Prognostic value of ambulatory blood pressure monitoring in refractory hypertension: a prospective study

When and how to use ambulatory blood pressure monitoring and home blood pressure monitoring for managing hypertension

Many individuals have different blood pressure (BP) values in the office setting compared to that outside the office setting. Therefore, confirming hypertension based on office BP (OBP) measurement alone can lead to misdiagnosis and mistreatment. The limitations of OBP measurement have led to the complementary use of out-of-office BP measurements, including 24-hour ambulatory blood pressure monitoring (ABPM) and home blood pressure monitoring (HBPM). This review aims to describe when and how ABPM or HBPM can be used to accurately diagnose and treat hypertension. Both methods should be performed using validated automated oscillometric devices. To minimize user errors, ABPM should be performed using standard techniques, whereas HBPM requires patient education regarding proper BP measurements. ABPM provides short-term comprehensive information on BP, including daytime, nighttime, morning, and 24-h BP. Therefore, ABPM is recommended for the initial diagnosis of hypertension, assessment of BP phenotypes and circadian patterns, and detection of nocturnal hypertension, Furthermore, ABPM plays a critical role in confirming true resistant hypertension thereby excluding pseudo-resistant hypertension. However, it is not suitable for long-term follow-up of patients with hypertension. In contrast, HBPM involves multiple BP readings taken at specific times during the day and evening over a long period. Therefore, HBPM is recommended for diagnosing hypertension and assessing BP phenotypes. However, this method has limitations in measuring nocturnal BP and circadian BP patterns. HBPM is preferred over ABPM for the long-term follow-up of patients with hypertension. This approach improves patient adherence to treatment and ultimately enhances the rate of control of hypertension. Additionally, both methods play an important role in diagnosing and treating white coat hypertension during pregnancy. Consequently, out-of-office BP measurement is essential to prevent the misdiagnosis and mistreatment of hypertension. However, these two methods offer different information regarding the BP status of an individual, and they indeed show discrepancies in the diagnosis of hypertensive phenotypes. Therefore, it is crucial to understand the advantages and limitations of both ABPM and HBPM to ensure their appropriate use in clinical practice.

Controversies in Hypertension V: Resistant and Refractory Hypertension

Apparent resistant hypertension, defined as uncontrolled office blood pressure despite ≥ 3 antihypertensive medications including a diuretic or use of ≥ 4 medications regardless of blood pressure, occurs in ≤ 15% of treated hypertensives. Apparent refractory hypertension, defined as uncontrolled office pressure despite use of 5 or more medications including a diuretic, occurs in ≤ 10% of resistant cases. Both are associated with increased comorbidity and enhanced cardiovascular risk. To rule out pseudo-resistant or pseudo-refractory hypertension, employ guideline-based methodology for obtaining pressure, maximize the regimen, rule out white-coat effect, and assess adherence. True resistant hypertension is characterized by volume overload and aldosterone excess, refractory by enhanced sympathetic tone. Spironolactone is the preferred agent for resistance, with lower doses. Spironolactone, potassium binders, or both, are preferred if the estimated glomerular filtration rate is below 45. If significant albuminuria, finerenone is indicated. The optimal treatment of refractory hypertension is unclear, but sympathetic inhibition (α-β blockade, centrally acting sympathoinhibitors, or both) seems reasonable. Renal denervation has shown minimal benefit for resistance, but its role in refractory hypertension remains to be defined.

Systolic Blood Pressure and Pulse Pressure Are Predictors of Future Cardiovascular Events in Patients with True Resistant Hypertension

Given the increased risk of cardiovascular events associated with resistant hypertension, predictive cardiovascular prognosis is extremely important. Ambulatory blood pressure monitoring (ABPM) is mandatory for resistant hypertension diagnosis, but its use for prognosis is scarce. This observational longitudinal study included 258 patients (mean age of 60.4 ± 11.2 years; 61.2% male), who underwent 24 h ABPM in a hypertension unit from 1999 to 2019. The outcomes were global cardiovascular events (cerebrovascular, coronary, and other cardiovascular events). The mean follow-up period was 6.0 ± 5.0 years. Sixty-eight cardiovascular events (61 nonfatal) were recorded. Patients who experienced cardiovascular events were generally older, with higher rates of chronic kidney disease and prior cardiovascular events. The 24 h systolic blood pressure (hazard ratio 1.44; 95% CI 1.10-1.88), night systolic blood pressure (1.35; 95% CI 1.01-1.80), and 24 h pulse pressure (2.07; 95% CI 1.17-3.67) were independent predictors of global cardiovascular events. Multivariate Cox analysis revealed a higher risk of future cardiovascular events, particularly in patients with a 24 h daytime and nighttime pulse pressure > 60 mm Hg with respective hazard ratios of 1.95; 95% CI 1.01-3.45; 2.15; 95% CI 1.21-3.83 and 2.07; 95% CI 1.17-3.67. In conclusion, APBM is a fundamental tool not only for the diagnosis of resistant hypertension, but also for predicting future cardiovascular events.

Interpretation of Ambulatory Blood Pressure Monitoring for Risk Stratification in Hypertensive Patients: The 'Ambulatory Does Prediction Valid (ADPV)' Approach

Several outcome-based prospective investigations have provided solid data which support the prognostic value of 24 h ambulatory blood pressure over and beyond cardiovascular traditional risk factors. Average 24 h, daytime, and nighttime blood pressures are the principal components of the ambulatory blood pressure profile that have improved cardiovascular risk stratification beyond traditional risk factors. Furthermore, several additional ambulatory blood pressure measures have been investigated. The correct interpretation in clinical practice of ambulatory blood pressure monitoring needs a standardization of methods. Several algorithms for its clinical use have been proposed. Implementation of the results of ambulatory blood pressure monitoring in the management of individual subjects with the aim of improving risk stratification is challenging. We suggest that clinicians should focus attention on ambulatory blood pressure components which have been proven to act as the main independent predictors of outcome (average 24 h, daytime, and nighttime blood pressure, pulse pressure, dipping status, BP variability).

