Arterial stiffness is an important determinant of cardiovascular risk. Augmentation index (AIx) is a measure of systemic arterial stiffness derived from the ascending aortic pressure waveform. The aim of the present study was to assess the effect of heart rate on AIx. We elected to use cardiac pacing rather than chronotropic drugs to minimize confounding effects on the systemic circulation and myocardial contractility. Twenty‐two subjects (13 male) with a mean age of 63 years and permanent cardiac pacemakers in situ were studied. Pulse wave analysis was used to determine central arterial pressure waveforms, non‐invasively, during incremental pacing (from 60 to 110 beats min−1), from which AIx and central blood pressure were calculated. Peripheral blood pressure was recorded non‐invasively from the brachial artery. There was a significant, inverse, linear relationship between AIx and heart rate (r=−0.76; P < 0.001). For a 10 beats min−1 increment, AIx fell by around 4 %. Ejection duration and heart rate were also inversely related (r=−0.51; P < 0.001). Peripheral systolic, diastolic and mean arterial pressure increased significantly during incremental pacing. Although central diastolic pressure increased significantly with pacing, central systolic pressure did not. There was a significant increase in the ratio of peripheral to central pulse pressure (P < 0.001), which was accounted for by the observed change in central pressure augmentation. These results demonstrate an inverse, linear relationship between AIx and heart rate. This is likely to be due to alterations in the timing of the reflected pressure wave, produced by changes in the absolute duration of systole. Consideration of wave reflection and aortic pressure augmentation may explain the lack of rise in central systolic pressure during incremental pacing despite an increase in peripheral pressure.

PWA is a simple and reproducible technique with which to measure PWV and AIx. Reproducibility accords with that reported by other workers using different methodologies. PWA may, therefore, be suitable for large-scale population and intervention studies investigating the clinical relevance of vascular stiffness.

Objectives To determine whether aortic pulse wave velocity (aPWV) improves prediction of cardiovascular (CVD) events beyond conventional risk factors. Background Several studies have shown that aPWV may be a useful risk factor for predicting CVD but have been underpowered to examine whether this is true for different sub-groups. Methods We undertook a systematic review and obtained individual participant data from 16 studies. Study-specific associations of aPWV with cardiovascular outcomes were determined using Cox proportional hazard models and random effect models to estimate pooled effects. Results Of 17,635 participants, 1,785 (10%) had a cardiovascular (CVD) event. The pooled age- and sex-adjusted hazard ratio [95% CI] per SD change in loge aPWV was 1.35 [1.22, 1.50, p<0.001] for coronary heart disease (CHD), 1.54 [1.34, 1.78, p<0.001] for stroke, and 1.45 [1.30, 1.61, p<0.001) for CVD. Associations stratified by sex, diabetes and hypertension were similar, but decreased with age (1.89, 1.77, 1.36 and 1.23 for ≤50, 51–60, 61–70 and >70 years respectively, pinteraction <0.001). After adjusting for conventional risk factors, aPWV remained a predictor: CHD 1.23, [1.11, 1.35 p<0.001]; stroke 1.28, [1.16, 1.42 p<0.001]; cardiovascular events 1.30 [1.18, 1.43, p<0.001]. Reclassification indices showed the addition of aPWV improved risk prediction (13% for 10 year CVD risk for intermediate risk) for some sub-groups. Conclusions Consideration of aPWV improves model fit and reclassifies risk for future cardiovascular events in models that include standard risk factors. aPWV may enable better identification of high-risk populations who may benefit from more aggressive cardiovascular risk factor management.

Abstract-Investigation of arterial stiffness, especially of the large arteries, has gathered pace in recent years with the development of readily available noninvasive assessment techniques. These include the measurement of pulse wave velocity, the use of ultrasound to relate the change in diameter or area of an artery to distending pressure, and analysis of arterial waveforms obtained by applanation tonometry. Here, we describe each of these techniques and their limitations and discuss how the measured parameters relate to established cardiovascular risk factors and clinical outcome. We also consider which techniques might be most appropriate for wider clinical application. Finally, the effects of current and future cardiovascular drugs on arterial stiffness are also discussed, as is the relationship between arterial elasticity and endothelial function. Arterial StiffnessData from the Framingham Heart Study have determined how systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP; the difference between SBP and DBP) change with advancing age. 1 DBP, largely determined by peripheral arterial resistance, increases until middle age and then tends to fall. In contrast, SBP and PP, influenced more by the stiffness of large arteries, as well as peripheral pulse wave reflection and the pattern of left ventricular ejection, increase continuously with age. Changes in the stiffness of the large arteries, such as the aorta and its major branches, largely account for the changes in SBP, DBP, and PP that occur from 50 years of age onward. Although DBP has traditionally been the major focus in the treatment of hypertension, over recent years SBP has become recognized as a stronger cardiovascular risk factor in older people. Thus, SBP has greater predictive value than DBP for coronary heart disease (CHD) in older people (Ͼ60 years). 2,3 Isolated systolic hypertension (ISH; SBP Ն140 mm Hg and DBP Ͻ90 mm Hg), is the most common subtype of hypertension in the middle aged and is overwhelmingly so in the elderly. 4 It is a major risk factor for stroke, 5 CHD, 2,3 and cardiovascular and total mortality. 6,7 Furthermore, measurement of SBP alone identifies Ͼ90% of hypertensives according to the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure VI criteria, whereas DBP alone identifies only Ϸ20%. 8 The treatment of ISH with conventional antihypertensive drugs is of proven clinical benefit. 9,10 However, although it is recognized that few hypertensives are controlled to target pressures, 11 it is much more commonly