A nondipping pattern and nocturnal hypertension are strongly associated with increased cardiovascular morbidity and mortality. Approximately 70% of individuals have blood pressure dips of ≥10% at night, whereas 30% have nondipping patterns, when blood pressure remains similar to daytime average or occasionally increases above daytime average. The various blood pressure categorizations afforded by ambulatory blood pressure monitoring are valuable for clinical management of high blood pressure because they increase the accuracy for diagnosis and the prediction of cardiovascular risk.

Treatment of hypertension with chronotherapy: is it time of drug administration?

OBJECTIVE

To review evidence for dosing antihypertensives at bedtime and possible cardiovascular risk reduction.

DATA SOURCES

A PubMed, EMBASE, and Cochrane Controlled Trials database literature search (1990-September 2014) limited to human subjects was performed using the search terms hypertension, chronotherapy, ambulatory blood pressure, morning administration, evening administration, and antihypertensives. Additional references were identified from literature citations.

STUDY SELECTION

All prospective studies assessing cardiovascular outcomes or comparing morning to evening administration of antihypertensives were selected.

DATA SYNTHESIS

Compared with morning administration, dosing one or more antihypertensive medications at bedtime helps induce a normal circadian blood pressure pattern and reduces the risk of cardiovascular disease morbidity and mortality in individuals with hypertension. Similar results have been reported in high-risk individuals with diabetes, chronic kidney disease, and resistant hypertension. A lack of diversity among studied populations and reliance on subgroup analyses are among the limitations of these data. All antihypertensive medications have not been studied in chronotherapy and do not uniformly achieve desired results. The most substantial evidence exists for medications affecting the renin-angiotensin-aldosterone system.

CONCLUSIONS

Despite growing evidence and promise as a cost-effective strategy for reducing cardiovascular risk, chronotherapy is not uniformly recommended in the treatment of hypertension. Careful selection of patients and antihypertensives for chronotherapy is required. Further investigation is needed to evaluate the definitive impact of chronotherapy on cardiovascular outcomes.

Evening -versus morning- dosing drug therapy for chronic kidney disease patients with hypertension: a systematic review

BACKGROUND/AIMS

There is a strong correlation between non-dipping status and cardiovascular events in chronic kidney disease (CKD) patients. Our study is designed to identify the effect of evening administration of antihypertensive drugs to hypertensive CKD patients.

METHODS

A comprehensive search of Medline, Embase, the Chinese Biomedical Literature Database, Wanfang Data, Chinese National Knowledge Infrastructure, and the Cochrane Central Register of Controlled Trials was performed in July 2014. Concurrent controlled or crossover trials (including randomized and non-randomized experimental trials) designed to evaluate the effects of evening- versus morning-dosing hypertensive drug regimens on clinical outcomes in CKD patients with hypertension were included. All statistical analyses were performed using the RevMan software, which is available free from the Cochrane Collaboration.

RESULTS

Seven trials involving 1277 patients were identified, and the randomized controlled trials (RCTs) and non-randomized controlled trials (non-RCTs) were classified into two groups. Taking at least one blood pressure-lowering medication at bedtime was not shown to reduce total death (P=0.056) or cardiovascular death (P=0.059) but was shown to reduce total events (P<0.001) and major cardiovascular events (P<0.001) in both RCTs and non-RCTs. Compared with a morning dosing regimen, taking antihypertensive drug in the evening significantly lowered nighttime systolic blood pressure (SBP) (P<0.0001) and diastolic blood pressure (P<0.05) in patients in the RCTs but did not affect blood pressure in patients in the non-RCTs (P<0.05). There is limited evidence from one non-RCT that taking an antihypertensive drug (benazepril 10 mg) in the evening did not increase adverse events (P=0.72) or withdrawals due to adverse events (P=0.64).

CONCLUSIONS

A regimen of antihypertensive drugs in the evening should be considered for CKD patients with hypertension to lower nighttime blood pressure and help prevent total events and cardiovascular mortality. More studies are needed to verify the results of this study.

The relationship between AASI and arterial atherosclerosis in ESRD patients

OBJECTIVE

To explore the relationship between ambulatory blood pressure and arterial atherosclerosis and provide simple and easy reference indicators for the prediction, prevention and prognosis of cardiovascular events in end-stage renal disease (ESRD) patients.

