Appropriate Time Interval to Repeat Ambulatory Blood Pressure Monitoring in Patients With White-Coat Resistant Hypertension

Options for patients with out-of-control blood pressure: after all avenues have been exhausted

INTRODUCTION

Uncontrolled hypertension is the leading risk factor for global mortality. Most hypertensive patients can be controlled with standard medication combinations, but some may not respond adequately to ≥3 or even to ≥5 antihypertensive agents.

AREAS COVERED

In this review, we summarize the recent literature on difficult-to-treat hypertension identified by a Medline search, and we discuss the options for fourth line and subsequent therapy.

EXPERT OPINION

It is essential to confirm resistant hypertension with out-of-office blood pressure measurements and to consider lifestyle factors, adherence to medication and secondary causes of hypertension. When true resistant hypertension is confirmed and blood pressure is not controlled with an optimal triple combination, preferably as a fixed dose combination tablet, spironolactone is usually recommended as the fourth medication. Comorbid conditions should be treated as appropriate with sodium-glucose-cotransporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, sacubitril-valsartan or finerenone. Renal denervation appears to be a useful addition to overcome some of the problems of medication adherence. The endothelin antagonist aprocitentan may be a final option in some countries. Of the drugs in development, the RNA based therapeutics that inhibit angiotensinogen synthesis appear to be some of the most promising.

Cutoffs for white-coat and masked blood pressure effects: an ambulatory blood pressure monitoring study

The values used to define white-coat and masked blood pressure (BP) effects are usually arbitrary. This study aimed at investigating the accuracy of various cutoffs based on the differences (ΔBP) between office BP (OBP) and 24h-ambulatory BP monitoring (ABPM) to identify white-coat (WCH) and masked (MH) hypertension, which are phenotypes coupled with adverse prognosis. This cross-sectional study included 11,350 [Derivation cohort; 45% men, mean age = 55.1 ± 14.1 years, OBP = 132.1 ± 17.6/83.9 ± 12.5 mmHg, 24 h-ABPM = 121.6 ± 11.4/76.1 ± 9.6 mmHg, 25% using antihypertensive medications (AH)] and 7220 (Validation cohort; 46% men, mean age = 58.6 ± 15.1 years, OBP = 136.8 ± 18.7/87.6 ± 13.0 mmHg, 24 h-ABPM = 125.5 ± 12.6/77.7 ± 10.3 mmHg; 32% using AH) unique individuals who underwent 24 h-ABPM. We compared the sensitivity, specificity, positive and negative predictive values and area under the curve (AUC) of diverse ΔBP cutoffs to detect WCH (ΔsystolicBP/ΔdiastolicBP = 28/17, 20/15, 20/10, 16/11, 15/9, 14/9 mmHg and ΔsystolicBP = 13 and 10 mmHg) and MH (ΔsystolicBP/ΔdiastolicBP = -14/-9, -5/-2, -3/-1, -1/-1, 0/0, 2/2 mmHg and ΔsystolicBP = -5 and -3mmHg). The 20/15 mmHg cutoff showed the best AUC (0.804, 95%CI = 0.794-0.814) to detect WCH, while the 2/2 mmHg cutoff showed the highest AUC (0.741, 95%CI = 0.728-0.754) to detect MH in the Derivation cohort. Both cutoffs also had the best accuracy to detect WCH (0.767, 95%CI = 0.754-0.780) and MH (0.767, 95%CI = 0.750-0.784) in the Validation cohort. In secondary analyses, these cutoffs had the best accuracy to detect individuals with higher and lower office-than-ABPM grades in both cohorts. In conclusion, the 20/15 and 2/2 mmHg ΔBP cutoffs had the best accuracy to detect hypertensive patients with WCH and MH, respectively, and can serve as indicators of marked white-coat and masked BP effects derived from 24 h-ABPM.

Orthostatic hypotension, orthostatic hypertension, and ambulatory blood pressure in patients with chronic kidney disease in CRIC

BACKGROUND

Orthostatic changes in blood pressure (BP), either orthostatic hypotension or orthostatic hypertension (OHTN), are common among patients with chronic kidney disease. Whether they are associated with unique out-of-office BP phenotypes is unknown.

