[Effet blouse blanche résiduel : un outil pertinent en soins premiers?]

BACKGROUND

White coat effect (WCE) and white coat hypertension (WCH) are hardly both compared in primary care.

OBJECTIVE

To assess the usefulness of repeated measures of systolic blood pressure (SBP) to dissociate various forms of white-coat interactions.

METHODS

An open cross-sectional study on consecutive patients treated or not for high blood pressure was made in family physicians' offices. SBP was measured 5 times by an electronic device. Measurements were performed before (SBP1) and after (SBP5) the office visit by a lay assistant and at the beginning (SBP2), middle (SBP3) and end (SBP4) of visit, by the family physician. Home BP (HBPM) was measured from 3 consecutive days by the patient. WCE and office WCE tail (OWCET) were defined, respectively, as a 10 mmHg SBP increase or decrease between SBP2-SBP1 or SBP4-SBP2. WCH was considered when HBPM was normal (SBP < 135 mmHg) at home and high during the SBP2 office visit.

RESULTS

Two hundred five patients (134 women versus 71 men, ratio 1.9, aged 59.8±15.7 years) were recruited. In categorical terms, there were 51 patients (25%) who presented with WCE, OWCET was seen in 121 patients (62%) and 47 patients (23%) had WCH. Only 36 patients (18%) presented both OWCET and WCE and 32 (16%) had both OWCET and WCH. The receiver operating characteristic curves (ROCs) of OWCET in diagnosing WCE or WCH were respectively 0.67 (p<0.0001) and 0.53 (NS).

CONCLUSION

Thus, OWCET was predictive of WCE and not of WCH and it is worthwhile to be measured in the family physician office.

Exaggerated blood pressure response to standing in young-to-middle-age subjects: prevalence and factors involved

PURPOSE

To investigate the prevalence of orthostatic hypertension and the association of the blood pressure (BP) level, supine BP decline, and white-coat effect with the orthostatic pressor response.

METHODS

We studied 1275 young-to-middle-age individuals with stage-1 hypertension. Orthostatic response was assessed three times over a 3 month period. The white-coat effect was assessed at baseline and after 3 months, and was calculated as the difference between office and average 24 h BP. In 660 participants, urinary epinephrine and norepinephrine were also measured.

RESULTS

An orthostatic systolic BP increase ≥ 20 mmHg was observed in 0.6-1.2% of the subjects during the three visits. Using the 20 mmHg cut-off, the prevalence of orthostatic hypertension was 0.6%. An orthostatic BP increase of ≥ 5 mmHg was found in 14.4% of participants. At baseline, the orthostatic response to standing showed an independent negative association with the supine BP level (p < 0.001), the supine BP change from the first to third measurement (p < 0.001), and the white-coat effect (p < 0.001). Similar results were obtained in the 1080 participants assessed at the third visit. Urinary epinephrine showed higher values in the top BP response decile (systolic BP increase ≥ 6 mmHg, p = 0.002 versus rest of the group).

CONCLUSION

An orthostatic systolic BP reaction ≥ 20 mmHg is rare in young adults. However, even lower BP increases may be clinically relevant. The BP level, the supine BP decline over repeated measurement, and the white-coat effect can influence the estimate of the BP response to standing and should be considered in clinical and pathogenetic studies.

Role of home blood pressure monitoring in resistant hypertension

The definition of resistant hypertension (RHT) has been updated to include failure to achieve target blood pressure (BP) despite treatment with ≥3 antihypertensive drugs, including diuretics, renin-angiotensin system blockers, and calcium channel blockers, prescribed at the maximum or maximally tolerated doses, or as success in achieving the target blood pressure but requiring ≥4 drugs. RHT is a major clinical problem, as it is associated with higher mortality and morbidity than non-RHT. Therefore, it is crucial to accurately identify RHT patients to effectively manage their disease. Out-of-clinic BP measurement, including home BP monitoring and ambulatory BP monitoring is gaining prominence for the diagnosis and management of RHT. Home BP monitoring is advantageous as it is feasibly repetitive, inexpensive, widely available, and because of its reproducibility over long periods. In addition, home BP monitoring has crucial advantage of allowing safe titration for the maximum or maximally tolerable dose, and for self-monitoring, thereby improving clinical inertia and nonadherence, and allowing true RHT to be more accurately identified.