METHOD

This prospective study consecutively collected clinical data of 114 ESRD hospitalized patients in the Department of Nephrology, the First Affiliated Hospital of Nanjing Medical University during August 2012 to December 2012. The data included laboratory data, the ambulatory blood pressure monitoring (ABPM), carotid ultrasound, two-dimensional echocardiography and the prognosis scores of the death risk.

RESULTS

(1) A series of ABPM parameters were closely associated with atherosclerosis (p ≤ 0.05). Ambulatory Arterial Stiffness Index (AASI) was the most representative parameter of ABPM and also the best indicator for atherosclerosis (logistic regression analysis, p = 0.005). (2) AASI was a comprehensive index of atherosclerosis (p < 0.001), which was associated with the increase of left ventricular diameter (p = 0.028) and the risk of death (p < 0.001). The independent risk factors of AASI were the growth of the age (p < 0.001), elevated serum fibrinogen (p = 0.009) and reduced serum albumin (p = 0.022).

CONCLUSION

AASI, as the representative of ABPM parameters, related well to atherosclerosis, which implied a broader application of ABPM in ESRD patients.

Diurnal and twenty-four hour patterning of human diseases: cardiac, vascular, and respiratory diseases, conditions, and syndromes

Various medical conditions, disorders, and syndromes exhibit predictable-in-time diurnal and 24 h patterning in the signs, symptoms, and grave nonfatal and fatal events, e.g., respiratory ones of viral and allergic rhinorrhea, reversible (asthma) and non-reversible (bronchitis and emphysema) chronic obstructive pulmonary disease, cystic fibrosis, high altitude pulmonary edema, and decompression sickness; cardiac ones of atrial premature beats and tachycardia, paroxysmal atrial fibrillation, 3rd degree atrial-ventricular block, paroxysmal supraventricular tachycardia, ventricular premature beats, ventricular tachyarrhythmia, symptomatic and non-symptomatic angina pectoris, Prinzmetal vasospastic variant angina, acute (non-fatal and fatal) incidents of myocardial infarction, sudden cardiac arrest, in-bed sudden death syndrome of type-1 diabetes, acute cardiogenic pulmonary edema, and heart failure; vascular and circulatory system ones of hypertension, acute orthostatic postprandial, micturition, and defecation hypotension/syncope, intermittent claudication, venous insufficiency, standing occupation leg edema, arterial and venous branch occlusion of the eye, menopausal hot flash, sickle cell syndrome, abdominal, aortic, and thoracic dissections, pulmonary thromboembolism, and deep venous thrombosis, and cerebrovascular transient ischemic attack and hemorrhagic and ischemic stroke. Knowledge of these temporal patterns not only helps guide patient care but research of their underlying endogenous mechanisms, i.e., circadian and others, and external triggers plus informs the development and application of effective chronopreventive and chronotherapeutic strategies.

Diurnal and twenty-four hour patterning of human diseases: acute and chronic common and uncommon medical conditions

The symptom intensity and mortality of human diseases, conditions, and syndromes exhibit diurnal or 24 h patterning, e.g., skin: atopic dermatitis, urticaria, psoriasis, and palmar hyperhidrosis; gastrointestinal: esophageal reflux, peptic ulcer (including perforation and hemorrhage), cyclic vomiting syndrome, biliary colic, hepatic variceal hemorrhage, and proctalgia fugax; infection: susceptibility, fever, and mortality; neural: frontal, parietal, temporal, and occipital lobe seizures, Parkinson's and Alzheimer's disease, hereditary progressive dystonia, and pain (cancer, post-surgical, diabetic neuropathic and foot ulcer, tooth caries, burning mouth and temporomandibular syndromes, fibromyalgia, sciatica, intervertebral vacuum phenomenon, multiple sclerosis muscle spasm, and migraine, tension, cluster, hypnic, and paroxysmal hemicranial headache); renal: colic and nocturnal enuresis and polyuria; ocular: bulbar conjunctival redness, keratoconjunctivitis sicca, intraocular pressure and anterior ischemic optic neuropathy, and recurrent corneal erosion syndrome; psychiatric/behavioral: major and seasonal affective depressive disorders, bipolar disorder, parasuicide and suicide, dementia-associated agitation, and addictive alcohol, tobacco, and heroin cravings and withdrawal phenomena; plus autoimmune and musculoskeletal: rheumatoid arthritis, osteoarthritis, axial spondylarthritis, gout, Sjögren's syndrome, and systemic lupus erythematosus. Knowledge of these and other 24 h patterns of human pathophysiology informs research of their underlying circadian and other endogenous mechanisms, external temporal triggers, and more effective patient care entailing clinical chronopreventive and chronotherapeutic strategies.