Resistant hypertension: Prevalence and profile of patients followed in a university ambulatory

BACKGROUND

Hypertension affects about 36 million Brazilians. It is estimated that 10%-20% of these have resistant hypertension. These patients are at an increased risk of early target organ damage, as well as cardiovascular and renal events.

OBJECTIVE

To estimate the prevalence of resistant hypertension in a specialized outpatient clinic, to describe the sociodemographic and clinical characteristics of these patients, and to identify possible factors associated with resistant hypertension.

METHODS

Data collection from medical records of hypertensive patients treated using oral antihypertensive drugs in optimized doses at a specialized university clinic from March 2014 to December 2014, after ethical approval statement. All patients were using appropriate antihypertensive drugs in optimized doses and assisted at a teaching-assistance clinic of internal medicine of the Bahiana School of Medicine and Public Health in Brazil.

RESULTS

A total of 104 patients were enrolled and 31.7% (n = 33) had criteria for resistant hypertension. Of the total participants, 75.7% were female and 54.8% were black or brown. The average age was 61.7 years (SD ± 10.1). In the resistant hypertension group, 63.6% had diabetes, compared to 32.4% in the hypertension group. Among resistant hypertensive patients, 51.5% had dyslipidemia. Regarding drug treatment, 75.8% of the resistant hypertension group and 51.4% of the hypertension group used statins. Among patients with resistant hypertension, 90.9% used angiotensin II receptor blockers and 66.7%, dihydropyridine calcium channel blockers. In the resistant hypertension group, 75.8% used beta-blockers, against 25.4% in the hypertension group.

CONCLUSION

The prevalence of hypertension was higher than that described in the global literature, which may be associated with the high percentage of black and brown ("pardos") patients in the population studied, and also because the study was performed in a specialized outpatient clinic.

A Pilot Study of Perioperative External Circumferential Cryoablation of Human Renal Arteries for Sympathetic Denervation

Purpose

Cryoablation, which induces cellular death without extensive tissue damage, has been extensively used to denervate the myocardium. However, periadventitial external circumferential application of cryotherapy to denervate the renal artery sympathetic nerves has, to our knowledge, never been tested in humans. The main aim of this study was to examine the safety and potential effects of cryotherapy on ambulatory blood pressure levels and other outcomes that are indirectly related to sympathetic tone, including pulse-wave velocity, central pulse pressure, and glucose levels.

Materials and Methods

Five patients who underwent the denervation of the renal arteries during open surgery of the abdominal aortic aneurysm and four controls who did not undergo denervation during the surgery were enrolled. An argon-powered cryotherapy catheter (Cardioblate; Medtronic Inc., USA) was applied periadventitially to each renal artery in the five patients and then activated by infusion with liquid nitrogen for 1 minute.

Results

No cryoablation-related complications occurred in the five consecutive patients. Their ambulatory blood pressures 3 to 5 months after surgery did not demonstrate any general blood pressure-reducing effects, but two patients responded favorably with the reduction of antihypertensive medication and decreased 24-hour blood pressure. The patients’ mean HbA1C levels decreased from 5.9±0.78% to 5.6±0.71% (P=0.042).

Conclusion

This pilot study suggests that periadventitial cryoablation during open surgery can be used in the study of renal denervation in humans, as it had no complications in five patients in this study. The effectiveness of cryoablation for treating hypertension should be proven in a phase II clinical trial.

Ambulatory blood pressure monitoring over 24 h: A Latin American Society of Hypertension position paper-accessibility, clinical use and cost effectiveness of ABPM in Latin America in year 2020

Accurate office blood pressure measurement remains crucial in the diagnosis and management of hypertension worldwide, including Latin America (LA). Office blood pressure (OBP) measurement is still the leading technique in LA for screening and diagnosis of hypertension, monitoring of treatment, and long-term follow-up. Despite this, due to the increasing awareness of the limitations affecting OBP and to the accumulating evidence on the importance of ambulatory BP monitoring (ABPM), as a complement of OBP in the clinical approach to the hypertensive patient, a progressively greater attention has been paid worldwide to the information on daytime and nighttime BP patterns offered by 24-h ABPM in the diagnostic, prognostic, and therapeutic management of hypertension. In LA countries, most of the Scientific Societies of Hypertension and/or Cardiology have issued guidelines for hypertension care, and most of them include a special section on ABPM. Also, full guidelines on ABPM are available. However, despite the available evidence on the advantages of ABPM for the diagnosis and management of hypertension in LA, availability of ABPM is often restricted to cities with large population, and access to this technology by lower-income patients is sometimes limited by its excessive cost. The authors hope that this document might stimulate health authorities in each LA Country, as well as in other countries in the world, to regulate ABPM access and to widen the range of patients able to access the benefits of this technique.

Apparent therapy-resistant hypertension as risk factor for the development of type 2 diabetes mellitus

OBJECTIVE

To evaluate whether the relationship between hypertension and type 2 diabetes mellitus (T2DM) is different for patients with uncontrolled hypertension, controlled hypertension or patients with apparent therapy-resistant hypertension (aTRH), compared with patients without hypertension.

METHODS

Using Cox proportional hazard models we evaluated the risk of new-onset T2DM in 8756 patients, at high risk for vascular disease. Hypertensive patients were subdivided according to blood pressure (BP) and use of BP-lowering drugs. BP ≥ 140/90 mmHg was defined as uncontrolled BP. aTRH was defined as uncontrolled BP despite being treated with at least three BP-lowering drugs including a diuretic, or the use at least four BP-lowering drugs irrespective of BP levels. Further analysis evaluated the risk of new-onset T2DM for patients with uncontrolled hypertension and for patients with aTRH, compared with patients with controlled hypertension and without hypertension, respectively.

RESULTS

Forty-five percent had controlled hypertension, 20% had uncontrolled hypertension, 5.7% had aTRH, and 29% were nonhypertensive. During a follow-up of 7.0 (interquartile range: 0-14) years there were 705 new cases of T2DM. Patients with hypertension had a 1.48 (95% confidence interval 1.22-1.80) times higher risk of new-onset T2DM than nonhypertensive patients. There was no significant difference in risk among different hypertension groups.

