24-hour Ambulatory Blood Pressure Measurements Research Articles

#2249 Morning blood pressure and heart rate surge in peritoneal dialysis patients

Abstract Background and Aims The increased surge of blood pressure (BP) early in the morning and the parallel increase of heart rate (HR) are risk factors for cardiovascular disease in general and CKD populations. Early morning changes in these parameters have not been investigated in peritoneal dialysis (PD) patients. The aim of the study is to correlate the morning fluctuations of BP and HR with left ventricular hypertrophy and cardiovascular risk. Method This was a cross-sectional study of PD patients followed-up in our Peritoneal Dialysis Unit (PDU). At their regular visit to our PDU, a 24-hour ambulatory BP measurement (Mobil-o-graph®) was performed. A diary was given to the patients in order to record the time they performed their evening exchange (continuous ambulatory peritoneal dialysis- CAPD) or connection to the automated peritoneal dialysis (APD) machine, the time they laid down, the time they approximately fell asleep, when they woke up in the morning, when they inclined from the bed and the time they performed the morning exchange or disconnection. The 24-hour BP recordings were analyzed in the available software and calculations were done based on the diary information; pre-awakening BP, HR surges, nocturnal dipping, weighted 24 h systolic BP and HR variability. Demographic, laboratory data and left heart hypertrophy parameters of the patients were also recorded. 35 patients were eligible for participation in the study; 2 denied participation, 1 was rejected due to ongoing cancer therapy and two patients were declined due to invalid BP measurements. Finally 30 patients (10 males and 20 females) were analyzed, 9 were on CAPD and 21 were on APD. Results The mean age of the patients was 60.5 ± 12.6 years old and the median PD vintage was 21.5 months (8.25-58) (Table 1). Left Ventricular Mass index (LVMi) was 99.01 ± 28 g/m2 (Table 1). The 24h systolic BP was 125.66 ± 10.9 mmHg and the diastolic BP was 79.59 ± 7.7 mmHg (Table 2). The mean pre-awaking Systolic BP surge was 10.76 ± 9.7 mmHg, the median non-dipping blood pressure 8.6 (IQR 1.11-12.86), the mean heart rate surge was 3.3 ± 4.7 /min and the mean non-dipping HR was 9.7 ± 5.9/min (Table 2). There was no statistically significant correlation of the parameters above with the LVMi. Patients with high cardiovascular risk (diabetes, coronary heart disease, heart failure) had statistically higher non-dipping BP (27 vs 12.3 mmHg, p = 0.034) and higher nighttime SPB (27 vs 20.74 mmHg, p = 0.024). When compared patients in CAPD vs APD, there were no differences in the pre-awaking BP or the rest of the measurements performed, although APD patients recorded interrupted sleep due to the alarms of the APD machine. Conclusion PD patients with high cardiovascular risk had higher nondipping BP and nighttime systolic BP compared with patients without cardiovascular disease. There were no correlations of BP and heart rate morning surge with left ventricular hypertrophy or PD mode.

A DIRECT COMPARISON OF TWO OBJECTIVE METHODS FOR DETECTION OF NON-ADHERENCE IN PATIENTS WITH UNCONTROLLED HYPERTENSION

Objective: Uncontrolled hypertension remains a major health challenge leading to premature death and cardiovascular morbidity. We have previously reported a prevalence of non–adherence to antihypertensive drugs from 8-30% of patients studied by either directly observed therapy (DOT) or serum drug concentrations (S- conc.) of antihypertensive medication. We aimed to investigate the prevalence of non–adherence in patients with uncontrolled hypertension consecutively referred to our outpatient clinic and to compare results from DOT and s-conc. in the same patient. Design and method: Nine, of planned 20 patients referred to 24-hour ambulatory blood pressure measurement (ABPM) were included in these preliminary results. Inclusion criteria was uncontrolled blood pressure (office SBP >140 mmHg) despite the use of three antihypertensive drugs. ABPM were measured at baseline and repeated after 3-4 weeks, the second time following DOT. S-conc. of antihypertensive drugs were measured by ultra-high-performance-liquid-chromatography tandem mass spectrometry at baseline and 24 hours after DOT. Patients with s-conc. of at least one drug below a predefined reference level were considered to be non–adherent. At the final visit patients evaluated how they experienced the DOT and s-conc. measurements by a visual analogue scale (VAS score) from 0 –10. Results: Of nine patients (age 36-79), five adherent (54,5%) and four (45,5%) non-adherent were detected by s-conc. Baseline mean for Ambulatory systolic blood pressure (ASBP) at visit one was 138±19 mmHg and mean ASBP after DOT 134±14 mmHg (p = 0,33). ASBP fell by 12±9 mmHg after DOT in the non-adherent group compared to a rise by 2±10 mmHg in the adherent group (p=0,079). Five patients completed the VAS evaluation, none of them experienced DOT or measuring s-conc. unpleasant. Conclusions: The difference in ASBP after DOT in the two groups showed a clear trend. Preliminary data in patients with uncontrolled hypertension show that both DOT and measurement of serum concentrations of antihypertensive drugs are reliable methods for detecting non–adherence and are well accepted by the patients. These methods may be used complementary in the outpatient clinic.

Office or home versus 24-hour blood pressure measurement in stable kidney transplant recipients.