Current therapeutic approaches to cardio-protection in hypertension

Targeting a specific blood pressure based upon patient risk has been the approach to reducing cardiovascular risk in patients with hypertension. Drug selection was based upon compelling indications with titration and the addition of other agents as needed until the blood pressure target was achieved. However, new information has emerged describing improved methods for measuring blood pressure, a re-evaluation of blood pressure targets and additional therapeutic approaches that together may further reduce cardiovascular risk in patients with hypertension.

Current issues in the management and monitoring of hypertension in chronic kidney disease

PURPOSE OF REVIEW

This review highlights recent developments in the management and monitoring of hypertension in adults with chronic kidney disease (CKD), not on dialysis.

RECENT FINDINGS

Ambulatory blood pressure (BP) monitoring and self-measured BP monitoring can classify abnormal BP patterns better than clinic BP readings. Self-measured BP monitoring lowers BP and allows tailoring of antihypertensive treatment. Dosing of antihypertensive medication at night improves nocturnal hypertension. Recent guidelines recommend a BP target less than 140/90 mmHg for patients with CKD without proteinuria and less than 130/80 mmHg for those with proteinuria. Lower salt intake is associated with a greater effect of renin-angiotensin-aldosterone system blockage in CKD. Lifestyle modification resulting in weight loss reduces BP in individuals with CKD. Of overweight or obese CKD patients, 8% report taking weight loss medication, which is a potential safety concern. Weight loss from intensive lifestyle modification in individuals with diabetes prevents CKD.

SUMMARY

Although we have effective tools to monitor and lower BP, we still need clinical outcome studies to inform BP targets for specific age groups, types of CKD disease, and comorbidities. How to treat obesity to improve hypertension and other comorbidities in patients with CKD remains another important area of research.

Validation of the integration of technology that measures additional "vascular" indices into an ambulatory blood pressure monitoring system

BACKGROUND

The objective of this study was to validate the novel integration of oscillometric (Vasotens(®)) technology into a BPLab(®) ambulatory blood pressure (BP) monitoring system to measure central BP, the aortic augmentation index, and pulse wave velocity (PWV) compared with the recommended and widely accepted tonometric method.

METHODS

The ARTERY Society guidelines for comparison of PWV measurement techniques were used as the basis for recruitment of 99 individuals (mean age 44±19 years, 52 males). The standard for comparison was the conventional "classic" SphygmoCor device.

RESULTS

Accordance of the two methods was satisfactory (r=0.98, mean difference of 2.9±3.5 mmHg for central systolic BP; r=0.98, mean difference of -1.1±2.3 mmHg for central diastolic BP; r=0.83, mean difference of -2.6%±13% for aortic augmentation index; r=0.85, mean difference of 0.69±1.4 for PWV).

CONCLUSION

The performance of Vasotens algorithms using an oscillometric ambulatory BP monitoring system is feasible for accurate diagnosis, risk assessment, and evaluation of the effects of antihypertensive drugs.

An armband wearable device for overnight and cuff-less blood pressure measurement

24-h blood pressure (BP) has significant prognostic value for cardiovascular risk screening, but the present BP devices are mainly cuff-based, which are unsuitable for long-term BP measurement, especially during nighttime. In this paper, we developed an armband wearable pulse transit time (PTT) system for 24-h cuff-less BP measurement and evaluated it in an unattended out-of-laboratory setting. Ten healthy young subjects participated in this ambulatory study, where PTT was measured at 30-min interval by this wearable system and the reference BP was measured by a standard oscillometric ambulatory BP monitor. Due to the misalignment of BP and PTT on their recording time caused by the different measurement principles of the two BP devices, a new estimation method has been proposed: transients in PTT were removed from the raw data by defined criteria, and then evenly interpolated, low-pass filtered, and resampled to synchronize at the time when BP was recorded. The results show that with the proposed method, the correlation between PTT and systolic BP (SBP) during nighttime with dynamic range of 21.8 ± 14.2 mmHg has improved from -0.50 ± 0.24 to -0.62 ± 0.20 , and the difference between the estimated and reference SBP has improved from 0.7 ± 10.7 to 2.8 ± 8.2 mmHg with root mean square error reduced from 10.7 to 8.7 mmHg. In addition, the correlation between a very low frequency component of SBP and PTT obtained from the proposed method during nighttime is -0.80 ± 0.10 and the difference is 2.4 ± 5.7 mmHg for a dynamic BP range of 13.5 ± 8.0 mmHg. It is therefore concluded from this study that the proposed wearable system has great potential to be used for overnight SBP monitoring, especially to measure the averaged SBP over a long period.

