Validation of a new piezo-electronic device for non-invasive measurement of arterial pulse wave velocity according to the artery society guidelines

Heart Rate from Progressive Volitional Cycling Test Is Associated with Endothelial Dysfunction Outcomes in Hypertensive Chilean Adults

BACKGROUND

A progressive volitional cycling test is useful in determining exercise prescription in populations with cardiovascular and metabolic diseases. However, little is known about the association between heart rate during this test and endothelial dysfunction (EDys) parameters in hypertensive (HTN) patients.

OBJECTIVE

To investigate the association between EDys markers (flow-mediated dilation [FMD], pulse wave velocity of the brachial artery [PWVba], and carotid-intima media thickness [cIMT]) and heart rate during a cycling test in HTN adults. A secondary aim was to characterize cardiovascular, anthropometric, and body composition outcomes in this population.

METHODS

This was a descriptive clinical study in which adults (men and women) were assigned to one of three groups: HTN, elevated blood pressure (Ele), or a normotensive control group (CG), and completed a progressive cycling test. The primary outcomes were FMD, PWVba, cIMT, and heart rate (HR) at 25-50 watts (HR_25-50), 50-100 watts (HR_50-100), and 75-150 watts (HR_75-150) of the Astrand test. Secondary outcomes included body mass index (BMI), waist circumference, body fat percentage (BF%), skeletal muscle mass (SMM), resting metabolic rate (RMR), and estimated body age, as measured by a bio-impedance digital scale.

RESULTS

Analyses of the associations between FMD, PWV, and HR_25-50, HR_50-100, and HR_75-150 watts revealed no significant association in the HTN, Ele, and CG groups. However, a significant association was found between cIMT and HR_75-150 watts in the HTN group (R² 47.1, β -0.650, p = 0.038). There was also a significant trend (p = 0.047) towards increasing PWVba in the CG, Ele, and HTN groups.

CONCLUSION

Heart rate during a progressive cycling test is associated with the EDys parameters cIMT in HTN patients, with particularly strong predictive capacity for vascular parameters in the second and third stages of the Astrand exercise test compared to normotensive control.

Accuracy of a new instrument for noninvasive evaluation of pulse wave velocity: the Arterial sTiffness faitHful tOol aSsessment project

BACKGROUND

Large artery stiffness, assessed by carotid--femoral pulse wave velocity (cfPWV), is a major risk factor for cardiovascular events, commonly used for risk stratification. Currently, the reference device for noninvasive cfPWV is SphygmoCor but its cost and technically challenging use limit its diffusion in clinical practice.

AIM

To validate a new device for noninvasive assessment of cfPWV, ATHOS (Arterial sTiffness faitHful tOol aSsessment), designed in collaboration with the Politecnico di Torino, against the reference noninvasive method represented by SphygmoCor.

METHODS

Ninety healthy volunteers were recruited. In each volunteer, we assessed cfPWV, using SphygmoCor (PWVSphygmoCor) and ATHOS (PWVATHOS) devices in an alternate fashion, following the ARTERY Society guidelines. The accuracy was assessed by Bland--Altman plot, and reproducibility was assessed by interoperator correlation coefficient (ICC).

RESULTS

Mean PWVATHOS and mean PWVSphygmoCor were 7.88 ± 1.96 and 7.72 ± 1.95 m/s, respectively. Mean difference between devices was 0.15 ± 0.56 m/s, with a high correlation between measurements (r = 0.959, P < 0.001). Considering only PWV values at least 8 m/s (n = 30), mean difference was 0.1 ± 0.63 m/s. The ICC was 97.7% with ATHOS.

CONCLUSION

ATHOS showed an excellent level of agreement with SphygmoCor, even at high PWV values, with a good reproducibility. Its simplicity of use could help increase clinical application of PWV assessment, improving patients' cardiovascular risk stratification.

Novel Indices of Home Blood Pressure Variability and Hypertension-Mediated Organ Damage in Treated Hypertensive Patients

INTRODUCTION

Although multiple home blood pressure variability (HBPV) indices have been proposed, the superiority of one over another is not clear in treated hypertensives.

AIM

We evaluated the correlation between different indices of HBPV and hypertension-mediated organ damage (HMOD) in this population and determined predictors of greater HBPV.

METHODS

We included adult treated hypertensives who performed an HBP monitoring (duplicate sitting BP readings in the morning, afternoon, and evening for 4 days, Omron HEM-705CP-II), laboratory measurements, transthoracic echocardiogram and carotid-femoral pulse wave velocity. We selected HBPV indices from three different calculation approaches: coefficient of variation (CoV), difference between maximum and minimum BP (MMD), and morning BP increase (MI), and evaluated their correlation with left ventricular mass index, relative wall thickness (RWT), ejection fraction, arterial stiffness and estimated glomerular filtration rate through a correlation matrix. For those variability indices significantly associated with HMOD, we constructed multiple linear regression models to determine independent predictors of HBPV.

