Assessment Of Carotid-femoral Pulse Wave Velocity Research Articles

THE INVESTIGATION OF TRANSFERABILITY OF DEFINITIONS OF CARDIOMETABOLIC AND VASCULAR AGING PHENOTYPES ACROSS MULTIPLE COHORTS

Objective: According to the European guidelines for the prevention of cardiovascular diseases (CVD) (2021), Russia was identified as a country with a very high CV risk. We aimed to investigate the applicability of the standardized definitions of vascular aging phenotypes (VP) in Russian population and align them with the existing reference datasets. Design and method: In 2012-2013 1,600 residents of St. Petersburg (age 21-67) were randomly examined as a part of the multicenter epidemiological study. Anthropometry, blood pressure measurement, blood biochemistry analysis were taken. Subjects completed questionnaires describing their lifestyle, current health condition and medication usage. 618 patients (42% men) from initial cohort with a mean age of 48 [37;55] years were randomly subsampled for carotid-femoral pulse wave velocity assessment (Sphygmocor). The VP were defined using the ‘Reference Values for Arterial Stiffness’ Collaboration database which included 16,867 measurements from eight European countries populations15 to 97 years. According to the criteria, patients with overt CVD, diabetes mellitus and the use of antihypertensive, lipid-lowering therapy were excluded from the analysis of VP. Results: The Russian cohort had significantly higher prevalence of CVD (11,4% compared to 6,9% in the Nreference population, p=5.65x10-5), intake of antihypertensives (28,1% compared to 14,3% in the reference, p<1x10-16) and lipid-lowering therapy (6,1% compared to 4,1%, p=0.025, Figure 1A). Additionally, our cohort had significantly higher prevalence of optimal BP (40,2% vs 28%, p=4.6x10-7) and lower prevalence of first-degree (p=0.048) and second degree (p=0.00084) hypertension (Figure 1B). Comparison of the prevalence of VP between the European and Russian cohorts showed a significant decrease of the early vascular aging (EVA) phenotype with age in the Russian population (p=0.011). The prevalence of the supernormal vascular aging phenotype (SUPERNOVA) in the group of 60-69 years old was higher in the Russian population (p=0.0035) Conclusions: A higher prevalence of CVD was demonstrated in the study cohort despite lower hypertension burden and higher CV drugs intake compared to the European cohort. Multidirectional trajectories of EVA and SUPERNOVA VP with age were detected in Russian population, potentially indicating the presence of the clearing selection pressure at the older age (Agreement No 075-15-2022-301).

A region-based cross-correlation approach for tonometric carotid–femoral Pulse Wave Velocity Assessment

This work introduces a novel region-based algorithm to determine carotid–femoral Pulse Wave Velocity (cfPWV), decoupling the assessment of this biomarker from point-to-point feature extraction. A dataset of 75 healthy participants, previously recruited to compare the performances of a new instrument, Athos, with the gold standard for non-invasive PWV (SphygmoCor), was used to set up a new algorithm for determining the clinical cfPWV. The proposed approach locates and processes a specific window on the carotid and femoral signals. Cross-correlation is employed to compute the pulse transit time within the pulses. Finally, the cfPWV is assessed. A set of indicators has been defined to quantify the stability and reliability of the window used by the algorithm. The results obtained through the proposed algorithm, the Intersecting Tangent method, and the direct application of the cross-correlation technique on signal epochs have been systematically compared with outcomes derived from the SphygmoCor device. The retrieved results show a Pearson coefficient r = 0.96, P< 0.001, with a mean difference of 0.16m/s for the first case, r = 0.965, P< 0.001, with a mean difference of −0.07m/s for the second, and r = 0.82, P< 0.001, with a mean difference of −1.04m/s for the third. Despite the intersecting tangent method showing slightly better agreement when comparing cfPWV values with those derived from the SphygmoCor, the proposed approach yields significantly lower errors (P< 0.05) in the presence of different levels of added noise, demonstrating greater robustness in this context. This outcome, combined with the excellent accuracy, sustains the suitability of the proposed method for clinical applications.

Carotid-femoral pulse wave velocity assessment by two different methods: implications for risk assessment.