Ambulatory blood pressure in chronic kidney disease

Chronic kidney disease (CKD) affects approximately 20 million adults in the United States. Patients with CKD have an increased risk of cardiovascular (CV) disease. Ambulatory blood pressure monitoring (ABPM) provides superior BP measurements when compared to office BP measurements in normotensive, hypertensive and CKD patients. ABPM measurements are often abnormal in CKD, with CKD patients frequently showing an altered circadian rhythm with an increased rate of non-dipping and reverse dipping. The prevalence of non-dippers and reverse-dippers increases progressively as stage of CKD progresses. ABPM has been shown to be a better tool for predicting CV risk, CKD progression, end stage renal disease (ESRD) or death than office-based pressures. ABPM is also additive and adds prognostic value for predicting CKD and CV outcomes when added to estimated glomerular filtration rate (eGFR). Although ABPM is time consuming, it is worth considering, as the data demonstrates that information from ABPM can potentially impact future CV and renal outcomes in patients with CKD.

Influences of the circadian clock on neuronal susceptibility to excitotoxicity

Stroke is the third leading cause of death and the primary cause of morbidity in the United States, thus posing an enormous burden on the healthcare system. The factors that determine the risk of an individual toward precipitation of an ischemic event possess a strong circadian component as does the ischemic event itself. This predictability provided a window of opportunity toward the development of chronopharmaceuticals which provided much better clinical outcomes. Experiments from our lab showed for the first time that neuronal susceptibility to ischemic events follows a circadian pattern; hippocampal neurons being most susceptible to an ischemic insult occurring during peak activity in a rodent model of global cerebral ischemia. We also demonstrated that the SCN2.2 cells (like their in vivo counterpart) are resistant to excitotoxicity by glutamate and that this was dependent on activation of ERK signaling. We are currently working on elucidating the complete neuroprotective pathway that provides a barricade against glutamate toxicity in the SCN2.2 cells. Our future experiments will be engaged in hijacking the neuroprotective mechanism in the SCN2.2 cells and applying it to glutamate-susceptible entities in an effort to prevent their death in the presence of excitotoxicity. Despite the advancement in chronopharmaceuticals, optimal clinical outcome with minimal adverse events are difficult to come by at an affordable price. Superior treatment options require a better understanding of molecular mechanisms that define the disease, including the role of the circadian clock.

Optimising the accuracy of blood pressure monitoring in chronic kidney disease: the utility of BpTRU

BACKGROUND

Accurate blood pressure monitoring is critical for the management of chronic kidney disease, but changes in management in secondary care clinics may be based on a single blood pressure reading, with a subsequent lack of accuracy. The aim of this study was to evaluate a fully automated sphygmomanometer for optimising the accuracy of blood pressure measurements in the setting of secondary care renal clinics.

METHODS

Patients had routine blood pressure measurements with a calibrated DINAMAP PRO400 monitor in a clinical assessment room. Patients then underwent repeat assessment with a DINAMAP PRO400 monitor and BpTRU device and subsequent 24 hour ambulatory blood pressure monitoring (ABPM).

RESULTS

The BpTRU systolic (± SD) reading (117.3 ± 14.1 mmHg) was significantly lower than the routine clinic mean systolic blood pressure (143.8 ± 15.5 mmHg; P < 0.001) and the repeat blood pressure taken with a DINAMAP PRO400 monitor in a quiet room (129.9 ± 19.9 mmHg; P < 0.001). The routine clinic mean diastolic (82.4 ± 11.2 mmHg) was significantly higher than the BpTRU reading (78.4 ± 10.0 mmHg; P < 0.001). Clinic BpTRU measurements were not significantly different to the daytime mean or overall mean of 24 hour ABPM.