CONCLUSION

Patients at high risk for cardiovascular disease with hypertension have a 1.48 times higher risk of new-onset T2DM than nonhypertensive counterparts. The risk did not differ between patients with controlled hypertension, uncontrolled hypertension, or aTRH.

Relation of blood pressure variability to left ventricular function and arterial stiffness in hypertensive patients

INTRODUCTION

Variability of blood pressure (BP) has been reported to be related to worse cardiovascular outcomes. We examined the impact of daytime systolic BP variability on left ventricular (LV) function and arterial stiffness in hypertensive patients.

METHODS

Ambulatory BP monitoring (ABPM) and echocardiography were performed in 116 hypertensive patients. We assessed BP variability as standard deviations of daytime systolic BP on 24-hour ABPM. Conventional echocardiographic parameters, area strain and three-dimensional diastolic index (3D-DI) using 3D speckle tracking were measured. Arterial stiffness was evaluated by acquiring pulse wave velocity (PWV) and augmentation index.

RESULTS

Patients with higher BP variability showed significantly increased left ventricular mass index (LVMI) and late mitral inflow velocity, as well as decreased E/A (early mitral inflow velocity/late mitral inflow velocity) ratio, area strain and 3D-DI than those with lower BP variability (LVMI: p = 0.02; A velocity: p < 0.001; E/A ratio: p < 0.001; area strain: p = 0.02; 3D-DI: p = 0.04). In addition, increased BP variability was associated with higher PWV and augmentation index (p < 0.001). Even among patients whose BP was well controlled, BP variability was related to LV mass, diastolic dysfunction and arterial stiffness.

CONCLUSION

Increased BP variability was associated with LV mass and dysfunction, as well as arterial stiffness, suggesting that BP variability may be an important determinant of target organ damage in hypertensive patients.

Evaluation of the applicability of deep breathing test in the diagnosis of hypertension with white-coat effect in Chinese patients in primary care

Purpose

The current gold standard for the diagnosis of white-coat effect is by the 24-h ambulatory blood pressure monitoring (ABPM) which may not be readily available in every primary care setting. Previous studies had shown that deep breathing, through modulating the baroreceptor reflex sensitivity to vagal stimulation over 30 to 60 s, was useful in detection of the white-coat effect. The aim of our study was to evaluate the diagnostic accuracy of the deep breathing test (DBT) as compared with the gold standard of ABPM in the diagnosis of hypertension with white-coat effect in Chinese patients in primary care.

Methods

This cross sectional study recruited 178 consecutive, eligible, consented, hypertensive patients receiving treatment at a local public primary care Hypertension Clinic.

The diagnostic accuracy of the DBT in all recruited patients, patients not taking beta-adrenergic blockers and patients with different clinic SBP cut-off before the DBT by means of area under the receiver operating characteristic (ROC) curve, sensitivity, specificity, positive and negative predictive values was evaluated.

Results

The results for the ROC curves for systolic and diastolic BP changes after the DBT were statistically insignificant. The ROC curve was statistically significant for SBP change in patients not taking beta-adrenergic blockers and with pre-DBT clinic SBP ≥ 165 mmHg (ROC curve area of 0.719, 95% CI 0.53 to 0.91, p = 0.04). The corresponding sensitivity and specificity of the DBT were 40.9 and 90.9% respectively if SBP drop was > 30 mmHg.

Conclusion

The DBT, even though could not be clinically applied to all patients, was proven to be a potential screening and diagnostic test for white-coat effect in Chinese hypertensive patients with a pre-test SBP of ≥165 mmHg and who were not taking beta-adrenergic blockers.

Trial registration

This study was approved by Kowloon East Cluster/ Kowloon Central Cluster Research Ethics Committee/Institutional Review Board of Hospital Authority of Hong Kong under the registration KC/KE-16-0084/ER-3.

Clinical value of ambulatory blood pressure in pediatric patients after renal transplantation

Hypertension is a highly prevalent co-morbidity in pediatric kidney transplant recipients. Undertreated hypertension is associated with cardiovascular complications and negatively impacts renal graft survival. Thus, the accurate measurement of blood pressure is of the utmost importance for the correct diagnosis and subsequent management of post-renal transplant hypertension. Data derived from the general population, and to a lesser extent from the pediatric population, indicates that ambulatory blood pressure monitoring (ABPM) is superior to blood pressure measurements taken in the clinical setting for the evaluation of true mean blood pressure, identification of patients requiring antihypertensive treatment, and in the prediction of cardiovascular outcome. This Educational Review will discuss the clinical value of ABPM in the identification of individual blood pressure phenotypes, i.e., normotension, new-onset hypertension, white-coat hypertension, masked hypertension, controlled blood pressure, and undertreated/uncontrolled hypertension in pediatric kidney transplant recipients. Finally, we examine the utility of performing repeated ABPM for treatment monitoring of post-renal transplant hypertension and on surrogate markers related to relevant clinical cardiovascular outcomes. Taken together, our review highlights the clinical value of the routine use of ABPM as a tool for identifying and monitoring hypertension in pediatric kidney transplant recipients.

The value of ABPM and subclinical target organ damage parameters in diagnosis of resistant hypertension

INTRODUCTION

We aimed to assess the effectiveness of ambulatory blood pressure monitoring (ABPM) and subclinical target organ damage parameters for diagnosis of resistant hypertension (RH).

METHODS

We assessed demographic and anthropometric variables, the incidence of cardiovascular events and subclinical target organ damage (n=112). We also studied the relationship between these variables and the ABPM results.

