Muscle and skin sympathetic nerve traffic during the "white-coat" effect

Heart rate variability modulates memory function in a virtual task

Heart rate variability (HRV) is considered one of the most relevant indicators of physical well-being and relevant biomarker for preventing cardiovascular risks. More recently, a growing amount of research has tracked an association between HRV and cognitive functions (i.e., attention). Research is still scarce on spatial orientation, a basic capability in our daily lives. It is also an important indicator of memory performance, and its malfunctioning working as an early sign of dementia. In this study, a total of 43 female students (M Age = 18.76; SD = 2.02) were measured in their lnRMSSD using the photoplethysmography technique with the Welltory smartphone app. They were also tested in their spatial memory with The Boxes Room, a virtual navigation test. Measures of physical activity were obtained with the International Physical Activity Questionnaire (IPAQ). Correlation analyses and repeated measures ANOVA were performed, comparing participants with high / low lnRMSSD in their spatial performance. Results showed that, at an equal level of physical activity, participants with a higher lnRMSSD were more effective in the early trials of The Boxes Room, being more precise in estimating the correct position of the stimuli. Moreover, a subsequent simple linear regression showed that a higher lnRMSSD was related to a smaller number of errors at the beginning of the spatial task. Overly, these results outline the relationship between HRV and navigation performance in early stages of processing, where the environment is still unknown and the situation is more demanding.

What is resistant arterial hypertension?

PURPOSE

The current review is to describe the definition and prevalence of resistant arterial hypertension (RAH), the difference between refractory hypertension, patient characteristics and major risk factors for RAH, how RAH is diagnosed, prognosis and outcomes for patients.

MATERIALS AND METHODS

According to the WHO, approximately 1.28 billion adults aged 30-79 worldwide have arterial hypertension, and over 80% of them do not have blood pressure (BP) under control. RAH is defined as above-goal elevated BP despite the concurrent use of 3 or more classes of antihypertensive drugs, commonly including a long-acting calcium channel blocker, an inhibitor of the renin-angiotensin system (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker), and a thiazide diuretic administered at maximum or maximally tolerated doses and at appropriate dosing frequency. RAH occurs in nearly 1 of 6 hypertensive patients. It often remains unrecognised mainly because patients are not prescribed ≥3 drugs at maximal doses despite uncontrolled BP.

CONCLUSION

RAH distinctly increases the risk of developing coronary artery disease, heart failure, stroke and chronic kidney disease and confers higher rates of major adverse cardiovascular events as well as increased all-cause mortality. Timely diagnosis and treatment of RAH may mitigate the associated risks and improve short and long-term prognosis.

High blood pressure with elevated resting heart rate: a high risk "Sympathetic" clinical phenotype

Epidemiological studies have unequivocally shown that elevated heart rate values measured at rest have an adverse prognostic impact in the hypertensive patient, being associated with an increased risk of cardiovascular events and complications. In recent years new data have been collected on this issue, strengthening the clinical relevance of elevated heart rate as a specific hypertensive phenotype. The present paper will review old and new data on the prognostic importance of resting tachycardia in the hypertensive patient. It will also examine the role of the sympathetic nervous system in the development of this alteration as well as its therapeutic implications. The different approaches to dynamically assess heart rate values in the clinical setting will be finally discussed.

Sympathetic Neural Mechanisms in Hypertension: Recent Insights

PURPOSE OF REVIEW

To examine published and unpublished data documenting the role of sympathetic neural factors in the pathogenesis of different hypertensive phenotypes. These phenotypes relate to attended or unattended blood pressure measurements, to nighttime blood pressure profile alterations, and to resistant, pseudoresistant, and refractory hypertension. Results of original clinical studies as well as of recent meta-analyses based on the behavior of different sympathetic biomarkers in various hypertensive forms will be also discussed.

RECENT FINDINGS

Studies performed in the past decade have shown that office blood pressure measurements, including in recent years those characterizing unattended or attended blood pressure assessment, are associated with profound changes in the behavior of different sympathetic biomarkers. This is the case for the clinical hypertensive phenotypes characterized by alterations in the nocturnal blood pressure profile and by sleep duration abnormalities. This is also the case for the clinical conditions defined as resistant, refractory, and pseudoresistant hypertension. Data reviewed in the present paper highlight the relevance of sympathetic neural factors in the development and progression of different clinical hypertensive phenotypes. This suggests that a common hallmark of the majority of the essential hypertensive states detectable in current clinical practice is represented by the alteration in the sympathetic blood pressure control.

Skin sympathetic nerve activity and nocturnal blood pressure nondipping in patients with postural orthostatic tachycardia syndrome

OBJECTIVE

Postural orthostatic tachycardia syndrome (POTS) is associated with abnormal blood pressure (BP) regulation and increased prevalence of nocturnal nondipping. We hypothesized that nocturnal nondipping of BP is associated with elevated skin sympathetic nerve activity (SKNA) in POTS.

METHOD

We used an ambulatory monitor to record SKNA and electrocardiogram from 79 participants with POTS (36 ± 11 years, 72 women), including 67 with simultaneous 24-h ambulatory BP monitoring.

RESULTS

Nocturnal nondipping of BP was present in 19 of 67 (28%) participants. The nondipping group had a higher average SKNA (aSKNA) from midnight of day 1 to 0100 h on day 2 than the dipping group ( P  = 0.016, P  = 0.030, respectively). The differences (Δ) of aSKNA and mean BP between daytime and night-time were more significant in the dipping group compared with the nondipping group (ΔaSKNA 0.160 ± 0.103 vs. 0.095 ± 0.099 μV, P  = 0.021, and Δmean BP 15.0 ± 5.2 vs. 4.9 ± 4.2 mmHg, P  < 0.001, respectively). There were positive correlations between ΔaSKNA and standing norepinephrine (NE) (r = 0.421, P  = 0.013) and the differences between standing and supine NE levels ( r  = 0.411, P  = 0.016). There were 53 (79%) patients with SBP less than 90 mmHg and 61 patients (91%) with DBP less than 60 mmHg. These hypotensive episodes were associated with aSKNA of 0.936 ± 0.081 and 0.936 ± 0.080 μV, respectively, which were both significantly lower than the nonhypotensive aSKNA (1.034 ± 0.087 μV, P  < 0.001 for both) in the same patient.

CONCLUSION

POTS patients with nocturnal nondipping have elevated nocturnal sympathetic tone and blunted reduction of SKNA between day and night. Hypotensive episodes were associated with reduced aSKNA.

Possible cardiovascular risks of white coat hypertension: updated

White-coat hypertension (WCH) has been defined as an increased blood pressure (BP) in the doctor's office and a normal BP outside the office by 24 hr ambulatory BP monitoring (ABPM) or home BP measurement. It is generated by fear and anxiety of whether an abnormal value could be found and indicate the existence of hypertension. When first described, it was defined as a neuro-defense reaction related to the presence of the doctor in their office or clinic and associated with an increase in heart rate. Initially it was considered a benign condition, not associated with the hypertension mediated organ damage (HMOD) and not requiring treatment. However, recent studies have shown that WCH is not a benign condition and is associated with HMOD and cardiovascular (CV) events (CVE). According to recent ACC/AHA guidelines, the outside of office normal BP should be < 130/80 mmHg and according to the ESC/ESH guidelines, the outside of office normal BP should be < 135/85 mmHg. The prevalence of WCH varies by different studies from 15% to 40% and up to 50% in older subjects. Currently, the management of WCH if not associated with CV risk factors should be conservative with healthy lifestyle changes and exercise. Drug therapy should be considered if these measures do not work or in the presence of CV risk factors, HMOD, or preexisting cardiovascular disease.