CONCLUSIONS

In patients with CKD, routine clinic blood pressure measurements were significantly higher than measurements using a BpTRU machine in a quiet room, but there was no significant difference in this setting between BpTRU readings and 24 hour ABPM. Adjusting clinic protocols to utilise the most accurate blood pressure technique available is a simple manoeuvre that could deliver major improvements in clinical practice.

Abnormalities in chronic kidney disease of ambulatory blood pressure 24 h patterning and normalization by bedtime hypertension chronotherapy

In chronic kidney disease (CKD), the prevalence of hypertension is very high, escalating with diminishing renal function. Typically, the diagnosis of hypertension and the clinical decisions regarding its treatment are based on daytime clinic blood pressure (BP) measurements. However, the correlation between BP level and target organ damage, cardiovascular risk and long-term prognosis is greater for ambulatory than clinic measurements. Moreover, evidence is consistent among numerous studies that the elevated risk and incidence of end-organ injury and fatal and non-fatal cardiovascular events are significantly associated with blunted night-time BP decline, and that the asleep BP better predicts cardiovascular events than either the awake or 24-h BP mean. The prevalence of abnormally high asleep BP is extensive in CKD, significantly increasing with its severity. In CKD, the diagnoses of hypertension and its therapeutic control are often inaccurate in the absence of complete and careful assessment of the entire 24 h, i.e. daytime and night-time, BP pattern. Accordingly, ambulatory BP monitoring should be the preferred method to comprehensively assess and decide the optimal clinical management of patients with CKD. Recent findings indicate therapeutic restoration of normal physiologic BP reduction during night-time sleep is the most significant independent predictor of decreased cardiovascular and cerebrovascular risk, both in patients with and without CKD, and is best achieved when antihypertensive medications, mainly those blocking the renin-angiotensin-aldosterone system, are routinely taken at bedtime.

Chinese herbal medicine qi ju di huang wan for the treatment of essential hypertension: a systematic review of randomized controlled trials

Background. Chinese herbs are potentially effective for hypertension. Qi Ju Di Huang Wan (QJDHW) is a commonly used Chinese herbal medicine as a monotherapy or in combination with other antihypertensive agents for the treatment of essential hypertension (EH). However, there is no critically appraised evidence such as systematic reviews or meta-analyses on the effectiveness and safety of QJDHW for EH. Methods and Findings. CENTRAL, PubMed, CBM, CNKI, VIP, and online clinical trial registry websites were searched for published and unpublished randomized controlled trials (RCTs) of QJDHW for essential hypertension up to January 2013 with no language restrictions. A total of 10 randomized trials involving 1024 patients were included. Meta-analysis showed that QJDHW combined with antihypertensive drugs was more effective in lowering blood pressure and improving TCM syndrome for the treatment of essential hypertension than antihypertensive drugs used alone. No trials reported severe adverse events related to QJDHW. Conclusions. Our review suggests that QJDHW combined with antihypertensive drugs might be an effective treatment for lowering blood pressure and improving symptoms in patients with essential hypertension. However, the finding should be interpreted with caution because of the poor methodological quality of included trials. There is an urgent need for well-designed, long-term studies to assess the effectiveness of QJDHW in the treatment of essential hypertension.

Chronotherapy improves blood pressure control and reduces vascular risk in CKD

In patients with chronic kidney disease (CKD), the prevalence of increased blood pressure during sleep and blunted sleep-time-relative blood pressure decline (a nondipper pattern) is very high and increases substantially with disease severity. Elevated blood pressure during sleep is the major criterion for the diagnoses of hypertension and inadequate therapeutic ambulatory blood pressure control in these patients. Substantial, clinically meaningful ingestion-time-dependent differences in the safety, efficacy, duration of action and/or effects on the 24 h blood pressure pattern of six different classes of hypertension medications and their combinations have been substantiated. For example, bedtime ingestion of angiotensin-converting-enzyme inhibitors and angiotensin-receptor blockers is more effective than morning ingestion in reducing blood pressure during sleep and converting the 24 h blood pressure profile into a dipper pattern. We have identified a progressive reduction in blood pressure during sleep--a novel therapeutic target best achieved by ingestion of one or more hypertension medications at bedtime--as the most significant predictor of decreased cardiovascular risk in patients with and without CKD. Recent findings suggest that in patients with CKD, ambulatory blood pressure monitoring should be used for the diagnosis of hypertension and assessment of cardiovascular disease risk, and that therapeutic strategies given at bedtime rather than on awakening are preferable for the management of hypertension.