RESULTS

Of the 112 patients referred from primary care with a diagnosis of RH, 69 (61.6%) were confirmed by ABPM. We found statistically significant differences (P<.001) between patients with RH and pseudo-resistant hypertension in the appearance of subclinical target organ damage. A percentage of 84 of the patients had microalbuminuria: 66.25±30.7mg/dl); 44.9% had stage 3 chronic kidney disease: the average glomerular filtration was 59ml/min/1.73m²; and 56.5% had left ventricular hypertrophy on echocardiography. Fundoscopy revealed that 64% of the patients had hypertensive retinopathy. Three variables were associated with an increased HR risk: microalbuminuria, hypertensive retinopathy and left ventricular hypertrophy (OR 5.7, 6.2 and 11.2, respectively).

CONCLUSIONS

This study shows that the systematic testing for target organ damage, particularly in terms of albuminuria, is a simple and inexpensive tool, with a high predictive value for RH (85%), which could be useful for prioritising patients who need ABPM.

The role of clinic blood pressure for the diagnosis of hypertension

PURPOSE OF REVIEW

Recent data from randomized clinical trials and updates to hypertension guidelines warrant a review of the literature for the diagnosis and management of hypertension in the clinic setting. Although there have been significant advances in ambulatory blood pressure (BP) monitoring and home BP monitoring, office BP (OBP) measurements remains the primary means of diagnosis and treatment.

RECENT FINDINGS

The current review focuses on updated guidelines, proper technique, device selection, and the recent controversy regarding unattended BP measurements. We review the data on cardiovascular outcomes, the comparison of OBP with ambulatory BP monitoring and home BP monitoring and some of the pitfalls of OBP measurements.

SUMMARY

The current review highlights the need for constant review of BP goals to minimize cardiovascular risk and some of the ongoing controversies regarding OBP measurements.

[Usefulness of patient education in antihypertensive treatment compliance in black Africans]

AIM OF THE STUDY

To evaluate the compliance for antihypertensive treatment and to assess the effects of patient education as tool to improve the compliance in hypertensive patients.

METHODS

We include prospectively all hypertensive patients followed in consultation in the cardiology department of the national police hospital in Ivory Coast. Compliance evaluation was made with the Girerd scale. After evaluation, all the patients benefit from an individual and/or collective education sessions. All the patients were followed and reevaluated after 1 year.

RESULTS

We included consecutive 1000 hypertensive patients (mean age 40±20 years, 80 % male). Among these, 50 % have been treated by a single therapy, 30 % by a fixed double therapy and 25 % by a fixed triple combined therapy. At the start of the study, a low compliance is observed in 60 % of patients, 25 % have minimal problems of observance and 15 % are compliant. In 70 %, the low compliance may be explained by misconceptions and is associated with a persistent hypertension. One year after the education program, the compliance is improved: non-compliant patients represent 5 % of the population, 10 % having slight problems on compliance and 85 % have a good compliance.

CONCLUSION

In hypertension, the therapeutic compliance is poor, and associated with various factors. However, patient education improves the therapeutic compliance and this should be systematically proposed in antihypertensive management in Africa.

Efficacy and safety of renal denervation for Chinese patients with resistant hypertension using a microirrigated catheter: study design and protocol for a prospective multicentre randomised controlled trial

INTRODUCTION

Available data show that approximately 8%-18% of patients with primary hypertension will develop resistant hypertension. In recent years, catheter-based renal denervation (RDN) has emerged as a potential treatment option for resistant hypertension. A number of observational studies and randomised controlled trials among non-Chinese patients have demonstrated its potential safety and efficacy.

METHODS AND ANALYSIS

This is a multicentre, randomised, open-label, parallel-group, active controlled trial that will investigate the efficacy and safety of a 5F saline-irrigated radiofrequency ablation (RFA) used for RDN in the treatment of Chinese patients with resistant hypertension. A total of 254 patients who have failed pharmacological therapy will be enrolled. Eligible subjects will be randomised in a 1:1 ratio to undergo RDN using the RFA plus antihypertensive medication or to receive treatment with antihypertensive medication alone. The primary outcome measure is the change in 24 hours average ambulatory systolic blood pressure from baseline to 3 months, comparing the RDN-plus-medication group with the medication-alone group. Important secondary endpoints include the change in office blood pressure from baseline to 6 months after randomisation. Safety endpoints such as changes in renal function will also be evaluated. The full analysis set, according to the intent-to-treat principle, will be established as the primary analysis population.

ETHICS AND DISSEMINATION

All participants will provide informed consent; the study protocol has been approved by the Independent Ethics Committee for each site. This study is designed to investigate the efficacy and safety of RDN using a 5F saline microirrigated RFA. Findings will be shared with participating hospitals, policymakers and the academic community to promote the clinical management of resistant hypertension in China.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT02900729; pre-results.

Epidemiology of Cerebrovascular Disease Among Chinese Canadian Adults With Type 2 Diabetes

BACKGROUND

First-generation Chinese Canadians have usually maintained different lifestyles before immigration to North America, and the question of whether Chinese Canadians with type 2 diabetes have a different stroke profile than that of non-Chinese Canadians remains unanswered.

OBJECTIVES

To determine whether 1) Chinese Canadians who have had a stroke within the last 15 years are more likely to have diabetes than non-Chinese Canadians and 2) to explore differences in stroke profiles between the 2 cohorts.

METHODS

Age- and sex-matched Chinese Canadians (n=70) and non-Chinese Canadians (n=107) were compared on the basis of stroke type, age at stroke onset, stroke etiology and common risk factors. Classifications for disease were done according to professional guidelines. Statistical analysis was done with Student t test and odds ratios to confirm differences between groups.

RESULTS

Chinese Canadians with stroke had a higher frequency of diabetes mellitus than non-Chinese Canadians. Chinese Canadians with diabetes were more likely to have small vessel disease, specifically lacunar stroke. Chinese Canadians at high risk for stroke were more likely to have a poor prognosis than non-Chinese Canadians, with near significance.

CONCLUSION

Chinese Canadians with diabetes who had ischemic strokes were especially susceptible to intracranial small vessel disease compared with non-Chinese Canadians. These results signify that risk factor prevalence and stroke types differ considerably between Chinese Canadians and non-Chinese Canadians residing in Toronto, warranting further study.

