Toward a definition of masked hypertension and white-coat hypertension among hemodialysis patients

Masked phenomenon: renal and cardiovascular complications; review and updates

BACKGROUND

In the in-clinic blood pressure (BP) recording setting, a sizable number of individuals with normal BP and approximately 30% of patients with chronic renal disease (CKD) exhibit elevated outpatient BP records. These individuals are known as masked hypertension (MHTN), and when they are on antihypertensive medications, but their BP is not controlled, they are called masked uncontrolled hypertension (MUHTN). The masked phenomenon (MP) (MHTN and MUHTN) increases susceptibility to end-organ damage (a two-fold greater risk for cardiovascular events and kidney dysfunction). The potential extension of the observed benefits of MP therapy, including a reduction in end-organ damage, remains questionable.

AIM AND METHODS

This review aims to study the diagnostic methodology, epidemiology, pathophysiology, and significance of MP management in end-organs, especially the kidneys, cardiovascular system, and outcomes. To achieve the purposes of this non-systematic comprehensive review, PubMed, Google, and Google Scholar were searched using keywords, texts, and phrases such as masked phenomenon, CKD and HTN, HTN types, HTN definition, CKD progression, masked HTN, MHTN, masked uncontrolled HTN, CKD onset, and cardiovascular system and MHTN. We restricted the search process to the last ten years to search for the latest updates.

CONCLUSION

MHTN is a variant of HTN that can be missed if medical professionals are unaware of it. Early detection by ambulatory or home BP recording in susceptible individuals reduces end-organ damage and progresses to sustained HTN. Adherence to the available recommendations when dealing with masked phenomena is justifiable; however, further studies and recommendation updates are required.

The association of home blood pressure with all-cause mortality in hemodialysis patients: A prospective observational study

INTRODUCTION

Prior observational studies conducted in the hemodialysis population have suggested a reverse association between dialysis-unit blood pressure (BP) and mortality. The present study aimed to investigate the prognostic association of home versus dialysis-unit BP with all-cause mortality in hemodialysis patients.

METHODS

At baseline, 146 patients receiving maintenance hemodialysis underwent assessment of their BP with the following methods: (i) 2-week averaged routine predialysis and postdialysis BP measurements; (ii) home BP monitoring for 1 week that included duplicate morning and evening BP measurements with the use of validated devices.

RESULTS

Over a median follow-up period of 38 months (interquartile range [IQR]: 22-54), 44 patients (31.1%) died. In Kaplan-Meier curves, predialysis and postdialysis systolic BP (SBP) was not associated with all-cause mortality, while home SBP appeared to be of prognostic significance (log rank p = 0.029). After stratifying patients into quartiles, all-cause mortality was lowest when home SBP was ranging from 128.1 to 136.8 mmHg (quartile 2). In univariate Cox regression analysis, using quartile 2 as a referent category, the risk of all-cause mortality was 3.32-fold higher in quartile 1, 1.53-fold higher in quartile 3 and 3.25-fold higher in quartile 4. The risk-association remained unchanged after adjustment for several confounding factors (adjusted hazard ratio: 4.79, 1.79, 3.63 for quartiles 1, 3, and 4 of home systolic BP, respectively).

CONCLUSION

Our findings suggest that among hemodialysis patients, 1-week averaged home SBP is independently associated with all-cause mortality. In sharp contrast, SBP recorded either before or after dialysis over 2 weeks is not prognostically informative.

White Coat Hypertension & Cardiovascular Outcomes

PURPOSE OF REVIEW

This review aims to inform the reader of the complexity of blood pressure responses when comparing blood pressure measured in the medical environment to that outside the medical environment. In addition, we summarize what is known about current predictors of white coat hypertension, reevaluate the relationship of white coat hypertension to cardiovascular outcomes, and provide some clinical guidance on management.

RECENT FINDINGS

Differences in outcomes exist when white coat effect occurs in unmedicated people versus the white coat effects in those on antihypertensive therapy. White coat hypertension is relatively common, carries a small but definite increase in cardiovascular risk, and is prone to conversion to sustained hypertension. Future research will hopefully tease out the roles of ancillary findings that characterize a white coat hypertensive (like modest elevations in creatinine, glucose and triglycerides) in the elevated cardiovascular risk, and test the effectiveness of mitigation strategies in these patients.

