Assessment Of Aortic Pulse Wave Velocity Research Articles

Pulse Wave Velocity Assessment for Cardiovascular Risk Prognostication in ESKD: Weighting Recent Evidence.

Among patients with end-stage kidney disease (ESKD), arterial stiffness is considered as a powerful predictor of cardiovascular (CV) morbidity and mortality. However, the relevance of aortic pulse wave velocity (PWV) as a prognostic biomarker for CV risk estimation is not yet fully clear. We performed a systematic search of Medline/PubMed database from inception through August 21, 2019 to identify observational cohort studies conducted in ESKD patients and exploring the association of PWV with CV events and mortality. Whereas "historical" cohort studies showed aortic PWV to be associated with higher risk of CV and all-cause mortality, recent studies failed to reproduce the independent predictive value of aortic PWV in older ESKD patients. Studies using state-of-the-art prognostic tests showed that the addition of aortic PWV to standard clinical risk scores could only modestly improve CV risk reclassification. Studies associating improvement in PWV in response to blood pressure (BP)-lowering with improvement in survival cannot demonstrate direct cause-and-effect associations due to their observational design and absence of accurate methodology to assess the BP burden. Despite the strong pathophysiological relevance of arterial stiffness as a mediator of CV disease in ESKD, the assessment of aortic PWV for CV risk stratification in this population appears to be of limited value. Whether aortic PWV assessment is valuable in guiding CV risk factor management and whether such a therapeutic approach is translated into improvement in clinical outcomes, is an issue of clinical relevance that warrants investigation in properly-designed randomized trials.

A novel methodology for rat aortic pulse wave velocity assessment by Doppler ultrasound: validation against invasive measurements.

There is still lack of a simple, accurate, and noninvasive method for rat aortic pulse wave velocity (PWV) measurement, especially the transit distance cannot be accurately measured. Thus, we aimed to derive an equation for aortic transit distance as a function of the nose-to-rump length (L) and to test the hypothesis that aortic PWV measured by new equation combined with Doppler ultrasound (the "equation method") may have stronger correlation with invasive measurements than traditional "body surface method." Two-hundred male Sprague-Dawley (SD) rats (age ranged 5-24 wk) were included in protocol 1, and the aortic transit distances were measured postmortem. In protocol 2, heart-femoral PWV and carotid-femoral PWV were measured by equation method (hfPWVE, cfPWVE) and also by traditional body surface method (hfPWVS, cfPWVS) in another 30 young and 28 old rats. These measurements were then validated against invasively measured hfPWVI and cfPWVI from the same animal. Protocol 1 showed that the heart-femoral transit distance could be calculated by 0.6086 × L - 1.6523, and the carotid-femoral transit distance by 0.4614 × L + 1.8335. In protocol 2, in young rats, the Pearson r between hfPWVE, cfPWVE, hfPWVS, and cfPWVS and their corresponding invasive measurement were 0.8962, 0.8509, 0.8387, and 0.7828, respectively (all P < 0.0001). In the old group, the results were 0.8718, 0.7999, 0.8330, and 0.7112, respectively (all P < 0.0001). The hfPWVE and cfPWVE showed better agreement with hfPWVI and cfPWVI and lower intra- and interobserver variability compared with hfPWVS and cfPWVS in both groups. These findings demonstrate that this novel methodology provides a simple and reliable method for rat noninvasive aortic PWV measurement.NEW & NOTEWORTHY First, when measuring aortic PWV in SD rat models, the heart-femoral transit distance can be estimated by 0.6086 × L - 1.6523, and the carotid-femoral distance transit distance can be estimated by 0.4614 × L + 1.8335, where L (in mm) is nose-to-rump length. Second, this novel methodology for aortic PWV measurement was validated with a closer correlation with the invasive measurements than traditional approach in young and old rats. Third, this study provides a simple and reliable method for rat noninvasive aortic PWV measurement.

Aortic Pulse-Wave Velocity Assessment in Atrial Fibrillation

Background and Introduction: Aortic stiffness, as a surrogate for central high blood pressure, is increasingly recognised as a novel risk factor in development of atrial fibrillation (AF). Aortic pulse wave velocity (aPWV) estimation is the recommended method to evaluate aortic stiffness non–invasively. However, no studies were performed to validate aPWV in AF.