METHODS

CRIC is a prospective, multicenter, observational cohort study of participants with CKD. BP measured at 2 min after standing and ambulatory BP monitoring (ABPM) were obtained on 1386 participants. Orthostatic hypotension was defined as a 20 mmHg drop in SBP or 10 mmHg drop in DBP when changing from seated to standing positions. Systolic and diastolic night-to-day ratio was also calculated. OHTN was defined as a 20 or 10 mmHg rise in SBP or DBP when changing from a seated to a standing position. White-coat effect (WCE) was defined as seated minus daytime ambulatory BP.

RESULTS

Of the 1386 participants (age: 58 ± 10 years, 44% female, 39% black), 68 had orthostatic hypotension and 153 had OHTN. Postural reduction in SBP or DBP was positively associated with greater systolic and diastolic WCE and systolic and diastolic night-to-day ratio. Orthostatic hypotension was positively associated with diastolic WCE (β = 3 [0.2, 5.9]). Diastolic OHTN was negatively associated with systolic WCE (β = -4 [-7.2, -0.5]) and diastolic WCE (β = -6 [-8.1, -4.2]).

CONCLUSION

Postural change in BP was associated with WCE and night-to-day-ratio. Orthostatic hypotension was positively associated with WCE and OHTN was negatively associated with WCE. These findings strengthen observations that postural changes in BP may associate with distinct BP patterns throughout the day. These observations are informative for subsequent research tailoring orthostatic hypotension and OHTN treatment to specific BP phenotypes.

The long-term reproducibility of the white-coat effect on blood pressure as a continuous variable from the Ohasama Study

There is little information about the reproducibility of the white coat effect, which was treated as a continuous variable. To investigate a long-term interval reproducibility of the white-coat effect as a continuous variable. We selected 153 participants without antihypertensive treatment (men, 22.9%; age, 64.4 years) from the general population of Ohasama, Japan, to assess the repeatedly measured white-coat effect (the difference between blood pressures at the office and home) in a 4-year interval. The reproducibility was assessed by testing the intraclass correlation coefficient (two-way random effect model-single measures). The white-coat effect for systolic/diastolic blood pressure slightly decreased by 0.17/1.56 mmHg at the 4-year visit on average. The Bland-Altman plots showed no significant systemic error for the white-coat effects (P ≥ 0.24). The intraclass correlation coefficient (95% confidence interval) of the white-coat effect for systolic blood pressure, office systolic blood pressure, and home systolic blood pressure were 0.41 (0.27-0.53), 0.64 (0.52-0.74), and 0.74 (0.47-0.86), respectively. Change in the white-coat effect was mainly affected by a change in office blood pressure. Long-term reproducibility of the white-coat effect is limited in the general population without antihypertensive treatment. The change in the white-coat effect is mainly caused by office blood pressure variation.

Reproducibility and Predictive Value of White-Coat Hypertension in Young to Middle-Age Subjects

(1) Aim. The aim of the study was to investigate the reproducibility of white-coat hypertension (WCH) and its predictive capacity for hypertension needing antihypertensive treatment (HT) in young to middle-age subjects. (2) Methods. We investigated 1096 subjects from the HARVEST. Office and 24 h blood pressures (BP) were measured at baseline and after 3 months. The reproducibility of WCH was evaluated with kappa statistics. The predictive capacity of WCH was tested in multivariate Cox models (N = 1050). (3) Results. Baseline WCH was confirmed at 3-month assessment in 33.3% of participants. Reproducibility was fair (0.27, 95%CI 0.20-0.37) for WCH, poor (0.14, 95%CI 0.09-0.19) for office hypertension, and moderate (0.47, 95%CI 0.41-0.53) for ambulatory hypertension. WCH assessed either at baseline or after 3 months (unstable WCH) was not a significant predictor of HT during 17.4 years of follow-up. However, participants who had WCH both at baseline and after 3 months (stable WCH) had an increased risk of HT compared to the normotensives (Hazard ratio, 1.50, 95%CI 1.06-2.1). (4) Conclusions. These results show that WCH has limited reproducibility. WCH diagnosed with two BP assessments but not with one showed an increased risk of future HT. Our data indicate that WCH should be identified with two sets of office and ambulatory BP measurements.