Comparison of Brachial Blood Pressure and Central Blood Pressure in Attended, Unattended, and Unattended Standing Situations

Central systolic blood pressure (cSBP) is an independent predictor of future cardiovascular disease. Unattended brachial SBP (bSBP) can eliminate the white-coat effect. However, unattended cSBP and unattended standing cSBP have never been reported. We aimed to compare bSBP and cSBP in attended, unattended, and unattended standing situations. We also aimed to compare the white-coat effect and unattended orthostatic BP change between bSBP and cSBP. Altogether, 104 hypertensive outpatients were included (mean age: 66.0 ± 9.8 years, 41.3% male, mean body mass index: 25.0 ± 4.5). Attended bSBP/cSBP values were 127.3 ± 15.7/119.2 ± 15.0, unattended bSBP/cSBP values were 122.7 ± 15.3/114.4 ± 15.1, and unattended standing bSBP/cSBP values were 123.6 ± 15.7/114.1 ± 14.8 mmHg (correlation coefficients/coefficients of determination between bSBP and cSBP: 0.971/0.943, 0.970/0.941, and 0.964/0.929, respectively; all p < 0.001). No significant difference was observed in the white-coat effect between bSBP and cSBP (4.6 ± 5.8 vs. 4.8 ± 5.7 mmHg). Although there was no significant difference between unattended sitting SBP and unattended standing SBP in terms of both bSBP and cSBP, a numerically small but significant difference was observed in the unattended orthostatic BP change between bSBP and cSBP (0.9 ± 8.0 vs. -0.3 ± 9.0 mmHg, p = 0.002). In conclusion, significant and strong correlations were observed between bSBP and cSBP in attended, unattended, and unattended standing BP measurements. The white-coat effect on bSBP was equivalent to that on cSBP. There was a numerically small but significant difference in the unattended orthostatic BP change between bSBP and cSBP.

The Impact of Measurement Methods on Office Blood Pressure and Management of Hypertension in General Practice

INTRODUCTION

The use of unattended automated office blood pressure (uAutoOBP) versus attended automated (aAutoOBP) and manual auscultatory office blood pressure (AuscOBP) measurements is a topic of current controversy.

AIM

To evaluate the differences between OBP measurements methods in the general practice (GP) setting.

METHODS

We first compared aAutoOBP and uAutoOBP in 42 consecutive patients with hypertension (group 1). Secondly, we compared AuscOBP to uAutoOBP measurements in 133 consecutive patients with hypertension (group 2). In addition, we analyzed the achieved OBP targets as recommended in the 2018 European Society of Cardiology (ESC) and the European Society of Hypertension (ESH) guidelines in group 2.

RESULTS

The mean age of patients in group 1 was 71 years (range 34-89 years, 54.8% females). The aAutoOBP and uAutoOBP systolic (131.7 and 131.6 mmHg) and diastolic (83.4 and 82.4 mmHg) mean values were not significantly different. The patient characteristics in group 2 were similar to group 1. We observed a significant difference between AuscOBP and uAutoOBP measurement for both systolic (149.4 versus 129.5 mm Hg) and diastolic (85.4 versus 81.6 mm Hg, p < 0.0001, respectively). Accordingly, 20.3% and 45.9% of patients reached the overall 2018 ESC/ESH systolic and diastolic OBP targets of < 140/80 mmHg according to AuscOBP and uAutoOBP (p < 0.0001).

CONCLUSION

The attended versus unattended status of automated OBP measurements had no impact on OBP values in GP. However, significantly higher OBP values and lower rates of achieved target OBP were observed by using AuscOBP measurements by physicians in comparison to automated OBP recordings.

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.

Defining the hemodynamic response of hypertensive and normotensive subjects through serial timed blood pressure readings in the clinic

Background

Every third patient in the clinic is misdiagnosed due to white-coat phenomenon, necessitating needless and costly treatment. We aimed to study the hemodynamic response of the physician’s visit on hypertensive and normotensive patients by investigating the trend of blood pressure (BP) before, during and 15 min after the physician-patient encounter.

Methods

A descriptive, cross-sectional study was conducted over a period of 8 months in the cardiology clinics at the Aga Khan University Hospital, Karachi. Both hypertensive and normotensive patients, aged ≥18 years, were recruited. Pregnant females or those with a history of volume loss were excluded. BP readings were taken using an automated, validated device (Omron-HEM7221-E) at three points: pre-clinic BP by the assessment nurse, in-clinic BP by the attending physician and post-clinic BP 15-min after the physician-patient encounter by a research assistant. Independent samples t-test was used to calculate the statistical difference between hypertensive and normotensive BP values.