The aim of this study was to quantify hypertension control and evaluate concordance between all commonly available blood pressure modalities in kidney transplant recipients (KTR). For this prospective cross-sectional study 89 stable KTR were recruited at the Charité Transplant Outpatient Clinic. For each study participant office (manual office blood pressure 'MOBP' and automated office blood pressure 'AOBP'), 7-day home (HBPM) and 24-hour ambulatory blood pressure measurement (24h-ABPM) were performed. 80 of the 89 patients recruited had sufficient blood pressure recordings. Mean blood pressure for MOBP, AOBP, HBPM and 24h-ABPM was 129/73, 126/71, 131/85 and 130/81mmHg, respectively. Uncontrolled hypertension, as defined by 24h-ABPM (mean≥130/80mmHg), was present in 53 (66%) patients. MOBP, AOBP and HBPM classified 19 (24%), 22 (28%) and 41 (51%) patients respectively as 'uncontrolled hypertensive'. The Bland-Altman plot showed good agreement between systolic MOBP, AOBP, HBPM and Daytime-ABPM (mean bias±SD: -1±13mmHg, -4±13mmHg, 1±10mmHg, respectively). Uncontrolled nighttime hypertension was present in 74 (93%) KTR, with 71 (89%) patients showing a non-physiological dipping pattern. Moderate positive correlation between Daytime-ABPM/HBPM and Nighttime-ABPM (Pearson Correlation Coefficients: 0.62-0.73), followed by MOBP/AOBP (Pearson Correlation Coefficients: 0.49-0.59) was noted. eGFR and proteinuria displayed weak correlation with 24h-, Daytime- and Nighttime-ABPM (absolute values of Pearson Correlation Coefficients: 0.04-0.41). No robust association with either 24h-, Daytime- or Nighttime-ABPM was observed for volume status exams. Masked hypertension is highly prevalent in KTR, especially due to high rates of uncontrolled nighttime hypertension. HBPM shows the narrowest limits of agreement with Daytime-ABPM. Daytime-ABPM and HBPM show the highest, albeit clinically insufficient, correlation with Nighttime-ABPM. Systematic integration of 24h-ABPM into clinical practice, as proposed by the '2023 ESH Guidelines for the Management of arterial hypertension', should not be withheld for the KTR population. Clinical trials evaluating treatment of hypertension in KTR are urgently needed.

Blood pressure measurements for diagnosing hypertension in primary care: room for improvement

BackgroundIn the adult population, about 50% have hypertension, a risk factor for cardiovascular disease and subsequent premature death. Little is known about the quality of the methods used to diagnose hypertension in primary care.ObjectivesThe objective was to assess the frequency of use of recognized methods to establish a diagnosis of hypertension, and specifically for OBPM, whether three distinct measurements were taken, and how correctly the blood pressure levels were interpreted.MethodsA retrospective population-based cohort study using electronic medical records of patients aged between 40 and 70 years, who visited their general practitioner (GP) with a new-onset of hypertension in the years 2012, 2016, 2019, and 2020. A visual chart review of the electronic medical records was used to assess the methods employed to diagnose hypertension in a random sample of 500 patients. The blood pressure measurement method was considered complete if three or more valid office blood pressure measurements (OBPM) were performed, or home-based blood pressure measurements (HBPM), the office- based 30-minute method (OBP30), or 24-hour ambulatory blood pressure measurements (24 H-ABPM) were used.ResultsIn all study years, OBPM was the most frequently used method to diagnose new-onset hypertension in patients. The OBP-30 method was used in 0.4% (2012), 4.2% (2016), 10.6% (2019), and 9.8% (2020) of patients respectively, 24 H-ABPM in 16.0%, 22.2%, 17.2%, and 19.0% of patients and HBPM measurements in 5.4%, 8.4%, 7.6%, and 7.8% of patients, respectively. A diagnosis of hypertension based on only one or two office measurements occurred in 85.2% (2012), 87.9% (2016), 94.4% (2019), and 96.8% (2020) of all patients with OBPM. In cases of incomplete measurement and incorrect interpretation, medication was still started in 64% of cases in 2012, 56% (2016), 60% (2019), and 73% (2020).ConclusionOBPM is still the most often used method to diagnose hypertension in primary care. The diagnosis was often incomplete or misinterpreted using incorrect cut-off levels. A small improvement occurred between 2012 and 2016 but no further progress was seen in 2019 or 2020. If hypertension is inappropriately diagnosed, it may result in under treatment or in prolonged, unnecessary treatment of patients. There is room for improvement in the general practice setting.

Blood Pressure Regulation and Hypertension in Obstructive Sleep Apnea Syndrome: A Historical Perspective.

In obstructive sleep apnea syndrome (OSAS), an underlying disease of secondary hypertension, repeated episodes of asphyxia due to obstructive sleep apnea (OSA), followed by arousal, lead to various cardiovascular consequences. Using a canine model of OSAS, it was found that a single load of OSA caused an abrupt increase in blood pressure (BP) (Apnea Surge in seconds), while multiple OSA episodes occurring nightly for 1-3 months led to a sustained elevation of BP during both nighttime and daytime. Epidemiological studies on 24-hour ambulatory BP measurements revealed that some hypertensive patients experienced elevated BP in the early morning (Morning Surge), which could be intensified by OSAS. The resonance of Apnea Surge in seconds and Morning Surge increases the risk of organ damage, triggers the cardiovascular events, and adversely affects the prognosis of hypertensive patients with OSAS.For ameliorating these risks, OSA should be treated with positive airway pressure properly.

