Stiff Arteries, Stiff Ventricles

Abstract

and uptake of cholesterol into the vessel wall. 17 Endothelial dysfunction is not irreversible, and many emerging nonpharmacological and pharmacological therapeutic strategies are under investigation that aim to reduce oxidative stress and promote nitric oxide release. 18 The observational study of Ohyama et al, 9 taken with other longitudinal data, provides supportive evidence of the role that declining arterial elasticity may have in the development of subclinical impairment of both systolic and diastolic functions.There are many approaches and technologies used to assess vascular stiffness that present both challenges and opportunities for advancing our understanding of hemodynamic factors in heart disease. 1 In the study of Ohyama et al,9 the velocity of the propagating systolic wavefront in the aorta was determined using phase contrast imaging-a noninvasive approach for assessing vascular stiffness that offers good agreement with intra-aortic pressure measurements. 19 Phase contrast imaging depends on adequate temporal sampling of the flow waveform particularly when model-fitting the systolic upstroke to minimize the influence of wave reflection effects. 20 The most relevant blood pressure metric is also debatable as, although 24-hour ambulatory monitoring may better represent the cumulative exposure to hypertension, transient changes in vascular stiffness also occur with acute variations in blood pressure. Another factor not addressed in this study is the variation in elastic properties of the aorta as the pulse wave travels distally, as both extracellular matrix composition and expression of vascular disease vary in different territories. A limitation of the tagged deformation imaging used is the absence of data on long-axis function that is an independent predictor of survival, after adjustment for clinical variables and short axis function, in patients with heart failure. 21 It would be appealing to combine complementary cardiac magnetic resonance data sets from the MESA cohort, including feature-tracking for strain assessment in each axis, to establish a comprehensive picture of longitudinal adaptations in LV mass, function, and aortic stiffness-findings that may not always be congruent with cross-sectional associations. 22 The right heart is also an important determinant of outcome in heart failure, and there is emerging evidence that a similar relationship exists between pulmonary artery stiffness and right ventricular function to that observed in the systemic circulation. 23Convincing data are still required on the putative feedback mechanisms between aortic and ventricular dysfunction, what processes might initiate and amplify the progression to heart failure in the general population, or any certainty as to whether outcomes in heart failure may be improved by modifying aortic elasticity independent of conventional risk factors. Pharmacological approaches to treat vascular stiffness, including angiotensin-converting inhibitors and calcium channel blockers, have achieved only modest results but ther...

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