Utility of ambulatory blood pressure monitoring for the management of hypertension

PURPOSE OF REVIEW

Hypertension is a leading cause of cardiovascular morbidity and mortality, affecting nearly 80 million individuals in the United States alone. Accurate measurement of blood pressure (BP) is the crucial first step to reduce the associated cardiovascular risk of hypertension. For decades, clinicians have relied on office BP measurements for the diagnosis and subsequent management of hypertension. However, it has been clearly demonstrated that ambulatory BP measurements are a better predictor of cardiovascular risk and can provide clinicians with important additional information to improve BP control and reduce cardiovascular risk. This article reviews the available data and provides clinical insights into the use of ambulatory BP monitoring for the management of hypertension.

RECENT FINDINGS

Ambulatory BP monitoring is uniquely capable of identifying patients with white-coat hypertension (WCH), masked hypertension and abnormal nocturnal BP profiles. Recently, ambulatory BP data have demonstrated the negative impact of WCH on right ventricular function, a greater prevalence of masked hypertension than previously recognized and the detrimental impact of nocturnal hypertension even in controlled hypertension.

SUMMARY

Ambulatory BP monitoring provides clinicians with the most comprehensive evaluation of hypertension and the ability to define individual BP phenotypes. Hence, these out-of-office measurements can be utilized to improve hypertension control, translating into a reduction of cardiovascular events.

Effects of Renal Denervation Documented in the Austrian National Multicentre Renal Denervation Registry

Renal denervation (RDN) is a new procedure for treatment-resistant hypertensive patients. In order to monitor all procedures undergone in Austria, the Austrian Society of Hypertension established the investigator-initiated Austrian Transcatheter Renal Denervation (TREND) Registry. From April 2011 to September 2014, 407 procedures in 14 Austrian centres were recorded. At baseline, office and mean 24-h ambulatory blood pressure (ABP) were 171/94 and 151/89 mmHg, respectively, and patients were taking a median of 4 antihypertensive medications. Mean 24-h ABP changes after 2–6 weeks, 3, 6 and 12 months were -11/-6, -8/-4, -8/-5 and -10/-6 mmHg (p<0.05 at all measurements), respectively. The periprocedural complication rate was 2.5%. Incidence of long-term complications during follow-up (median 1 year) was 0.5%. Office BP and ABP responses showed only a weak correlation (Pearson coefficient 0.303). Based on the data from the TREND registry, ambulatory blood pressure monitoring in addition to office BP should be used for patient selection as well as for monitoring response to RDN. Furthermore, criteria for optimal patient selection are suggested.

The use of ambulatory blood pressure measurement

Measurement of ambulatory blood pressure is recommended by the National Institute for Health and Care Excellence guidelines to confirm the diagnosis of hypertension in the UK. This article describes the use of ambulatory devices, and discusses the benefits and disadvantages of their use in clinical practice.

Blood pressure variability: assessment, predictive value, and potential as a therapeutic target

A large body of evidence has consistently supported the relationship between blood pressure (BP) levels and the risk of cardiovascular complications. In recent years, several independent studies have also indicated that this risk may not only depend on the magnitude of the blood pressure elevation per se but also on the presence of other associated conditions such as increased blood pressure variability. This concept has been supported by a series of reports, most of which post hoc analyses of clinical trials in hypertension, showing that increasing values of BP variability (BPV) (either in the short term, in the midterm, or in the long term) may predict development, progression, and severity of cardiac, vascular, and renal organ damage, as well as cardiovascular events and mortality. Remarkably, studies conducted in populations at high cardiovascular risk have shown increasing values of BPV in the individual subjects (so-called intra- or within-individual BPV) to be strong predictors of cardiovascular morbidity and mortality, even to a larger extent than average BP values. However, in subjects at low to moderate cardiovascular risk, the contribution of BPV to cardiovascular risk prediction over and beyond average BP values has been shown to be only moderate. The aim of this paper is to critically review the evidence addressing the prognostic relevance of different components of BPV addressing a yet open question, i.e., whether routine assessment of BPV in clinical practice should be regarded as an additional target of antihypertensive treatment to improve cardiovascular protection.

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.

Resistant and Refractory Hypertension: Antihypertensive Treatment Resistance vs Treatment Failure

Resistant or difficult to treat hypertension is defined as high blood pressure that remains uncontrolled with 3 or more different antihypertensive medications, including a diuretic. Recent definitions also include controlled blood pressure with use of 4 or more medications as also being resistant to treatment. Recently, refractory hypertension, an extreme phenotype of antihypertensive treatment failure has been defined as hypertension uncontrolled with use of 5 or more antihypertensive agents, including a long-acting thiazide diuretic and a mineralocorticoid receptor antagonist. Patients with resistant vs refractory hypertension share similar characteristics and comorbidities, including obesity, African American race, female sex, diabetes, coronary heart disease, chronic kidney disease, and obstructive sleep apnea. Patients with refractory vs resistant hypertension tend to be younger and are more likely to have been diagnosed with congestive heart failure. Refractory hypertension might also differ from resistant hypertension in terms of underlying cause. Preliminary evidence suggests that refractory hypertension is more likely to be neurogenic in etiology (ie, heightened sympathetic tone), vs a volume-dependent hypertension that is more characteristic of resistant hypertension in general.