Pulse Wave Analysis in Obese Children with and without Metabolic Syndrome

To compare pulse wave analysis (PWA) of obese children with and without metabolic syndrome (MS) with healthy, non-obese children and to evaluate the association between PWA findings and additional risk factors present in children with MS and obesity. From the obese patients examined between June 2019 and June 2021, 41 patients with MS, 36 obese patients without MS, and 34 healthy non-obese children of similar age and gender were evaluated retrospectively. Anthropometric measurements, biochemical evaluation, 24-hour ambulatory blood pressure (BP) measurement (ABPM), left ventricular mass index (LVMI) and PWA measurements were compared. When the three groups were compared, weight standard deviation score (SDS), height SDS and body mass index SDS were all significantly higher in the MS group (p<0.05). The following measurements were significantly higher in both MS and non-MS obese patients compared to the control group: from ABPM measures, the systolic and mean arterial pressure BP SDSs load; from PWA, the night central systolic BP, 24-hour, day and night pulse pressure values and 24-hour, day and night pulse wave velocity (PWV) rates; and from cardiac evaluations, the LVMI and relative wall thickness measurements (all p<0.05). Furthermore, the 24-hour and daytime central systolic (cSBP) and diastolic BP (cDBP) values were significantly different between the three groups, being the highest in the MS group (p<0.05). Obesity causes higher office, ambulatory and central BP, PWV and LVMI. However our results suggest that additional risk factors associated with MS do not contribute to these parameters, except for 24-hour and daytime cSBP and cDBP values.

Twenty-Four-Month Blood Pressure Results After Renal Denervation Using Endovascular Ultrasound.

BACKGROUND Renal denervation has proven its efficacy to lower blood pressure in comparison to sham treatment in recent randomized clinical trials. Although there is a large body of evidence for the durability and safety of radiofrequency-based renal denervation, there are a paucity of data for endovascular ultrasound-based renal denervation (uRDN). We aimed to assess the long-term efficacy and safety of uRDN in a single-center cohort of patients. METHODS AND RESULTS Data from 2 previous studies on uRDN were pooled. Ambulatory 24-hour blood pressure measurements were taken before as well as 3, 6, 12, and 24 months after treatment with uRDN. A total of 130 patients (mean age 63±9 years, 24% women) underwent uRDN. After 3, 6, 12, and 24 months, systolic mean 24-hour ambulatory blood pressure values were reduced by 10±12, 10±14, 8±15, and 10±15 mm Hg, respectively, when compared with baseline (P<0.001). Corresponding diastolic values were reduced by 6±8, 6±8, 5±9, and 6±9 mm Hg, respectively (P<0.001). Periprocedural adverse events occurred in 16 patients, and all recovered without sequelae. CONCLUSIONS In this single-center study, uRDN effectively lowered blood pressure up to 24 months after treatment.

The platelet-to-lymphocyte ratio as an indirect outcome predictor in primary hypertension: a retrospective study.

Nondipper hypertensive patients have higher levels of platelet-to-lymphocyte ratio, a new studied inflammatory biomarker in primary hypertension. Furthermore, these patients have a higher risk of cardiovascular morbidity and mortality. This study aimed to assess the relationship between platelet-to-lymphocyte ratio and hypertensive pattern (dipper vs nondipper) and the association between the hypertensive pattern and major adverse cardiovascular events. A retrospective analysis was performed. One hundred fifty-three patients were included and classified as dipper or nondipper according to 24-hour ambulatory blood pressure measurements. Platelet-to-lymphocyte ratio was calculated based on complete blood count data. The dipper group included 109 patients, and the nondipper group included 44 patients. Nondipper patients have 2.11 more risk of presenting a higher platelet-to-lymphocyte ratio than dipper individuals (odds ratio [OR] = 2.11; 95% CI, 1.220-3.664; P = .007). Nondipper patients also registered earlier cardiovascular events, such as acute myocardial infarction and stroke (P < .001). Nondipper hypertensive individuals registered higher levels of platelet-to-lymphocyte ratio and earlier cardiovascular events than dipper patients. Therefore, platelet-to-lymphocyte ratio could be used as an indirect predictor of cardiovascular risk in primary hypertension and contribute to optimize preventive strategies.

Safety and efficacy of renal sympathetic denervation: a 9-year long-term follow-up of 24-hour ambulatory blood pressure measurements.