Several devices are available for carotid-femoral pulse wave velocity (cfPWV) measurement, and a cut-off value for reference cfPWV has been established. However, discrepancies between devices have been reported. The aim of the study was to establish the concordance of two common techniques (Complior and SphygmoCor), taking into account the anatomical distance between the measurement sites, and to investigate the impact on cardiovascular risk stratification. cfPWV, central and peripheral blood pressure were assessed in patients attending the hypertension outpatient clinic. The subtracted carotid-femoral distance was estimated both according to the manufacturer's recommendations and correcting the obtained values by 10.3%. Bland-Altman plots, Pearson's correlation coefficient, Lin's concordance correlation coefficient and multivariate models were used to investigate the difference in cfPWV. cfPWV assessed in 118 patients (age 55 ± 12 years, 61% hypertensive patients, BMI 28.9 ± 4.4 kg/m2) with the Complior device was lower than that assessed with the SphygmoCor device, regardless of correcting the subtracted carotid-femoral distance (8.7 vs. 10.3 m/s and 9.3 m/s, respectively; P value < 0.001). The average difference was -1.59 ± 1.5 and -0.617 ± 1.39 m/s for corrected and uncorrected SphygmoCor values, respectively, SBP, BMI and female being the main determinants of the difference. Cardiovascular risk stratification changed in up to 40% of the study population, depending on the device and the arterial distance estimation. The concordance between the Complior and the SphygmoCor device is poor when the anatomical artery length is controlled for and in the presence of cardiovascular risk factors, resulting in a difference in classification of cardiovascular risk.

Carotid-femoral pulse wave velocity assessment using novel cuff-based techniques

Carotid-femoral pulse wave velocity, a predictor of cardiovascular outcome, is conventionally measured using a tonometer sequentially placed upon the carotid and femoral arteries, gated using an electrocardiogram. Leg cuff detection of the femoral pulse removes the need for signal gating, reduces the time required for a single measurement, but gives different pulse wave velocity values to tonometric analysis. A novel algorithm to correct for the transit time and distance related to the additional femoral segment was applied to the cuff-based approach in this study. Eighty-eight individuals were recruited across four centres and carotid-femoral pulse wave velocity measured in triplicate using two operators with both a tonometer-based device and a device using an inflated thigh cuff with and without the use of the novel algorithm. Comparison was made by Bland-Altman and regression analysis. The unadjusted cuff-based approach gave lower pulse wave velocity values than the tonometer-based approach (6.11 ± 1.27 and 7.02 ± 1.88 m/s, P < 0.001). With application of the algorithm, the cuff-based device gave similar pulse wave velocity values (7.04 ± 1.72 m/s) as the tonometer-based approach (P = 0.86). Analysis of covariance with age showed a difference between the tonometer and cuff-based methods (P < 0.001), with a dependence upon age (P = 0.004). The adjusted cuff-based method gave similar results to the tonometer-based method (P = 0.94), with no dependence upon age (P = 0.46). This study provided validation of a cuff-based assessment of carotid-femoral pulse wave velocity against the universally accepted tonometric method. Adjusting the cuff-based method for the additional femoral segment measured gives results comparable to the tonometer-based method, for which the majority of population data exist to date.

Crucial importance of using a sliding calliper to measure distance for carotid-femoral pulse wave velocity assessment

In the past, different methods have been used to measure the carotid-femoral distance for the assessment of pulse wave velocity (PWV). However, the latest consensus published advises to use 80% of the direct straight carotid-femoral distance (D(0.8)) using either a flexible tape or a sliding calliper. We studied the influence of the use of a tape measure and a calliper on PWV values and provided equations to derive the straight D(0.8) distance from previous methodologies. PWV was measured in patients referred for ambulatory blood pressure monitoring. Carotid-femoral, carotid-sternal notch, and sternal notch-femoral distances were measured with a tape and a sliding calliper. Two hundred and fifty-nine patients (141 men and 118 women) were recruited consecutively. Their BMI ranged from 18 to 45 kg/m(2) (28.4 ± 5.0, mean ± SD). As expected, distances measured with tape were longer (3.1 ± 1.3 cm for D(0.8)) leading to higher values of PWV (0.6 ± 0.3 m/s for PWV(0.8)). This difference was similar in men and women and depended for 20% on the BMI. Equations explaining more than 85% of variance can be used to convert tape carotid-femoral, carotid-sternal notch, and tape sternal notch-femoral distances to D(0.8). It is crucial to use a sliding calliper to assess distances for PWV measurement. The overestimation with flexible tape depends on the BMI but not on the sex. Conversion equations between previous methods and the D(0.8) method can be used.