Epidemiology of Hypertension among Patients on Peritoneal Dialysis Using Standardized Office and Ambulatory Blood Pressure Recordings

INTRODUCTION

Prior studies conducted in peritoneal dialysis (PD) patients in the late 1990s provided considerably variable estimates of the prevalence and control of hypertension. The present study aimed to investigate the current state of hypertension management in this high-risk population.

METHODS

In 140 stable PD patients, we performed standardized automated office blood pressure (BP) measurements and 24-h ambulatory BP monitoring (ABPM) using the Mobil-O-Graph device (IEM, Germany). Office and ambulatory hypertension was diagnosed in patients with office BP ≥140/90 mm Hg and 24-h BP ≥130/80 mm Hg, respectively. Patients treated with ≥1 BP-lowering medications were also classified as hypertensives.

RESULTS

The prevalence of office and ambulatory hypertension was 92.9% and 95%, respectively. In all, 92.1% of patients were being treated with an average of 2.4 BP-lowering medications daily. Adequate BP control was achieved in 52.3% and 38.3% of hypertensives by office BP and ABPM, respectively. The agreement between these 2 techniques in the identification of patients with BP levels above the diagnostic thresholds of hypertension was moderate (k-statistic: 0.524). In all, 5% of patients were normotensives with both techniques, 31.4% had controlled hypertension, 5% had white-coat hypertension, 19.3% had masked hypertension, and 39.3% had sustained hypertension. Isolated nocturnal hypertension was detected in 23.6% of patients, whereas no patient had isolated daytime hypertension.

CONCLUSION

Among PD patients, hypertension is highly prevalent and remains often inadequately controlled. The use of ABPM enables the better classification of severity of hypertension and identification of isolated nocturnal hypertension, which is a common BP phenotype in the PD population.

The Key Role of Ambulatory Blood Pressure Monitoring in the Detection of Masked Hypertension and Other Phenomena in Frail Geriatric Patients

Background and Objectives: This study aims to determine prevalence of masked uncontrolled hypertension (MUH) in frail geriatric patients with arterial hypertension and thus show the role of ambulatory blood pressure monitoring (ABPM) since hypertension occurs in more than 80% of people 60+ years and cardiovascular diseases are the main cause of death worldwide. Despite modern pharmacotherapy, use of combination therapy and normal office blood pressure (BP), patients’ prognoses might worsen due to inadequate therapy (never-detected MUH). Materials and Methods: 118 frail geriatric patients (84.2 ± 4.4 years) treated for arterial hypertension with office BP < 140/90 mmHg participated in the study. 24-h ABPM and clinical examination were performed. Results: Although patients were normotensive in the office, 24-h measurements showed that BP values in 72% of hypertensives were not in the target range: MUH was identified in 47 (40%) patients during 24 h, in 48 (41%) patients during daytime and nocturnal hypertension in 60 (51%) patients. Conclusions: ABPM is essential for frail geriatric patients due to high prevalence of MUH, which cannot be detected based on office BP measurements. ABPM also helps to detect exaggerated morning surge, isolated systolic hypertension, dipping/non-dipping, and set and properly manage adequate treatment, which reduces incidence of cardiovascular events and contributes to decreasing the financial burden of society.

The Relation of Clinic and Ambulatory BP with the Risk of Cardiovascular Events and All-Cause Mortality among Patients on Peritoneal Dialysis

Large observational studies showed a U-shaped association of clinic blood pressure (BP) with mortality among patients undergoing peritoneal dialysis (PD). Whether ambulatory BP provides a more direct risk signal in this population remains unknown. In a prospective cohort of 108 PD patients, standardized clinic BP was recorded at baseline with the validated device HEM-705 (Omron, Healthcare, Bannockburn, IL, USA) and 24-h ambulatory BP monitoring was performed using the Mobil-O-Graph monitor (IEM, Stolberg, Germany). Over a median follow-up of 16 months (interquartile range: 19 months), 47.2% of the overall population reached the composite outcome of non-fatal myocardial infarction, non-fatal stroke, or all-cause death. In Cox-regression analysis, systolic but not diastolic BP was prognostically informative. Compared with the reference quartile 1 of 24-h systolic BP (SBP), the multivariate-adjusted hazard ratio for the composite outcome was 1.098 (95% confidence interval (CI): 0.434–2.777) in quartile 2, 1.004 (95% CI: 0.382–2.235) in quartile 3 and 2.449 (95% CI: 1.156–5.190) in quartile 4. In contrast, no such association was observed between increasing quartiles of clinic SBP and composite outcome. The present study shows that among PD patients, increasing ambulatory SBP is independently associated with higher risk of adverse cardiovascular events and mortality, providing superior prognostic information than standardized clinic SBP.