Results

Of 180 participants, 71% (n = 128) were hypertensive and 57% (n = 103) of all were males. The mean age of the participants was 57 ± 15 years. The mean and standard deviation(±SD) systolic BP (SBP) taken pre-clinic, in-clinic and 15-min post-clinic for hypertensive population was 128.7 ± 20 mmHg, 137.1 ± 21 mmHg and 127.9 ± 19 mmHg. The mean and standard deviation(±SD) SBP taken pre-clinic, in-clinic and 15 min post-clinic for normotensive population was 112 ± 16 mmHg, 115.8 ± 20 mmHg and 111.8 ± 15 mmHg. The hypertensive SBP values showed statistically significant difference from the normotensive values (difference in pre-clinic SBP: 16.7 mmHg, p-value < 0.001; in-clinic SBP: 21.3 mmHg, p-value < 0.001; and 15 min post-clinic: 16.1 mmHg, p-value < 0.001).

Conclusions

Hypertensive and normotensive patients display congruent hemodynamics upon visiting the physician, the alert response being accentuated amongst the hypertensive group. In-clinic BP readings are higher for both hypertensive and normotensive patients making them unreliable for screening and management of hypertension amongst both the groups.

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

Purpose

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

Methods

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

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

Results

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

Conclusion

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

Trial registration

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

The Post Clinic Ambulatory Blood Pressure (PC-ABP) study correlates Post Clinic Blood Pressure (PCBP) with the gold standard Ambulatory Blood Pressure

Objective

Our previous study showed that post-clinic blood pressure (BP) taken 15 min after a physician–patient encounter was the lowest reading in a routine clinic. We aimed to validate this reading with 24 h Ambulatory Blood Pressure Monitoring (ABPM) readings. A cross-sectional study was conducted in the cardiology clinics at the Aga Khan University, Pakistan. Hypertensive patients aged ≥ 18 years, or those referred for the diagnosis of hypertension were included.

Results

Of 150 participants, 49% were males. 76% of all participants were hypertensive. Pre-clinic BP reading was measured by a nurse, in-clinic by a physician and 15 min post-clinic by a research assistant using a validated, automated BP device (Omron-HEM7221-E). All patients were referred for 24 h ABPM. Among the three readings taken during a clinic visit, mean (± SD) systolic BP (SBP) pre-clinic, in-clinic, and 15 min post-clinic were 153.2 ± 23, 152.3 ± 21, and 140.0 ± 18 mmHg, respectively. Mean (± SD) diastolic BP (DBP) taken pre-clinic, in-clinic and 15 min post-clinic were 83.5 ± 12, 90.9 ± 12, and 86.4 ± 11 mmHg respectively. Mean (± SD) daytime ambulatory SBP, DBP and pulse readings were 134.7 ± 15, 78.7 ± 15 mmHg, and 72.6 ± 12/min, respectively. Pearson correlation coefficients of pre-clinic, in-clinic and post-clinic SBP with daytime ambulatory-SBP were 0.4 (p value: < 0.001), 0.5 (p value: < 0.001) and 0.6 (p value: < 0.001), respectively. Post-clinic BP has a good correlation with ambulatory BP and may be considered a more reliable reading in the clinic setting.

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.

[Prevalence of true resistant hypertension among uncontrolled hypertensive patients referred to a tertiary health care center]

OBJECTIVES

Estimate the prevalence of resistant hypertension (rHTN) in uncontrolled hypertensive treated patients referred to a tertiary care center specialized for hypertension management.

METHODS

The study was prospective observational. Between January 2013 and April 2015, we recruited hypertensive treated patients, 18years age or older, under antihypertensive drugs since at least 12months, and referred to the hypertension unit of Tizi-ouzou university hospital for uncontrolled hypertension. rHTn was defined as an office blood pressure≥140mmHg despite a triple therapy including renin angiotensin system blockers, calcium antagonists and diuretics at optimal doses, since at least 4weeks.

RESULTS

We screened 2367 patients with a mean age of 61.1±11.2years and 64.2% of men. Eight hundred forty-three (35.6%) patients had suboptimal treatment, 364 (15.4%) a poor adherence to treatment and 202 (8.5%) a white-coat effect. An excessive salt intake and a drug-related hypertension were identified in 281 (11.9%) and 36 (1.5%) patients, respectively. A secondary cause of hypertension was diagnosed in 468 (19.8%) subjects. Finally, only 173 patients showed a true rHTN requiring four drugs or more and its prevalence was 7.3% (CI 95%: 6.3-8.3).

CONCLUSION

Less than one patient from ten referred in our center for uncontrolled hypertension had a true rHTN, and more than fifty percent of patients had pseudo-resistance. Most of patients with seemingly rHTN can reach blood pressure target provided they undergo thorough work up and care by a specialized team.