Nighttime mean arterial pressure is associated with left ventricular hypertrophy in white‐coat hypertension

White‐coat hypertension (WCH) is associated with increased cardiovascular risks. To investigate the relationship between WCH and left ventricular hypertrophy (LVH), the authors recruited 706 participants who underwent anthropometric measurements, blood laboratory analysis, 24h ambulatory blood pressure monitoring (ABPM), and echocardiography. The authors defined WCH as elevated office BP but normal ABPM over 24h, daytime, and nighttime periods. The authors compared the proportion of LVH between the true normotension (NT) and the WCH population, and further assessed the associations between BP indexes and LVH in the two groups, respectively. The proportion of LVH was significantly higher in the WCH group than in NT participants (19.70% vs. 13.12%, P = .036). In the NT group, 24h SBP, 24h PP, daytime SBP, daytime PP and SD of nighttime SBP were associated with LVH after adjustment for demographic and blood biochemical data (all P < .05). In the WCH population, LVH was associated with 24h SBP, nighttime SBP, nighttime MAP, and office SBP after adjustment (all P < .05). However, on forward logistic regression analysis with all the BP indexes listed above, only 24h SBP (OR = 1.057, 1.017–1.098, P < .001) in the NT group, and nighttime MAP (OR = 1.114, 1.005–1.235, P < .05) and office SBP (OR = 1.067, 1.019–1.117, P < .001) in the WCH group were still significantly associated with LVH. Our study suggests that the proportion of LVH is higher in WCH patients than in the NT population. Furthermore, elevated nighttime MAP and office SBP may play critical roles in the development of LVH in the WCH population.

"What if It's not Just an Item of Clothing?" - A Narrative Review and Synthesis of the White Coat in the Context of Aged Care

Although increasingly disputed, the white coat uniform is ubiquitous in geriatric care, which may reflect a phenomenon called medicalisation of ageing. This narrative review is the first attempt at integrating several theoretical approaches, such as the "white coat effect" and "enclothed cognition", in order to gain a comprehensive understanding of the use of this clothing item. Based on extensive empirical evidence, we will examine the consequences of wearing a uniform, not only on patients (in this case, older patients) and healthcare professionals, but also on their relationship. The white coat has powerful symbolic functions for healthcare professionals and is still preferred by older adults. However, the negative repercussions of wearing a uniform require us to question its use, particularly in environments where older persons live, such as nursing homes.

White Coat Uncontrolled Hypertension in Teleconsultation: A New and Frequent Entity

Introduction

Cardiovascular risk seems not to be greater in patients with white coat uncontrolled hypertension (WUCH) than in patients with sustained blood pressure (BP) control. Therefore, its detection is important to avoid overtreatment. The COVID-19 pandemic determined a massive migration of hypertension consultations from the face-to-face modality to teleconsultations, and it is unknown whether WUCH exists in this context.

Aim

We aimed to evaluate the prevalence of WUCH through home BP monitoring (HBPM) in treated hypertensive patients evaluated by teleconsultation.

Methods

We included treated hypertensive patients that owned a digital BP monitor. During teleconsultation, patients were asked to perform two BP measurements and then a 7-day HBPM, using the same device. Patients were classified as having WUCH if BP was ≥ 140 and/or 90 mmHg in teleconsultation and < 135/85 mmHg on HBPM. The prevalence of WUCH and its 95% confidence interval were estimated. One-way ANOVA, the Chi-square test or Fisher’s exact test were used to compare the characteristics of these patients with the other groups.

Results

We included 341 patients (45.2% male, mean age 62.3 years). The prevalence of WUCH was 33.1% (95% CI 28.3–38.3%). Significant differences were found in terms of age, the number of antihypertensive drugs and the use of calcium channel blockers, all lower in the WUCH group as compared with the groups with elevated BP on HBPM.

Conclusion

WUCH exists in teleconsultation and is very frequent. It can be easily detected though HBPM, thus avoiding overmedication, and its potential impact on side-effects and health costs.

Evaluation of 30-Minute Office Blood Pressure in a Diverse Urban Population

BACKGROUND

Previous studies have shown benefits of 30-minute office blood pressure (OBP-30) but did not report on race and gender. The purpose of this study was to determine if similar effects are seen in a diverse urban population.

METHODS

Patients with diabetes and/or cardiovascular disease (age 18-89) were invited to participate. Blood pressure was measured using standard procedure (SOBP). Patients were left alone in an exam room connected to an automated office blood pressure monitor which obtained BP readings every 5 minutes for 30 minutes. The last 5 measurements were averaged for the OBP-30 measurement. Primary outcomes were BPs measured using SOBP and OBP-30. Multivariate logit methods were used to estimate the average probability of having a BP measured <140/90 mm Hg (BPM <140/90) for the 2 measurement methods. Differences were computed across methods, in total and by sex and race, all other factors held constant.

RESULTS

The adjusted probability of having a BPM <140/90 was 47.1% using SOBP and 66.7% using OBP-30 (P < 0.01). Using SOBP, females had a 26.2 PP lower probability of having a BPM <140/90 (P < 0.001) than males. Relative to white patients, Black patients had a 43.9 PP lower (P < 0.001) and other races a 38.5 PP lower (P < 0.001) probability of having a BPM <140/90 using SOBP. Using OBP-30, these differences narrowed and became statistically insignificant.

CONCLUSIONS

OBP-30 may increase the probability of BPM meeting goals, especially in females and patients who are Black, indigenous, or persons of color.

White-Coat Hypertension: Pathophysiological and Clinical Aspects: Excellence Award for Hypertension Research 2020

Few issues of modern cardiovascular medicine have been as controversial as the relationship between white-coat hypertension (WCH), that is, a common condition in which office blood pressure is elevated while out-of-office blood pressure (ambulatory blood pressure or home blood pressure) is normal. While earlier studies showed no increased risk of cardiovascular events in WCH compared with the normotensive state, more recent studies have changed this conclusion by showing that an increased cardiovascular risk represents a trait of this hypertensive phenotype. The present article will review a number of issues related to WCH, that is, its definition, pathophysiological background, clinical alterations, and prognostic significance. This will be done by considering the available evidence published during the last decades, with special focus on the data collected in PAMELA (Pressioni Arteriose Monitorate e Loro Associazioni)-a research project performed with a cross-sectional and longitudinal design, which has provided a series of novel clinical information on WCH throughout the years. The final part of the article will discuss the therapeutic implications of the abovementioned evidence, as well as some controversial or still undefined issues related to WCH, whose investigation will be an important goal to pursue by future research.

Russian Medical Society for Arterial Hypertension expert consensus. Resistant hypertension: detection and management

The diagnosis of resistant arterial hypertension allows us to single out a separate group of patients in whom it is necessary to use special diagnostic methods and approaches to treatment. Elimination of reversible factors leading to the development of resistant arterial hypertension, such as non-adherence to therapy, inappropriate therapy, secondary forms of arterial hypertension, leads to an improvement in the patient's prognosis. Most patients with resistant hypertension should be evaluated to rule out primary aldosteronism, renal artery stenosis, chronic kidney disease, and obstructive sleep apnea. The algorithm for examining patients, recommendations for lifestyle changes and a step-by-step therapy plan can improve blood pressure control. It is optative to use the most simplified treatment regimen and long-acting combined drugs. For a separate category of patients, it is advisable to perform radiofrequency denervation of the renal arteries.