A comparative meta-analysis of prospective observational studies on masked hypertension and masked uncontrolled hypertension defined by ambulatory and home blood pressure

BACKGROUND

In a comparative meta-analysis, we investigated the prognostic value of masked hypertension and masked uncontrolled hypertension defined by ambulatory or home blood pressure (BP) monitoring.

METHODS

We searched English literature published till 2 September 2018 to identify prospective observational studies. Masked hypertension was defined as a normal clinic BP (<140/90 mmHg) in the presence of an elevated 24 h, daytime or night-time ambulatory or home BP. Clinical outcomes included all-cause and cardiovascular mortality, and fatal and nonfatal cardiovascular, stroke, cardiac, coronary and renal disease events.

RESULTS

In total, 21 studies (n = 130 318) were included. Overall, compared with normotensive participants, masked hypertensive patients had a 5.7/2.9 mmHg higher clinic BP and 18.7/9.8 mmHg higher out-of-office BP. The pooled risk ratio for masked hypertension versus normotension was 1.67 (95% confidence interval, 1.32-2.13) and 2.19 (1.72-2.78) for all-cause (eight studies) and cardiovascular mortality (three studies), respectively, and 1.71 (1.53-1.91), 1.95 (1.36-2.80), 1.76 (1.33-2.33), 1.62 (0.27-9.60), 3.85 (2.03-7.31) for fatal and nonfatal cardiovascular (15 studies), stroke (two studies), cardiac (two studies), coronary (two studies) and renal disease events (two studies), respectively. Risk ratios for all-cause mortality (1.78 versus 1.40, P = 0.16) and fatal and nonfatal cardiovascular events (1.81 versus 1.61, P = 0.29) were similar between studies on ambulatory and home BP monitoring in the overall analyses. The analyses in subgroups according to treatment status (untreated, treated or mixed) and sampling approach (population or referred patients) were confirmatory.

CONCLUSION

Masked hypertension and masked uncontrolled hypertension were associated with unfavorable clinical outcomes, regardless of the out-of-office BP monitoring techniques.

The relationship of volume overload and its control to hypertension in hemodialysis patients

Hypertension is highly prevalent and associated with poor clinical outcomes among individuals receiving maintenance hemodialysis (HD). Volume overload is a key modifiable contributor to hypertension and cardiovascular disease in the HD population. Despite their importance, assessment and treatment of volume overload and hypertension remain major clinical challenges and have substantial implications for both clinical outcomes and patient experiences of care. This review will summarize current data on the diagnosis, epidemiology, pathophysiology, and clinical consequences of hypertension and volume overload in HD patients. We will also identify priorities for future research studies.

Cardiovascular Events and Mortality in White Coat Hypertension: A Systematic Review and Meta-analysis

BACKGROUND

The long-term cardiovascular risk of isolated elevated office blood pressure (BP) is unclear.

PURPOSE

To summarize the risk for cardiovascular events and all-cause mortality associated with untreated white coat hypertension (WCH) and treated white coat effect (WCE).

DATA SOURCES

PubMed and EMBASE, without language restriction, from inception to December 2018.

STUDY SELECTION

Observational studies with at least 3 years of follow-up evaluating the cardiovascular risk of WCH or WCE compared with normotension.

DATA EXTRACTION

2 investigators independently extracted study data and assessed study quality.

DATA SYNTHESIS

27 studies were included, comprising 25 786 participants with untreated WCH or treated WCE and 38 487 with normal BP followed for a mean of 3 to 19 years. Compared with normotension, untreated WCH was associated with an increased risk for cardiovascular events (hazard ratio [HR], 1.36 [95% CI, 1.03 to 2.00]), all-cause mortality (HR, 1.33 [CI, 1.07 to 1.67]), and cardiovascular mortality (HR, 2.09 [CI, 1.23 to 4.48]); the risk for WCH was attenuated in studies that included stroke in the definition of cardiovascular events (HR, 1.26 [CI, 1.00 to 1.54]). No significant association was found between treated WCE and cardiovascular events (HR, 1.12 [CI, 0.91 to 1.39]), all-cause mortality (HR, 1.11 [CI, 0.89 to 1.46]), or cardiovascular mortality (HR, 1.04 [CI, 0.65 to 1.66]). The findings persisted across several sensitivity analyses.