Echocardiographic Assessment of Aortic Pulse-Wave Velocity: Validation against Invasive Pressure Measurements

Aortic pulse-wave velocity (PWV) is a measure of aortic stiffness that has a prognostic role in various diseases and in the general population. A number of methods are used to measure PWV, including Doppler ultrasound. Although echocardiography has been used for PWV measurement, to the authors' knowledge, it has never been tested against an invasive reference method at the same time point. Therefore, the aim of this study was to compare prospectively an echocardiographic PWV measurement, called echo-PWV, with an invasive study. Forty-five patients (mean age, 66years; 60% men) underwent simultaneous intra-arterial pressure recording and echocardiographic Doppler flow evaluation during elective cardiac catheterization. Proximal pressure and Doppler waveforms were acquired in the aortic arch. Distal pressure waveforms were registered in the right and distal Doppler waveforms in the left external iliac artery. Transit time was measured as a delay of the foot of pressure or Doppler waveform in the distal relative to the proximal location. Distance was measured on the catheter for invasive PWV and over the surface for echo-PWV. Echo-PWV was calculated as distance divided by transit time. In the whole group, mean invasive PWV was 9.38m/sec and mean echo-PWV was 9.51m/sec (P=.78). The Pearson' correlation coefficient between methods was 0.93 (P<.0001). A Bland-Altman plot revealed a mean difference between invasive PWV and echo-PWV of 0.13±0.79m/sec. Echo-PWV, based on Doppler echocardiography, is a reliable method of aortic PWV measurement, with a close correlation with invasive assessment. Wider implementation of the echo-PWV method for the evaluation of aortic wall stiffness can further expand the clinical and scientific utility of echocardiography.

Importance of time delay estimation methods for aortic pulse wave velocity assessment with phase-contrast MRI

Importance of time delay estimation methods for aortic pulse wave velocity assessment with phase-contrast MRI

Association of Aortic Pulse Wave Velocity with the Severity of Coronary Artery Disease in Patients with Acute ST Elevation Myocardial Infarction

Background: Arterial stiffness assessed noninvasively with aortic pulse wave velocity (PWV) has been associated with atherosclerosis in the coronary arteries and also cardiovascular mortality. The aim of this study was to evaluate the association between aortic PWV and severity of coronary artery disease (CAD) in patients with acute ST elevation myocardial infarction (STEMI). Methods: This cross sectional analytical study was conducted over 200 acute STEMI patients who were purposively selected and agreed to do coronary angiogram during index hospital admission. Assessment of aortic PWV was performed noninvasively with the commercially available SphygmoCor system using applanation tonometry with high fidelity micromanometer on the day before angiogram. Study subjects were subdivided into two groups on the basis of PWV. In group I: aortic PWV was d” 10 m/sec and in group II: aortic PWV was&gt; 10 m/sec. One hundred patients were included in each group. Angiographic severity of CAD was assessed by vessel score, Friesinger score and Leaman score. Results: Vessel score 0 and 1 were significantly higher in group I (p&lt;0.05) where vessel score 2 and 3 were significantly higher in group II (p&lt;0.05).The mean PWV in the group with normal angiographic result was 8.10±2.9 m/sec, and in patients with single vessel disease it was 11.65±3.46m/sec. In those with double and triple vessel disease the mean value of PWV was found 13.85±3.80 and 15.70±4.66 m/sec respectively. The mean value of PWV increased in proportion with the number of vessel involved by CAD and the differences were statistically significant (p=0.001).The mean value of PWV was observed 8.5±2.3 and 12.5±3.7m/sec in insignificant and significant CAD respectively using Friesinger score and the difference was statistically significant (p&lt;0.05).There was statistically significant positive linear relation between the values of PWV and vessel score(r=.62, p=0.01), Friesinger score(r=.64, p=0.01) and Leaman score(r=.45, p=0.01). Conclusion: Aortic PWV is associated with the extent and severity of CAD. This noninvasive, cheap, radiation free method may be considered as risk stratification tool beyond other investigations. DOI: http://dx.doi.org/10.3329/cardio.v6i2.18351 Cardiovasc. j. 2014; 6(2): 116-121

Evaluation of reducing temporal resolution on the accuracy of aortic pulse wave velocity assessment from velocity encoded MRI