Sympathetic Neural Mechanisms Underlying Attended and Unattended Blood Pressure Measurement

[Figure: see text].

Lifestyle, psychological, socioeconomic and environmental factors and their impact on hypertension during the coronavirus disease 2019 pandemic

SUMMARY

The coronavirus disease 2019 (COVID-19) pandemic considerably affects health, wellbeing, social, economic and other aspects of daily life. The impact of COVID-19 on blood pressure (BP) control and hypertension remains insufficiently explored. We therefore provide a comprehensive review of the potential changes in lifestyle factors and behaviours as well as environmental changes likely to influence BP control and cardiovascular risk during the pandemic. This includes the impact on physical activity, dietary patterns, alcohol consumption and the resulting consequences, for example increases in body weight. Other risk factors for increases in BP and cardiovascular risk such as smoking, emotional/psychologic stress, changes in sleep patterns and diurnal rhythms may also exhibit significant changes in addition to novel factors such as air pollution and environmental noise. We also highlight potential preventive measures to improve BP control because hypertension is the leading preventable risk factor for worldwide health during and beyond the COVID-19 pandemic.

The pressioni arteriose monitorate e loro associazioni (PAMELA) research project: a 25-year long journey

INTRODUCTION

Among the observational studies performed in the area of blood pressure measurements in the population the Pressioni Arteriose Monitorate E Loro Associazioni (PAMELA) investigation represents an unique research for a number of reasons.

EVIDENCE ACQUISITION AND SYNTHESIS

The PAMELA study combines clinic, home and 24-hour blood pressure measurements in all partiicipants, which were representative of the general population. Examination included metabolic variables, allowing us to determine the interrelationships between bood pressure and metabolic profile. The protocol also included evaluation of organ damage, such as left ventricular hypertrophy, left ventricular diastolic dysfunction, left atrial dimensions and aortic root diameters. Finally, PAMELA represents one of the few studies with a prolonged follow-up, the last survey being completed three years ago and data collected are actually under analysis. This will allow to update the information related to cardiovascular morbidity and mortality in the study cohort.

CONCLUSIONS

The present paper will provide an overview of the various scientific contributions of the PAMELA study to the epidemiology, pathophysiology and clinical aspects of hypertension and hypertension related cardiovascular risk.

Coconut Oil Supplementation Does Not Affect Blood Pressure Variability and Oxidative Stress: A Placebo-Controlled Clinical Study in Stage-1 Hypertensive Patients

Exploring an alternative to improve the clinical management of hypertension, we tested the hypothesis that food supplementation with coconut oil (EVCO), alone or combined with aerobic exercise training, could exert an antihypertensive effect (primary outcome) in patients with stage 1 hypertension. Forty-five hypertensive volunteers of both genders participated in a placebo-controlled clinical trial. The volunteers were submitted to 24-hour ambulatory blood pressure monitoring, analysis of blood pressure variability (BPV), measurement of serum malondialdehyde (MDA) and nutritional assessment. Results indicate that EVCO consumption had no adverse effects. The supplementation did not increase the caloric intake compared with placebo, and the dietary constituents were similar between groups, except for the saturated fats, especially lauric acid. The analysis of blood pressure indicated absence of antihypertensive effect of EVCO alone or combined with physical training. Furthermore, no effects on blood pressure variability and oxidative stress were observed in the supplemented hypertensive patients. Thus, despite the results observed in pre-clinical studies, the current clinical study did not provide evidence to support the use of coconut oil as an adjuvant in the management of hypertension in humans.

Office blood pressure measurement: A comprehensive review

The conventional auscultatory methods for measuring blood pressure have been used to screen, diagnose, and manage hypertension since long. However, these have been found to be prone to errors especially the white coat phenomena which cause falsely high blood pressure readings. The Mercury sphygmomanometer and the Aneroid variety are no longer recommended by WHO for varying reasons. The Oscillometric devices are now recommended with preference for the Automated Office Blood Pressure measurement device which was found to have readings nearest to the Awake Ambulatory Blood Pressure readings. The downside for this device is the cost barrier. The alternative is to use the simple oscillometric device, which is much cheaper, with the rest and isolation criteria of the SPRINT study. This too may be difficult due to space constraints and the post‐clinic blood measurement is a new concept worth further exploration.

Current status of white coat hypertension: where are we?

White coat hypertension (WCH) is characterised by an elevated clinic blood pressure (BP) with normal ambulatory or home BP. It is well recognised in clinical practice and occurs in approximately one-third of untreated patients with elevated clinic BP. Current evidence suggests that WCH is associated with cardiovascular risk factors, including the development of sustained hypertension and the presence of target organ damage. However, its effects on cardiovascular outcomes remain a matter of debate. There is also insufficient evidence from randomised controlled trials to determine whether WCH warrants treatment. This narrative review aims to provide an update on the current understanding of WCH. It focuses on the clinical characteristics and potential implications of WCH, its relationship to cardiovascular risk and the evidence regarding treatment. Gaps in existing research are also highlighted.

[Mechanisms for the Development of Blood Pressure Variability and the Potential of Antihypertensive Drugs in Their Correction]

Blood pressure variability (BPV) is the fluctuations of blood pressure over a certain period of time under the influence of various factors. The issue of increased BPV is of particular clinical importance due to high predictive value of this parameter as a risk factor for fatal and non-fatal cardiovascular, cerebrovascular and renal events. It is proved that in the BPV increasing, the key role is played by impairments in arterial baroreflexes, which, in turn, are mediated by increased vascular stiffness, impact of angiotensin II and the sympathetic nervous system, endothelial dysfunction, nitric oxide deficiency and aging, including the vascular aging. Antihypertensive drugs that targeting largest amount of pathophysiological mechanisms in BPV increasing have a most advantages in correcting excessive pressure fluctuations. In this regard such drugs are perindopril and amlodipine, which can eliminate almost the entire spectrum of increased BPV causes and, therefore, optimally reduce the cardiovascular risk.

A case of an extreme white coat effect

In this report, we present a challenging case of a 63-year-old Caucasian woman with an extreme stress response to blood pressure (BP) measurements. Office- and ambulatory BP measurements consistently found systolic BP above 200 mmHg. However, antihypertensive medication made her dizzy and extremely unwell, and she could barely tolerate treatment with a moderate dose of angiotensin-converting enzyme (ACE) inhibitor. Finger-cuff-based measurements (Finapres Finometer®) revealed extreme hypertension in relation to contact with medical professionals, but hypotension when the patient was seated alone unobserved. Months after, the patient suffered a hemorrhagic stroke possibly related to her extreme BP-fluctuations in stressful situations.

Resistant Hypertension: Detection, Evaluation, and Management: A Scientific Statement From the American Heart Association

Resistant hypertension (RH) is defined as above-goal elevated blood pressure (BP) in a patient despite the concurrent use of 3 antihypertensive drug classes, commonly including a long-acting calcium channel blocker, a blocker of the renin-angiotensin system (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker), and a diuretic. The antihypertensive drugs should be administered at maximum or maximally tolerated daily doses. RH also includes patients whose BP achieves target values on ≥4 antihypertensive medications. The diagnosis of RH requires assurance of antihypertensive medication adherence and exclusion of the "white-coat effect" (office BP above goal but out-of-office BP at or below target). The importance of RH is underscored by the associated risk of adverse outcomes compared with non-RH. This article is an updated American Heart Association scientific statement on the detection, evaluation, and management of RH. Once antihypertensive medication adherence is confirmed and out-of-office BP recordings exclude a white-coat effect, evaluation includes identification of contributing lifestyle issues, detection of drugs interfering with antihypertensive medication effectiveness, screening for secondary hypertension, and assessment of target organ damage. Management of RH includes maximization of lifestyle interventions, use of long-acting thiazide-like diuretics (chlorthalidone or indapamide), addition of a mineralocorticoid receptor antagonist (spironolactone or eplerenone), and, if BP remains elevated, stepwise addition of antihypertensive drugs with complementary mechanisms of action to lower BP. If BP remains uncontrolled, referral to a hypertension specialist is advised.