LIMITATION

Paucity of studies evaluating isolated cardiac outcomes or reporting participant race/ethnicity.

CONCLUSION

Untreated WCH, but not treated WCE, is associated with an increased risk for cardiovascular events and all-cause mortality. Out-of-office BP monitoring is critical in the diagnosis and management of hypertension.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Prevalence and control of hypertension by 48-h ambulatory blood pressure monitoring in haemodialysis patients: a study by the European Cardiovascular and Renal Medicine (EURECA-m) working group of the ERA-EDTA

Background

Population-specific consensus documents recommend that the diagnosis of hypertension in haemodialysis patients be based on 48-h ambulatory blood pressure (ABP) monitoring. However, until now there is just one study in the USA on the prevalence of hypertension in haemodialysis patients by 44-h recordings. Since there is a knowledge gap on the problem in European countries, we reassessed the problem in the European Cardiovascular and Renal Medicine working group Registry of the European Renal Association-European Dialysis and Transplant Association.

Methods

A total of 396 haemodialysis patients underwent 48-h ABP monitoring during a regular haemodialysis session and the subsequent interdialytic interval. Hypertension was defined as (i) pre-haemodialysis blood pressure (BP) ≥140/90 mmHg or use of antihypertensive agents and (ii) ABP ≥130/80 mmHg or use of antihypertensive agents.

Results

The prevalence of hypertension by 48-h ABP monitoring was very high (84.3%) and close to that by pre-haemodialysis BP (89.4%) but the agreement of the two techniques was not of the same magnitude (κ statistics = 0.648; P &lt;0.001). In all, 290 participants were receiving antihypertensive treatment. In all, 9.1% of haemodialysis patients were categorized as normotensives, 12.6% had controlled hypertension confirmed by the two BP techniques, while 46.0% had uncontrolled hypertension with both techniques. The prevalence of white coat hypertension was 18.2% and that of masked hypertension 14.1%. Of note, hypertension was confined only to night-time in 22.2% of patients while just 1% of patients had only daytime hypertension. Pre-dialysis BP ≥140/90 mmHg had 76% sensitivity and 54% specificity for the diagnosis of BP ≥130/80 mmHg by 48-h ABP monitoring.

Conclusions

The prevalence of hypertension in haemodialysis patients assessed by 48-h ABP monitoring is very high. Pre-haemodialysis BP poorly reflects the 48 h-ABP burden. About a third of the haemodialysis population has white coat or masked hypertension. These findings add weight to consensus documents supporting the use of ABP monitoring for proper hypertension diagnosis and treatment in this population.

Blood pressure targets for hemodialysis patients

The association between blood pressure (BP) and mortality is unique in hemodialysis patients compared with that in the general population. This is because of an altered benefit-risk balance associated with BP reduction in these patients. An adequately designed study comparing BP targets in hemodialysis patients remains to be conducted. The current evidence available to guide dialysis providers regarding treatment strategies for managing hypertension in this population is limited to large observational studies and small randomized controlled trials. In this opinion article, we review these data and discuss the key points regarding BP management for hemodialysis patients. Our aim is to provide a practical opinion regarding BP targets that nephrologists can incorporate into clinical practice, with a focus on moving away from dialysis unit BPs and focusing on out-of-dialysis unit BPs.

Masked hypertension: understanding its complexity

Masked hypertension, which is present when in-office normotension translates to out-of-office hypertension, is present in a surprisingly high percentage of untreated persons and an even higher percentage of patients after beginning antihypertensive medication. Not only are persons with prehypertension more likely to have masked hypertension than those with optimal blood pressure (BP), but also they frequently develop target organ damage prior to transitioning to sustained hypertension. Furthermore, the frequency of masked hypertension is high in individuals of African inheritance and in the presence of increased cardiovascular risk factors and disease states, such as diabetes and chronic renal failure. Nocturnal hypertension and non-dipping may be early markers of masked hypertension. Twenty-four hour ambulatory BP monitoring (ABPM), which can detect nighttime and 24 h elevated BP, remains the gold standard for diagnosing masked hypertension. Almost one-third of treated patients with masked hypertension remain as 'masked uncontrolled hypertension', and it becomes important, therefore, to use ABPM (and supplemental home BP monitoring) for the effective diagnosis and control of hypertension.

