Wave Reflection and Arterial Stiffness in the Prediction of 15-Year All-Cause and Cardiovascular Mortalities

Abstract

Abstract-The value of increased arterial wave reflection, usually assessed by the transit time-dependent augmentation index and augmented pressure (Pa), in the prediction of cardiovascular events may have been underestimated. We investigated whether the transit time-independent measures of reflected wave magnitude predict cardiovascular outcomes independent of arterial stiffness indexed by carotid-femoral pulse wave velocity. A total of 1272 participants (47% women; mean age: 52Ϯ13 years; range: 30 to 79 years) from a community-based survey were studied. Carotid pressure waveforms derived by tonometry were decomposed into their forward wave amplitudes, backward wave amplitudes (Pb), and a reflection index (ϭ[Pb/(forward wave amplitudeϩPb)]), in addition to augmentation index, Pa, and reflected wave transit time. During a median follow-up of 15 years, 225 deaths occurred (17.6%), including 64 cardiovascular origins (5%). In univariate Cox proportional hazard regression analysis, pulse wave velocity, Pa, and Pb predicted all-cause and cardiovascular mortality in both men and women, whereas augmentation index, reflected wave transit time, and reflection index were predictive only in men. In multivariate analysis accounting for age, height, and heart rate, Pb predicted cardiovascular mortality in both men and women, whereas Pa was predictive only in men. Per 1-SD increment (6 mm Hg), Pb predicted 15-year cardiovascular mortality independent of brachial but not central pressure, pulse wave velocity, augmentation index, Pa, and conventional cardiovascular risk factors with hazard ratios of Ϸ1.60 (all PϽ0.05). In conclusion, Pb, a transit time-independent measure of reflected wave magnitude, predicted long-term cardiovascular mortality in men and women independent of arterial stiffness. (Hypertension. 2010;55:799-805.)

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?

“…Most of these studies have performed only one PWV measurement as it is not otherwise stated. 1,3,[17][18][19][20][21][22][23][24][25][26][27][28] One study reported that one PWV measurement was performed 29 and two studies 30,31 referred that two and three PWV measurements were performed, respectively, and an average value was then calculated. Thus, based on the results of this study, a substantial variation (and 'bias') in the determined CVR and the calculated statistical measures may exist, which depends on the number of PWV measurements.…”

The association between aortic augmentation index and cardiovascular risk factors in a large unselected population

“…3,4 However, concerns have been raised as to whether AIx is a reliable measurement of vascular compliance in the elderly 5,6 due to the curvilinear association between AIx and age. 6,7 Interestingly, findings have been contradictory regarding AIx as predictor of CVD where AIx has been associated with increased risk of CVD in highrisk populations 8,9 and in men, 10,11 while its use as a predictor in women 12,13 and in the general population is less certain. 13,14 The association between AIx and traditional CVD risk factors has been analysed in several studies with different methodology and various findings.…”

“…6,7 Interestingly, findings have been contradictory regarding AIx as predictor of CVD where AIx has been associated with increased risk of CVD in highrisk populations 8,9 and in men, 10,11 while its use as a predictor in women 12,13 and in the general population is less certain. 13,14 The association between AIx and traditional CVD risk factors has been analysed in several studies with different methodology and various findings. [15][16][17][18] Recently, a large study of subjects from the general population reported that associations between AIx and CVD risk factors are dependant of age, and that age had a larger influence on AIx than traditional CVD risk factors.…”

Head-to-head comparison of the cardio-ankle vascular index between patients with acute coronary syndrome and stable angina pectoris

“…[8][9][10][11] In addition, the aortic stiffness assessed by invasive methods is also a powerful and independent risk factor for recurrent acute coronary events in patients with coronary artery disease (CAD), including stable angina pectoris (SAP). 12 Hence, we hypothesized that the arterial stiffness assessed by CAVI in ACS patients would be significantly higher than that in SAP patients.…”