Genome-wide association study of white-coat effect in hypertensive patients

Background: White-coat effect (WCE) confounds diagnosis and treatment of hypertension. The prevalence of white-coat hypertension is higher in Europe and Asia compared to other continents suggesting that genetic factors could play a role. Methods: To study genetic variation affecting WCE, we conducted a two-stage genome-wide association study involving 1343 Finnish subjects. For the discovery stage, we used Genetics of Drug Responsiveness in Essential Hypertension (GENRES) cohort (n = 206), providing the mean WCE values from up to four separate office/ambulatory recordings conducted on placebo. Associations with p values <1 × 10^-5 were included in the replication step in three independent cohorts: Haemodynamics in Primary and Secondary Hypertension (DYNAMIC) (n = 182), Finn-Home study (n = 773) and Dietary, Lifestyle and Genetic Determinants of Obesity and Metabolic Syndrome (DILGOM) (n = 182). Results: No single nucleotide polymorphisms reached genome-wide significance for association with either systolic or diastolic WCE. However, two loci provided suggestive evidence for association. A known coronary artery disease risk locus rs2292954 in SPG7 associated with systolic WCE (discovery p value = 2.2 × 10^-6, replication p value = 0.03 in Finn-Home, meta-analysis p value 2.6 × 10^-4), and rs10033652 in RASGEF1B with diastolic WCE (discovery p value = 4.9 × 10^-6, replication p value = 0.04 in DILGOM, meta-analysis p value = 5.0 × 10^-3). Conclusion: This study provides evidence for two novel candidate genes, SPG7 and RASGEF1B, associating with WCE. Our results need to be validated in even larger studies carried out in other populations.

Stabilization period before capturing an ultra-short vagal index can be shortened to 60 s in endurance athletes and to 90 s in university students

Purpose

To find the shortest, acceptable stabilization period before recording resting, supine ultra-short-term Ln RMSSD and heart rate (HR).

Method

Thirty endurance-trained male athletes (age 24.1 ± 2.3 years, maximal oxygen consumption (VO₂max) 64.1 ± 6.6 ml·kg^-1·min^-1) and 30 male students (age 23.3 ± 1.8 years, VO₂max 52.8 ± 5.1 ml·kg^-1·min^-1) were recruited. Upon awaking at home, resting, supine RR intervals were measured continuously for 10 min using a Polar V800 HR monitor. Ultra-short-term Ln RMSSD and HR values were calculated from 1-min RR interval segments after stabilization periods from 0 to 4 min in 0.5 min increments and were compared with reference values calculated from 5-min segment after 5-min stabilization. Systematic bias and intraclass correlation coefficients (ICC) including 90% confidence intervals (CI) were calculated and magnitude based inference was conducted.

Results

The stabilization periods of up to 30 s for athletes and up to 60 s for students showed positive (possibly to most likely) biases for ultra-short-term Ln RMSSD compared with reference values. Stabilization periods of 60 s for athletes and 90 s for students showed trivial biases and ICCs were 0.84; 90% CI 0.72 to 0.91, and 0.88; 0.79 to 0.94, respectively. For HR, biases were trivial and ICCs were 0.93; 0.88 to 0.96, and 0.93; 0.88 to 0.96, respectively.

Conclusion

The shortest stabilization period required to stabilize Ln RMSSD and HR was set at 60 s for endurance-trained athletes and 90 s for university students.

Twenty-four-hour ambulatory blood pressure monitoring in very elderly patients: Comparison of in-hospital versus home follow-up results

Elevated blood pressure (BP) is frequently diagnosed in very elderly hospitalized patients. Accurate diagnosis of hypertension is challenging in the hospital environment, due to the "white coat effect," and both overtreatment and undertreatment can adversely affect clinical outcome. Twenty-four-hour ambulatory blood pressure monitoring (ABPM) has the potential to avoid the "white coat effect" and accurately guide the management of hypertension. However, effects of the hospital environment on ABPM are unknown in the very elderly. We set out to enroll 45 patients, age ≥70 years, with elevated conventional BP during hospitalization in this observational study. It was prespecified by protocol to assess initially the difference between 24-hour BP during hospital-admission and home follow-up. Subsequent analysis should investigate the change in anxiety (Hospital Anxiety and Depression Scale-A [HADS-A]) after discharge, the correlation with change in 24-hour BP after discharge, and the prevalence of orthostatic hypertension. Thirty-one patients were included in the final analysis (age 83.5 ± 4.4 years; 71% female). Twenty-four-hour BP decreased significantly after hospital discharge (systolic from 133.5 ± 15.6 to 126.2 ± 14.4 mm Hg [millimeter of mercury], P = .008; diastolic from 71.0 ± 9.0 to 68.3 ± 8.6 mm Hg, P = .046). Anxiety level (HADS-A) decreased significantly after discharge, from 7.5 (interquartile range [IQR]: 4.0-13.8) to 5.0 (IQR: 4.0-8.0, P = .012). The change in anxiety was a predictor of change in systolic BP after discharge (F[1,20] = 5.9, P = .025). Sixty-one percent of the patients had significant orthostatic hypotension during hospital stay. In conclusion, 24-hour BP in very elderly patients is lower in the home environment than during hospitalization. This phenomenon seems to be directly linked to a lower anxiety-level at home. Reassessing hypertension at home may decrease the need for (intensified) antihypertensive medical therapy in a substantial number of patients. This is particularly important in the very elderly, who have a high prevalence of symptomatic and asymptomatic orthostatic hypotension, making them prone to hazardous effects of antihypertensive therapy.

The Cardiovascular Risk of White-Coat Hypertension

BACKGROUND

The role of white-coat hypertension (WCH) and the white-coat-effect (WCE) in development of cardiovascular disease (CVD) risk remains poorly understood.

OBJECTIVES

Using data from the population-based, 11-cohort IDACO (International Database on Ambulatory Blood Pressure Monitoring in Relation to Cardiovascular Outcomes), this study compared daytime ambulatory blood pressure monitoring with conventional blood pressure measurements in 653 untreated subjects with WCH and 653 normotensive control subjects.

METHODS

European Society Hypertension guidelines were used as a 5-stage risk score. Low risk was defined as 0 to 2 risk factors, and high risk was defined as ≥3 to 5 risk factors, diabetes, and/or history of prior CVD events. Age- and cohort-matching was done between 653 untreated subjects with WCH and 653 normotensive control subjects.

RESULTS

In a stepwise linear regression model, systolic WCE increased by 3.8 mm Hg (95% confidence interval [CI]: 3.1 to 4.6 mm Hg) per 10-year increase in age, and was similar in low- and high-risk subjects with or without prior CVD events. Over a median 10.6-year follow-up, incidence of new CVD events was higher in 159 high-risk subjects with WCH compared with 159 cohort- and age-matched high-risk normotensive subjects (adjusted hazard ratio [HR]: 2.06; 95% CI: 1.10 to 3.84; p = 0.023). The HR was not significant for 494 participants with low-risk WCH and age-matched low-risk normotensive subjects. Subgroup analysis by age showed that an association between WCH and incident CVD events is limited to older (age ≥60 years) high-risk WCH subjects; the adjusted HR was 2.19 (95% CI: 1.09 to 4.37; p = 0.027) in the older high-risk group and 0.88 (95% CI: 0.51 to 1.53; p = 0.66) in the older low-risk group (p for interaction = 0.044).