Renal sympathetic denervation (RDN) has been shown to lower arterial blood pressure both in the presence and in the absence of antihypertensive medication in an observation period of up to 3 years. However, long-term results beyond 3 years are scarcely reported. We performed a long-term follow-up on patients who were previously enrolled in a local renal denervation registry and who underwent radiofrequency RDN with the Symplicity Flex® renal denervation system between 2011 and 2014. The patients were assessed to evaluate their renal function by performing 24-hour ambulatory blood pressure measurement (ABPM), recording their medical history, and conducting laboratory tests. Ambulatory blood pressure readings for 24 h were available for 72 patients at long-term follow-up (FU) [9.3 years (IQR: 8.5-10.1)]. We found a significant reduction of ABP from 150.1/86.1 ± 16.9/12.0 mmHg at baseline to 138.3/77.1 ± 16.5/11.1 mmHg at long-term FU (P < 0.001 for both systolic and diastolic ABP). The number of antihypertensive medications used by the patients significantly decreased from 5.4 ± 1.5 at baseline to 4.8 ± 1.6 at long-term FU (P < 0.01). Renal function showed a significant but expected age-associated decrease in the eGFR from 87.8 (IQR: 81.0-100.0) to 72.5 (IQR: 55.8-86.8) ml/min/1.73 m2 (P < 0.01) in patients with an initial eGFR > 60 ml/min/1.73 m2, while a non-significant decrease was observed in patients with an initial eGFR < 60 ml/min/1.73 m2 at long-term FU [56.0 (IQR: 40.9-58.4) vs. 39.0 (IQR: 13.5-56.3) ml/min/1.73 m2]. RDN was accompanied by a long-lasting reduction in blood pressure with a concomitant reduction in antihypertensive medication. No negative effects could be detected, especially with regard to renal function.

#6157 PREDICTORS OF 24 PULSE WAVE VELIOCITY IN HYPERTENSIVE CHRONIC KIDNEY DISEASE PATIENTS: A CASE CONTROL STUDY

Abstract Background and Aims Pulse wave velocity (PWV) is a significant predictor of chronic kidney disease (CKD) progression and death in people with impaired kidney function. It is known that patients with type 2 diabetes mellitus have higher values of PWV. Our study assessed the difference in arterial stiffness parameters (value of peripheral and central blood pressure parameters and PWV) according diabetic status and to evaluate predictors of PWV in hypertensive CKD patients. Method This case control, cross-sectional study included 252 hypertensive CKD patients 143 (56.7%) men and 109 (43.3%) women, aged 67 years (IQR = 15). For each participant data about sex, age, height, presence of CKD, AH and other comorbidities were collected. Laboratory parameters (urea, creatinine, estimated glomerular filtration rate (eGFR), glycated hemoglobin (HbA1c)) were obtained from peripheral blood and 24-hour urine samples were collected to analyze albuminuria. Each participant underwent 24-hour ambulatory blood pressure measurement using the IEM Mobil-O-Graph based on the oscillometry. Tanita MC780 Multi Frequency segmental body composition analyzer was used to measure body weight and level of visceral fat. Body mass index (BMI) was calculated. Results Out of 252 participants with AH and CKD, 107 (42.5%) also had DM. Participants with DM were older (p&amp;lt;0001), had higher pulse pressure (p&amp;lt;0.001) and PWV (p&amp;lt;0.001) while the levels of peripheral and central diastolic pressure (p&amp;lt;0.001) were lower. Regarding body composition parameters, DM participants had higher BMI (p = 0.001) and visceral fat level (p&amp;lt;0.001). Positive predictors of PWV adjusted for age, sex, presence of DM and eGFR were HbA1c (β = 0.216, p = 0.007), albuminuria (β = 0.000, p = 0.002), central and peripheral systolic and diastolic blood pressure (β = 0.035, p&amp;lt;0.001; β = 0.035, p&amp;lt;0.001; β = 0.033, p&amp;lt;0.001; β = 0.035, p&amp;lt;0.001), pulse pressure (β = 0.047, p&amp;lt;0.001) and mean arterial pressure (β = 0.042, p&amp;lt;0.001). Body composition parameters were not found to be significant predictors of PWV. Conclusion We found significant differences in 24-hour blood pressure parameters and body composition in relation to the presence of DM. One possible explanation for the lower peripheral and central diastolic blood pressure in diabetic participants is the older age of these participants. Accordingly, PWV as a parameter of arterial stiffness, which is higher in DM participants, could also be due to the age difference. As for the predictors of PWV, the expected predictors were parameters of blood pressure. HbA1c and albuminuria were also associated with PWV as parameter of arterial stiffness in CKD participants with AH.

THE IMPACT OF OBESITY ON THE CONTROL OF TREATED HYPERTENSIVE PATIENTS

Objective: Obesity is as a risk factor for hypertension, but there are few studies evaluating its impact on the response to antihypertensive drug and on the control of hypertensive patients. The aim of our study was to determine the effect of obesity on the control of treated hypertension. Design and method: We analyzed recordings of ambulatory blood pressure measurement (ABPM) in 84 treated hypertensive patients aged &gt; 18 years, in the cardiology department of Mohamed Taher Maamouri University hospital in Nabeul. Patients were stratified into two groups: obese (Body Mass Index (BMI) &gt;30 kg/m2) and non-obese. Hypertension control is defined by 24-hour ambulatory blood pressure (BP) = &lt; 130/80 mmHg, daytime = &lt; 135/85 mmHg and nighttime = &lt; 120/70 mmHg. The comparisons of percentages were carried out by the Chi-square test. Results: Our Population was composed of 33 obese and 51 non-obese patients. The mean age of our population was 59.37±13.1 years. BMI in obese was significantly higher than in non-obese (34.47±5.4 versus 25.36±2.5; p&lt;0.001). The prevalence of uncontrolled patients was significantly higher in obese patients detected in 24-hour ABPM (75.8% versus 51%; p = 0.039), in daytime ABPM (69.7% versus 41.2%; p = 0.014) and in night-time ABPM (90.9% versus 68.6%; p = 0.018) than in normal weight patients. Conclusions: Prevalence of uncontrolled hypertension was higher with higher BMI values. The level of blood pressure control in our sample remains relatively insufficient. To achieve a better control of hypertension, we must insist on therapeutic compliance and on the correction of risk factors, particularly obesity, which is significantly associated with an increase in BP.