Reproducibility of masked hypertension and office-based hypertension: a systematic review and meta-analysis

Blood pressure (BP) phenotypes have a prognostic significance for target organ damage in long-term studies. However, it remains uncertain whether a single baseline phenotype classification is reproducible over time and represents accurately the patients' BP status. The aim of this study was to systematically investigate the reproducibility of masked hypertension and office-based hypertension either with ambulatory BP monitoring (ABPM) or home BP monitoring (HBPM). PubMed, Cochrane Library and Web of Science were searched to identify studies with paired baseline office BP and ABPM or HBPM measurements at two timepoints. The outcome of the analysis was the individual phenotype reproducibility between the baseline and follow-up timepoints. The used effect measure was Cohen's kappa coefficient. We found 15 studies eligible for the meta-analysis enrolling a total of 5729 patients. The reproducibility of masked hypertension was better with ABPM, kappa reliability test: 0.41 [95% confidence interval (CI): 0.32-0.49], than with HBPM, kappa reliability test: 0.26 (95% CI: 0.10-0.40). The reproducibility of office-based hypertension with both methods was low, indicating slight agreement. Kappa reliability test was slightly better with ABPM (κ: 0.27, 95% CI: 0.12-0.41) than with HBPM (κ: 0.18, 95% CI: 0.08-0.27). This systematic review and meta-analysis show a slight to fair reproducibility of masked hypertension and office-based hypertension assessed through ABPM and HBPM. Considering that poor reproducibility may be a result of office BP measurements, an ABPM/HBPM-based strategy should be established for the evaluation and treatment of patients with masked hypertension or office-based hypertension.

Management of resistant hypertension

PURPOSE OF REVIEW

Resistant hypertension is defined as blood pressure above patient goal despite three different antihypertensive agents at optimal dose including a diuretic. Resistant hypertension is increasingly common issue in clinical practice and it is a major risk factor of cardiovascular disease.

RECENT FINDINGS

All patients with resistant hypertension should be evaluated for possible correctable factors associated with pseudoresistance, such as poor adherence, white coat hypertension and suboptimal measurement of blood pressure. In patients with resistant hypertension, thiazide diuretics should be considered as one of the first agents, in addition to mineralocorticoids receptor antagonist.

SUMMARY

Resistant hypertension can be associated with secondary cause that is why treatment can be challenging and should always include lifestyle modification and evaluation for possible secondary causes, in addition to adding a fourth agent or considering newer interventional therapies, such as renal denervation or other device-based options.

Treatment of Resistant and Refractory Hypertension

Resistant hypertension (RHTN) is defined as uncontrolled blood pressure despite the use of ≥3 antihypertensive agents of different classes, including a diuretic, usually thiazide-like, a long-acting calcium channel blocker, and a blocker of the renin- angiotensin system, either an ACE (angiotensin-converting enzyme) inhibitor or an ARB (angiotensin receptor blocker), at maximal or maximally tolerated doses. Antihypertensive medication nonadherence and the white coat effect, defined as elevated blood pressure when measured in clinic but controlled when measured outside of clinic, must be excluded to make the diagnosis. RHTN is a high-risk phenotype, leading to increased all-cause mortality and cardiovascular disease outcomes. Healthy lifestyle habits are associated with reduced cardiovascular risk in patients with RHTN. Aldosterone excess is common in patients with RHTN, and addition of spironolactone or amiloride to the standard 3-drug antihypertensive regimen is effective at getting the blood pressure to goal in most of these patients. Refractory hypertension is defined as uncontrolled blood pressure despite use of ≥5 antihypertensive agents of different classes, including a long-acting thiazide-like diuretic and an MR (mineralocorticoid receptor) antagonist, at maximal or maximally tolerated doses. Fluid retention, mediated largely by aldosterone excess, is the predominant mechanism underlying RHTN, while patients with refractory hypertension typically exhibit increased sympathetic nervous system activity.

Prognostic Importance of Resistant Hypertension in Patients With Type 2 Diabetes: The Rio de Janeiro Type 2 Diabetes Cohort Study

OBJECTIVE

To evaluate the prognostic importance of resistant hypertension (RHT) for the development of complications in a cohort of individuals with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 646 patients had the diagnosis of apparent treatment-resistant hypertension (aRHT) based on mean office blood pressure (BP) levels during the 1st year of follow-up. They were reclassified as white-coat/controlled or true/uncontrolled RHT according to 24-h ambulatory BP monitoring (ABPM), using the traditional BP cutoffs and the new 2017 American College of Cardiology (ACC)/American Heart Association (AHA) criteria. Multivariate Cox analyses examined the associations between RHT diagnoses and the occurrence of microvascular and cardiovascular complications and all-cause and cardiovascular mortality.