CONCLUSIONS

WCE size is related to aging, not to CVD risk. CVD risk in most persons with WCH is comparable to age- and risk-adjusted normotensive control subjects.

Clinic Versus Daytime Ambulatory Blood Pressure Difference in Hypertensive Patients

Clinic blood pressure (BP) is usually higher than daytime ambulatory BP in hypertensive patients, but some recent studies have challenged this view, suggesting that this relationship is strongly influenced by age. We used the Spanish ambulatory BP monitoring cohort to examine differences between clinic and daytime BP by age among 104 639 adult hypertensive patients (office systolic/diastolic BP ≥140/90 mm Hg or treated) in usual primary-care practice, across the wide age spectrum. To assess the impact of age, cardiovascular variables, and clinic BP on the clinic–daytime BP differences, we built multivariable regression models of the average BP differences, white-coat hypertension (high clinic BP and normal daytime BP), and masked hypertension (normal clinic BP and high daytime BP). In most patients, mean clinic BP values were higher than daytime BP at all ages. Some 36.7% of patients had white-coat hypertension (amounting to 50% at clinic systolic BP of 140–159 mm Hg) and 3.9% had masked hypertension (amounting to 18% at clinic systolic BP of 130–139 mm Hg). Age explained 0.1% to 1.7% of the variance of quantitative or categorical BP differences ( P <0.001). Cardiovascular variables explained an additional 1.6% to 3.4% of the variance ( P <0.001). Finally, clinic BP generally explained ≥20% more of the variance ( P <0.01). In this large study in usual clinical practice, clinic BP misclassified hypertension status in >40% of patients. This misclassification was not importantly influenced by age but was more evident in patients with borderline/grade 1 hypertension. These findings reinforce the importance of ambulatory BP monitoring for defining BP status in routine clinical practice.

Visit-to-Visit Variability and Reduction in Blood Pressure After a 3-Month Cardiac Rehabilitation Program in Patients With Cardiovascular Disease

Visit-to-visit variability (VVV) in blood pressure (BP) has been shown to be a predictor of cardiovascular events. It is unknown whether CR can improve VVV in BP as well as reducing BP. We enrolled 84 patients who had cardiovascular disease (CVD) and participated in a 3-month CR program. We measured systolic and diastolic BP (SBP and DBP), pulse pressure (PP), and heart rate (HR) before exercise training at each visit and determined VVV in BP or HR expressed as the standard deviation of the average BP or HR. Patients who had uncontrolled BP at baseline and who did not change their antihypertensive drugs throughout the study period showed a significant reduction of both SBP and DBP with a decrease in PP after 3 months. Patients who did not change their antihypertensive drugs were divided into larger (L-) and smaller (S-) VVV in the SBP groups and L- and S-VVV in the DBP groups according to the average value of VVV in SBP or DBP. In the L-VVV in the SBP and DBP groups, VVV in SBP and DBP in the 1st month was significantly decreased after the 3rd month in both groups. HR at baseline was significantly decreased after 3 months. In addition, CR induced a significant increase in the level of high-density lipoprotein cholesterol (HDL-C) in blood. In conclusion, CR improved VVV in BP in patients with L-VVV in BP and evoked a significant reduction in HR and an increase in HDL-C. These effects due to the CR program may be cardioprotective.

ABPM Induced Alarm Reaction: A Possible Cause of Overestimation of Daytime Blood Pressure Values Reduced By Treatment with Beta-Blockers

INTRODUCTION

Alarm reaction to clinical blood pressure (BP) measurement, defined white-coat effect (WCE), can cause overestimation of true BP values.

AIM

To assess whether ambulatory blood pressure monitoring (ABPM) can similarly affect BP values during the initial hours of recording.

METHODS

In 420 ABPMs selected for a first systolic BP (SBP) reading at least 10 mmHg higher than the mean daytime SBP, we calculated mean diurnal and 24 h SBP with and without the exclusion of the two first hours of recording defined as the WCE window (WCEw). We also calculated the magnitude and duration of WCE. These analyses were also performed separately in patients off anti-hypertensive treatment (n = 156), and on treatment with and without the inclusion of beta-blockers (respectively n = 113 and 151).

RESULTS

Exclusion of WCEw period reduced mean diurnal and 24 h SBP respectively from 135 ± 0.5 to 133 ± 0.5 (p < 0.01) and from 131 ± 0.5 to 130 ± 0.5 (p < 0.02). As a result the percentage of patients diagnosed as having diurnal or 24 h hypertension was reduced respectively from 48 to 40 % and from 52 to 47 %. The magnitude of WCEw was similar in both genders but the duration was longer in females (66 ± 2 vs. 56 ± 2 min, p < 0.01). Treatment with beta-blockers was associated with a shorter duration of WCE in both genders but this effect was statistically significant only in males.

CONCLUSIONS

In some patients ABPM is not free from WCE. WCE may affect the overall estimation of BP profile and is longer but less blunted by beta-blockers in females than in males.

The effect of two different renal denervation strategies on blood pressure in resistant hypertension: Comparison of full-length versus proximal renal artery ablation

BACKGROUND

Renal denervation (RDN) is used to manage blood pressure (BP) in patients with resistant hypertension (rHT), but effectiveness is still a concern, and key arterial portion for successful RDN is not clear.

OBJECTIVE

The aim of this study was to investigate the efficacy and safety of proximal versus full-length renal artery ablation in patients with resistant hypertension (rHT).

METHODS

Forty-seven patients with rHT were randomly assigned to receive full-length ablation (n = 23) or proximal ablation (n = 24) of the renal arteries. All lesions were treated with radiofrequency energy via a saline-irrigated catheter. Office BP was measured during 12 months of follow-up and ambulatory BP at baseline and 6 months (n = 15 in each group).

RESULTS

Compared with full-length ablation, proximal ablation reduced the number of ablation points in both the right (6.1 ± 0.7 vs. 3.3 ± 0.6, P < 0.001) and the left renal arteries (6.2 ± 0.7 vs. 3.3 ± 0.8, P < 0.001), with significantly shorter RF delivery time (P < 0.001), but higher RF power (P = 0.011). Baseline office BPs was 179.4 ± 13.7/102.8 ± 9.4 mm Hg in the full-length group and 181.9 ± 12.8/103.5 ± 8.9 mm Hg in the proximal group (P > 0.5). Similar office BPs was reduced by -39.4 ± 11.5/-20.9 ± 7.1 mm Hg at 6 months and -38.2 ± 10.3/-21.5 ± 5.8 mm Hg at 12 months in the full-length group (P < 0.001), -42.0 ± 11.6/-21.4 ± 7.9 mm Hg at 6 months and -40.9 ± 10.3/-22.1 ± 5.6 mm Hg at 12 months in the proximal group (P < 0.001), and progressive BP reductions were observed over the 6 months (P < 0.001) in both groups. The drop in ambulatory 24-hr SBP and DBP were significantly less than the drop in office BP (P < 0.001). No renovascular or other adverse complications were observed.

