Measuring blood pressure accurately.

Out-of-office blood pressure measurement in children and adolescents

Ambulatory Blood Pressure in Chronic Kidney Disease: Ready for Prime Time?

Out-of-Office Blood Pressure Monitoring: A Comparison of Ambulatory Blood Pressure Monitoring and Home (Self) Monitoring Of Blood Pressure.

Clinical Value of Ambulatory Blood Pressure Monitoring in CKD

Ambulatory Blood Pressure Monitoring: Profiles in Chronic Kidney Disease Patients and Utility in Management.

Introduction For practical reasons, blood pressure values measured by physicians or nurses in a medical environment remain the clinical basis of the diagnosis and management of arterial hypertension around the world as recommended by all guidelines [1–4]. Nevertheless, measurements of blood pressure outside the office have gained an increasing popularity over the last decades not only to ascertain the diagnosis of hypertension but also to follow the impact of therapeutic interventions. Out-of-office blood pressure measurements can be obtained either by 24-h ambulatory blood pressure monitoring or by home blood pressure monitoring. As reviewed recently [5], both sets of out-of-office blood pressure offer undeniable advantages when compared to office blood pressure. First, both ambulatory blood pressure and home blood pressure monitoring provide more reliable and reproducible information on blood pressure. Second, blood pressure values obtained by ambulatory blood pressure and home blood pressure monitoring appear to be more closely related to target organ damage than office blood pressure and hence have a greater prognostic relevance than office blood pressure. Third, certain diagnosis such as white coat hypertension and masked hypertension can only be diagnosed using out-of-office blood pressure measurements. Fourth, when used in the clinical follow-up of treated hypertensive patients to evaluate the impact of drug treatment, ambulatory blood pressure monitoring as well as home blood pressure monitoring has the advantage of not being affected by a placebo effect. Finally, evidence has been provided that treatment-induced reduction in 24-h blood pressure may predict better than office blood pressure the regression of end organ damage (particularly the cardiac one) induced by antihypertensive drug. Many of these information have been achieved during the past two decades by a number of studies carried out in different populations around the world, including the Pressioni Arteriose Monitorate E Loro Associazioni (PAMELA) study [6–10]. When should out-office blood pressure be measured? Despite their advantages, ambulatory blood pressure monitoring as well as home blood pressure monitoring is not regarded as a routine procedure that should be applied to all hypertensive patients essentially for economical reasons. However, this issue is debated because the clinical information gathered with these measurements may potentially result in financial savings when applied adequately. The European and American guidelines for the management of hypertension have defined some indications for the use of ambulatory blood pressure monitoring in hypertension [1,2]. These include patients with resistant hypertension, patients with a high variability of office blood pressure, low-risk patients with a high blood pressure, patients with suspected episodes of hypotension, patients with a large discrepancy between office and home blood pressures, and finally patients with special clinical conditions such as pregnancy or sleep apnea syndrome. Outside these indications, the use of ambulatory blood pressure monitoring could be discussed both in terms of feasibility and economics. Theoretically, a measurement of out-of-office blood pressure could be recommended to all new patients with as suspected hypertension to confirm the diagnosis of hypertension and to refine the patient's cardiovascular risk profile. Therefore, ambulatory blood pressure monitoring could be recommended to all high cardiovascular risk patients before starting any treatment and later under therapy to ascertain the adequacy of the control of blood pressure. Ambulatory blood pressure values in diabetic patients In this issue of the Journal of Hypertension, Leitao et al.[11] report the results of a cross-sectional study performed to estimate the daytime ambulatory blood pressure monitoring values corresponding to the target office blood pressure of 130/80 mmHg for diabetic (as defined by the American Diabetes Association) and to assess which diabetic patients may actually benefit from ambulatory blood pressure monitoring. They included 554 patients in this analysis. Regression analyses were performed to analyze the ambulatory blood pressure monitoring values corresponding to office blood pressure and receiver operating characteristics (ROC) curves were used to assess the sensitivity and specificity of office blood pressure in diagnosing daytime ambulatory blood pressure monitoring hypertension. According to their regression equations, the daytime ambulatory