RESULTS

During a median follow-up of 10 years, 177 patients had a cardiovascular event (145 major ones); 222 patients died (101 from cardiovascular diseases); 200 had a renal event; 156 had a retinopathy event; and 174 patients had a neuropathy event. In relation to non-RHT individuals, aRHT (present in 44.6% and 50% by the traditional and new criteria, respectively) predicted all cardiovascular and mortality outcomes, with hazard ratios (HRs) between 1.64 and 2.16, but none of the microvascular outcomes. True RHT increased the HRs (from 1.81 to 2.25) and additionally predicted renal outcomes. White-coat/controlled RHT implied an increased risk (HRs 1.33-1.86) that was intermediate between non-RHT and true RHT individuals. Classifications using the traditional and the new ACC/AHA criteria were equivalent.

CONCLUSIONS

In patients with type 2 diabetes, the presence of aRHT implied an increased risk of cardiovascular and mortality outcomes, and classification based on ABPM predicted renal outcomes and improved cardiovascular/mortality risk stratification.

[Position statement on ambulatory blood pressure monitoring (ABPM) by the Spanish Society of Hypertension (2019)]

Conventional blood pressure (BP) measurement in clinical practice is the most used procedure for the diagnosis and treatment of hypertension (HT), but is subject to considerable inaccuracies due to, on the one hand, the inherent variability of the BP itself and, on the other hand biases arising from the measurement technique and conditions, Some studies have demonstrated the prognosis superiority in the development of cardiovascular disease using ambulatory blood pressure monitoring (ABPM). It can also detect "white coat" hypertension, avoiding over-diagnosis and over-treatment in many cases, as well detecting of masked hypertension, avoiding under-detection and under-treatment. ABPM is recognised in the diagnosis and management of HT in most of international guidelines on hypertension. The present document, taking the recommendations of the European Society of Hypertension as a reference, aims to review the more recent evidence on ABPM, and to serve as guidelines for health professionals in their clinical practice and to encourage ABPM use in the diagnosis and follow-up of hypertensive subjects. Requirements, procedure, and clinical indications for using ABPM are provided. An analysis is also made of the main contributions of ABPM in the diagnosis of "white coat" and masked HT phenotypes, short term BP variability patterns, its use in high risk and resistant hypertension, as well as its the role in special population groups like children, pregnancy and elderly. Finally, some aspects about the current situation of the Spanish ABPM Registry and future perspectives in research and potential ABPM generalisation in clinical practice are also discussed.

Prognostic Importance of Ambulatory Blood Pressure Monitoring in Resistant Hypertension: Is It All that Matters?

PURPOSE OF REVIEW

This article reviews the current knowledge on the prognostic importance of ambulatory blood pressure (BP) monitoring parameters in patients with apparent treatment-resistant hypertension.

RECENT FINDINGS

Although mean 24-h ambulatory BPs have been consistently established as better cardiovascular risk predictors than clinic (office) BPs in several clinical settings, and ambulatory BP monitoring is generally indicated in patients with resistant hypertension; there were only five previous longitudinal prospective studies that specifically evaluated the prognostic importance of ambulatory BP monitoring parameters in resistant hypertensive patients. These studies are carefully reviewed here. In conjunction, they demonstrated that office BP levels have little, if any, prognostic value in resistant hypertensive patients. Otherwise, several ambulatory BP monitoring parameters are strong cardiovascular risk predictors, particularly nighttime sleep BPs and the non-dipping pattern. Most relevant, the ambulatory BP monitoring diagnosis of true resistant hypertension (i.e., patients with uncontrolled ambulatory BPs, either daytime or nighttime) doubled the risk of future occurrence of major cardiovascular events in contrast to patients with white-coat resistant hypertension (i.e., with controlled ambulatory BPs despite uncontrolled office BPs). This review reinforces the pivotal role of serial ambulatory BP monitoring examinations in the clinical management of patients with resistant hypertension.

