19 Sep 10
By H Baumgartner, C Otto
Aortic stenosis (AS) is the most frequent indication for valve replacement in Europe and North America, and correct diagnosis and timing of surgery are critical. Although it is evident that patients with symptoms attributable to severe AS require prompt valve replacement, there remain some unresolved issues in clinical decision making.
By Z Hachicha, J Dumesnil, P Pibarot
This study was designed to examine the prognostic value of valvuloarterial impedance (Zva) in patients with aortic stenosis (AS).
We previously showed that the Zva is superior to standard indexes of AS severity in estimating the global hemodynamic load faced by the left ventricle (LV) and predicting the occurrence of LV dysfunction. This index is calculated by dividing the estimated LV systolic pressure (systolic arterial pressure + mean transvalvular gradient) by the stroke volume indexed for the body surface area.
We retrospectively analyzed the clinical and echocardiographic data of 544 consecutive patients having at least moderate AS (aortic jet velocity =2.5 m∑s-1) and no symptoms at baseline. The primary end point for this study was the overall mortality regardless of the realization of aortic valve replacement (AVR).
Four-year survival was significantly (p < 0.001) lower in the patients with a baseline Zva =4.5 mm Hg∑ml-1∑m2 (65 ± 5%) compared with those with Zva between 3.5 and 4.5 mm Hg∑ml-1∑m2 (78 ± 4%) and those with Zva =3.5 mm Hg∑ml-1∑m2 (88 ± 3%). The risk of mortality was increased by 2.76-fold in patients with Zva =4.5 mm Hg∑ml-1∑m2 and by 2.30-fold in those with a Zva between 3.5 and 4.5 mm Hg∑ml-1∑m2 after adjusting for other risk factors and type of treatment (surgical vs. medical).
Increased Zva is a marker of excessive LV hemodynamic load, and a value >3.5 successfully identifies patients with a poor outcome. These findings suggest that beyond standard indexes of stenosis severity, the consideration of Zva may be useful to improve risk stratification and clinical decision making in patients with AS.
17 Mar 08
By R Ramaraj, V L Sorrell
Aortic stenosis is the most common valvular lesion in Europe and North America. It primarily presents as calcific aortic stenosis in 2-7% of the population aged >65 years. About 80% of adult patients with symptomatic aortic stenosis are male. As 1-2% of the population is born with a congenital bicuspid aortic valve and populations are ageing, aortic stenosis is becoming more common. By 2020, about 3.5 million people in England are expected to have aortic sclerosis and 150000 will have severe aortic stenosis. Here we provide an overview to help diagnosis and a summary of the management of AS and its sequelae. Many of the points made in this review are based on randomised controlled trials. However, observational studies and the guideline recommendations of the American Heart Association and the American College of Cardiology and of the European Society of Cardiology are also included to provide comprehensive overviews that are beyond the scope of this article.