blood pressure monitoring corresponding to the target office blood pressure of 130/80 mmHg was 129/79 mmHg and the daytime ambulatory blood pressure monitoring value corresponding to 140/90 mmHg at the office was 134/82 mmHg. As expected, discrepancies between ambulatory blood pressure monitoring and office blood pressure were due essentially to masked hypertension (about 10% of cases) and white coat hypertension (between 19% for systolic blood pressure and 26% for diastolic blood pressure). Interestingly, when office blood pressure was lower than 120 mmHg systolic and 70 mmHg diastolic, the sensitivity to rule out hypertension using ambulatory blood pressure monitoring was 90%. Similarly, when office blood pressure was more than 145 mmHg systolic and more than 90 mmHg diastolic the sensitivity to confirm hypertension using ambulatory blood pressure monitoring was 90%. Within these two sets of limits, 38% of patients would be misclassified if only office blood pressure values would be considered for the diagnosis. Thus, using the cut-off values of less than 120/70 mmHg and more than 140/90 mmHg at the office, 56% of the population sample would need an ambulatory blood pressure monitoring to confirm the diagnosis of hypertension. According to these results, only diabetics with an office blood pressure between 120 and 140 mmHg systolic and/or a diastolic blood pressure between 70 and 90 mmHg would really benefit from an out-office assessment of blood pressure. This would limit the use of ambulatory blood pressure monitoring to only 50% of the diabetic patients. Studies implications and limitations The results of this provide interesting practical information on the use of ambulatory blood pressure monitoring in diabetic patients. However, they also have some limitations. The first one is the fact that the entire analysis is based on daytime ambulatory blood pressure only. Although the authors have measured 24-h blood pressure, they have not considered the nighttime blood pressure. This is unfortunate because there is increasing evidence that nighttime is a better predictor of cardiovascular risk than daytime blood pressure. Moreover, diabetic patients are often characterized by an absence of the physiological fall in blood pressure reflecting a nondipping pattern at night. Diabetes may even be the cause of a reverse dipping, that is an increase in blood pressure at night. Both the nondipping and the reverse dipping pattern of blood pressure have been associated with an increased risk of developing target organ damages such as left ventricular hypertrophy, microalbuminuria, renal dysfunction, and cerebral vascular lesions [5,12]. Thus, when assessing the cardiovascular risk profile linked to hypertension in diabetic patients, nighttime blood pressure should be included. Indeed, it is not uncommon in diabetes that daytime normotensive patients exhibit a nocturnal hypertension. This type of patients would be misdiagnosed using the algorithm proposed by the authors. Recently, the results of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial have shown that in diabetic patients the reduction of cardiovascular morbidity and mortality obtained by lowering office blood pressure below 120 mmHg systolic is not greater than that seen reducing blood pressure below 130 mmHg [13]. On the contrary, a systolic blood pressure below 120 mmHg may result in an increased risk of developing cardiac complications, as suggested by the recent post hoc analysis of diabetic patients with coronary heart diseases having participated in the INternational VErapamil SR-Trandolapril (INVEST) Study [14]. If a low blood pressure increases the risk of cardiac complications in diabetics, one might have to reconsider the necessity to perform an ambulatory blood pressure monitoring in diabetic patients with a blood pressure <120/70 mmHg in contrast to the proposals of Leitao et al. Indeed, in treated diabetic patients with a low office blood pressure, ambulatory blood pressure monitoring could be of importance to diagnosis episodes of asymptomatic hypotension episodes which might increase their cardiac risk. Thus, in the analysis of daytime and nighttime blood pressure values, it would be of interest to assess whether the percentage of ambulatory blood pressure values below a certain level is indeed associated with an increased risk of some cardiovascular complications. In this respect, it is important to mention that the analysis presented by Leitao et al. does not provide any information on the presence in this particular patients population of cardiac organ damage. The study also does not provide any data such on the occurrence of cardiovascular events and deaths, as it was not a prospective cohort study. Both these two sets of information should be thus provided by future clinical trials.

Peridialytic, Intradialytic, and Interdialytic Blood Pressure Measurement in Hemodialysis Patients

Renal denervation in hypertension patients: Proceedings from an expert consensus roundtable cosponsored by SCAI and NKF.