Background Aortic pulse wave velocity (PWV), the propagation speed of blood flow velocity waves through the aorta, is a marker of aortic stiffness with prognostic value in various diseases with vascular expression. One-directional throughplane velocity-encoded (VE) MRI, planned perpendicular to the ascending aorta and additionally transecting the proximal descending aorta (Figure 1), is a validated method for assessing PWV over the aortic arch. However, the effect of the temporal resolution (Tres) of VE MRI on the accuracy of PWV assessment has not yet been established. Therefore, the aim of this study was to evaluate the effect of reducing Tres on the accuracy of aortic PWV and how this relates to physiological variation. Methods Five patients referred for cardiac MRI and ten healthy volunteers within similar age range (mean age 32 ± 14 years) were prospectively included. PWV was assessed from velocity mapping using VE MRI on 3T MRI (Ingenia, Philips) with velocity sensitivity of 150 cm/s. Reference PWV (PWVref) was achieved from VE MRI with maximal number of reconstructed phases (Tres = 5 ms). The effect of temporal Tres on PWV was evaluated by temporal downsampling (50% [Tres = 10 ms], 67% [Tres = 15 ms], 75% [Tres = 20 ms], and 80% [Tres = 25 ms]), first by reducing phases during repeated reconstruction of the original acquired high-temporal data. Next, downsampling was performed by data removal as well as by data

Aortic pulse wave velocity assessment in CMR: a novel method for transit time estimation

Background Aortic pulse wave velocity (PWV) is considered as the “gold standard” measurement of arterial stiffness and is commonly calculated as the ratio between the distance separating two locations along the artery and the transit time (Δt) needed for the pressure or velocity wave to cover this distance. PWV is increasingly assessed by means of cardiovascular magnetic resonance (CMR). Our goal was evaluate the efficiency of a novel method for Δt estimation, based on the principle of group delay (TT-GD method).

Accuracy of aortic pulse wave velocity assessment with velocity-encoded MRI: validation in patients with Marfan syndrome

The leading cause of premature death in patients with Marfan syndrome (MFS) is aortic dissection and subsequent rupture after progressive aorta dilatation due to increased wall stiffening. Pulse Wave Velocity (PWV), defined as the systolic flow velocity wave front propagation speed through the aorta, is a marker of wall stiffness with proven prognostic value in MFS. Recently it was demonstrated that, although time-consuming, PWV-assessment from two-directional in-plane velocity-encoded MRI covering the whole aorta in three parallel oblique-sagittal slices is the most accurate approach (1). 2-slice free-breathing through-plane velocity-encoded MRI at three locations perpendicular to the aorta (2) is traditionally used for PWV-estimation. Accelerated multi-slice acquisition with breath-holding and more-densed sampling along the aorta might improve accuracy.

Improved aortic pulse wave velocity assessment from multislice two‐directional in‐plane velocity‐encoded magnetic resonance imaging

To evaluate the accuracy and reproducibility of aortic pulse wave velocity (PWV) assessment by in-plane velocity-encoded magnetic resonance imaging (MRI). In 14 patients selected for cardiac catheterization on suspicion of coronary artery disease and 15 healthy volunteers, PWV was assessed with multislice two-directional in-plane velocity-encoded MRI (PWV(i.p.)) and compared with conventionally assessed PWV from multisite one-directional through-plane velocity-encoded MRI (PWV(t.p.)). In patients, PWV was also obtained from intraarterially acquired pressure-time curves (PWV(pressure)), which is considered the gold standard reference method. In volunteers, PWV(i.p.) and PWV(t.p.) were obtained in duplicate in the same examination to test reproducibility. In patients, PWV(i.p.) showed stronger correlation and similar variation with PWV(pressure) than PWV(t.p.) (Pearson correlation r = 0.75 vs. r = 0.58, and coefficient of variation [COV] = 10% vs. COV = 12%, respectively). In volunteers, repeated PWV(i.p.) assessment showed stronger correlation and less variation than repeated PWV(t.p.) (proximal aorta: r = 0.97 and COV = 10% vs. r = 0.69 and COV = 17%; distal aorta: r = 0.94 and COV = 12% vs. r = 0.90 and COV = 16%; total aorta: r = 0.97 and COV = 7% vs. r = 0.90 and COV = 13%). PWV(i.p.) is an improvement over conventional PWV(t.p.) by showing higher agreement as compared to the gold standard (PWV(pressure)) and higher reproducibility for repeated MRI assessment.