Effect of supine versus sitting position on noninvasive assessment of aortic pressure waveform: a randomized cross-over study.

Biomarkers derived noninvasively from the aortic blood pressure (BP) waveform provide information regarding cardiovascular (CV) risk independently of brachial BP (bBP). Although body position has significant impact on the assessment of bBP, its effect on aortic hemodynamics remains unknown. This study investigated the changes in both brachial and aortic hemodynamics, between the supine and sitting position. In this randomized cross-over study, the bBP and the aortic pressure waveform were assessed after a 5 min rest (sitting and supine in randomized order); aortic BP, pulse pressure (PP) amplification, augmentation index (AIx) and subendocardial viability index (SEVR) were assessed. Sixty-one subjects were examined (36 males, mean age 50±12 years). Mean BP did not differ between the sitting and supine position (110.8±13.7 vs 110.9±14.9, respectively, P=0.945). However, significant difference between the sitting and supine position in brachial PP (45.9±16.0 vs 52.6±15.6, respectively, P<0.001), aortic PP (36.7±15.2 vs 43.1±13.9, P<0.001), PP amplification (1.28±0.1 vs 1.23±0.1, P<0.001), AIx (26.9±11.9 vs 31.1±10.2, P<0.001) and SEVR (179.6±25.7 vs 161.2±25.8, P<0.001) were found. Review of the literature identified underestimation of the role of body position on aortic hemodynamics. In conclusion, increased PP in both the aorta and brachial artery were found in the supine compared to the sitting position. Reduced PP amplification and SEVR were further observed in the supine position, due to increased pressure wave reflections (AIx).

Patients' preference for ambulatory versus home blood pressure monitoring.

Patient's preference might influence compliance with antihypertensive treatment and thereby long-term blood pressure (BP) control. This study compared patients' preference in using ambulatory (ABPM) versus home BP monitoring (HBPM). Subjects referred for hypertension were evaluated with 24-h ABPM and 7-day HBPM. Participants filled a questionnaire including demographics and Likert scale questions regarding their acceptance, preference, disturbance, activity restriction and feasibility of using ABPM and HBPM. A total of 119 patients were invited and 104 (87%) were included (mean age 51±11 years, 58% men, 38% time to work >8 h). A total of 82% reported a positive overall opinion for HBPM versus 63% for ABPM (P<0.05). 62% considered ABPM as more reliable than HBPM but 60% would choose HBPM for their next BP evaluation (P<0.05 for both comparisons). Moderate to severe discomfort from ABPM was reported by 55% and severe restriction of their daily activities by 30% compared with 13% and 7%, respectively, from HBPM (P<0.001 for both comparisons). The overall score for HBPM and ABPM (range 4-25; higher score indicating worse performance) was 6.6±2.5 and 10±4.0 (mean difference 4.4±4.6, P<0.001), respectively. In binary logistic regression models, neither previous experience with BP monitoring nor demographic characteristics appeared to influence patients' preference. These data suggest that HBPM is superior to ABPM in terms of overall acceptance and preference by hypertensive patients. Patients' preference deserves further research and should be taken into account in decision making in clinical practice.

Identification of the hemodynamic modulators and hemodynamic status in uncontrolled hypertensive patients.

Only 20-30% out of the treated hypertensive patients in Europe are achieving blood pressure (BP) control. Among other recognized factors, these poor results could be attributable to the fact that for many doctors it is very difficult to detect which is the predominant hemodynamic cause of the hypertension (hypervolemia, hyperinotropy or vasoconstriction). The aim of the study was to use non-invasive thoracic electrical bioimpedance (TEB) to evaluate hemodynamic modulators and subsequent hemodynamic status in uncontrolled hypertensive patients, receiving at least two antihypertensive drugs. A number of 134 uncontrolled hypertensive patients with essential hypertension were evaluated in nine European Hypertension Excellence centers by means of TEB (the HOTMAN(®) System). Baseline office systolic and diastolic BP averaged 156/92 mmHg. Hemodynamic measurements show that almost all patients (98.5%) presented at least one altered hemodynamic modulator: intravascular hypervolemia (96.4%) and/or hypoinotropy (42.5%) and/or vasoconstriction (49.3%). Eleven combinations of hemodynamic modulators were present in the study population, the most common being concomitant hypervolemia, hypoinotropy and vasoconstriction in 51(38%) patients. Six different hemodynamic states (pairs of mean arterial pressure and stroke index) were found. Data suggest that there is a strong relation between hypertension and abnormal hemodynamic modulators. This method might be helpful for treatment individualization of hypertensive patients.

Home versus ambulatory blood pressure monitoring in the diagnosis of clinic resistant and true resistant hypertension.