Blood pressure in hemodialysis: targets?

PURPOSE OF REVIEW

In the absence of 'hard' clinical-trial evidence to define optimal blood pressure (BP) targets and validate different BP measurement techniques, management of hypertension in hemodialysis is based on expert opinions. In this review, we provide a comparative evaluation of out-of-dialysis BP monitoring versus dialysis-unit BP recordings in diagnosing hypertension, guiding its management and prognosticating mortality risk.

RECENT FINDINGS

Owing to their high variability and poor reproducibility, predialysis and postdialysis BP recordings provide inaccurate reflection of the actual BP load outside of dialysis. Contrary to the reverse association of peridialytic BP with mortality, elevated home and ambulatory BP provides a direct mortality signal. Out-of-dialysis BP monitoring, even when done in the clinic, is a reliable approach to manage hypertension in the dialysis unit. Whenever none of these measures are available, median intradialytic SBP can provide a better estimate of interdialytic BP levels compared with peridialytic BP measurements.

SUMMARY

Although out-of-dialysis BP monitoring have better diagnostic accuracy and prognostic validity, randomized trials are needed to ascertain BP targets for managing hypertension in hemodialysis patients.

Masked uncontrolled hypertension in patients on maintenance hemodialysis

Masked uncontrolled hypertension (MUCH) has been proven to be associated with increased cardiovascular risk in the general population. We performed the current analysis to determine its prevalence in dialysis patients and its association with pulse wave velocity (PWV). From 368 participants of another cohort study, we selected 145 subjects with controlled predialysis blood pressure (BP). All subjects underwent ambulatory BP monitoring and PWV measurement. MUCH was defined as controlled predialysis BP with daytime BP⩾135/85 mm Hg (definition-1); total ambulatory BP⩾130/80 mm Hg (definition-2); and either daytime BP⩾135/85 mm Hg or nighttime BP⩾120/70 mm Hg (definition-3). The prevalence of MUCH was 43.4% (definition-1), 55.9% (definition-2) and 74.5% (definition-3). Multivariable logistic regression analysis showed that the use of antihypertensive medication was the most consistent predictor of MUCH within all 3 definitions (all odds ratio (OR)⩾4.28, P<0.001). Predialysis systolic BP (both OR>1, P⩽0.04), predialysis diastolic BP (both OR>1, P⩽0.001) and hemoglobin (both OR<1, P=0.02) were all significantly associated with MUCH in two models. Interdialytic weight gain (OR=0.52, P=0.02) was associated with MUCH under definition-2, and BMI (OR=0.86, P=0.03) was associated with MUCH under definition-3. Patients with MUCH had significantly elevated PWV compared with their counterparts according to all three definitions with or without adjusting for covariates (all P⩽0.03). In conclusion, MUCH affects a large proportion of dialysis patients with controlled predialysis BP and is associated with increased PWV. Patients on antihypertensive medications and with higher predialysis BP are more likely to have MUCH.

Decoding white coat hypertension

There is arguably no less understood or more intriguing problem in hypertension that the "white coat" condition, the standard concept of which is significantly blood pressure reading obtained by medical personnel of authoritative standing than that obtained by more junior and less authoritative personnel and by the patients themselves. Using hospital-initiated ambulatory blood pressure monitoring, the while effect manifests as initial and ending pressure elevations, and, in treated patients, a low daytime profile. The effect is essentially systolic. Pure diastolic white coat hypertension appears to be exceedingly rare. On the basis of the studies, we believe that the white coat phenomenon is a common, periodic, neuro-endocrine reflex conditioned by anticipation of having the blood pressure taken and the fear of what this measurement may indicate concerning future illness. It does not change with time, or with prolonged association with the physician, particularly with advancing years, it may be superimposed upon essential hypertension, and in patients receiving hypertensive medication, blunting of the nighttime dip, which occurs in about half the patients, may be a compensatory mechanisms, rather than an indication of cardiovascular risk. Rather than the blunted dip, the morning surge or the widened pulse pressure, cardiovascular risk appears to be related to elevation of the average night time pressure.