Determinants of concentric left ventricular hypertrophy in patients with resistant hypertension: RESIST-POL study

Left ventricular hypertrophy, especially concentric hypertrophy, has been shown to be an independent factor of cardiovascular diseases in patients with hypertension. Obstructive sleep apnea (OSA) and/or metabolic syndrome (MS) are common in patients with resistant hypertension (RHTN). The aim of this study was to evaluate factors associated with concentric hypertrophy in patients with RHTN. Data from 155 patients (92M, 63F) was analyzed. All patients underwent a thorough examination including: biochemical evaluations, ambulatory blood pressure monitoring, polysomnography and echocardiography. MS was defined by The Adult Treatment Panel III. Clinically significant OSA was defined as apnea/hypopnea index (AHI)>15 events per hour. Left ventricular mass index (LVMI) and relative wall thickness (RWT) were calculated. Four types of LV geometry were distinguished based on the LVMI and RWT. Patients were divided into four groups based on the LV geometric patterns: group 1 (normal geometry) (n=38, 24.4%); group 2 (concentric remodeling) (n=40, 25.8%); group 3 (eccentric hypertrophy) (n=26, 16.8%); and group 4 (concentric hypertrophy) (n=51, 33%). MS was found in 64% and OSA (AHI>15) in 43.2% of patients. Factors independently associated with concentric hypertrophy were: age (OR-1.51; 95% CI-1.00-2.27; P<0.04), OSA>15 events per hour (OR-2.73; 95% CI-1.26-5.93; P=0.01) and nighttime systolic blood pressure (SBP) (OR-1.69; 95% CI-1.32-2.17; P=0.0001). Concentric hypertrophy was the most common type of left ventricular disorder in patients with RHTN. Nighttime SBP and clinically significant OSA were independently associated with concentric hypertrophy in patients with RHTN.

Systolic and diastolic short-term blood pressure variability and its determinants in patients with controlled and uncontrolled hypertension: a retrospective cohort study

Absolute blood pressure (BP) values are not the only causes of adverse cardiovascular consequences. BP variability (BPV) has also been demonstrated to be a predictor of mortality for cardiovascular events; however, its determinants are still unknown. This study considers 426 subjects with ambulatory BP monitoring (ABPM) measuring 24-h, diurnal and nocturnal absolute BP values and their standard deviations of the mean, along with nocturnal fall, age, sex and current treatment. Patients were divided in two subgroups, controlled and uncontrolled BP, and BPV of patients with "true" and "false" resistant hypertension was also analyzed. Nocturnal and 24-h BPV were higher in the group with uncontrolled hypertension. Multiple regression analysis showed that absolute BP, age, nocturnal fall, but not sex predicted BPV. Patients with "true" resistant hypertension had greater BPV than "false" resistant hypertension patients. Absolute BP resulted as the main determinant of 24-h and nocturnal BPV but not daytime BPV. Also nocturnal BP fall and age resulted as predictors of BPV in treated and untreated patients. Patients with "true" resistant hypertension have a higher BPV, suggesting a higher sympathetic activation. Evidence is still limited regarding the importance of short-term BPV as a prognostic factor and assessment of BPV cannot yet represent a parameter for routine use in clinical practice. Future prospective trials are necessary to define which targets of BPV can be achieved with antihypertensive drugs and whether treatment-induced reduction in BPV is accompanied by a corresponding reduction in cardiovascular events.

Non-interventional management of resistant hypertension

Hypertension is one of the most popular fields of research in modern medicine due to its high prevalence and its major impact on cardiovascular risk and consequently on global health. Indeed, about one third of individuals worldwide has hypertension and is under increased long-term risk of myocardial infarction, stroke or cardiovascular death. On the other hand, resistant hypertension, the “uncontrollable” part of arterial hypertension despite appropriate therapy, comprises a much greater menace since long-standing, high levels of blood pressure along with concomitant debilitating entities such as chronic kidney disease and diabetes mellitus create a prominent high cardiovascular risk milieu. However, despite the alarming consequences, resistant hypertension and its effective management still have not received proper scientific attention. Aspects like the exact prevalence and prognosis are yet to be clarified. In an effort to manage patients with resistant hypertension appropriately, clinical doctors are still racking their brains in order to find the best therapeutic algorithm and surmount the substantial difficulties in controlling this clinical entity. This review aims to shed light on the effective management of resistant hypertension and provide practical recommendations for clinicians dealing with such patients.

Dynamic resistant hypertension patterns as predictors of cardiovascular morbidity: a 4-year prospective study

OBJECTIVE

Little is known regarding the clinical course and prognosis of resistant hypertension (RHT). We evaluated predictors of persistent RHT and the associated cardiovascular risk.

METHODS

We studied 1911 treated hypertensive patients (aged 59±11 years, 49% men) for a mean period of 3.9 years. At baseline, clinical data were collected and patients underwent echocardiographic measurements, routine blood testing and additional workup for exclusion of secondary causes of RHT (office-based uncontrolled hypertension under at least three drugs including a diuretic or controlled hypertension under four or more drugs). Endpoint of interest was the composite of coronary artery disease and stroke.

MAIN RESULTS

Four groups were identified depending on presence or absence of RHT at baseline and follow-up: 1153 patients (60%) never having RHT, 189 (10%) with resolved RHT, 204 (11%) with incident RHT and 365 (19%) with persistent RHT. Two-thirds of the patients with RHT at baseline remained resistant at the end of the study. Independent variables associated with both incident and persistent RHT were diabetes mellitus, history of cardiovascular disease, hypertension duration, SBP, left ventricular hypertrophy and glomerular filtration rate. Persistent RHT compared with never-having RHT was associated with a 2.2-fold increased risk for cardiovascular morbidity (95% CI: 1.21-4.05, P = 0.01) after adjustment for risk factors.

CONCLUSION

In treated hypertensive patients, among prospective RHT dynamic patterns, persistent RHT is frequent and independently associated with adverse cardiovascular prognosis.

A technology-based quality innovation to identify undiagnosed hypertension among active primary care patients

PURPOSE

The goal of this study was to develop a technology-based strategy to identify patients with undiagnosed hypertension in 23 primary care practices and integrate this innovation into a continuous quality improvement initiative in a large, integrated health system.

METHODS

In phase 1, we reviewed electronic health records (EHRs) using algorithms designed to identify patients at risk for undiagnosed hypertension. We then invited each at-risk patient to complete an automated office blood pressure (AOBP) protocol. In phase 2, we instituted a quality improvement process that included regular physician feedback and office-based computer alerts to evaluate at-risk patients not screened in phase 1. Study patients were observed for 24 additional months to determine rates of diagnostic resolution.