Ambulatory blood pressure (ABP) monitoring is recommended as a standard method for the evaluation of resistant hypertension (RH). This study assessed the diagnostic value of home blood pressure (HBP) monitoring in RH. Subjects on stable treatment with ≥3 antihypertensive drugs were included. Clinic RH (CRH) was defined as elevated clinic blood pressure and true RH (TRH) as elevated ABP. The diagnosis of CRH was verified by ABP and HBP monitoring. The diagnostic value of HBP was assessed by taking ABP as reference method. Threshold for hypertension diagnosis was ≥135/85 mm Hg (systolic and/or diastolic) for HBP and awake ABP and ≥140/90 mm Hg for clinic blood pressure. Among 73 subjects on ≥3 antihypertensive drugs, 44 (60%) had CRH and 40 (55%) TRH. There was agreement between ABP and HBP in diagnosing CRH in 82% of the cases (26 subjects (59%) with CRH and 10 (23%) without CRH; kappa 0.59). Regarding the diagnosis of TRH, there was agreement between ABP and HBP in 74% of the cases (36 subjects (49%) with TRH and 18 (25%) without TRH; kappa 0.46). The sensitivity, specificity, and positive and negative predictive values of HBP in detecting CRH were 93%, 63%, and 81% and 83%, respectively, and TRH were 90%, 55%, and 71%, and 82%, respectively (ABP taken as reference method). These data suggest that HBP is a reliable alternative to ABP in the evaluation of RH. These methods are necessary in both uncontrolled and controlled subjects on triple therapy to detect the white coat phenomenon and also masked RH.

Assessment of differences between repeated pulse wave velocity measurements in terms of 'bias' in the extrapolated cardiovascular risk and the classification of aortic stiffness: is a single PWV measurement enough?

Currently, there is no recommendation regarding the minimum number of pulse wave velocity (PWV) measurements to optimize individual's cardiovascular risk (CVR) stratification. The aim of this study was to examine differences between three single consecutive and averaged PWV measurements in terms of the extrapolated CVR and the classification of aortic stiffness as normal. In 60 subjects who referred for CVR assessment, three repeated measurements of blood pressure (BP), heart rate and PWV were performed. The reproducibility was evaluated by the intraclass correlation coefficient (ICC) and mean±s.d. of differences. The absolute differences between single and averaged PWV measurements were classified as: ≤0.25, 0.26-0.49, 0.50-0.99 and ≥1 m s(-1). A difference ≥0.5 m s(-1) (corresponding to 7.5% change in CVR, meta-analysis data from >12 000 subjects) was considered as clinically meaningful; PWV values (single or averaged) were classified as normal according to respective age-corrected normal values (European Network data). Kappa statistic was used to evaluate the agreement between classifications. PWV for the first, second and third measurement was 7.0±1.9, 6.9±1.9, 6.9±2.0 m s(-1), respectively (P=0.319); BP and heart rate did not vary significantly. A good reproducibility between single measurements was observed (ICC>0.94, s.d. ranged between 0.43 and 0.64 m s(-1)). A high percent with difference ≥0.5 m s(-1) was observed between: any pair of the three single PWV measurements (26.6-38.3%); the first or second single measurement and the average of the first and second (18.3%); any single measurement and the average of three measurements (10-20%). In only up to 5% a difference ≥0.5 m s(-1) was observed between the average of three and the average of any two PWV measurements. There was no significant agreement regarding PWV classification as normal between: the first or second measurement and the averaged PWV values. There was significant agreement in classification made by the average of the first two and the average of three PWV measurements (κ=0.85, P<0.001). Even when high reproducibility in PWV measurement is succeeded single measurements provide quite variable results in terms of the extrapolated CVR and the classification of aortic stiffness as normal. The average of two PWV measurements provides similar results with the average of three.

The optimal home blood pressure monitoring schedule based on the Didima outcome study.

This study investigated the optimal schedule for home blood pressure (HBP) monitoring that has the greatest prognostic ability and provides the most reliable assessment of HBP. The Didima study assessed the value of HBP (duplicate morning and evening measurements, 3 days) in predicting cardiovascular events in the general population (662 adults, 8.2+/-0.2 years follow-up). Criteria for the optimal monitoring schedule were stabilization of mean HBP, its variability (standard deviation (s.d.)) and hazard ratios (HRs) of cardiovascular events per 1 mm Hg HBP increase. By averaging more readings (1-12), there was a progressive decline in average HBP and its s.d. and increase in HR, with most of these benefits achieved on the second day (8 readings) and little additional benefit obtained on the third day (12 readings). The first day gave higher and more unstable HBP values (higher s.d.) with less prognostic ability (lower HR). The first HBP readings per occasion gave higher values but with similar prognostic ability as the second readings taken 1 min later. There was little difference in average HBP between morning and evening readings with no prognostic superiority of morning readings. In conclusion, by averaging more readings the average HBP and its variability are reduced and the prognostic ability improved. Any aspect of HBP monitoring (first or second readings, morning or evening) has similar prognostic ability. The first day gives higher and unstable values with lower prognostic ability and should be better discarded. These data validate the HBP monitoring schedule proposed by the European Society of Hypertension.

Are there really differences between home and daytime ambulatory blood pressure? Comparison using a novel dual-mode ambulatory and home monitor.