Hypertension is associated with more end-organ damage, cardiovascular events, and disability-adjusted life years lost in the United States compared with all other modifiable risk factors. Several guidelines and scientific statements now endorse the use of out-of-office blood pressure (BP) monitoring with ambulatory BP monitoring or home BP monitoring to confirm or exclude hypertension status based on office BP measurement. Current ambulatory or home BP monitoring devices have been reliant on the placement of a BP cuff, typically on the upper arm, to measure BP. There are numerous limitations to this approach. Cuff-based BP may not be well-tolerated for repeated measurements as is utilized with ambulatory BP monitoring. Furthermore, improper technique, including incorrect cuff placement or use of the wrong cuff size, may lead to erroneous readings, affecting diagnosis and management of hypertension. Compared with devices that utilize a cuff, cuffless BP devices may overcome challenges related to technique, tolerability, and overall utility in the outpatient setting. However, cuffless devices have several potential limitations that limit its routine use for the diagnosis and management of hypertension. The review discusses the different approaches for determining BP using various cuffless devices including engineering aspects of cuffless device technologies, validation protocols to test accuracy of cuffless devices, potential barriers to widespread implementation, and future areas of research. This review is intended for the clinicians who utilize out-of-office BP monitoring for the diagnosis and management of hypertension.

Management of Hypertension in Patients With Diabetic Kidney Disease: Summary of the Joint Association of British Clinical Diabetologists and UK Kidney Association (ABCD-UKKA) Guideline 2021

> Two statisticians meet . > > -How do you do? > > -How do I do? Compared to whom? > > — Anonymous Thomas Pickering coined the term white-coat hypertension to denote individuals who were not on treatment for hypertension but who had elevated office blood pressure and normal daytime blood pressure measured with ambulatory blood pressure monitoring (ABPM). Clearly, these individuals would be at low cardiovascular risk.1 The traditional definition of white-coat hypertension is based, therefore, on an elevated office blood pressure with a normal blood pressure during the awake period with ABPM. However, because of the contribution of asleep blood pressure as a predictor of outcome, it seems counterproductive to exclude this period from consideration. The most recent European guidelines2 propose, therefore, an alternative definition of white-coat hypertension, which encompasses subjects with office systolic/diastolic blood pressure readings of ≥140/90 mm Hg and a 24-hour blood pressure <130/80 mm Hg. The purpose of this review is to provide new insights into the characteristics, definitions, and cardiovascular risk assessment in persons with white-coat hypertension, and it will be limited primarily to ABPM with a primary focus on prospective studies. ### Prevalence and Diagnosis White-coat hypertension occurs in 15% to 30% of subjects with an elevated office blood pressure,2,3 and the phenomenon is reasonably reproducible.2,4 Although there are no pathognomonic diagnostic features of white-coat hypertension, this condition occurs more frequently in women, older adults, nonsmokers, recently diagnosed patients with hypertension with a limited number of conventional blood pressure measurements in the office setting who have mild hypertension, pregnant women, and subjects without evidence of target organ damage.2,5,6 The misdiagnosis of subjects with white-coat hypertension as being truly hypertensive can result in them being penalized for employment and insurance rating, as well as being prescribed unnecessary lifelong treatment with potential side …

To the Editor: We read with interest the paper by Sega et al regarding the prognostic value of ambulatory, home, and office blood pressure in the PAMELA population.1 However, we find that the main conclusions of the report may be driven by the lack of adjustment for confounders. The relationships between level of blood pressure and risk were not adjusted for age, which may have a major influence on risk over a long time span. There is indeed a relation between age and blood pressure,2 and therefore, these results may be biased. The comparisons of the various blood pressures were also not adjusted for potential confounders, with the argument that “no adjustment for age, sex, and other cardiovascular risk factors was made because comparisons between the predictive value of various blood pressure values involved the same sample.” However, it has been shown in a general Belgian population that the within-subject differences between office and ambulatory blood pressure measurements increased with older age and greater body mass index.3 In addition, in the Danish MONICA population, the within-subject differences between office and ambulatory blood pressure measurements increased with older age, diagnosis of hypertension, male gender, and presence of diabetes.4 So, to assess the true prognostic value of office blood pressure versus that of ambulatory blood pressure, it is mandatory to explore whether adjustments for other relevant cardiovascular risk factors would change the results. Recently, it was shown in the Danish MONICA population that ambulatory blood pressure was a much better predictor of all-cause mortality and cardiovascular mortality than office blood pressure, taking other relevant risk factors into account.5 Accordingly, to make the results from previous studies comparable to the PAMELA study, we would like to know the results of adjusted analyses. Until that time, the conclusion that …