Hypertension in the Hemodialysis Patient

Hypertension is common yet difficult to manage in the hemodialysis patients population. This chapter discusses various aspects of this problem including its prevalence, distinctive pathophysiology, methods of diagnosis and pharmacological and non pharmacological treatment approaches. The topic is relevant to any health care provider taking care of hemodialysis patients.

Role of 24-h ambulatory blood pressure monitoring in children with chronic kidney disease

Hypertension is common in children with chronic kidney disease (CKD) and is a major determinant of CKD progression. Ambulatory blood pressure monitoring (ABPM) has been proposed to be better in detecting hypertension as compared to casual blood pressure (CBP). This study aims to study the usefulness of ABPM in detecting masked hypertension, evaluating the adequacy of blood pressure (BP) control and predicting left ventricular hypertrophy (LVH) amongst children with CKD. A prospective cross-sectional study of 46 children with stage 3–5 CKD was conducted at the Pediatric Nephrology department of a tertiary hospital in South India. All children underwent CBP, ABPM and an echocardiography. Results were categorized as normal BP; confirmed hypertension; masked hypertension and white coat hypertension. Out of 46 children studied, 11 were undergoing dialysis. While 39.1% children had stage 3 and 4 CKD each, 21.7% had stage 5 CKD. Masked hypertension was detected in 19.6% and 21.7% had confirmed hypertension. Thirty-four (73.9%) children were already receiving antihypertensive medication. In these, CBP was elevated in 23.5% and ABP in 47%. Among children with hypertension as defined by ABPM, LVH was detected in 32.2%. We found that higher the number of abnormal ABPM indices (assessed by BP Index, nocturnal dipping and BP Load) higher the likelihood of LVH (P = 0.046). ABPM is better in detecting hypertension and monitoring adequacy of treatment in children with CKD. The high prevalence of masked hypertension and its association with LVH supports early echocardiography and ambulatory BP monitoring to evaluate cardiovascular risks in this population.

Moderator's view: Ambulatory blood pressure monitoring and home blood pressure for the prognosis, diagnosis and treatment of hypertension in dialysis patients

Major health agencies now recommend the systematic application of ambulatory blood pressure monitoring (ABPM) for the diagnosis of hypertension. Given the exceedingly high prevalence of nocturnal hypertension, masked and white coat hypertension and the overt inadequacy of peridialysis (pre-, intra- and post-dialysis) BP measurements, more extensive application of ABPM for the diagnosis of hypertension in dialysis patients would appear logical. In a recent survey performed in NDT Educational, organizational problems and/or cognitive resistance emerged as important factors hindering more extensive application of ABPM and home BP by nephrologists. External validation of observations made in landmark studies in a single institution about hypertension subcategorization by ABPM is urgently needed. Furthermore, apparent cognitive resistance by nephrologists may be justified by the fact that these techniques have been insufficiently tested in the dialysis population for applicability in everyday clinical practice, tolerability, organizational impact and cost-effectiveness. We should be more resolute in abandoning peridialysis measurements for diagnosing and treating hypertension in haemodialysis patients. Home BP is a formidable educational instrument for patient empowerment and self-care, and evidence exists that this technique is superior to peridialysis values to better hypertension control as defined on the basis of ABPM. We should strive to promote more extensive application of home BP monitoring to diagnose and manage hypertension in haemodialysis patients. ABPM with novel, user friendly and better tolerated techniques is to be awaited in the near future.

The complexity of masked hypertension: diagnostic and management challenges

Masked hypertension, defined as discordant in-office normotension versus out-of-office hypertension, is present in approximately 10 % to 40 % of patients not receiving antihypertensive treatment. Not only are persons with prehypertension more likely to have masked hypertension, but they also frequently develop target organ damage before transitioning to established sustained hypertension. Moreover, the percentage of persons with masked hypertension increases in the presence of cardiovascular disease, diabetes, or chronic renal failure. The gold standard for diagnosing masked hypertension is the 24-hour ambulatory BP monitor (ABPM), but home BP monitoring (HBPM) has also been a useful alternative procedure. Importantly, initiating antihypertensive treatment exclusively with the use of in-office BP monitoring may result in almost one-third of patients remaining with high-risk masked uncontrolled hypertension, which underscores the importance of HBPM and ABPM as supplements to in-office BP monitoring for the effective treatment of hypertension.