Several studies compared blood pressure (BP) at home (HBP) with ambulatory BP (ABP), but using different devices, which contribute to differences in measured BP. A novel dual-mode device allowing ABP and HBP monitoring (Microlife WatchBPO3) was validated according to the European Society of Hypertension International Protocol and used to compare the two methods. In the validation study, 33 subjects were assessed with simultaneous BP measurements taken by 2 observers (connected mercury sphygmomanometers) 4 times, sequentially with 3 measurements taken using the tested device. Absolute observer-device BP differences were classified within 5/10/15 mm Hg zones. Measurements with

Diagnostic accuracy of a home blood pressure monitor to detect atrial fibrillation.

Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with an increased long-term risk of stroke. A screening test for early diagnosis has the potential to prevent AF-related strokes. This study assessed the diagnostic accuracy of an automated device for self-home blood pressure (BP) monitoring, which implements an algorithm for AF detection. A modified, automated oscillometric device for self-home BP monitoring (Microlife BPA100 Plus, Microlife, Heerbrugg, Switzerland) with an AF detector was used to carry out triplicate BP measurements in subjects with sinus rhythm, AF and non-AF arrhythmias. During each BP measurement, the electrocardiogram (ECG) was recorded simultaneously. A total of 217 simultaneous BP measurements and ECG recordings were obtained from 73 subjects. Twenty-seven subjects (37%) had AF, 23 (31%) non-AF arrhythmias and 23 (31%) had sinus rhythm. A single measurement had 93% sensitivity and 89% specificity for detecting AF. For two measurements, in which one of them was required to detect AF, the sensitivity was 100% and specificity 76%, whereas for three measurements, in which two of them were required to detect AF, the sensitivity was 100% and specificity 89% (kappa=0.86 for an agreement with ECG). Using the latter approach, there were five false positive cases all having irregularities in approximately 50% of the heartbeats. In patients with tachyarrhythmia, the device underestimated heart rate. These data suggest that an electronic device for self-home BP monitoring, which implements an algorithm for AF diagnosis has an excellent diagnostic accuracy and might, therefore, be used as a reliable screening test for the early diagnosis.

Diagnostic value of rapid urease test and urea breath test for Helicobacter pylori detection in patients with Billroth II gastrectomy: a prospective controlled trial.

AIM: The aim of this work was to assess the reliability of rapid urease test (RUT) and urea breath test (UBT) for detecting Helicobacter pylori (H. pylori) in patients with Billroth II (BII) gastrectomy, using histology as reference. METHODS: In this prospective controlled study, 31 consecutive patients with BII gastrectomy and 73 controls who had an indication for endoscopy were included. Their H. pylori status was assessed with biopsies for histology, RUT and UBT. Histology served as the gold standard. Only the biopsies from the gastric fundus were evaluated. Specificity, sensitivity, positive and negative predictive value, degree of agreement and k-statistics were used. RESULTS: RUT and UBT for detecting H. pylori in the control group had excellent agreement [97%, kappa (k)=0.94 and 99%, k=0.97 respectively] with biopsies. In BII patients, RUT from fundic biopsies had very good agreement (87%, k=0.74) compared to histology from fundic biopsies, whereas the UBT was unreliable (agreement: 71%, k=0.41) compared to histology. CONCLUSION: The RUT from fundic biopsies in BII patients is a reliable test for H. pylori detection, whereas the UBT is unreliable.

Can an electronic device with a single cuff be accurate in a wide range of arm size? Validation of the Visomat Comfort 20/40 device for home blood pressure monitoring.

An appropriate cuff according to the individual's arm circumference is recommended with all blood pressure (BP) monitors. An electronic device for home monitoring has been developed (Visomat Comfort 20/40) that estimates the individual's arm circumference by measuring the cuff filing volume and makes an adjustment of measured BP taking into account the estimated arm circumference. Thus the manufacturer recommends the use of a single cuff for arm circumference 23-43 cm. The device accuracy was assessed using the European Society of Hypertension International Protocol. Simultaneous BP measurements were obtained in 33 adults by two observers (connected mercury sphygmomanometers) four times, sequentially with three measurements taken using the tested device. Absolute device-observer BP differences were classified into < or =5, < or =10 and < or =15 mm Hg zones. For each participant the number of measurements with a difference < or =5 mm Hg was calculated. The device produced 60/89/97 measurements within 5/10/15 mm Hg respectively for systolic BP, and 72/97/98 for diastolic. Twenty-three subjects had at least two of their systolic BP differences < or =5 mm Hg and three had no differences < or =5 mm Hg (for diastolic 27 and 1, respectively). Mean device-observer BP difference (systolic/diastolic) was 3.7 +/- 5.6/-1.5 +/- 4.7 mm Hg (4.7 +/- 4.9/ - 1.7 +/- 4.3 in arm circumference 23-29 cm [39 readings] and 3.1 +/- 5.9/-1.4 +/- 5.0 in arm 30-34 cm [60 readings], P=NS). In conclusion, the device fulfils the International Protocol requirements and can be recommended for clinical use. Interestingly, the device was accurate using a single cuff in a wide range of arm circumference (23-34 cm). This study provides no information about the device accuracy in larger arms.