PRESCRIPTION OF SINGLE-PILL ANTIHYPERTENSIVE COMBINATION THERAPY

Objective: The need for polytherapy is common among people affected by arterial hypertension (AH). A single-pill combination is a response to decreased medication adherence, especially in elderly people often suffering from more than one disease, which tends to improve blood pressure control and cardiovascular outcomes. The aim of our study was to determine the frequency of use of a single-pill antihypertensive combination (SPC) therapy and possible differences in presence of comorbidities. Design and method: 324 hypertensive participants on pharmacological treatment were included in this research, of which 51.2% were men, and with an overall median age of 64 years (IQR = 17). For each participant undergoing 24-hour ambulatory blood pressure measurement, data about pharmacological therapy, weight, height and comorbidities such as chronic kidney disease (CKD) and diabetes mellitus (DM) were obtained from their most recent medical records combined with self reports. Body mass index (BMI) was calculated. Results: 148 (45.7%) participants were prescribed a SPC. Participants taking a SPC had lower presence of CKD (23.7% with CKD vs. 76.3% without CKD, p&lt;0.001). No significant difference was found in the presence of DM (p = 0.496). Another interesting finding was more frequent use of SPC therapy among patients with higher BMI (p = 0.029). Conclusions: The results show that less than half of the participants in our study were prescribed an SPC. From this we can conclude that more attention should be paid to educating people about the options for antihypertensive treatment and simplifying therapy regimen. Another point we should highlight is the limited availability of SPCs in the treatment of hypertension in patients suffering from CKD.

MEDICATION ADHERENCE AND GENDER DIFFERENCE IN HYPERTENSIVE PATIENTS

Objective: One of the major clinical problems in the management of arterial hypertension (AH) is adherence to the medical regimen. Failure to adhere affects not only patients causing disease progression, reduced functional abilities as well as lower quality of life, but also the healthcare system due to medication waste and increased hospital visits and admissions. Data about hypertensive medication adherence in our region are lacking. Therefore, we aimed to assess medication adherence in our hypertensive patients in order to identify possible strategies to improve and enhance mentioned adherence. Design and method: This study included 324 participants with AH, of which 51.2 % were men, and with an overall median age of 64 years (IQR = 17). Along with the 24-hour ambulatory blood pressure measurement, each patient completed a medication adherence questionnaire, Morisky Medication Adherence Scale (MMAS-8). This self-reported questionnaire consists of 8 questions with a total score ranging from 0 to 8 and a lower score indicates lower adherence to the prescribed pharmacological antihypertensive therapy. Results: 51 (15.7%) participants had low, 114 (35.2%) had moderate and 159 (49.1%) had high medication adherence. There was no significant difference in MMAS-8 score regarding age (p = 0.334), however, men were found to have -higher adherence to antihypertensive therapy than women (58.5% vs. 41.5% had high adherence, respectively, p = 0.018). Conclusions: The results of our study showed that more than half of our hypertensive patients (50.9%) are not completely adherent to antihypertensive medication. Among all of them women were found to have lower adherence compared to men. Low medication adherence could lead to substantial worsening of disease as well as increased health care costs in care of hypertensive patients. Therefore, the presented results highlight the need for patient education and support to increase patient adherence in order to reduce cardiovascular risk.

RESULTS OF SIMULTANEOUS LEFT AND RIGHT UPPER ARM 24-HOUR AMBULATORY BLOOD PRESSURE MEASUREMENT: A WAKE UP-CALL FOR BETTER HYPERTENSION MANAGEMENT

Objective: Cuff-based 24-hour ambulatory blood pressure (BP) measurement is considered as the gold standard for hypertension diagnosis and treatment monitoring, its clinical value being ubiquitously accepted. This study wants to quantify the measurement discrepancies in simultaneous and synchronized 24-hour ambulatory BP measurements on both arms. Identifying and understanding measurement uncertainties could improve future hypertension management and further stimulate research on alternative, cuff-less systems with adequate measurement precision. Methods: We conducted simultaneous 24-hour ambulatory BP measurements on both arms in 52 healthy young adults. Broadly used and validated cuff-devices (BoSo TM-2430) were synchronized to start BP measurement within one second of each other. Further, we recorded cuff-pressures of both cuff-based devices and the hydrostatic pressure differences between both cuffs throughout the recording. We then scored pressure curves for disturbances (e.g., pressure spikes during deflation) and were able to correct measurements for hydrostatic differences between the arms. This enabled us to not only quantify the extent of measurement inaccuracy but to describe its origins and possible countermeasures. Design and method: Measured BP levels from left and right arm showed limits of agreement in the Bland Altman Plot of &gt; 33 mmHg for systolic and &gt; 30 mmHg for diastolic values over 24 h. Daytime values deviated more than nocturnal values (systolic: &gt; 35 mmHg vs. &gt; 27 mmHg systolic, and diastolic: &gt; 32 mmHg vs. &gt; 24 mmHg, respectively). Linear regression retrieved R2 = 0.39 (p &lt; 0.001) for systolic and R2 = 0.20 (p &lt; 0.001) for diastolic values. Exclusion of artefactual cuff pressure curves improved limits of agreement to &gt; 23 mmHg for systolic and &gt; 19mmHg for diastolic measurements. Subsequently, it improved correlation coefficients to R2 = 0.54 (p &lt; 0.001) for systolic and R2 = 0.35 (p &lt; 0.001) for diastolic values. Correction of hydrostatic differences between the arms had a negligible effect on limits of agreement and strength of correlation. Results: Comparison of synchronized 24-hour BP measurements obtained on both arms showed large measurement uncertainties with possible implications on clinical grading of hypertension and dipping pattern. Exclusion of artefactual cuff pressure curves, not detected by the conventional software of BP devices, mitigates the effect but cannot eliminate worrying discrepancies. These results strongly support the need to further investigate the clinical implications of BP measurement uncertainty. They should further stimulate research on alternative means of BP measurement which might overcome some of the problems related to cuff-based BP monitoring.