CONCLUSIONS

The results indicate that proximal RDN has a similar efficacy and safety profile compared with full-length RDN, and propose the proximal artery as the key portion for RDN. © 2016 Wiley Periodicals, Inc.

Target organ complications and prognostic significance of alerting reaction: analysis from the Dallas Heart Study

OBJECTIVE

Noninvasive blood pressure (BP) measurement often triggers a transient rise in BP, known as an alerting reaction. However, the prevalence and prognostic significance of the alerting reaction has never been assessed in the general population.

METHODS

We evaluated the association between the alerting reaction and left ventricular mass by MRI and urinary albumin-to-creatinine ratio in the Dallas Heart Study, a large population sample of 3069 individuals. Participants were categorized into four groups based on levels of consecutive BP: first, normal first BP and average third to fifth (avg3-5) BP of less than 140/90 mmHg (control group); second, high first BP of at least 140/90 mmHg and normal (avg3-5) BP (alerting reaction group); third, normal first BP and high (avg3-5) BP; and fourth, high first to fifth BP. Then, associations between BP categories with incident cardiovascular outcomes (coronary heart disease, stroke, atrial fibrillation, heart failure, and cardiovascular death) over a median follow-up period of 9.4 years were assessed.

RESULTS

The sample-weighted prevalence of isolated hypertension during the first BP measurement was 9.6%. Presence of an alerting reaction was independently associated with increased left ventricular mass, urinary albumin-to-creatinine ratio, cardiovascular events after adjustment for traditional cardiovascular risk factors, and baseline BP (adjusted hazard ratio 1.24, 95% confidence interval 1.07-1.43).

CONCLUSION

Our study indicated that the alerting reaction is independently associated with increased cardiovascular and renal complications.

Prevalence and determinants of white coat effect in a large UK hypertension clinic population

White coat hypertension (WCH) is common and termed white coat effect (WCE) in those on treatment for hypertension. The UK guideline suggests that all patients in stage 1 and 2 hypertension, but not stage 3 hypertension, should have ambulatory blood pressure monitoring (ABPM) performed before commencing treatment. The relationship between office blood pressure (BP) and ABPM and the factors that influence the WCE were examined in a large British cohort (n=2056) from 2 hypertension clinics (1998-2011). Data were collected prospectively: the median age was 56 years: 53% were female, 76% Caucasian, 9% African Caribbean, 15% South Asian and 86% taking antihypertensives. Fifty-one percent had WCE and differences between clinic BP and ABPM measurements increased with the stage of hypertension varying from 2/4 (normotensive), 13/10 (stage 1 hypertension), 24/14 (stage 2) and 40/20 mm Hg (stage 3). The degree of difference is greater in this study than described in other populations. A positive correlation was found between clinic systolic and diastolic BP and the WCE (r=0.74 and r=0.56, respectively, P<0.0001). Significant (P<0.05) independent associations of systolic WCE were clinic systolic BP (β=0.707), Caucasian ethnicity (South Asian β=-0.06; African Caribbean β=-0.043), female gender (male β=-0.047), nonsmoking status (smoker β=-0.100) and reduced renal function (estimated glomerular filtration rate β=-0.036). Significant independent associations of diastolic WCH were clinic diastolic BP (β=0.624), age (β=0.207), female gender (male β=-0.104), Caucasian ethnicity (South Asian β=-0.052, African Caribbean β=-0.079) and being a nonsmoker (β=-0.082) or ex-smoker (β=0.046). The results support current UK guidelines but suggest those with stage 3 hypertension would also benefit from ABPM.

White coat hypertension: improving the patient-health care practitioner relationship

White coat hypertension is characterized by the variability of a patient’s blood pressure measurements between the physician’s office and the patient’s home environment. A patient with white coat hypertension has high blood pressure levels in the physician’s office and normal blood pressure levels in their typical environment. This condition is likely caused by the patient’s anxiety within the physician’s office and in the presence of the physician. Research has shown that improving the relationship between a patient and their health care provider can decrease the patient’s anxiety, with the implication of decreasing the patient’s likelihood of demonstrating white coat hypertension. This review provides an overview of the previous literature regarding white coat hypertension, its prevalence, and the consequences for those who develop persistent hypertension. Furthermore, this review discusses the implications of improving patient and health care provider interactions through effective communication, empathy, and trust, as well as the implications for future research studies in improving the patient and health care provider’s relationship.

A polymorphism in the major gene regulating serum uric acid associates with clinic SBP and the white-coat effect in a family-based study

OBJECTIVES

Hyperuricemia associates with hypertension, but it is uncertain whether this relationship is causal in nature. Glucose transporter 9 (GLUT9) gene is a major genetic determinant of plasma uric acid levels in humans. Since polymorphisms are randomly distributed at mating (Mendelian randomization), studies based on GLUT9 polymorphisms may provide unconfounded assessment of the nature of the link between uric acid and hypertension.

METHODS

We tested the association between uric acid, the rs734553 polymorphism of the GLUT9 gene and arterial pressure in a family-based study including 449 individuals in a genetically homogenous population in Southern Italy.

RESULTS

Serum uric acid levels were strongly associated (P < 0.001) with all components of clinic and 24-h ambulatory blood pressures (BPs). However, only clinic SBP and the white-coat effect (the difference in clinic systolic and daytime systolic ambulatory blood pressure monitoring) associations remained significant after adjustment for classical risk factor and the estimated glomerular filtration rate. Serum uric acid was strongly associated with the risk allele (T) of the rs734553 polymorphism (P < 0.001). Furthermore, TT individuals showed higher clinic SBP (129 + SEM 1 mmHg) than GT (125 + 1 mmHg) and GG individuals (122 + 3 mmHg), as well as a higher white-coat effect (P = 0.02), confirming that the association between uric acid and these BP components is unconfounded by environmental risk factors.

CONCLUSION

Results in this family-based study are compatible with the hypothesis that uric acid is a causal risk factor for hypertension. Trials testing uric acid-lowering interventions are needed to definitively establish the causal implication of hyperuricemia in human hypertension. [Corrected]

Acute post-exercise change in blood pressure and exercise training response in patients with coronary artery disease

We tested the hypothesis that acute post-exercise change in blood pressure (BP) may predict exercise training responses in BP in patients with coronary artery disease (CAD). Patients with CAD (n = 116, age 62 ± 5 years, 85 men) underwent BP assessments at rest and during 10-min recovery following a symptom-limited exercise test before and after the 6-month training intervention (one strength and 3-4 aerobic moderate-intensity exercises weekly). Post-exercise change in systolic BP (SBP) was calculated by subtracting resting SBP from lowest post-exercise SBP. The training-induced change in resting SBP was -2 ± 13 mmHg (p = 0.064), ranging from -42 to 35 mmHg. Larger post-exercise decrease in SBP and baseline resting SBP predicted a larger training-induced decrement in SBP (β = 0.46 and β = -0.44, respectively, p < 0.001 for both). Acute post-exercise decrease in SBP provided additive value to baseline resting SBP in the prediction of training-induced change in resting SBP (R(2) from 0.20 to 0.26, p = 0.002). After further adjustments for other potential confounders (sex, age, baseline body mass index, realized training load), post-exercise decrease in SBP still predicted the training response in resting SBP (β = 0.26, p = 0.015). Acute post-exercise change in SBP was associated with training-induced change in resting SBP in patients with CAD, providing significant predictive information beyond baseline resting SBP.

Is the failure of SYMPLICITY HTN-3 trial to meet its efficacy endpoint the "end of the road" for renal denervation?

