Aortic pulse wave velocity is a worldwide accepted index to evaluate aortic stiffness and can be assessed noninvasively by several methods. This study sought to determine if commonly used noninvasive devices can all accurately estimate aortic pulse wave velocity. Pulse wave velocity was estimated in 102 patients (aged 65±13 years) undergoing diagnostic coronary angiography with 7 noninvasive devices and compared with invasive aortic pulse wave velocity. Devices evaluating carotid-femoral pulse wave velocity (Complior Analyse, PulsePen ET, PulsePen ETT, and SphygmoCor) showed a strong agreement between each other ( r >0.83) and with invasive aortic pulse wave velocity. The mean difference ±SD with the invasive pulse wave velocity was −0.73±2.83 m/s ( r =0.64) for Complior-Analyse: 0.20±2.54 m/s ( r =0.71) for PulsePen-ETT: −0.04±2.33 m/s ( r =0.78) for PulsePen ET; and −0.61±2.57 m/s ( r =0.70) for SphygmoCor. The finger-toe pulse wave velocity, evaluated by pOpmètre, showed only a weak relationship with invasive aortic recording (mean difference ±SD =−0.44±4.44 m/s; r =0.41), and with noninvasive carotid-femoral pulse wave velocity measurements ( r <0.33). Pulse wave velocity estimated through a proprietary algorithm by BPLab (v.5.03 and v.6.02) and Mobil-O-Graph showed a weaker agreement with invasive pulse wave velocity compared with carotid-femoral pulse wave velocity (mean difference ±SD =−0.71±3.55 m/s, r =0.23; 1.04±2.27 m/s, r =0.77; and −1.01±2.54 m/s, r =0.71, respectively), revealing a negative proportional bias at Bland-Altman plot. Aortic pulse wave velocity values provided by BPLab and Mobil-O-Graph were entirely dependent on age-squared and peripheral systolic blood pressure (cumulative r 2 =0.98 and 0.99, respectively). Thus, among the methods evaluated, only those assessing carotid-femoral pulse wave velocity (Complior Analyse, PulsePen ETT, PulsePen ET, and SphygmoCor) appear to be reliable approaches for estimation of aortic stiffness.

Our study shows that the short-term repeatability of PWV measures is good but not homogenous across different devices and at different PWV values. These findings, obtained in patients at high cardiovascular risk, may be relevant when evaluating the prognostic importance of PWV.

Background Estimation of the balance between subendocardial oxygen supply and demand could be a useful parameter to assess the risk of myocardial ischemia. Evaluation of the subendocardial viability ratio (SEVR, also known as Buckberg index) by invasive recording of left ventricular and aortic pressure curves represents a valid method to estimate the degree of myocardial perfusion relative to left ventricular workload. However, routine clinical use of this parameter requires its noninvasive estimation and the demonstration of its reliability. Methods and Results Arterial applanation tonometry allows a noninvasive estimation of SEVR as the ratio of the areas directly beneath the central aortic pressure curves obtained during diastole (myocardial oxygen supply) and during systole (myocardial oxygen demand). However, this “traditional” method does not account for the intra‐ventricular diastolic pressure and proper allocation to systole and diastole of left ventricular isometric contraction and relaxation, respectively, resulting in an overestimation of the SEVR values. These issues are considered in the novel method for SEVR assessment tested in this study. SEVR values estimated with carotid tonometry by "traditional” and "new” method were compared with those evaluated invasively by cardiac catheterization. The “traditional” method provided significantly higher SEVR values than the reference invasive SEVR: average of differences±SD= 44±11% (limits of agreement: 23% – 65%). The noninvasive “new” method showed a much better agreement with the invasive determination of SEVR: average of differences±SD= 0±8% (limits of agreement: ‐15% to 16%). Conclusions Carotid applanation tonometry provides valid noninvasive SEVR values only when all the main factors determining myocardial supply and demand flow are considered.

Objective: Mean arterial pressure (MAP) is usually calculated by adding one-third of pulse pressure (PP) to DBP. This formula assumes that the average value of pulse waveform is constant in all individuals and coincides with 33.3% of PP amplitude (MAP = DBP + PP × 0.333). Other formulas were lately proposed to improve the MAP estimation, adding to DBP an established percentage of PP: MAP = DBP + PP × 0.40; MAP = DBP + PP × 0.412; MAP = DBP + PP × 0.333 + 5 mmHg. Methods: The current study evaluated the integral of brachial pulse waveform recorded by applanation tonometry in 1526 patients belonging to three distinct cohorts: normotensive or hypertensive elderly, hypertensive adults, and normotensive adults. Results: The percentage of PP to be added to DBP to obtain MAP was extremely variable among individuals, ranging from 23 to 58% (mean: 42.2 ± 5.5%), higher in women (42.9 ± 5.6%) than men (41.2 ± 5.1%, P < 0.001), lower in the elderly cohort (40.9 ± 5.3%) than in the general population cohort (42.8 ± 6.0%, P < 0.001) and in the hypertensive patients (42.4 ± 4.8%, P < 0.001). This percentage was significantly associated with DBP (β = 0.357, P < 0.001) and sex (β = 0.203, P < 0.001) and significantly increased after mental stress test in 19 healthy volunteers (from 39.9 ± 3.2 at baseline, to 43.0 ± 4.0, P < 0.0001). The average difference between MAP values estimated by formulas, compared with MAP assessed on the brachial tonometric curve, was (mean ± 1.96 × SD): −5.0 ± 6.7 mmHg when MAP = DBP + PP × 0333; −1.2 ± 6.1 mmHg when MAP = DBP + PP × 0.40; −0.6 ± 6.1 mmHg when MAP = DBP + PP × 0.412; −0.4 ± 6.7 mmHg when MAP = DBP + PP × 0.333 + 5. Conclusion: Due to high interindividual and intraindividual variability of pulse waveform, the estimation of MAP based on fixed formulas derived from SBP and DBP is unreliable. Conversely, a more accurate estimation of MAP should be based on the pulse waveform analysis.

Measurement of PWV and of variables derived from the central pulse waveform analysis by carotid tonometry is not biased by the presence of local atherosclerotic plaques.