RELATION BETWEEN WAIST CIRCUMFERENCE AND THE RENAL HEMODYNAMIC IN PATIENTS WITH UNCOMPLICATED HYPERTENSION GRADE 1-2

Objective: Abdominal adiposity, measured by waist circumference (WC), is associated with increased mortality in patients with hypertension. Little is known about the impact of abdominal obesity on the renal perfusion and function in patients with hypertension. We analyzed whether abdominal adiposity changes renal hemodynamics in 36 patients with uncomplicated hypertension grade 1-2 without other cardiovascular (CV) disease. Design and method: We analysed the renal hemodynamic using steady state input clearance with infusion of para-aminohippuric acid and inulin, respectively. Intraglomerular pressure and resistances of the afferent (RA) and efferent (RE) arterioles were calculated according to the Gomez equation. The study population was divided in into two groups based on median of WC of the total study population. Results: The study cohort consisted of 36 male, non-smoking individuals, aged 36 ± 10 years with mean WC of 96.1 ± 10.4 cm and mean BMI of 27 ± 3.8 kg/m2. True hypertension was confirmed using 24-hour ambulatory blood pressure (BP) measurement. Patients in the high WC group (19 patients) showed mean office BP of 145/ 90 mmHg and mean 24-hour ambulatory BP of 139/ 86 mmHg, whereas patients in the low WC group (17 patients) showed mean office BP of 144/ 88 mmHg and mean 24-hour-ambulatory BP of 140/ 86 mmHg (office BP: p = 0.895/ p = 0.662, 24-hour-ambulatory BP: p = 0.645/ p = 0.918). Renal vascular resistance and RA were higher in the high WC compared to the low WC group, whereas glomerular filtration rate and renal plasma flow were lower in the high WC compared to the low WC group (table 1). Conclusions: Higher WC in young, male patients with hypertension grade 1-2 without other cardiovascular disease was associated with increased renal vascular resistance predominantly at the afferent site leading to reduced glomerular filtration rate.

Office blood pressure versus ambulatory blood pressure measurement in childhood obesity

BackgroundThe prevalence of obesity-related co-morbidities is rising parallel to the childhood obesity epidemic. High blood pressure (BP), as one of these co-morbidities, is detected nowadays at increasingly younger ages. The diagnosis of elevated BP and hypertension, especially in the childhood population, presents a challenge to clinicians. The added value of ambulatory blood pressure measurement (ABPM) in relation to office blood pressure (OBP) measurements in obese children is unclear. Furthermore, it is unknown how many overweight and obese children have an abnormal ABPM pattern. In this study we evaluated ABPM patterns in a population of overweight and obese children and adolescents, and compared these patterns with regular OBP measurements.MethodsIn this cross-sectional study in overweight or obese children and adolescents aged 4–17 years who were referred to secondary pediatric obesity care in a large general hospital in The Netherlands, OBP was measured during a regular outpatient clinic visit. Additionally, all participants underwent a 24-hour ABPM on a regular week-day. Outcome measures were OBP, mean ambulatory SBP and DBP, BP load (percentage of readings above the ambulatory 95th blood pressure percentiles), ambulatory BP pattern (normal BP, white-coat hypertension, elevated BP, masked hypertension, ambulatory hypertension), and BP dipping.ResultsWe included 82 children aged 4–17 years. They had a mean BMI Z-score of 3.3 (standard deviation 0.6). Using ABPM, 54.9% of the children were normotensive (95% confidence interval 44.1–65.2), 26.8% had elevated BP, 9.8% ambulatory hypertension, 3.7% masked hypertension, and 4.9% white-coat hypertension. An isolated night-time BP load > 25% was detected in almost a quarter of the children. 40% of the participants lacked physiologic nocturnal systolic BP dipping. In the group of children with normal OBP, 22.2% turned out to have either elevated BP or masked hypertension on ABPM.ConclusionsIn this study a high prevalence of abnormal ABPM patterns in overweight or obese children and adolescents was detected. Additionally, OBP poorly correlated with the child’s actual ABPM pattern. Herewith, we emphasized the usefulness of ABPM as an important diagnostic tool in this population.

How Does Occupational Lifting Affect Ambulatory Blood Pressure, Relative Aerobic Workload and Level of Physical Activity?