RESULTS

We included 204 patients, mean age 67.2 (± 13.8) years, 64% female. CoV and MMD for systolic BP showed the greatest correlation with HMOD. Factors independently associated both with CoV and MMD were: older age (b = 0.07; 95% CI 0.04-0.07; p < 0.001 and b = 0.4; 95% CI 0.2-0.5; p < 0.001, respectively), history of stroke (b = 3.6; 95% CI 0.9-6.4; p = 0.01 and b = 25.7; 95% CI 10.1-41.2; p = 0.001, respectively), and body mass index [b = - 0.1; 95% CI - 0.2 to (- 0.02); p = 0.01 and b = - 0.5; 95% CI - 0.9 to (- 0.1); p = 0.01, respectively].

CONCLUSION

CoV and MMD showed the greatest association with HMOD in treated hypertensives. Older age, history of stroke and lower body mass index were easy-to-detect predictors.

Current assessment of pulse wave velocity: comprehensive review of validation studies

OBJECTIVE

Carotid-femoral pulse wave velocity (PWV) is considered the gold standard for arterial stiffness assessment in clinical practice. A large number of devices to measure PWV have been developed and validated. We reviewed different validation studies of PWV estimation techniques and assessed their conformity to the Artery Society Guidelines and the American Heart Association recommendations.

METHODS

Pubmed and Medline (1995-2017) were searched to identify PWV validation studies. Of the 96 article retrieved, 26 met the inclusion criteria.

RESULTS

Several devices had been developed and validated to noninvasively measure arterial stiffness, using applanation tonometry (SphygmoCor, PulsePen), piezoelectric mechanotransducers (Complior), cuff-based oscillometry (Arteriograph, Vicorder and Mobil-O-Graph), photodiode sensors (pOpmètre) and devices assessing brachial-ankle pulse wave velocity and cardiac-ankle PWV. Ultrasound technique and MRI remain confined to clinical research. Good agreement was found with the Artery Society Guidelines. Two studies (Complior, SphygmoCor Xcel) showed best adherence with the guidelines. In Arteriograph, MRI, ultrasound and SphygmoCor Xcel validation studies sample size was smaller than the minimum suggested by the guidelines. High discrepancies between devices were shown in distance estimation: in two studies (Arteriograph, Complior) path length was estimated in conformity to the guidelines. Transit time was calculated using the intersecting tangent method, but in two studies (Vicorder, pOpmètre) best agreement was found using the maximum of the second derivative. Six studies reached the accuracy level 'excellent' defined in the Artery guidelines.

CONCLUSION

Method to assess transit time and path length need validation in larger populations. Further studies are required in different risk population to implement clinical applicability of every device.

Validation of a new piezoelectric device for noninvasive measurement of central aortic systolic blood pressure

OBJECTIVE

The objective of this study was to compare the aortic piezoelectric device for noninvasive measurement of central aortic systolic blood pressure (cSBP) with the SphygmoCor.

PARTICIPANTS AND METHODS

A total of 85 participants from both sexes, aged 18-80 years, were stratified into three age groups (<30, 30-60, >60 years), with an equal number of healthy volunteers and hypertensive patients. We performed three cSBP measurements with each device, in an alternate manner, using the Bland-Altman method to determine the level of agreement. The standard of the Association for the Advancement of Medical Instrumentation for brachial blood pressure evaluation was used for the comparison.

RESULTS

The mean cSBPs were 109.3±12.05 and 109.0±12.2 mmHg with the SphygmoCor and the Aortic device, respectively, showing a strong correlation (r=0.98, P<0.001). A mean difference of 0.35±2.43 mmHg (95% confidence interval: 0.17-0.87, P=NS) was obtained with the Bland-Altman method. The 95% limits of agreement was -4.4 to +5.1 mmHg.

CONCLUSION

Complying with the Association for the Advancement of Medical Instrumentation criteria, cSBP measurements obtained with the Aortic and the SphygmoCor devices are equivalent.

Arterial Stiffness in Treated Hypertensive Patients With White-Coat Hypertension

Arterial stiffness, assessed through pulse wave velocity (PWV), independently predicts cardiovascular outcomes. In untreated persons, white-coat hypertension (WCH) has been related to arterial stiffness, but data in treated patients with WCH are scarce. The authors aimed to determine a possible association between WCH and arterial stiffness in this population. Adult treated hypertensive patients underwent home blood pressure monitoring and PWV assessment. Variables associated with PWV in univariable analyses were entered into a multivariable linear regression model. The study included 121 patients, 33.9% men, median age 67.9 (interquartile range 18.4) years, 5.8% with diabetes, and 3.3% with a history of cardiovascular or cerebrovascular disease. In multivariable analysis, WCH in treated hypertensive patients remained a determinant of PWV: β=1.1 (95% confidence interval, 0.1-2.1 [P=.037]; adjusted R² 0.49). In conclusion, WCH is independently associated with arterial stiffness in treated hypertensive patients. Whether this high-risk association is offset by antihypertensive treatment should be further investigated.