Response to Letters Regarding Article, “Differential Impact of Blood Pressure-Lowering Drugs on Central Aortic Pressure and Clinical Outcomes: Principal Results of the Conduit Artery Function Evaluation (CAFE) Study”

Abstract

We respond to recent correspondence relating to the Conduit Artery Function Evaluation study (CAFE), 1 published in Circulation earlier this year.We thank Drs Nieminen, Kahonen, and Kobie for their remarks and suggestions. We agree that increased stroke volume at lower heart rates should be considered as a contributor to the elevated pulse pressure (PP) seen with atenolol-based treatment in the CAFE study. We did not assess stroke volume, and further studies are required to define the impact of blood pressure (BP)-lowering therapies on stroke volume and its contribution to central aortic pressures. Nevertheless, our data do suggest an important role for increased wave reflections in determining higher central aortic pressures with atenolol-based when compared with amlodipine-based treatment. Indeed, the higher central but not brachial PP with atenolol-based therapy in the CAFE study supports the hypothesis that the main driver of differential central aortic pressures was drug effects on pressure wave reflections rather than changes in stroke volume.We agree with Drs Safar and Fournier that the findings of the CAFE study are consistent with their report of differential drug effects on central aortic pressures in the Preterax in Regression of Arterial Stiffness in a Controlled Double-Blind Study (REA-SON). 2 We concur with the view that vascular structural changes are likely to make an important contribution to the long-term hemodynamic effects of BP-lowering therapy, especially wave reflection, and we suggested in our article that different BPlowering treatments may modify central aortic pressures and hemodynamics through differential effects on vascular structure. 1 The fact that the most beneficial effects on central aortic pressure have been observed with vasodilator therapy, in contrast to ␤-blockade, supports the view that a reduction in vascular resistance, by vasodilation and subsequent vascular remodeling, is an important determinant of reduced wave reflection and central aortic pressure, thereby defining the characteristics of optimal BP-lowering therapy.Cameron and colleagues are concerned that the data in their article 3 may have been misinterpreted. We clarify that our reference to their work related to the accuracy and validation of the transfer function rather than the derivation of central aortic pressures, which are prone to and dependent on the same level of inaccuracy as the measurement of brachial BP by cuff sphygmomanometry.We thank Dr Dart et al for their comments and interest in our study but would like to point out fundamental differences between the design and objectives of the CAFE study and The Australian National Blood Pressure Study 2 (ANBP2). substudy of central aortic pressures. 4 The prespecified primary objective 5 of the CAFE study was to examine the hypothesis that 2 different BP-lowering regimens would have different effects on derived central arterial pressures and hemodynamics despite similar effects on brachial pressures. This was convincingly demonstrated by the findings of ...

Incremental value of arterial wave reflections in the determination of left ventricular diastolic dysfunction in untreated patients with essential hypertension

“…Thus, further studies are required to assess whether reduction in arterial stiffness may lead to improvement in LV diastolic function and consequently to morbidity and mortality in patients with essential hypertension as implicated in previous studies. 47 In our study we included newly diagnosed untreated hypertensive patients and thus, the mean age of our study population was 56 ± 15 years. As we have missed out part of the elderly population, we are not able to extrapolate our conclusions for patients over 70 years of age.…”

Comparison of two measuring instruments, B-pro and SphygmoCor system as reference, to evaluate central systolic blood pressure and radial augmentation index

“…[1][2][3][4] However, there is growing evidence that central aortic arterial pressure may be better than peripheral arterial pressure in predicting cardiovascular events. [5][6][7] The gold standard for assessing central arterial pressure is direct measurement with an intra-aortic transducer. However, the technical difficulties of this technique preclude its use in clinical practice.…”

More than a REASON to use arterial stiffness as risk marker and therapeutic target in hypertension

“…2 Most of them showed a significant association with poor CV outcome over and above classical CV risk factors. [2][3][4][5][6] However, consistent data support the measurement of PWV as the most simple, non-invasive, robust and reproducible method to determine arterial stiffness. 2,7 A recent systematic review and meta-analysis 7 of 17 longitudinal studies evaluated the predictive value of aortic PWV for future CV events and all-cause mortality.…”

“…Finally, prolonged survival was favorably associated with the use of an angiotensinconverting enzyme inhibitor, whereas the use of beta-blockers and/or CCBs had no direct impact on outcomes. 3 More recently, in the Conduit Artery Function Evaluation (CAFE) study, 4 a subanalysis of the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT), 2073 participants underwent radial artery applanation tonometry and measurement of PWV. In keeping with the REASON study, 9 the results indicate that atenolol had lesser effect on central aortic BP and PP, despite similar brachial artery BP reduction, than a CCB regimen.…”