The study by Protogerou et al.[1], published in this issue of the Journal of Hypertension, sheds light on the role of 24-h ambulatory aortic blood pressure (BP) as a correlate of target organ damage in hypertension. The main findings of the study are that both 24-h aortic and 24-h brachial BP are superior to conventional office BP measurements in predicting BP-related cardiac damage, and that 24-h ambulatory aortic BP is more closely associated with left ventricular hypertrophy than 24-h ambulatory brachial BP. On account of the results of this study, the authors suggest that the information on aortic BP derived from ambulatory BP monitoring (ABPM) improves the ability of regression models to detect the presence of left ventricular hypertrophy and to discriminate between individuals with and without left ventricular hypertrophy. There is a general consensus that 24-h ABPM is a better method for diagnosing hypertension and predicting BP-related cardiovascular risk than conventional office brachial BP measurements. Twenty-four-hour ambulatory BP (ABP) shows a stronger correlation with subclinical organ damage than office BP [2] and, more importantly, is a significantly better predictor of cardiovascular events [3–6]. The prognostic information offered by 24-h ABPM is independent of and incremental to that provided by office BP measurements [4–7]. In particular, ABP has the unique ability to provide information on 24-h average BP, on nocturnal BP and day–night BP changes, as well as on 24-h BP variability, which all provide independent prognostic information over and above that provided by office BP measurements [8–12]. The clinical relevance of ABPM is, therefore, clearly established in both treated and untreated hypertensive individuals [13]. The question is now whether the clinical value of ABPM might be further increased by incorporating information on ambulatory central BP. The possibility to combine the advantages of 24-h ABPM with those of central BP assessment by using devices which offer the estimate of central BP over the 24 h, in addition to the assessment of ambulatory brachial BP, sounds indeed attractive from both the clinical and experimental point of view. Central BP, that is, BP in the ascending aorta, is considered an important physiologic parameter as it reflects the hemodynamic relationship between the heart and the aorta, both in systole and in diastole. In the systolic phase, central BP represents the pressure against which the left ventricle has to eject blood during systolic contraction. Thus, central arterial pressure reflects both left ventricular stroke volume and afterload, defines cardiac work, and contributes to the development of left ventricular hypertrophy in hypertensive individuals. In the diastolic phase, central BP is a key determinant of the blood flow delivery to the myocardium. Thus, central SBP is an accurate marker of the actual pressure load imposed on the left ventricle and represents a more informative measurement, from a clinical perspective, than peripheral SBP, as shown by a few important clinical studies. Safar et al.[14] showed in end-stage renal disease patients undergoing hemodialysis that carotid pulse pressure (PP), directly measured by carotid tonometry, was a more powerful predictor of overall mortality than brachial PP. In that study, a lower peripheral BP amplification, that is, a greater central BP for any given level of brachial BP, was a significant predictor of all-cause (including cardiovascular) mortality, independent of age and other standard confounding factors. The Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) [15] showed a lower incidence of cardiovascular events among patients treated with the calcium-channel blocker amlodipine than with the β-blocker atenolol, with a small difference in the reduction of brachial SBP values between the treated groups. However, the Conduit Artery Functional Endpoint (CAFE) study [16], a substudy of the ASCOT, showed a lower central SBP and PP in the individuals randomized to receiving an amlodipine-based compared with those receiving a beta-blocker-based treatment, in spite of the similar values in brachial SBP. Therefore, the authors suggested that, in ASCOT, the greater reduction in cardiovascular events in the group randomized to amlodipine could be because of a greater effect of this drug in lowering central SBP. In a systematic review and meta-analysis, Vlachopoulos et al.[17] showed that central SBP and indices of central pulse amplification carry a significant predictive value for cardiovascular events and all-cause mortality. As a result of the anatomical proximity, the stress imposed on the heart, kidneys, and the brain is indeed driven more directly by aortic than by peripheral pressure [18]. Indeed, central BP has a closer relation to left ventricular mass and concentric geometry [19], and to carotid intima–media thickness and glomerular filtration rate [20], than peripheral BP. Despite all the above evidence, however, the 2013 European Society of Hypertension (ESH) and European Society of Cardiology (ESC) guidelines for the management of arterial hypertension [21] did not recommend the routine clinical measurement of central BP, with the exception of isolated systolic hypertension in the young, in whom the increase of SBP measured at the brachial artery may be because of a high amplification phenomenon, with normal values of central BP. There are important reasons why the ESH and ESC hypertension guidelines have been so cautious in recommending a more extensive clinical use of central BP. First, the additive predictive value of central BP beyond brachial BP was either marginal or not statistically significant in most studies [21]. Second, at least two serious methodological problems in relation to central BP measurement, both clearly highlighted in the study by Protogerou et al.