Occupational physical activity (OPA), including occupational lifting (OL), seems to increase the risk of cardiovascular disease (CVD). Knowledge about the association between OL and risk of CVD is sparse, but repeated OL is assumed to result in prolonged raised blood pressure and heart rate (HR) eventually augmenting the risk of CVD. To disentangle parts of the mechanisms behind the raised 24-hour ambulatory blood pressure measurement (24h-ABPM), by exposure to OL, this study aimed to explore the acute differences in 24h-ABPM, relative aerobic workload (RAW) and OPA across workdays with and without OL, and secondary to assess the feasibility and rater agreement of direct field observations of the frequency and load of occupational lifting. This controlled cross-over study investigates associations between moderate to high OL and 24h-ABPM, RAW in per cent of heart rate reserve (%HRR) and level of OPA. This included 2x24h monitoring of 24h-ABPM (Spacelabs 90217), PA (Axivity) and HR (Actiheart), comprising a workday containing OL and a workday without. The frequency and burden of OL were directly observed in field. The data were time synchronized and processed in the Acti4 software. Differences across workdays with and without OL in 24h-ABPM, RAW and OPA were evaluated using repeated 2 × 2 mixed-models among 60 blue-collar workers in Denmark.. Exposure to OL was estimated by direct manual field observation, registering burden and frequency of OL. Interrater reliability tests were performed across 15 participants representing 7 occupational groups. Interclass correlation coefficient (ICC) estimates of total burden lifted and frequency of lifts were calculated, based on a mean-rating (k = 2), absolute-agreement, 2 way mixed-effects model, indicating the raters as fixed effects. OL led to non-significant increases in ABPM during work-time (systolic Δ1.79 mmHg, 95%CI -4.49-8.08, diastolic Δ0.43 mmHg, 95%CI -0.80-1.65), and on 24-hours basis (systolic Δ1.96 mmHg, 95%CI -3.80-7.72, diastolic Δ0.53 mmHg, 95%CI -3.12-4.18), significant increases in RAW during work (Δ7.74 %HRR, 95%CI 3.57-11.91) as well as a raised level of OPA (Δ4156.88 steps, 95%CI 1898.83-6414.93, Δ-0.67 hours of sitting time, 95%CI -1.25-0.10, Δ-0.52 hours of standing time, 95%CI -1.03-0.01, Δ0.48 hours of walking time, 95%CI 0.18-0.78). ICC estimates were 0.998 (95% CI 0.995-0.999) for total burden lifted and 0.992 (95% CI 0.975-0.997) for frequency of lift. OL increased both intensity and volume of OPA among blue-collar workers, which supposedly to contributes to an augmented risk of CVD. Although this study finds hazardous acute effects, further investigations are needed to evaluate the long-term effects of OL on ABPM, HR and volume of OPA, also effects of cumulative exposure to OL would be relevant to investigate. OL significantly raised the intensity and volume of OPA. Direct field observation of occupational lifting showed an excellent interrater reliability.

PS-C11-6: SIMULTANEOUS MEASUREMENT OF 24-HOUR AMBULATORY BLOOD PRESSURE IN BOTH ARMS REVEALS CLINICALLY RELEVANT DIFFERENCES: A WAKEUP-CALL FOR HYPERTENSION MANAGEMENT

Objective: Cuff-based 24-hour ambulatory blood pressure measurement is the gold standard for hypertension diagnosis and treatment monitoring. The clinical value of ambulatory blood pressure (BP) measurement is ubiquitously accepted. This study wants to quantify the measurement discrepancies in simultaneous and synchronized 24-hour ambulatory BP measurements on both arms. Identifying and understanding measurement uncertainties could improve future hypertension management and originate true confidence in alternative, cuff-less systems with equal measurement precision. Methods: We conducted simultaneous 24-hour ambulatory blood pressure measurements on both arms in 52 healthy young adults. The broadly used and validated cuff-devices (BoSo TM-2430) were synchronized to start BP measurement within one second of each other. Further, we recorded, cuff-pressures of both cuff-based devices and the hydrostatic pressure differences between both cuffs. We then scored pressure curves for disturbances (e.g., pressure spikes during deflation) and were able to correct measurements for hydrostatic differences between the arms. This enabled us to not only quantify the extent of measurement uncertainty but to describe its origins and possible countermeasures. Results: Measured BP levels from left and right arm showed limits of agreement in the Bland Altman Plot of &gt; 33 mmHg for systolic and &gt; 30 mmHg for diastolic values over 24 h. Daytime values deviated more than nocturnal values (systolic: &gt; 35 mmHg vs. &gt; 27 mmHg systolic, and diastolic: &gt; 32 mmHg vs. &gt; 24 mmHg). Linear regression retrieved R2 = 0.39 (p &lt; 0.001) for systolic and R2 = 0.20 (p &lt; 0.001) for diastolic values. Exclusion of disturbed cuff pressure curves improved limits of agreement to &gt; 23 mmHg for systolic and &gt; 19mmHg for diastolic measurements. Subsequently, it improved correlation coefficients to R2 = 0.54 (p &lt; 0.001) for systolic and R2 = 0.35 (p &lt; 0.001) for diastolic values. Correction of hydrostatic differences between the arms had an negligible effect on limits of agreement and strength of correlation. Conclusion: Comparison of synchronized 24-hour BP measurements on both arms showed large measurement uncertainties with possible implications on clinical grading of hypertension and dipping pattern. Exclusion of disturbed cuff pressure curves, not detected by the conventional software of BP devices, mitigates the effect but still results in worrying discrepancies. These results are an imperative to further investigate the clinical implications of BP measurement uncertainty. It further inspires the courageous exploration of alternative means of BP measurement which might offer comparable measurement certainty.