Poor agreement between dialysis unit blood pressure and interdialytic ambulatory blood pressure

Although ambulatory blood pressure (ABP) monitoring (ABPM) is often considered to have an advantage over dialysis unit blood pressure (BP) in dialysis patients, the exact relationship between these two measurements of BP has not been well determined. In a cohort of 90 Chinese dialysis patients, agreement between dialysis unit BP (predialysis and postdialysis BP) and interdialytic ABP was evaluated using Bland-Altman plots and Lin's concordance correlation coefficient for quantitative analysis, and inter-rater agreement (κ) for qualitative analysis. Limits of agreement between dialysis unit BP and ABP were wide (predialysis systolic BP: -33.5 to 20.9 mm Hg; predialysis diastolic BP: -22.2 to 11.9 mm Hg; postdialysis systolic BP: -25.4 to 26.5 mm Hg; postdialysis diastolic BP: -18.4 to 12.3 mm Hg). Lin's concordance correlation coefficient exhibited a poor agreement with concordance correlation coefficients of 0.75, 0.81, 0.64, and 0.75 for predialysis systolic BP, postdialysis systolic BP, predialysis diastolic BP, and postdialysis diastolic BP, respectively. When BP level was classified into quartiles, an increasing trend for incorrect classification rate was observed with deleterious hypertension, with the highest value in grade 3 hypertension (100% and 75.0% for predialysis and postdialysis BP, respectively). Therefore, these data suggest that agreement between dialysis unit BP and interdialytic ABP is poor in Chinese dialysis patients, and the bias for patients with higher degree of hypertension is more prominent.

Closer look at white-coat hypertension

This review aims to clarify novel concepts regarding the clinical and laboratory aspects of white-coat hypertension (WCHT). Recent studies on the clinical and biological implications of WCHT were compared with existing knowledge. Studies were included if the WCHT patients were defined according to the 2013 European Society of Hypertension guidelines, i.e., an office blood pressure (BP) of ≥ 140/90 mmHg, a home BP of ≤ 135/85 mmHg, and a mean 24-h ambulatory BP of ≤ 130/80 mmHg. WCHT studies published since 2000 were selected, although a few studies performed before 2000 were used for comparative purposes. True WCHT was defined as normal ABPM and home BP readings, and partial WCHT was defined as an abnormality in one of these two readings. The reported prevalence of WCHT was 15%-45%. The incidence of WCHT tended to be higher in females and in non-smokers. Compared with normotensive (NT) patients, WCHT was associated with a higher left ventricular mass index, higher lipid levels, impaired fasting glucose, and decreased arterial compliance. The circadian rhythm in WCHT patients was more variable than in NT patient’s, with a higher pulse pressure and non-dipping characteristics. Compared with sustained hypertension patients, WCHT patients have a better 10-year prognosis; compared with NT patients, WCHT patients have a similar stroke risk, but receive more frequent drug treatment. There are conflicting results regarding WCHT and markers of endothelial damage, oxidative stress and inflammation, and the data imply that WCHT patients may have a worse prognosis. Nitric oxide levels are lower, and oxidative stress parameters are higher in WCHT patients than in NT patients, whereas the antioxidant capacity is lower in WCHT patients than in NT patients. Clinicians should be aware of the risk factors associated with WCHT and patients should be closely monitored especially to identify target organ damage and metabolic syndrome.

Significance of white-coat and masked hypertension in chronic kidney disease and end-stage renal disease