Resistant hypertension is a common medical problem that is increasing with the advent of an increasingly older and heavier population. The etiology of resistant hypertension is almost always multifactorial, but the results of numerous studies indicate that renal sympathetic activation is a particularly common cause of resistance to antihypertensive treatment. Consistent with the belief in a pivotal role of renal sympathetic stimulation, there has been a growing interest in renal denervation (RDN) treatment strategies. The long-awaited results of SYMPLICITY HTN-3 study disclosed that the reduction in blood pressure by the SYMPLICITY device did not differ from that in the sham-procedure arm of the study. In the present article, we identify several factors that explain why the study failed to demonstrate any benefit from the intervention. The reasons are multifactorial and include inadequate screening at entry and frequent medication changes during the study. Additional problems include the lack of experience of many operators with the SYMPLICITY device and procedure variability, as attested to by a diminished number of ablation "quadrants." Also a factor was the inability of the first generation Medtronic device to allow four ablations to be performed simultaneously. We recommend that future RDN studies adhere to more rigorous screening procedures, and utilize newer multi-site denervation systems that facilitate four ablations simultaneously. Drug optimization should be achieved by monitoring adherence throughout the study. Nevertheless, we are optimistic about a future role of RDN. To optimize chances of success, increased efforts are necessary to identify the appropriate patients for RDN and investigators must use second and third generation denervation devices and techniques.

Evidence of parasympathetic hyperactivity in functionally overreached athletes

PURPOSE

We analyzed HR variability (HRV) to detect alterations in autonomic function that may be associated with functional overreaching (F-OR) in endurance athletes.

METHODS

Twenty-one trained male triathletes were randomly assigned to either intensified training (n = 13) or normal training (n = 8) groups during 5 wk. HRV measures were taken daily during a 1-wk moderate training (baseline), a 3-wk overload training, and a 1-wk taper.

RESULTS

All the subjects of the intensified training group demonstrated a decrease in maximal incremental running test performance at the end of the overload period (-9.0% ± 2.1% of baseline value) followed by a performance supercompensation after the taper and were therefore diagnosed as F-OR. According to a qualitative statistical analysis method, a likely to very likely negative effect of F-OR on HR was observed at rest in supine and standing positions, using isolated seventh-day values and weekly average values, respectively. When considering the values obtained once per week, no clear effect of F-OR on HRV parameters was found. In contrast, the weekly mean of each HRV parameter showed a larger change in indices of parasympathetic tone in the F-OR group than the control group in supine position (with a 96%/4%/0% chance to demonstrate a positive/trivial/negative effect on Ln RMSSD after the overload period; 77%/22%/1% on LnHF) and standing position [98%/1%/1% on Ln RMSSD; 99%/0%/1% on LnHF; 95%/1%/4% on Ln(LF + HF)]. During the taper, theses responses were reversed.

CONCLUSIONS

Using daily HRV recordings averaged over each week, this study detected a progressive increase in the parasympathetic modulation of HR in endurance athletes led to F-OR. It also revealed that due to a wide day-to-day variability, isolated, once per week HRV recordings may not detect training-induced autonomic modulations in F-OR athletes.

Home and ambulatory blood pressure in resistant hypertension

Since their introduction in the clinical setting home and ambulatory blood pressure measurements have gained growing popularity in the diagnosis and treatment of essential hypertension for a number of reasons. These reasons include: 1) the lack of the so-called "white-coat effect", 2) the ability of the two approaches to provide information on blood pressure phenomena of prognostic value, and 3) the close relationship of the derived values with the risk of developing fatal and non-fatal cardiovascular events. These features also apply to resistant hypertension, in which these approaches allow a precise definition of the diagnosis of this clinical condition, by excluding the presence of white-coat hypertension. Assessment of "out-of-office" blood pressure also allows us to define the patterns of blood pressure variability in this clinical condition as well as its relationships with target organ damage. Finally, home as well as ambulatory blood pressure measurements allow us to investigate the effects of therapeutic interventions, including those associated with the radiofrequency ablation of renal nerves. The present paper will provide a critical review of the main features of home and ambulatory blood pressure measurement in resistant hypertension, highlighting their main advantages as compared to office blood pressure. The prognostic significance, relationships with target organ damage and implications for treatment will also be discussed.

Muscle and skin sympathetic nerve traffic during physician and nurse blood pressure measurement

OBJECTIVE

Previous studies have shown that blood pressure assessment by a nurse markedly attenuates the pressor and tachicardic responses triggered by the physician blood pressure measurement. Whether and to what extent this attenuation reflects a different pattern of the neuroadrenergic responses to doctor or nurse blood pressure evaluation is unknown.

METHODS

In 19 lean untreated mild essential hypertensive patients (age 39.1 ± 2.4 years, mean ± SEM), we measured beat-to-beat mean arterial pressure (Finapres), heart rate (ECG), and efferent postganglionic muscle and skin sympathetic nerve traffic [muscle sympathetic nerve activity (MSNA) and skin sympathetic nerve activity (SSNA), respectively, by microneurography], before, during, and following a 10-min sphygmomanometric BP measurement by a doctor or by a nurse unfamiliar to the patients. Measurements were repeated at a 30-min interval to obtain, in separate periods, muscle and skin sympathetic nerve traffic recordings. Both the sequences (doctor vs. nurse and muscle vs. skin sympathetic nerve traffic) were randomized.

RESULTS

A doctor visit induced sudden, marked, and prolonged blood pressure and heart rate increases, accompanied by a muscle sympathetic nerve traffic inhibition (average response: -18.1 ± 4.3%, P < 0.01) coupled with a skin sympathetic nerve traffic excitation (average response: +46.1 ± 5.5%, P < 0.01). In contrast, a nurse visit elicited blood pressure and heart rate responses markedly and significantly reduced (-72.1 ± 11 and -81.7 ± 13% respectively, P < 0.01) as compared with those seen during the doctor's visit. This was the case also for muscle and skin sympathetic neural responses (-44.3 ± 9 and -65.6 ± 13%, P < 0.01).

CONCLUSION

These data provide the first evidence that the blunted pressor and tachicardic responses to nurse's blood pressure measurements are accompanied by an attenuation of the adrenergic neural responses seen during the alerting reaction accompanying doctor's blood pressure measurement.

Visit-to-visit and ambulatory blood pressure variability as predictors of incident cardiovascular events in patients with hypertension

BACKGROUND

Visit-to-visit blood pressure variability (BPV) has been shown to be a prognostic indicator in hypertensive patients. We designed this study to clarify the impacts of clinic and ambulatory BPV in predicting cardiovascular disease (CVD).

METHODS

We performed ambulatory BP monitoring (ABPM) in 457 hypertensive patients. Visit-to-visit BPV and ambulatory BPV were calculated as the SDs of clinic BP, awake BP, and sleep BP. The mean age of the subjects was 67.0 ± 9.2 years, and they were followed for 67 ± 26 months. Stroke, myocardial infarction, and sudden cardiac death were defined as Hard CVD events, and these plus angina, heart failure, and other CVDs were defined as All CVD events. Multivariable Cox hazard regression models predicting CVD events were used to estimate the adjusted hazard ratio (HR) and 95% confidence interval (CI) for different measures of BPV with adjustment for significant covariates.

RESULTS

In multivariable analyses, the BPV of clinic systolic BP (SBP) was an independent predictor for All CVD events (HR, 2.20; 95% CI, 1.25-3.88; P < 0.01), but not for Hard CVD events (P = 0.20). On the other hand, the BPV of sleep SBP was an independent predictor for Hard CVD events (HR, 2.21; 95% CI, 1.08-4.53; P = 0.03), but not for All CVD events (P = 0.88). Diastolic BPV exhibited the same pattern.