Effect of Intensive Versus Standard Clinic-Based Hypertension Management on Ambulatory Blood Pressure: Results From the SPRINT (Systolic Blood Pressure Intervention Trial) Ambulatory Blood Pressure Study

The effect of clinic-based intensive hypertension treatment on ambulatory blood pressure (BP) is unknown. The goal of the SPRINT (Systolic Blood Pressure Intervention Trial) ambulatory BP ancillary study was to evaluate the effect of intensive versus standard clinic-based BP targets on ambulatory BP. Ambulatory BP was obtained within 3 weeks of the 27-month study visit in 897 SPRINT participants. Intensive treatment resulted in lower clinic systolic BP (mean difference between groups=16.0 mm Hg; 95% confidence interval, 14.1-17.8 mm Hg), nighttime systolic BP (mean difference=9.6 mm Hg; 95% confidence interval, 7.7-11.5 mm Hg), daytime systolic BP (mean difference=12.3 mm Hg; 95% confidence interval, 10.6-13.9 mm Hg), and 24-hour systolic BP (mean difference=11.2 mm Hg; 95% confidence interval, 9.7-12.8 mm Hg). The night/day systolic BP ratio was similar between the intensive (0.92±0.09) and standard-treatment groups (0.91±0.09). There was considerable lack of agreement within participants between clinic systolic BP and daytime ambulatory systolic BP with wide limits of agreement on Bland-Altman plots. In conclusion, targeting a systolic BP of <120 mm Hg, when compared with <140 mm Hg, resulted in lower nighttime, daytime, and 24-hour systolic BP, but did not change the night/day systolic BP ratio. Ambulatory BP monitoring may be required to assess the effect of targeted hypertension therapy on out of office BP. Further studies are needed to assess whether targeting hypertension therapy based on ambulatory BP improves clinical outcomes.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01835249.

Acute Sildenafil Use Reduces 24-Hour Blood Pressure Levels in Patients With Resistant Hypertension: A Placebo-Controlled, Crossover Trial

The authors previously demonstrated that acute administration of sildenafil-a phosphodiesterase 5 (PDE5) inhibitor-improves hemodynamic parameters in patients with resistant hypertensive (RH), but its effect on ambulatory blood pressure monitoring (ABPM) is unknown. This interventional, nonrandomized, single-blinded, placebo-controlled, crossover trial included 26 patients with RH. A dose of sildenafil (187.5mg) was given, and after a washout period of 14 days the patients received a single oral dose of placebo and the protocol was repeated. The patients underwent 24-hour ABPM recordings the day before and immediately after the protocols. The reduction of systolic (-8.8±1.4 vs 1.3±1.2 mm Hg, P=.02), diastolic (-5.3±3.3 vs 1.8±1.1 mm Hg, P=.03), and mean (-7.9±3.6 vs 0.8±0.9 mm Hg, P=.01) 24-hour BP were found after the use of sildenafil compared with placebo. Improvement in daytime BP levels was also observed (systolic -6.0±4.7 vs 4.4±1.5 mm Hg [P=.02] and mean -4.8±3.9 vs 3.5±1.4 mm Hg [P=.02] for sildenafil vs placebo, respectively). Considering its antihypertensive effect, sildenafil may represent a therapeutic option for RH treatment.

Short-Term and Long-Term Reproducibility of Hypertension Phenotypes Obtained by Office and Ambulatory Blood Pressure Measurements

The authors aimed to assess the reproducibility of normotension and white-coat, masked, and sustained hypertension in 839 untreated patients who underwent two separate assessments (median, 3; interquartile range, 0-13 months) by both office and ambulatory blood pressure (BP) monitoring (ABPM). The proportion of patients falling into the same category in the two assessments was: 52% normotension and 55% white-coat, 47% masked, and 82% sustained hypertension. The most frequent switch was to sustained hypertension (26% of white-coat and 33% of masked hypertension). No clinical factors predicted the change in category, except for higher office diastolic BP in patients with masked hypertension who developed sustained hypertension, compared with those who remained with masked hypertension (84±4 mm Hg vs 80±5 mm Hg; P=.006). The reproducibility of hypertension phenotypes was highly dependent on the time between assessments. The authors conclude that white-coat and masked hypertension phenotypes are only reproducible in the short-term, while they frequently shift towards sustained hypertension in the long-term.