Hypertension is a frequent and modifiable cardiovascular risk factor with a cyclic relationship with chronic kidney disease (CKD). The diagnosis, treatment, monitoring and control of high blood pressure are all mandatory not only in CKD but also in end-stage renal disease (ESRD). As demonstrated by studies using population and hypertensive patients, white-coat hypertension (WCHT) and masked hypertension (MHT) carry a particular degree of risk. The advantages of ambulatory techniques in the management and prognostic stratification of patients with CKD and ESRD have also been recognized. However, most of the evidence underlines the importance of nocturnal hypertension and neglects WCHT and MHT. The absence of specific reports involving untreated and treated patients hinders the ability to significantly discriminate WCHT from the white-coat effect and MHT from masked uncontrolled hypertension. The heterogeneous definitions that are used add additional difficulty in translating experimental evidence into clinical practice. Reaching a consensus in definitions is mandatory for designing future research. Cross-sectional studies underscore the frequency of misdiagnosis, potentially leading to undertreatment (MHT) and overtreatment (WCHT) in renal disease. The divergent prevalence of WCHT and MHT reported in CKD could be related to the diverse definitions of hypertension and the heterogeneity of the pathologies pooled under the CKD definition. Even in the absence of randomized clinical trials specifically addressing this issue, the scarce longitudinal studies confirm that WCHT carries a risk close to that of sustained normotension, whereas MHT is associated with a risk close or identical to that of sustained hypertension.

Forty-four-hour interdialytic ambulatory blood pressure monitoring and cardiovascular risk in pediatric hemodialysis patients

Background

Children undergoing chronic hemodialysis are at risk of cardiovascular disease and often develop left ventricular hypertrophy (LVH). Twenty-four-hour ambulatory blood pressure monitoring (ABPM) is known to better predict cardiovascular morbidity than casual blood pressure (BP) measurement. Given the BP variability attributed to interdialytic fluid overload, 44-h ABPM should better delineate cardiovascular morbidity in pediatric hemodialysis patients.

Methods

In this cross-sectional study, 17 children (16.7 ± 2.9 years) on chronic hemodialysis underwent 44-h interdialytic ABPM and routine echocardiogram. Left ventricular mass index (LVMI) was calculated by height-based equation; LVH was defined as an LVMI in the ≥95th percentile for height-age and gender. Hypertension was defined by the recommendations of the Fourth Report of the National High Blood Pressure Education Program for casual measurements, and by those of the American Heart Association for ABPM.

Results

Twenty-four percentage of patients were hypertensive by casual post-dialytic systolic BP, whereas 59% were hypertensive by ABPM. Eighty-eight percentage of patients had abnormal cardiac geometry: 53% had LVH. Thirty-five percentage (6 of 17) had masked hypertension, including four with abnormal cardiac geometry, of which, three had LVH. LVMI correlated with ABPM, but not with casual measurements. Strongest correlations with an increased LVMI were with 44-h diastolic BP: at night (r = 0.53, P = 0.03) and total load (r = 0.57, P = 0.02). LVH was similarly associated with 44-h nighttime BP: systolic (P = 0.02), diastolic (P = 0.01) and mean arterial (P = 0.01).

Conclusions

Casual BP measurement underestimates hypertension in pediatric hemodialysis patients and does not correlate well with indicators of cardiovascular morbidity. In contrast, 44-h interdialytic ABPM better characterizes hypertension, with nighttime parameters most strongly predicting increased LVMI and LVH.

Cardiovascular risk assessment in children following kidney transplantation

CV diseases are the leading cause of death among patients with ESRD. RTX decreases the CV risk; however, it still remains definitely higher than that of the general population. Large multicenter and longitudinal studies are difficult to perform and hard end-points of CV events are usually missing among pediatric population. Thus, appropriate estimation of CV risk is of crucial importance to define the potential hazards and to evaluate the effect of treatments aimed to reduce the risk. A number of validated non-invasive methods are available to assess the extent of CV damage in adults, such as calcification scores, cIMT, aPWV, 24-h ABPM, AASI, and HRV; however, they need adaptation, standardization, and validation in pediatric studies. cIMT and PWV are the most promising methods, as pediatric normative values are already present. The up-to-date treatment of ESRD aims not only to save life, but to offer the patient a life expectancy approaching that of the healthy population and to ensure a reasonable quality of life.

The controversies of diagnosing and treating hypertension among hemodialysis patients

This review discusses 10 current controversies regarding the dialysis patient with hypertension. The clinician is faced with a dilemma at the bedside on how to evaluate blood pressure and treat this condition in a patient on long-term hemodialysis. The evidence base to give firm recommendations is thin, but the epidemiological evidence tells us to do nothing. This appears to be an incorrect strategy, at least based on what we know today. Evaluating home BP in every dialysis patient, evaluating volume status on a regular basis, and treating hypertension predominantly with nonpharmacological strategies are worthwhile.