[1], have not yet been satisfactorily addressed: the actual reliability of the methods used to measure central BP and the difficulties related to calibration of the tonometric pressure waveform to derive central BP. Central BP can be estimated either directly from the common carotid waveform or from the peripheral (radial or brachial) waveform with the use of a transfer function [22]. It has been widely documented that the shape of the pressure wave in the common carotid artery is comparable to that recorded in the ascending aorta [23–25]. Several studies comparing carotid tonometry with the invasive method concluded that applanation tonometry at the carotid artery level is a valuable tool for aortic pulse-wave recording and central (aortic) BP values assessment [24,25]. On the other hand, over the last few years, a large number of devices have been proposed aimed at assessing central BP using individual and generalized inverse transfer functions to reconstruct the aortic waveform from radial or brachial artery waveforms. One of the main challenges of this indirect method is related to the difficulty in recording and analyzing the brachial arterial pressure wave. Another important and yet unresolved problem is the current uncertainty about the reliability of the transfer functions applied either to radial or to brachial noninvasive arterial waveforms, especially when obtained under peculiar hemodynamic conditions, like those characterizing pregnancy, heart failure, and the elderly or young individuals. In the study by Protogerou et al.[1], central BP was assessed by means of an indirect method based on a generalized transfer function applied to the brachial pulse waves recorded through an oscillometric system. Although a validation study of this system has been published [26], in this validation study only central SBP values obtained from 30 patients were reported, and no data were provided on pulse waveform characteristics of the same individuals. Moreover, invasive validation studies concerning devices for assessing central BP, which only focus on central SBP values, carry the risk of providing misleading results, whenever they ignore the concomitant validation of the device ability to assess the arterial wall properties. In fact, given the significant and close linear correlation found by a number of studies between invasive central SBP, measured directly in the ascending aorta by a catheter, and brachial SBP, measured by an oscillometric method, one might come to the paradoxical suggestion that a relatively accurate measurement of aortic SBP might simply be obtained by subtracting 10 mmHg from brachial oscillometric SBP values, with no need of pulse waveform analysis [27]. Thus, given the importance of this topic, and because of the diverse approaches followed by the available validation studies, more rigorous criteria should urgently be provided by scientific international societies in order to establish reliable protocols and methods for a better standardized validation of devices aimed at assessing central BP. A major limitation of all systems currently proposed to estimate central BP is their inability to provide absolute values of aortic pressure. A calibration of the pulse waveform obtained through tonometric recordings is indeed always required, and two alternative calibration methods are usually followed, both of which have been evaluated in the study by Protogerou et al.[1]. According to the first approach, brachial SBP and DBP values determined by a validated conventional sphygmomanometric method are assigned to the peak and trough points of the tonometric pressure wave recorded at the level of the reference artery (i.e. brachial artery in the study by Protogerou et al.[1]). With the second approach, the brachial pulse waveform is calibrated using mean BP and DBP values again obtained by a validated conventional sphygmomanometric method. The latter calibration procedure is based on the observation that mean BP is constant throughout the large artery tree and that DBP does not change substantially from the central to the peripheral part of the arterial system [28,29]. In the study by Protogerou et al.