RESULTS

Of the 1,432 patients targeted for inclusion in the study, 475 completed the AOBP protocol during the 6 months of phase 1. Of the 1,033 at-risk patients who remained active during phase 2, 740 (72%) were classified by the end of the follow-up period: 361 had hypertension diagnosed, 290 had either white-coat hypertension, prehypertension, or elevated blood pressure diagnosed, and 89 had normal blood pressure. By the end of the follow-up period, 293 patients (28%) had not been classified and remained at risk for undiagnosed hypertension.

CONCLUSIONS

Our technology-based innovation identified a large number of patients at risk for undiagnosed hypertension and successfully classified the majority, including many with hypertension. This innovation has been implemented as an ongoing quality improvement initiative in our medical group and continues to improve the accuracy of diagnosis of hypertension among primary care patients.

Precise assessment of noncompliance with the antihypertensive therapy in patients with resistant hypertension using toxicological serum analysis

BACKGROUND

The aim of our study was to assess the prevalence of pseudo-resistance caused by noncompliance with treatment among patients with severe resistant hypertension and to analyze the contributing factors.

METHOD

Three hundred and thirty-nine patients (195 men) with resistant essential hypertension were studied. The first group consisted of 176 patients admitted for hospitalization for exclusion of a secondary cause to our hypertension centre (103 men); the second one consisted of 163 out-patients (92 men) investigated for the first time in an out-patient hypertension clinic. Unplanned blood sampling for assessment of serum antihypertensive drug concentrations by means of liquid chromatography-mass spectrometry was performed in all patients.

RESULTS

Our main finding is a surprisingly low compliance with drug treatment in out-patients with resistant hypertension (23% partially noncompliant and 24% totally noncompliant - in total, 47% prevalence of noncompliance). Eighty-one percent of hospitalized patients were positive, in 10% the results were partially positive and in 9% of the patients, the drugs were all negative. The compliance among hospitalized patients was probably better due to lower numbers of prescribed drugs and expected thorough investigation. More frequently, noncompliance was found in nonworking (potential purpose-built behaviour), younger and less well educated patients. The most frequent noncompliance was to doxazosine, spironolactone and hydrochlorothiazide. We have observed a surprisingly low compliance with treatment among out-patients with severe hypertension.

CONCLUSION

We conclude that the evaluation of antihypertensive drugs concentrations is a useful and precise method for assessment of noncompliance in patients with resistant hypertension. This evaluation is useful before starting the diagnostic work-up of secondary forms of hypertension and before assignment patients into protocols with new therapy modalities such as renal denervation.

Cross-sectional study of indices of dynamic components of ambulatory blood pressure and cardiac damage in elderly male patients with essential hypertension

BACKGROUND AND AIMS

Blood pressure control is closely related to target organ damage in elderly patients with hypertension. The aim of this study was to determine the relationship between ambulatory blood pressure monitoring (ABPM) indices and cardiac damage in elderly male patients with treated essential hypertension (EH).

METHOD

This study included 998 Chinese men (mean age, 78.44 ± 12.02 years) with EH. Participants underwent cardiac function assessment, laboratory testing, and ABPM, including ABP, BP variability, BP circadian rhythms, and hypertensive or hypotensive time indices. The relationships between ABPM indices and cardiac damage (expressed by shape and function) were assessed using ridge regression analysis.

RESULTS

Ridge regression analysis revealed the following after adjustments for age, common cardiovascular risk factors, disease, and medications: N-terminal fragment pro-B-type natriuretic peptide was negatively correlated with the diastolic blood pressure nocturnal fall rate; the peak early/atrial velocity (E/A) ratio E/A ratio was negatively correlated with the 24 h mean systolic blood pressure (24 hmSBP), daytime SBP (dSBP), and nocturnal SBP (nSBP); and ejection fraction (EF) was negatively correlated with 24 h SBP percent time of elevation (24 hSBP PTE %) and 24 h DBP percent time of elevation (24 hDBP PTE %). Left ventricular mass (LVM) was positively correlated with the 24 hmSBP, dSBP, nSBP, 24 h mean pulse pressure (24 hmPP), day mean pulse pressure, and nocturnal mean arterial pressure, whereas LVM was negatively correlated with the NDBPF.

CONCLUSIONS

Our study showed that the ABPM indices associated with cardiac damage may be regarded as an early predictive marker for cardiac function impairment in elderly male patients with EH.

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.

Effects of renal denervation on ambulatory blood pressure measurements in patients with resistant arterial hypertension

BACKGROUND

The sympathetic nervous system is an important factor in hypertension. In patients suffering from resistant hypertension, transfemoral renal sympathetic denervation (RDN) reduces office blood pressure (BP) values.

HYPOTHESIS

Ambulatory BP measurement (ABPM) is a better predictor than office BP of cardiovascular morbidity and mortality. We thus believe that ABPM should be added to the systematic evaluation and follow-up protocol when treating patients with resistant hypertension with RDN. Therefore, we evaluated the effect of RDN on mean 24-hour BP by the use of ABPM.

METHODS

Patients with resistant hypertension (office systolic BP >160 mm Hg, or >150 mm Hg in patients with diabetes) have been treated with RDN. Ambulatory BP measurement was performed at baseline and at 3 and 6 months after RDN. Patients with a 24-hour systolic BP reduction of ≥5 mm Hg were classified as responders.

RESULTS

Of 86 patients initially enrolled in the study, 5 had to be excluded from the analysis because of <70% valid ABPM recordings. Out of the 81 studied patients, we found 49 responders (60.5%). In all patients, office BP decreased from 169.9/87.8 mm Hg to 153.5/86.3 mm Hg (P < 0.001/P = not significant [NS]) and 24-hour BP decreased from 144.3/86.0 mm Hg to 139.9/84.0 mm Hg (P = 0.025/P = NS) 6 months after RDN. In responders, office BP decreased from 169.6/90.3 mm Hg to 143.7/79.7 mm Hg (P < 0.001/P < 0.001). The ABPM levels started at 144.3/84.7 mm Hg and decreased to 138.3/81.5 mm Hg (P = 0.025/P = 0.045). In nonresponders, office BP was 150.2/84.0 mm Hg and 24-hour BP was 144.5/84.7 mm Hg at baseline; at 6 months, office BP was 168.7/96.4 mm Hg (P < 0.001/P = NS) and 24-hour BP was 142.2/81.5 mm Hg (P = NS/P = NS).