CONCLUSIONS

These findings suggest that visit-to-visit BPV and ambulatory BPV are separately useful in predicting cardiovascular outcomes.

Should ambulatory blood pressure monitoring be mandatory for future studies in resistant hypertension: a perspective

Recent technologic advances rekindled interventional management of resistant hypertension, either by carotid baroreceptor activation or renal sympathetic denervation. Interventional techniques result in impressive falls in office blood pressure (BP); however, ambulatory BP reductions are rather modest. This disparity between office and ambulatory BP reductions is observed with antihypertensive drugs, but at a much lower degree. Available explanations are not convincing, therefore, we propose that sympathetic overactivity may partially explain this divergence. Further studies are needed to prove or disprove our hypothesis.

Origin of heart rate variability and turbulence: an appraisal of autonomic modulation of cardiovascular function

Heart period constantly changes on a beat to beat basis, due to autonomic influences on the sinoatrial node, and changes can be quantified as heart rate variability (HRV). In addition, after a premature ventricular beat, there are reproducible variations in RR interval, also due to baroreflex mediated autonomic influences on the sinoatrial node, that can be measured as heart rate turbulence (HRT). Impaired autonomic function as measured by HRV and HRT has proven to predict adverse outcomes in clinical settings. The ability of reduced HRV and HRT to predict adverse outcomes has been explained by their dependency on vagal mechanisms that could reflect an increased sympathetic and a reduced vagal modulation of sinus node, thus favoring cardiac electrical instability. Analysis of non-linear dynamics of HRV has also been utilized to describe the fractal like characteristic of the variability signal and proven effective in identify patients at risk for sudden cardiac death. Despite the clinical validity of these measures, it has also been evident that the relationship between neural input and sinus node responsiveness is extremely complex and variable in different clinical conditions. Thus, abnormal HRV or HRT on a clinical Holter recordings may reflect non-neural as well as autonomic mechanisms, and this also needs to be taken into account when interpreting any findings. However, under controlled conditions, the computation of the low and high frequency components of HRV and of their normalized powers or ratio seems capable of providing valid information on sympatho-vagal balance in normal subjects, as well as in most patients with a preserved left ventricular function. Thus, analysis of HRV does provide a unique tool to specifically assess autonomic control mechanisms in association with various perturbations. In conclusion, HRV measures are of substantial utility to identify patients with an increased cardiac mortality and to evaluate autonomic control mechanisms, but their ability to capture specific levels of autonomic control may be limited to controlled laboratory studies in relatively healthy subjects.

Heart Rate Dynamics after Exercise in Cardiac Patients with and without Type 2 Diabetes

Purpose: The incidence of cardiovascular events is higher in coronary artery disease patients with type 2 diabetes (CAD + T2D) than in CAD patients without T2D. There is increasing evidence that the recovery phase after exercise is a vulnerable phase for various cardiovascular events. We hypothesized that autonomic regulation differs in CAD patients with and without T2D during post-exercise condition. Methods: A symptom-limited maximal exercise test on a bicycle ergometer was performed for 68 CAD + T2D patients (age 61 ± 5 years, 78% males, ejection fraction (EF) 67 ± 8, 100% on β-blockade), and 64 CAD patients (age 62 ± 5 years, 80% males, EF 64 ± 8, 100% on β-blockade). Heart rate (HR) recovery after exercise was calculated as the slope of HR during the first 60 s after cessation of exercise (HRR_slope). R–R intervals were measured before (5 min) and after exercise from 3 to 8 min, both in a supine position. R–R intervals were analyzed using time and frequency methods and a detrended fluctuation method (α₁). Results: BMI was 30 ± 4 vs. 27 ± 3 kg m² (p < 0.001); maximal exercise capacity, 6.5 ± 1.7 vs. 7.7 ± 1.9 METs (p < 0.001); maximal HR, 128 ± 19 vs. 132 ± 18 bpm (p = ns); and HRR_slope, −0.53 ± 0.17 vs. −0.62 ± 0.15 beats/s (p = 0.004), for CAD patients with and without T2D, respectively. There was no differences between the groups in HRR_slope after adjustment for METs, BMI, and medication (ANCOVA, p = 0.228 for T2D and, e.g., p = 0.030 for METs). CAD + T2D patients had a higher HR at rest than non-diabetic patients (57 ± 10 vs. 54 ± 6 bpm, p = 0.030), but no other differences were observed in HR dynamics at rest or in post-exercise condition. Conclusion: HR recovery is delayed in CAD + T2D patients, suggesting impairment of vagal activity and/or augmented sympathetic activity after exercise. Blunted HR recovery after exercise in diabetic patients compared with non-diabetic patients is more closely related to low exercise capacity and obesity than to T2D itself.

Diagnosis and management of patients with white-coat and masked hypertension

White-coat hypertension is characterized by an elevation in clinic blood pressure but normal home or ambulatory blood-pressure values, whereas patients with masked hypertension have normal clinic blood pressure and elevated ambulatory or home blood-pressure load. Both white-coat and masked hypertension are frequent clinical entities that need appropriate recognition and a close diagnostic follow-up. White-coat and masked hypertension seem to be associated with organ damage and increased cardiovascular risk, although not invariably. In addition, patients with masked or white-coat hypertension have an increased risk of abnormalities affecting their glucose and lipid profiles. Therefore, the diagnosis of these conditions should be accurate and include the assessment of cardiovascular as well as of metabolic risk. Once diagnosed, first-line therapeutic interventions should be nonpharmacological and aim at lifestyle changes, but drug treatment can be indicated, particularly when the patient's cardiovascular risk profile is elevated or when target-organ damage is detected.

Evening heart rate measured at home is associated with visceral obesity and abnormal fat distribution in patients with hypertension

BACKGROUND

Our aim was to examine the association between heart rate (HR) and visceral obesity and abnormal fat distribution in patients undergoing treatment for hypertension. We also ascertained whether such associations differ depending on the time of day when HR is measured and the venue at which the measurement is carried out (office or home).

METHODS

The study enrolled a total of 390 patients (mean age 63.9 years; 45% men) receiving treatment with antihypertensive drugs other than β blockers or nondihydropyridine Ca-channel blockers. Office blood pressure (BP) and HR as well as home BP and HR, both morning and evening, were measured in all these patients for 14 days. The amount of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were determined using abdominal computed tomography (CT).

RESULTS

Evening HR was positively associated with VAT (r = 0.26) and negatively associated with SAT (r = -0.16); as a consequence, evening HR was closely associated with the VAT/SAT ratio (r = 0.30; all P < 0.01). In contrast, neither office nor morning HR was associated with VAT. The significant association between evening HR and VAT remained unchanged even after adjustment for significant covariates including SAT (P = 0.001). A multiple logistic regression analysis revealed that a 1-s.d. increase (10 beats per minute) in evening HR was significantly associated with visceral obesity (defined as VAT ≥100 cm)(2) (odds ratio (95% confidence interval: 1.7 (1.3-2.3)), P < 0.001), and that this association was independent of body mass index (BMI) and abdominal obesity (waist circumference ≥85 cm for men and ≥90 cm for women).

CONCLUSIONS

In these patients receiving treatment for hypertension, high evening HR was associated with visceral obesity, independent of the presence of subcutaneous fat and BMI. This novel finding could explain why cardiovascular risk is higher in individuals with high HR.