Masked Hypertension and Elevated Nighttime Blood Pressure in CKD: Prevalence and Association with Target Organ Damage

BACKGROUND AND OBJECTIVES

Masked hypertension and elevated nighttime BP are associated with increased risk of hypertensive target organ damage and adverse cardiovascular and renal outcomes in patients with normal kidney function. The significance of masked hypertension for these risks in patients with CKD is less well defined. The objective of this study was to evaluate the association between masked hypertension and kidney function and markers of cardiovascular target organ damage, and to determine whether this relationship was consistent among those with and without elevated nighttime BP.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a cross-sectional study. We performed 24-hour ambulatory BP in 1492 men and women with CKD enrolled in the Chronic Renal Insufficiency Cohort Study. We categorized participants into controlled BP, white-coat, masked, and sustained hypertension on the basis of clinic and 24-hour ambulatory BP. We obtained echocardiograms and measured pulse wave velocity in 1278 and 1394 participants, respectively.

RESULTS

The percentages of participants with controlled BP, white-coat, masked, and sustained hypertension were 49.3%, 4.1%, 27.8%, and 18.8%, respectively. Compared with controlled BP, masked hypertension independently associated with low eGFR (-3.2 ml/min per 1.73 m(2); 95% confidence interval, -5.5 to -0.9), higher proteinuria (+0.9 unit higher in log2 urine protein; 95% confidence interval, 0.7 to 1.1), and higher left ventricular mass index (+2.52 g/m(2.7); 95% confidence interval, 0.9 to 4.1), and pulse wave velocity (+0.92 m/s; 95% confidence interval, 0.5 to 1.3). Participants with masked hypertension had lower eGFR only in the presence of elevated nighttime BP (-3.6 ml/min per 1.73 m(2); 95% confidence interval, -6.1 to -1.1; versus -1.4 ml/min per 1.73 m(2); 95% confidence interval, -6.9 to 4.0, among those with nighttime BP <120/70 mmHg; P value for interaction with nighttime systolic BP 0.002).

CONCLUSIONS

Masked hypertension is common in patients with CKD and associated with lower eGFR, proteinuria, and cardiovascular target organ damage. In patients with CKD, ambulatory BP characterizes the relationship between BP and target organ damage better than BP measured in the clinic alone.

Ambulatory Blood Pressure Monitoring in the Diagnosis, Prognosis, and Management of Resistant Hypertension: Still a Matter of our Resistance?

Resistant hypertension, commonly described as the failure to achieve goal blood pressure (BP) despite an appropriate regimen of three antihypertensive drugs at the maximal tolerated doses, one of which is diuretic, is increasingly recognized as an important problem of public health. Large population studies with office measurements suggest that the prevalence of resistance hypertension is approximately at 6-12 % of the general hypertensive population and 8-28 % of treated hypertensives. However, these estimations do not take into account factors of pseudo-resistance, most importantly, the white-coat effect that can be effectively ruled out with ambulatory blood pressure monitoring (ABPM). Recent studies have clearly shown that when ABPM is used, at least 30-35 % of patients labeled as "resistant hypertensives" turn out to have well-controlled BP on ambulatory basis, a finding changing entirely the estimates of prevalence of resistance hypertension and actual patient handling. Furthermore, current evidence suggests that ABPM is a much more accurate predictor of cardiovascular events in resistant hypertension compared to office BP and thus can offer a better risk stratification for these high-risk individuals. Finally, ABPM offers the potential of a better evaluation of the effect of pharmacologic and non-pharmacologic therapeutic interventions. This review attempts to summarize recent evidence on the advantages of ABPM in the diagnosis, prognosis, and management of resistant hypertension.

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

Hypertension, a common risk factor for cardiovascular disease, is usually diagnosed and treated based on blood pressure readings obtained in the clinic setting. Blood pressure may differ considerably when measured inside versus outside of the clinic setting. Over the past several decades, evidence has accumulated on the following 2 approaches for measuring blood pressure outside of the clinic: ambulatory blood pressure monitoring (ABPM) and home blood pressure monitoring (HBPM). Both of these methods have a stronger association with cardiovascular disease outcomes than clinic blood pressure measurement. Controversy exists about whether ABPM or HBPM is superior for estimating risk for cardiovascular disease and under what circumstances these methods should be used in clinical practice for assessing blood pressure outside of the clinic. This review describes ABPM and HBPM procedures, the blood pressure phenotypic measurements that can be ascertained, and the evidence that supports the use of each approach to measuring blood pressure outside of the clinic. It also describes barriers to the successful implementation of ABPM and HBPM in clinical practice, proposes core competencies for the conduct of these procedures, and highlights important areas for future research.