CONCLUSIONS

Office BP and AMBP levels can be significantly lowered by RDN in patients with resistant hypertension.

Night blood pressure responses to atenolol and hydrochlorothiazide in black and white patients with essential hypertension

BACKGROUND

Night blood pressure (BP) predicts patient outcomes. Variables associated with night BP response to antihypertensive agents have not been fully evaluated in essential hypertension.

METHODS

We sought to measure night BP responses to hydrochlorothiazide (HCTZ), atenolol (ATEN), and combined therapy using ambulatory blood pressure (ABP) monitoring in 204 black and 281 white essential hypertensive patients. Initial therapy was randomized; HCTZ and ATEN once daily doses were doubled after 3 weeks and continued for 6 more weeks with the alternate medication added for combined therapy arms. ABP was measured at baseline and after completion of each drug. Night, day, and night/day BP ratio responses (treatment - baseline) were compared in race/sex subgroups.

RESULTS

Baseline night systolic BP and diastolic BP, and night/day ratios were greater in blacks than whites (P < 0.01, all comparisons). Night BP responses to ATEN were absent and night/day ratios increased significantly in blacks (P < 0.05). At the end of combined therapy, women, blacks, and those starting with HCTZ as opposed to ATEN had significantly greater night BP responses (P < 0.01). Variables that significantly associated with ATEN response differed from those that associated with HCTZ response and those that associated with night BP response differed from those that associated with day BP response.

CONCLUSIONS

In summary, after completion of HCTZ and ATEN therapy, women, blacks, and those who started with HCTZ had greater night BP responses. Reduced night BP response and increased night/day BP ratios occured with ATEN in blacks. Given the prognostic significance of night BP, strategies for optimizing night BP antihypertensive therapy should be considered.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT00246519.

Apparent and true resistant hypertension: definition, prevalence and outcomes

Resistant hypertension, defined as blood pressure (BP) remaining above goal despite the use of > or =3 antihypertensive medications at maximally tolerated doses (one ideally being a diuretic) or BP that requires > or =4 agents to achieve control, has received more attention with increased efforts to improve BP control rates and the emergence of device-based therapies for hypertension. This classically defined resistant group consists of patients with true resistant hypertension, controlled resistant hypertension and pseudo-resistant hypertension. In studies where pseudo-resistant hypertension cannot be excluded (for example, 24-h ambulatory BP not obtained), the term apparent resistant hypertension has been used to identify 'apparent' lack of control on > or =3 medications. Large, well-designed studies have recently reported the prevalence of resistant hypertension. Pooling prevalence data from these studies and others within North America and Europe with a combined sample size of >600,000 hypertensive participants, the prevalence of resistant hypertension is 14.8% of treated hypertensive patients and 12.5% of all hypertensives. However, the prevalence of true resistant hypertension, defined as uncontrolled both by office and 24-h ambulatory BP monitoring with confirmed medication adherence, may be more meaningful in terms of identifying risk and estimating benefit from newer therapies like renal denervation. Rates of cardiovascular events and mortality follow mean 24-h ambulatory BPs in patients with resistant hypertension, and true resistant hypertension represents the highest risk. The prevalence of true resistant hypertension has not been directly measured in large trials; however, combined data from smaller studies suggest that true resistant hypertension is present in half of the patients with resistant hypertension who are uncontrolled in the office. Our pooled analysis shows prevalence rates of 10.1% and 7.9% for uncontrolled resistant hypertension among individuals treated for hypertension and all hypertensive individuals, respectively.

Ambulatory blood pressure monitoring and prognosis in the management of essential hypertension

Over the past decade, several prospective outcome studies have demonstrated that ambulatory blood pressure measurements provide a better prediction of major cardiovascular events compared with clinic blood pressure measurements. This review summarizes the advantages of ambulatory blood pressure over clinic blood pressure to predict outcome in untreated and treated hypertensive subjects. Based on available evidence, an operational flow-chart in order to interpret results of ambulatory blood pressure for a better management of these subjects is suggested.

Inter-arm blood pressure differences compared with ambulatory monitoring: a manifestation of the 'white-coat' effect?

BACKGROUND

Inter-arm difference in blood pressure of >10 mmHg is associated with peripheral vascular disease, but it is unclear how much of the difference in sequential right and left arm blood pressure measurements might be due to a 'white-coat' effect.

AIM

To use ambulatory blood pressure monitoring (ABPM) to better understand the clinical significance of inter-arm differences in blood pressure.

DESIGN AND SETTING

Retrospective study in a teaching hospital in Birmingham.

METHOD

Anonymised clinical data collected from 784 patients attending a single hospital-based hypertension clinic were retrospectively analysed. Each participant had blood pressure measured sequentially in both arms, followed by ABPM over the subsequent 24 hours.

RESULT

Data were available for 710 (91%) patients, of whom 39.3% (279) had a blood pressure difference of 10 mmHg or more between each arm. Compared to daytime systolic ABPM, the difference was 25.1 mmHg using the arm with the highest reading, but only 15.5 mmHg if the lower reading was taken (mean difference 9.6 mmHg (95% confidence interval [CI] = 9.0 mmHg to 10.3 mmHg)). However, differences between mean right (20.7 mmHg) or left (19.9 mmHg) arm blood pressure and daytime systolic ABPM were very similar.

CONCLUSION

Compared with ABPM, use of the higher of the left and right arm readings measured sequentially appears to overestimate true mean blood pressure. As there is no significant difference in the extent of disparity with ABPM by left or right arm, this is unlikely to be due to arm dominance and may be due to the 'white-coat' effect reducing blood pressure on repeated measurement. Where a large inter-arm blood pressure difference is detected with sequential measurement, healthcare professionals should re-measure the blood pressure in the original arm.