S-52-5: MEASURING DRUG LEVELS USING A DRIED BLOOD SPOT COMBINED WITH PERSONALIZED FEEDBACK TO IMPROVE RESISTANT HYPERTENSION: A RANDOMIZED CONTROLLED TRIAL

Introduction: Identification of non-adherence to antihypertensive drugs is crucial to improve resistant hypertension (RH). For this therapeutic drug monitoring is the most reliable method. Objectives: The primary objective of this study is to determine whether drug levels measured with a dried blood spot (DBS) method combined with personalized feedback leads to a decrease in prevalence of RH after 12 months due to an increase in adherence. Design and method: This is a multi-center single-blinded randomized controlled trial (RHYME-RCT, NL6736). Eligible patients based on previous blood pressure readings underwent DBS sampling and a 24-hour ambulatory blood pressure measurement (ABPM) simultaneously. Patients with a daytime systolic blood pressure (SBP) &gt; 135 and/or diastolic blood pressure (DBP) &gt; 85 mmHg were randomized to a standard treatment (control) arm or intervention arm. The intervention was performed by the treating physician and included information on drug levels and a personalized feedback conversation based on a feedback tool. The follow-up period was one year and included visits at 3, 6 and 12 (T = 12) months inclusion. At each visit an 24h-ABPM and DBS were performed. Results: A total of 141 patients were measured at baseline, of which 100 patients had blood pressures &gt; 135/85 mmHg and were randomized to the intervention (n = 49) or control arm (n = 51). The adherence rate in the excluded population (n = 41) was 78.0%. The randomized patients had a mean age of 59.4 ± 11 years and were predominantly male (70.0%). The prevalence of RH decreased from 100% in both arms to 73.2% at T = 12 in the intervention arm (p = 0.002, n = 37) and 59.1% at T = 12 in the control arm (p &lt; 0.001, n = 41). Adherence rates improved from 67.3% to 92.1% in the intervention arm (p = 0.021) and 68.6% to 71.4% in the control arm (p = 1.000). This increase in adherence was significantly higher in the intervention arm compared to the control arm (p = 0.018). No statistically significant difference was found after 12 months between the two arms in the degree of RH (p = 0.171), SBP (p = 0.297) or DBP (p = 0.655). Conclusions: Measuring blood pressure and drug levels led to a decrease in the prevalence of RH in both arms and improved non-adherence in the intervention arm. However, the improvements in adherence did not lead to a lower blood pressure and degree of having RH. The fact that one third was excluded at baseline because of normotension suggests that participation in a study already leads to improvement of adherence and thus blood pressure control.

PS-C35-4: ASSOCIATION OF SODIUM INTAKE WITH ADVERSE LEFT ATRIAL FUNCTION AND LEFT ATRIOVENTRICULAR COUPLING

Objective: In this study, we investigated the relationship between 24-hour urinary sodium (a surrogate for estimating dietary sodium intake), ambulatory blood pressure parameters, cardiac MRI-assessed left atrial function and left atrioventricular coupling, as well as the influence of nighttime blood pressure and body mass index(BMI) on 24-hour urinary sodium and subclinical cardiac function. Design and method: Participants in our study included 398 individuals, all of whom were subjected to 24-hour urine collection, 24-hour ambulatory blood pressure measurement, and cardiac magnetic resonance imaging to determine left atrial function (myocardial strain) as well as left atrioventricular coupling index. LACI is defined as the ratio of left atrial end-diastolic volume divided by left ventricular end-diastolic volume. Our study evaluated the relationship between 24-hour urinary sodium and ambulatory blood pressure parameters, left atrial function, and left atrioventricular coupling index, and used mediation analysis to explain the indirect effects of nighttime blood pressure and BMI between 24-hour urinary sodium and left atrial function and left atrioventricular coupling index. Results: It was found that the average age of the participants was 55.70 ± 11.30 years old, with 58% of the participants being male and 47.5% experiencing hypertension. The mean urinary sodium value was 172.01 ± 80.24mmol/24 hours, and the average body mass index was 25.46 ± 3.78 kg/m2. After adjusting for age, gender, history of diabetes, smoking status, alcohol consumption, and use of diuretics, 24-hour urinary sodium was correlated with multiple ambulatory blood pressure parameters, especially with nighttime diastolic blood pressure. Left atrial structure and function (left atrial reservoir function and left atrial conduit function) and left atrioventricular coupling index were correlated (P &lt; 0.05). Mediation analysis showed that BMI explained 16% of the indirect effect of 24-hour urinary sodium and left atrial function (left atrial reservoir function and left atrial conduit function), and 30% of the indirect effect of LACI. Independent of the mediator, 24-hour urinary sodium had a significant direct effect on left atrial reservoir function, left atrial conduit function, and left atrioventricular coupling. Conclusions: Higher 24-hour urinary sodium was associated with a greater BMI as well as poor left atrial function and left atrioventricular coupling, and the BMI mediated the relationship between 24-hour urinary sodium and subclinical left cardiac function, and, more importantly, 24-hour urinary sodium may directly affect the left atrial function and left atrioventricular coupling independent of intermediary factors.