[1], the correlation of central BP with cardiac damage was markedly different when different calibration methods were used. When mean and diastolic brachial BP values were applied for the calibration of the peripheral pressure waveform, 24-h average aortic SBP was significantly better associated with left ventricular mass than 24-h average brachial SBP. On the contrary, the correlation of 24-h aortic SBP with left ventricular mass was worse than that of 24-h brachial SBP when systolic and diastolic brachial BP values were used for calibration. Remarkably, however, SBP values were higher in aorta than in brachial artery when pulse waves were calibrated using mean and diastolic brachial BP. This counterintuitive finding contrasts with the widely held physiologic assumption that SBP actually increases ongoing from the aorta to peripheral arteries. The authors justify this result with a possible underestimation of the brachial SBP by the oscillometric method, suggesting that systolic and diastolic (rather than mean and diastolic) oscillometric BP values should be applied in calibration of peripheral pulse waveforms when assessing the amplification phenomenon. This suggestion appears, however, to be inconsistent with the demonstration provided by the authors themselves of a greater predicting value of central BP when calibrated based on the mean and diastolic brachial BP values, and weakens the clinical value of the correlation found in this study between the central pressure estimated in this way and cardiac damage. Several other studies showed that the two methods of calibration may lead to absolute differences in central SBP estimation of up to 15 mmHg between each other, and compared with invasive measurements, independently of the used device [26,30,31]. Also, imprecision in determining brachial mean pressure by oscillometry may negatively affect the accuracy of central BP estimation [31]. Understanding and addressing these discordances is, therefore, a crucial issue in the process of clinical implementation of central BP measuring devices. Despite the clear theoretical advantages of central 24-h BP monitoring, more investigations and technical improvements are thus needed before recommending central BP for routine clinical use, as wisely suggested by the 2013 ESH and ESC guidelines for the management of arterial hypertension [21]. Even more caution is needed when proposing ambulatory estimates of central BP all over the 24 h. Indeed, all available methods for estimating central BP have been tested and more or less properly validated at rest, with no systematic validation of their performance in ambulant individuals over 24 h. Such a dynamic validation, admittedly, is not an easy task and has to face a number of methodological difficulties. Similar difficulties are faced also when validating oscillometric devices for ABPM at the brachial artery level, a validation which is commonly done only at rest [32]. The accuracy at rest of ABPM devices is then somehow uncritically extrapolated to the dynamic conditions of a truly ambulatory recording. The only partial justification for this procedure is that individuals are advised to stop any activity and to keep their arm still at the time of each oscillometric cuff inflation [12]. In the past, only a few studies attempted to validate ABPM devices in truly dynamic conditions, and this was done against ambulatory intra-arterial BP recordings. These studies clearly showed that the discrepancy between automated BP readings and intra-arterial BP values was much greater in ambulatory conditions than at rest [33]. This approach can no longer be recommended nowadays, both for technical and ethical reasons. Research is, therefore, still needed to develop more suitable protocols to validate devices for ambulatory central or peripheral BPM. These protocols, for example, should allow the dynamic assessment of the accuracy of devices for central and peripheral ABPM against noninvasive reference standards in a laboratory environment by simulating some of the activities and recording conditions of daily life. In conclusion, the study by Protogerou et al.[1] provides interesting suggestions on the possible clinical relevance of central ABPM. However, a number of yet unresolved methodological issues related to the calibration and accuracy of central BP estimates, in particular when obtained under ambulatory conditions, still do not allow to recommend this approach in clinical practice and strongly suggest the need of additional studies in this stimulating field. ACKNOWLEDGEMENTS All authors had access to the data and a role in writing this article. Conflicts of interest P.S. is a consultant for DiaTecne s.r.l. The other authors have no conflicts to report.

Self blood pressure monitoring at home by wrist devices: a reliable approach?

he conventional measurement of blood pressure(BP) in the office or clinic has been the cornerstonefor hypertension management for decades. How-ever, because of the white-coat and the masked hyper-tension phenomena, out-of-office BP monitoring withambulatory or home measurements is often required [1].ExtensiveresearchonambulatoryBPmonitoringhasestab-lished its role as the most accurate tool for hypertensiondiagnosis [1–3].Onthecontrary,despitetheincreasinguseof home BP monitoring by hypertensive patients in thedaily management of their high BP condition, research inthisfield,inparticularwhenconsideringoutcometrials,hasbeen delayed as compared to ambulatory BP monitoring[4,5].