Advantages of Ambulatory Blood Pressure Monitoring in Assessing the Efficacy of Antihypertensive Therapy

The cumulative evidence in the past three decades situates ambulatory blood pressure monitoring (ABPM) as a central element in diagnosing and predicting the prognosis of subjects with hypertension. However, for various reasons, this diagnostic and prognostic importance has not been translated in equal measure into making decisions or guiding antihypertensive treatment. Mean 24-h, daytime, and night-time blood pressure estimates, the occurrence of divergent phenotypes between clinic measurements, and ABPM, as well as the main elements that determine blood pressure variability over 24 h, especially night-time dipping, are all elements that in addition to providing evidence for patient prognosis, can be used to guide antihypertensive treatment follow-up enabling greater precision in defining the effect of the drugs. In recent years, specific indices have been developed using 24-h monitoring, evaluate the duration of treatment action, the homogeneity of the effect over the monitoring period, and its possible effects on variability. In future controlled clinical trials on antihypertensive therapies it is necessary to evaluate the effects of those treatments on hard endpoints based on therapy guided by ABPM.

Is home blood pressure monitoring useful in the management of patients with resistant hypertension?

BACKGROUND

Ambulatory blood pressure (BP) monitoring (ABPM) is a cornerstone in resistant hypertension (RHT) management. However, it has higher cost and lower patients' acceptance than home BP monitoring (HBPM). Our objective was to evaluate HBPM usefulness in the management of patients with RHT.

METHODS

A total of 240 patients were submitted to 24-hour ABPM and 5-day HBPM (triplicate morning and evening measurements). Patients with uncontrolled office BP (≥140/90mm Hg) were classified as true RHT (daytime or home BP ≥135/85mm Hg) or white-coat RHT (daytime or home BP <135/85mm Hg), and patients with controlled office BP were classified as masked RHT (daytime or home BP ≥135/85mm Hg) or controlled RHT (daytime or home BP <135/85mm Hg). Sensitivity, specificity, predictive values, and likelihood ratios for HBPM were calculated. Agreement between the procedures was evaluated using kappa coefficients and the Bland-Altman method.

RESULTS

Mean office BP was 157±26/84±16mm Hg, mean daytime BP was 134±18/77±13mm Hg, and mean home BP was 143±20/76±14mm Hg. The ABPM and HBPM diagnoses were 35% and 48%, respectively, for true RHT; 36% and 23%, respectively, for white-coat RHT; 7% and 17%, respectively, for masked RHT; and 22% and 13%, respectively, for controlled RHT. HBPM overestimated systolic BP by 8.8 (95% confidence interval (CI) = 6.8-10.7) mm Hg and diastolic BP by 0.2 (95% CI = -1.0 to 1.4) mm Hg. The specificity, sensitivity, and positive and negative predictive values of HBPM in detecting controlled ambulatory BP were 91%, 55%, 89%, and 59%.

CONCLUSIONS

HBPM presented good agreement with ABPM and can be used as a complementary method in the follow-up of resistant hypertensive patients, particularly in those with controlled ambulatory BPs.

Rates, amounts, and determinants of ambulatory blood pressure monitoring claim reimbursements among Medicare beneficiaries

Ambulatory blood pressure monitoring (ABPM) can be used to identify white coat hypertension and guide hypertensive treatment. We determined the percentage of ABPM claims submitted between 2007 and 2010 that were reimbursed. Among 1970 Medicare beneficiaries with submitted claims, ABPM was reimbursed for 93.8% of claims that had an International Classification of Diseases, Ninth Revision, diagnosis code of 796.2 ("elevated blood pressure reading without diagnosis of hypertension") versus 28.5% of claims without this code. Among claims without an International Classification of Diseases, Ninth Revision, diagnosis code of 796.2 listed, those for the component (eg, recording, scanning analysis, physician review, reporting) versus full ABPM procedures and performed by institutional versus non-institutional providers were each more than two times as likely to be successfully reimbursed. Of the claims reimbursed, the median payment was $52.01 (25th-75th percentiles, $32.95-$64.98). In conclusion, educating providers on the ABPM claims reimbursement process and evaluation of Medicare reimbursement may increase the appropriate use of ABPM and improve patient care.

European Society of Hypertension position paper on ambulatory blood pressure monitoring

Ambulatory blood pressure monitoring (ABPM) is being used increasingly in both clinical practice and hypertension research. Although there are many guidelines that emphasize the indications for ABPM, there is no comprehensive guideline dealing with all aspects of the technique. It was agreed at a consensus meeting on ABPM in Milan in 2011 that the 34 attendees should prepare a comprehensive position paper on the scientific evidence for ABPM.This position paper considers the historical background, the advantages and limitations of ABPM, the threshold levels for practice, and the cost-effectiveness of the technique. It examines the need for selecting an appropriate device, the accuracy of devices, the additional information and indices that ABPM devices may provide, and the software requirements.At a practical level, the paper details the requirements for using ABPM in clinical practice, editing considerations, the number of measurements required, and the circumstances, such as obesity and arrhythmias, when particular care needs to be taken when using ABPM.The clinical indications for ABPM, among which white-coat phenomena, masked hypertension, and nocturnal hypertension appear to be prominent, are outlined in detail along with special considerations that apply in certain clinical circumstances, such as childhood, the elderly and pregnancy, and in cardiovascular illness, examples being stroke and chronic renal disease, and the place of home measurement of blood pressure in relation to ABPM is appraised.The role of ABPM in research circumstances, such as pharmacological trials and in the prediction of outcome in epidemiological studies is examined and finally the implementation of ABPM in practice is considered in relation to the issue of reimbursement in different countries, the provision of the technique by primary care practices, hospital clinics and pharmacies, and the growing role of registries of ABPM in many countries.

Resistant hypertension: patient characteristics, risk factors, co-morbidities and outcomes

Among the vast population of hypertensive subjects, between 10 and 15% do not achieve an adequate blood pressure (BP) control despite the use of at least three antihypertensive agents. This group, designated as having resistant hypertension (RH), represents one of the most important clinical challenges in hypertension evaluation and management. Resistant hypertensives are characterized by several clinical particularities, such as a longer history of hypertension, obesity and other accompanying factors, such as diabetes, left ventricular hypertrophy, albuminuria and renal dysfunction. In addition to other diagnostic and therapeutic maneuvers, such as excluding secondary hypertension, ensuring treatment adherence and optimizing therapeutic schemes, ambulatory BP monitoring (ABPM) is crucial in the clinical evaluation of patients with RH. ABPM distinguish between those with out-of-office BP elevation (true resistant hypertensives) and those having white-coat RH (WCRH; normalcy of 24-h BPs), the prevalence of the latter estimated in about one-third of the population with RH. True resistant hypertensives also exhibit more frequently other co-morbidities, more severe target organ damage and a worse cardiovascular prognosis, in comparison to those with WCRH. Some device-based therapies have recently been developed for treatment of RH. This requires a better characterization of a potential candidate population. A better knowledge of the clinical features of resistant hypertensive subjects, the confirmation of elevated BP values out of the doctor's office, and improvements in the search for secondary causes would help to select those candidates for newer therapies, once the pharmacological possibilities have been exhausted.

Hyperaldosteronism as a common cause of resistant hypertension

Resistant hypertension affects an estimated 10-15 million American adults and is increasing in prevalence. The etiology of resistant hypertension is almost always multifactorial, including obesity, older age, high dietary salt, chronic kidney disease, and aldosterone excess. Classical primary aldosteronism and lesser degrees of aldosterone excess, possibly originating from visceral adipocytes, contribute broadly to antihypertensive treatment resistance. Treatment of resistant hypertension is predicated on appropriate lifestyle changes and use of effective combinations of antihypertensive agents from different classes. Blockade of aldosterone with spironolactone has been shown to be particularly effective for treatment of resistant hypertension. The antihypertensive benefit of spironolactone is not limited to patients with demonstrable hyperaldosteronism but instead can be effective in resistant hypertensive patients regardless of aldosterone levels. Chlorthalidone is a potent, long-acting thiazide-like diuretic and should be used preferentially to treat resistant hypertension as it is superior to normally used doses of hydrochlorothiazide.